BIO-BASED POLYURETHANE RESIN, BIO-BASED POLYURETHANE RESIN SOLUTION, AND PRINTING INK

Abstract

Provided are: a polyurethane resin having a high degree of biomass, the polyurethane resin useful as a binder for a printing exhibiting excellent adhesion performance particularly to biomass plastic base materials and having excellent dispersibility of a pigment contained at a high concentration; and a printing ink using the polyurethane resin. A bio-polyurethane resin obtained by reacting a bio-polyol (A) and an isocyanate (B), wherein the (A) is a bio-polyester polyol being a polymerized product of a diol component (a) and a dicarboxylic acid component (b) each containing a plant-derived component, the (a) contains at least one selected from ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,10-decanediol, and dimer diols each derived from a plant, the (b) contains plant-derived succinic acid and an additional dicarboxylic acid, and plant-derived succinic acid/additional carboxylic acid=98/2 to 5/95, and a content of plant-derived components is 35% or more based on 100% by mass of the bio-polyurethane resin, and a printing ink.

Claims

1. A bio-polyurethane resin obtained by reacting a bio-polyol component (A) and an isocyanate component (B), wherein: the bio-polyol component (A) is a bio-polyester polyol being a polymerized product of a multifunctional alcohol component and a multifunctional carboxylic acid component, the polymerized product obtained from a raw material comprising: a diol component (a) comprising a plant-derived component; and a dicarboxylic acid component (b) comprising a plant-derived component; the diol component (a) comprises at least one selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,10-decanediol, and dimer diols each derived from a plant; the dicarboxylic acid component (b) comprises plant-derived succinic acid and an additional dicarboxylic acid, and a molar ratio thereof, plant-derived succinic acid/additional dicarboxylic acid, is 98/2 to 5/95; and a content of plant-derived components is 35% by mass or more based on 100% by mass of the bio-polyurethane resin.

2. The bio-polyurethane resin according to claim 1, wherein the additional dicarboxylic acid is at least any one of plant-derived sebacic acid or dimer acids.

3. The bio-polyurethane resin according to claim 1, further comprising a polyamine component (C) as a reaction component and having a urethane urea bond in a structure thereof

4. The bio-polyurethane resin according to claim 3, having an active amino group at a terminal thereof, wherein the terminal active amino group has a concentration of 15 to 100μ equivalent per 1 g of a solid content of the bio-polyurethane resin.

5. The bio-polyurethane resin according to claim 1, further comprising an organic solvent, wherein: the bio-polyurethane resin is dissolved in the organic solvent and is in a form of a solution; and the organic solvent does not contain toluene or does not contain any of toluene and methyl ethyl ketone.

6. A bio-polyurethane resin solution being a polyester-based polyurethane resin solution comprising: a polyester-based polyurethane resin obtained by polymerizing a polyester polyol, an organic diisocyanate, and a polyamine, having a urethane urea bond in a structure thereof, and having an active amino group at a terminal thereof; and an organic solvent, wherein: the polyester polyol is a polymerized product of a multifunctional carboxylic acid component and a multifunctional alcohol component each obtained from a raw material for synthesis comprising a plant-derived component; the multifunctional carboxylic acid component comprises a dimer acid and succinic acid in a range where a molar ratio of plant-derived succinic acid/dimer acid is 98/2 to 5/95, and the multi-functional alcohol component comprises 1,3-propanediol; and a proportion of plant-derived components in a solid content of the polyester-based polyurethane resin having an active amino group at a terminal thereof is 35% by mass or more.

7. The bio-polyurethane resin solution according to claim 6, wherein part of or all of the succinic acid is a plant-derived component, and part of or all of the dimer acid is a plant-derived component and/or part of or all of the 1,3-propanediol is a plant-derived component.

8. The bio-polyurethane resin solution according to claim, wherein the terminal active amino group in the polyester-based polyurethane resin having the active amino group at the terminal thereof has a concentration of 15 to 100μ equivalent per 1 g of a solid content of the polyester-based polyurethane resin.

9. The bio-polyurethane resin solution according to claim 6, wherein the organic solvent does not contain toluene or does not contain any of toluene and methyl ethyl ketone.

10. The bio-polyurethane resin solution according to claim 6, wherein the organic solvent is a mixed solvent of ethyl acetate and isopropyl alcohol, or a mixed solvent of ethyl acetate, isopropyl alcohol, and methyl ethyl ketone.

11. A printing ink comprising: a pigment; and a binder for a printing ink, wherein the bio-polyurethane resin solution according to any one of claim 6 in an amount such that a proportion of plant-derived components in a solid content of the ink is 10% by mass or more as the binder for a printing ink.

12. The printing ink according to claim 11, to be used for gravure printing, flexographic printing, screen printing, offset printing, or inkjet printing.

13. The printing ink according to claim 11, to be used for printing onto a film package, a paper package, a building material, or tissue paper.

14. A printing ink comprising: a pigment; and a binder for a printing ink, wherein the printing ink comprises the bio-polyurethane resin in the form of a solution according to claim 5 in an amount such that a proportion of plant-derived components in a solid content of the ink is 10% by mass or more as the binder for a printing ink.

Description

EXAMPLES

[0086] Next, the present invention will be described more specifically giving Examples and Comparative Examples. It is to be noted that “parts” or “%” below is on a mass basis unless otherwise noted.

[0087] [Preparation of Polyurethane Resin Solution]

Example 1

[0088] Firstly, a polyester polyol was prepared in the manner as described below. As a multifunctional carboxylic acid component (hereinafter, referred to as dicarboxylic acid component), dimer acid (dimer purity of 98%) obtained from a plant-derived component/succinic acid obtained from a plant-derived component=90/10 (molar ratio) was used, and as a multifunctional alcohol component (hereinafter, referred to as diol component), 1,3-propanediol obtained from a plant-derived component was used. These components were each used in an appropriate amount so as to obtain a target molecular weight and polymerized to obtain a polyester diol PE (1) 100% obtained from plant-derived components, the PE (1) having a hydroxyl value of 37.3 mgKOH/g, an acid value of 0.3 mgKOH/g, and a number average molecular weight of 3000, as shown in Table 1-1.

[0089] Next, 500 parts of the polyester diol PE (1) obtained above and 66.4 parts of isophorone diisocyanate (hereinafter, abbreviated as IPDI), which is an organic diisocyanate, were loaded in a reaction container and reacted at 100° C. for 5 hours in a nitrogen gas stream to obtain a urethane prepolymer having an NCO group content of 1.87% as shown in Table 2-1. The obtained urethane prepolymer was dissolved in 188.8 parts of ethyl acetate, which is an organic solvent for dilution, to make a urethane prepolymer solution (1) having a non-volatile content of 75%.

[0090] Subsequently, a mixture (diamine solution) of 23.6 parts of isophorone diamine (hereinafter, abbreviated as IPDA), which is a polyamine, 981.4 parts of ethyl acetate, and 206.5 parts of isopropyl alcohol (hereinafter, abbreviated as IPA) was blended, 755.2 parts of the urethane prepolymer solution (1) obtained previously was dropped in the mixture under stirring, and a resultant mixture was reacted at 40° C. for 1 hour. As a result, a polyurethane resin solution PU1 of the present Example having a non-volatile content (solid content) of 30%, a viscosity of 1150 mPa.Math.s (25° C.), a terminal amino group concentration of 42.8μ equivalent per 1 g of the solid content of the resin, and 84.7% of plant-derived components in the solid content of the resin was obtained. Table 2-1 shows the combination and characteristics of the polyurethane resin solution PU1 obtained above.

Example 2

[0091] A polyurethane resin solution was prepared basically in the same manner as in Example 1. As a dicarboxylic acid component, dimer acid (dimer purity of 98%) obtained from a plant-derived component/succinic acid obtained from a plant-derived component=60/40 (molar ratio) was used, and as a diol component, 1,3-propanediol obtained from a plant-derived component was used. These components were each used in an appropriate amount and polymerized to obtain a polyester diol PE (2) 100% obtained from plant-derived components, the PE (2) having a hydroxyl value of 56.0 mgKOH/g, an acid value of 0.3 mgKOH/g, and a number average molecular weight of 2000, as shown in Table 1-1.

[0092] Next, 500 parts of the polyester diol PE (2) obtained above and 88.6 parts of IPDI were loaded in a reaction container and reacted at 100° C. for 5 hours in a nitrogen gas stream to obtain a urethane prepolymer having an NCO group content of 2.03% as shown in Table 2-1. The obtained urethane prepolymer was dissolved in 196.2 parts of ethyl acetate to make a urethane prepolymer solution (2) having a non-volatile content of 75%.

[0093] Subsequently, a mixture of 26.6 parts of IPDA, 1024.0 parts of ethyl acetate, and 215.3 parts of IPA was blended, 784.9 parts of the urethane prepolymer solution (2) obtained above was dropped in the mixture under stirring, and a resultant mixture was reacted at 40° C. for 1 hour. As a result, a polyurethane resin solution PU2 of the present Example having a non-volatile content of 30%, a viscosity of 1020 mPa.Math.s (25° C.), a terminal amino group concentration of 46.2μ equivalent per 1 g of the solid content of the resin, and 81.3% of plant-derived components in the solid content of the resin was obtained. Table 2-1 shows the combination and characteristics of the polyurethane resin solution PU2 obtained above.

Example 3

[0094] A polyurethane resin solution was prepared basically in the same manner as in Example 1. As a dicarboxylic acid component, dimer acid (dimer purity of 98%) obtained from a plant-derived component/succinic acid obtained from a plant-derived component=2/98 (molar ratio) was used, and as a diol component, 1,3-propanediol obtained from a plant-derived component was used. These components were each used in an appropriate amount and polymerized to obtain a polyester diol PE (3) having 100% of plant-derived components, the PE (3) having a hydroxyl value of 37.3 mgKOH/g, an acid value of 0.3 mgKOH/g, and a number average molecular weight of 3000, as shown in Table 1-1.

[0095] Next, 500 parts of the polyester diol PE (3) obtained above and 59.0 parts of IPDI were loaded in a reaction container and reacted at 100° C. for 5 hours in a nitrogen gas stream to obtain a urethane prepolymer having an NCO group content of 1.42% as shown in Table 2-1. The obtained urethane prepolymer was dissolved in 186.4 parts of ethyl acetate to make a urethane prepolymer solution (3) having a non-volatile content of 75%.

[0096] Subsequently, a mixture of 18.2 parts of IPDA, 958.5 parts of ethyl acetate, and 202.0 parts of IPA was blended, 745.4 parts of the urethane prepolymer solution (3) obtained above was dropped in the mixture under stirring, and a resultant mixture was reacted at 40° C. for 1 hour. As a result, a polyurethane resin solution PU3 of the present Example having a non-volatile content of 30%, a viscosity of 1100 mPa.Math.s (25° C.) a terminal amino group concentration of 42.7μ equivalent per 1 g of the solid content of the resin, and 86.6% of plant-derived components in the solid content of the resin was obtained. Table 2-1 shows the combination and characteristics of the polyurethane resin solution PU3 obtained above.

Example 4

[0097] Firstly, a polyester polyol was prepared in the manner as described below. As a dicarboxylic acid component, petroleum-derived adipic acid, and as a diol component, petroleum-derived neopentyl glycol/1,4-butanediol=70/30 (molar ratio) were used. These components were each used in an appropriate amount and polymerized to obtain a polyester diol PE (4) 100% obtained from petroleum-derived components, the PE (4) having a hydroxyl value of 37.3 mgKOH/g, an acid value of 0.3 mgKOH/g, and a number average molecular weight of 3000, as shown in Table 1-1.

[0098] Next, 250 parts of the polyester diol PE (4) obtained above, 250 parts of the polyester diol PE (2) obtained in Example 2 and 100% obtained from plant-derived components, and 73.8 parts of IPDI were loaded in a reaction container and reacted at 100° C. for 5 hours in a nitrogen gas stream to obtain a urethane prepolymer having an NCO group content of 1.73% as shown in Table 2-1. The obtained urethane prepolymer was dissolved in 191.3 parts of ethyl acetate to make a urethane prepolymer solution (4) having a non-volatile content of 75%.

[0099] Subsequently, a mixture of 22.4 parts of IPDA, 504.3 parts of ethyl acetate, 208.7 parts of IPA, and 486.9 parts of MEK was blended, 765.1 parts of the urethane prepolymer solution (4) obtained previously was dropped in the mixture under stirring, and a resultant mixture was reacted at 40° C. for 1 hour. As a result, a polyurethane resin solution PU4 of the present Example having a non-volatile content of 30%, a viscosity of 1050 mPa.Math.s (25° C.), a terminal amino group concentration of 43.7μ equivalent per 1 g of the solid content of the resin, and 41.9% of plant-derived components in the solid content of the resin was obtained. Table 2-1 shows the combination and characteristics of the polyurethane resin solution PU4 obtained above.

Example 5

[0100] Firstly, a polyester polyol was prepared in the manner as described below. As a dicarboxylic acid component, dimer acid (dimer purity of 98%) obtained from a plant-derived component/succinic acid obtained from a plant-derived component/adipic acid obtained from a petroleum-based and -derived component=10/30/60 (molar ratio) “note: additional dicarboxylic acid/plant-derived succinic acid=70/30 and dimer acid/plant-derived succinic acid=10/30=25/75 (molar ratio)”, and as a diol component, 1,3-propane diol obtained from plant-derived component/neopentyl glycol obtained from a petroleum-based and -derived component=30/70 (molar ratio) were used. These components were each used in an appropriate amount and polymerized to obtain a polyester diol PE (5) having 41.2% of plant-derived components, the PE (5) having a hydroxyl value of 30.2 mgKOH/g, an acid value of 0.3 mgKOH/g, and a number average molecular weight of 3710, as shown in Table 1-1.

[0101] Next, 500 parts of the polyester diol PE (5) obtained above and 47.8 parts of IPDI were loaded in a reaction container and reacted at 100° C. for 5 hours in a nitrogen gas stream to obtain a urethane prepolymer having an NCO group content of 1.18% as shown in Table 2-1. The obtained urethane prepolymer was dissolved in 182.0 parts of ethyl acetate, which is an organic solvent for dilution, to make a urethane prepolymer solution (5) having a non-volatile content of 75%.

[0102] Subsequently, a mixture of 14.7 parts of IPDA, 933.6 parts of ethyl acetate, and 197.0 parts of IPA was blended, 730.4 parts of the urethane prepolymer solution (5) obtained above was dropped in the mixture under stirring, and a resultant mixture was reacted at 40° C. for 1 hour. As a result, a polyurethane resin solution PU5 of the present Example having a non-volatile content of 30%, a viscosity of 1200 mPa.Math.s (25° C.) a terminal amino group concentration of 40.9μ equivalent per 1 g of the solid content of the resin, and 36.6% of plant-derived components in the solid content of the resin was obtained. Table 2-1 shows the combination and characteristics of the polyurethane resin solution PU5 obtained above.

Examples 6 to 13

[0103] Polyester polyols PE (6) to PE (12) were each prepared using raw materials for synthesis shown in Table 1-2 in the same manner as in Example 1. Table 1-2 shows the hydroxyl value, acid value, number average molecular weight, and plant-derived component ratio of each of the prepared polyester diols PE (6) to PE (12).

[0104] Next, each of the polyester diols PE (6) to PE (12) obtained above and IPDI were reacted in a reaction container according to the combination shown in Table 2-2 in the same manner as in Example 1 to obtain each urethane prepolymer. Table 2-1 shows the NCO % of each urethane prepolymer. Each of the urethane prepolymers obtained above was dissolved in a predetermined amount of ethyl acetate to make urethane prepolymer solutions (6) to (13) each having a non-volatile content of 75%.

[0105] Subsequently, a mixture of IPDA, ethyl acetate, and IPA was blended in a mass ratio shown in Table 2-2, the whole amount of the urethane prepolymer solution obtained above was dropped in the mixture under stirring, and a resultant mixture was reacted at 40° C. for 1 hour. As a result, polyurethane resin solutions PU6 to PU13 of the present Examples were each obtained. Table 2-2 shows the combination and characteristics of each of the polyurethane resin solutions PU6 to PU13 obtained above together. It is to be noted that as shown in Table 2-2, the polyurethane resin solution PU13 as well as the polyurethane resin solution PU6 uses the polyester diol PE (6) as a raw material, but the amino group equivalent is considerably different from that of the polyurethane resin solution PU6 as a result of changing the amount of IPDI and the amount of IPDA used from those in the case of producing the polyurethane resin solution PU6.

TABLE-US-00001 TABLE 1-1 Raw material compositions and characteristics of polyester diols used in Examples and Comparative Examples Polyester diol No. PE (1) PE (2) PE (3) PE (4) PE (5) Dicarboxylic acid Adipic acid 100 60 component Bio-succinic acid 10 40 98 30 (molar ratio) Bio-dimer acid 90 60 2 10 Bio-sebacic acid Diol NPG 70 70 component 1,4-BD 30 (molar ratio) Bio-EG Bio-1,4-BD Bio-1,2-PD Bio-1,3-PD 100 100 100 30 Hydroxyl value (mgKOH/g) 37.3 56.0 37.3 37.3 30.2 Acid value (mgKOH/g) 0.3 0.3 0.3 0.3 0.3 Number average molecular weight 3000 2000 3000 3000 3710 Bio % 100 100 100 0 41.2

TABLE-US-00002 TABLE 1-2 Raw material compositions and characteristics of polyester diols used in Examples and Comparative Examples PE PE PE PE PE PE PE Polyester diol No. (6) (7) (8) (9) (10) (11) (12) Dicarboxylic acid Adipic acid 60 60 20 60 component Bio-succinic acid 40 40 40 40 40 80 (molar ratio) Bio-dimer acid 60 60 60 Bio-sebacic acid 40 Diol NPG 30 70 30 component 1,4-BD (molar ratio) Bio-EG 30 Bio-1,4-BD 30 Bio-1,2-PD 30 100 70 30 Bio-1,3-PD 70 70 70 70 Hydroxyl value (mgKOH/g) 37.4 37.4 37.4 37.4 37.4 37.4 37.4 Acid value (mgKOH/g) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Number average molecular weight 3000 3000 3000 3000 3000 3000 3000 Bio % 100 100 100 62.5 47.1 47.8 55.2

[0106] The abbreviations in Table 1-1 and Table 1-2 are as described below.

[0107] NPG: Neopentyl glycol

[0108] EG: Ethylene glycol

[0109] 1,4-BD: 1,4-Butanediol

[0110] 1,2-PD: 1,2-Propanediol

[0111] 1,3-PD: 1,3-Propanediol

TABLE-US-00003 TABLE 2-1 Combinations and characteristics of bio-polyurethane resin solutions of Examples Example Polyurethane resin 1 2 3 4 5 solution No. PU1 PU2 PU3 PU4 PU5 Urethane No. (1) (2) (3) (4) (5) prepolymer PE (1) 500 solution PE (2) 500 250 PE (3) 500 PE (4) 250 PE (5) 500 IPDI 66.4 88.6 59.0 73.8 47.8 NCO % 1.87 2.03 1.42 1.73 1.18 Ethyl acetate 188.8 196.2 186.4 191.3 182.0 IPDA 23.6 26.6 18.2 22.4 14.7 Ethyl acetate 981.4 1024.0 958.5 504.3 933.6 IPA 206.5 215.3 202.0 208.7 197.0 MEK 486.9 Solid content (%) 30 30 30 30 30 Viscosity/mPas (25° C.) 1150 1020 1100 1050 1200 Amino group equivalent 42.8 46.2 42.7 43.7 40.9 (μeq/g) Bio % 84.7 81.3 86.6 41.9 36.6

TABLE-US-00004 TABLE 2-2 Combinations and characteristics of bio-polyurethane resin solutions of Examples Example Polyurethane resin 6 7 8 9 10 11 12 13 solution No. PU6 PU7 PU8 PU9 PU10 PU11 PU12 PU13 Urethane No. (6) (7) (8) (9) (10) (11) (12) (13) prepolymer solution PE (6) 500 500 PE (7) 500 PE (8) 500 PE (9) 500 PE (10) 500 PE (11) 500 PE (12) 500 IPDI 66.6 66.6 66.6 66.6 59.2 66.6 66.6 64.8 NCO % 1.87 1.87 1.87 1.87 1.41 1.87 1.87 1.77 Ethyl acetate 188.9 188.9 189.9 189.9 186.4 189.9 189.9 188.3 IPDA 23.5 23.5 23.5 23.5 18.0 23.5 23.5 21.3 Ethyl acetate 981.1 981.1 981.1 981.1 958.6 981.1 981.1 973.7 IPA 206.5 206.5 206.5 206.5 202.0 206.5 206.5 205.1 Solid content (%) 30 30 30 30 30 30 30 30 Viscosity/mPas 1180 1180 1180 1200 1200 1200 1210 1400 (25° C.) Amino group 41.0 41.0 41.0 41.0 41.6 41.0 41.0 21.4 equivalent (μeq/g) Bio % 84.7 84.7 84.7 53.0 40.8 40.5 46.8 85.3

[0112] The abbreviations in Table 2-1 and Table 2-2 are as described below.

[0113] IPDI: Isophorone diisocyanate

[0114] IPDA: Isophorone diamine

[0115] IPA: Isopropyl alcohol

[0116] MEK: Methyl ethyl ketone

Comparative Example 1

[0117] A polyurethane resin solution of the present Comparative Example was prepared in the same manner as in Example 1 except that succinic acid which is essential in the present invention and obtained from a plant-derived component was not used as a raw material in the polymerization for the polyester polyol. Firstly, as a dicarboxylic acid component, only a dimer acid (dimer purity of 98%) obtained from a plant-derived component was used, and as a diol component, 1,3-propanediol obtained from a plant-derived component was used. These components were used each in an appropriate amount and polymerized to obtain a polyester diol PE (13) 100% obtained from plant-derived components, the PE (13) having a hydroxyl value of 37.3 mgKOH/g, an acid value of 0.3 mgKOH/g, and a number average molecular weight of 3000, as shown in Table 3.

[0118] Next, 500 parts of the polyester diol PE (13) obtained above and 66.4 parts of IPDI were loaded in a reaction container and reacted at 100° C. for 5 hours in a nitrogen gas stream to obtain a urethane prepolymer having an NCO group content of 1.87% as shown in Table 4. The obtained urethane prepolymer was dissolved in 188.8 parts of ethyl acetate to make a urethane prepolymer comparative solution (C1) having a non-volatile content of 75%.

[0119] Subsequently, a mixture of 23.8 parts of IPDA, 981.9 parts of ethyl acetate, and 206.6 parts of IPA was blended, 755.2 parts of the urethane prepolymer comparative solution (C1) obtained above was dropped in the mixture under stirring, and a resultant mixture was reacted at 40° C. for 1 hour. As a result, a polyurethane resin solution PU-C1 of the present Comparative Example having a non-volatile content of 30%, a viscosity of 1090 mPa.Math.s (25° C.), a terminal amino group concentration of 47.1μ equivalent per 1 g of the solid content of the resin, and 84.7% of plant-derived components in the solid content of the resin was obtained. Table 4 shows the combination and characteristics of the polyurethane resin solution PU-C1 obtained above.

Comparative Example 2

[0120] A polyurethane resin solution of the present Comparative Example was prepared in the same manner as in Example 1 except that as a dicarboxylic acid component, only succinic acid obtained from a plant-derived component was used without using an additional dicarboxylic acid such as the dimer acid to make the dicarboxylic acid component 100% composed of succinic acid. Firstly, as a dicarboxylic acid component, only succinic acid obtained from a plant-derived component was used, and as a diol component, 1,3-propanediol obtained from a plant-derived component was used. These components were used each in an appropriate amount and polymerized to obtain a polyester diol PE (14) 100% obtained from plant-derived components, the PE (14) having a hydroxyl value of 37.3 mgKOH/g, an acid value of 0.3 mgKOH/g, and a number average molecular weight of 3000 as shown in Table 3.

[0121] Next, 500 parts of the polyester diol PE (14) obtained above and 62.7 parts of IPDI were loaded in a reaction container and reacted at 100° C. for 5 hours in a nitrogen gas stream to obtain a urethane prepolymer having an NCO group content of 1.65% as shown in Table 4. The obtained urethane prepolymer was dissolved in 187.6 parts of ethyl acetate to make a urethane prepolymer comparative solution (C2) having a non-volatile content of 75%.

[0122] Subsequently, a mixture of 20.9 parts of IPDA, 969.9 parts of ethyl acetate, and 204.3 parts of IPA was blended, 750.3 parts of the urethane prepolymer comparative solution (C2) obtained above was dropped in the mixture under stirring, and a resultant mixture was reacted at 40° C. for 1 hour. As a result, a polyurethane resin solution PU-C2 of the present Comparative Example having a non-volatile content of 30%, a viscosity of 1180 mPa.Math.s (25° C.), a terminal amino group concentration of 41.7μ equivalent per 1 g of the solid content of the resin, and 85.7% of plant-derived components in the solid content of the resin was obtained. Table 4 shows the combination and characteristics of the polyurethane resin solution PU-C2 obtained above.

Comparative Example 3

[0123] In a reaction container, 180 parts of the polyester diol PE (2) used in Example 2 and 100% obtained from plant-derived components, 320 parts of the polyester diol PE (4) used in Example 4 and 100% obtained from petroleum-derived components, and 59.0 parts of IPDI were loaded and reacted at 100° C. for 5 hours in a nitrogen gas stream to obtain a urethane prepolymer having an NCO group content of 1.42% as shown in Table 4. The obtained urethane prepolymer was dissolved in 186.4 parts of ethyl acetate to obtain a urethane prepolymer comparative solution (C3) in which large amounts of the petroleum-derived components were used, the urethane prepolymer comparative solution (C3) having a non-volatile content of 75%.

[0124] Subsequently, a mixture of 18.2 parts of IPDA, 958.5 parts of ethyl acetate, and 202.0 parts of IPA was blended, 745.4 parts of the urethane prepolymer comparative solution (C3) obtained above was dropped in the mixture under stirring, and a resultant mixture was reacted at 40° C. for 1 hour. As a result, a polyurethane resin solution PU-C3 of the present Comparative Example having a low degree of biomass, the PU-C3 having a non-volatile content of 30%, a viscosity of 1100 mPa.Math.s (25° C.), a terminal amino group concentration of 42.7μ equivalent per 1 g of the solid content of the resin, and 31.2% of plant-derived components in the solid content of the resin was obtained. Table 4 shows the combination and characteristics of the polyurethane resin solution PU-C3 obtained above.

Comparative Example 4

[0125] A polyurethane resin solution of the present Comparative Example was prepared basically in the same manner as in Examples except that succinic acid, which is essential in the present invention, and as a diol component, the components, such as 1,3-propane diol, which are specified in the present invention were not used in the preparation of a polyester polyol. It is to be noted that the resin of the present Comparative Example corresponds to the resin described in Production Example 9 of Patent Literature 1 previously described.

[0126] Firstly, as a dicarboxylic acid component, only a dimer acid (dimer purity of 98%) obtained from a plant-derived component, and as a diol component, 1,6-hexanediol obtained from a petroleum-derived component were used, and these components were each used in an appropriate amount and polymerized to obtain a polyester diol PE (15) having a hydroxyl value of 57.0 mgKOH/g, an acid value of 0.4 mgKOH/g, a number average molecular weight of 2000, and 81.1% of plant-derived components as shown in Table 3. In a reaction container, 500 parts of the obtained polyester diol PE (15) and 111.0 parts of IPDI were loaded and reacted at 100° C. for 5 hours in a nitrogen gas stream to obtain a urethane prepolymer having an NCO group content of 3.36% as shown in Table 4. The obtained urethane prepolymer was dissolved in 203.7 parts of ethyl acetate to obtain a urethane prepolymer comparative solution (C4) having a non-volatile content of 75%.

[0127] Subsequently, a mixture of 38.8 parts of IPDA, 1100.6 parts of ethyl acetate, and 230.2 parts of IPA was blended, 814.7 parts of the urethane prepolymer comparative solution (C4) obtained above was dropped in the mixture under stirring, and a resultant mixture was reacted at 40° C. for 1 hour. As a result, a polyurethane resin solution PU-C4 of the present Comparative Example having a non-volatile content of 30%, a viscosity of 1020 mPa.Math.s (25° C.), a terminal amino group concentration of 42.5μ equivalent per 1 g of the solid content of the resin, and 61.6% of plant-derived components in the solid content of the resin was obtained. Table 4 shows the combination and characteristics of the polyurethane resin solution PU-C4 obtained above.

Comparative Examples 5 to 8

[0128] The carboxylic acid components and the diol components shown in Table 3 were each used in an appropriate amount and polymerized in the same manner as in Example 1 to prepare a polyester diol PE (16) 100% obtained from petroleum-derived components and a polyester diol PE (17) 100% obtained from plant-derived components, the PE (16) and the PE (17) each having a hydroxyl value, an acid value, a number average molecular weight, and a plant-derived component ratio shown in Table 3.

[0129] Next, in a reaction container, the polyester diol PE (6) used previously in Example 6 and Example 13, and the polyester diol PE (16) and the polyester diol PE (17), which are obtained above, were each used with IPDI according to the combination in Table 4 and reacted in the same manner as in Examples to obtain each urethane prepolymer having an NCO % shown in Table 4. Obtained each urethane prepolymer was dissolved in a predetermined amount of ethyl acetate to obtain urethane prepolymer comparative solutions (C5) to (C8) each having a non-volatile content of 75%.

[0130] Subsequently, each mixture of IPDA, ethyl acetate, and IPA was blended in a mass ratio shown in Table 4, the whole amount of each urethane prepolymer solution obtained above was dropped in the mixture under stirring, and a resultant mixture was reacted at 40° C. for 1 hour. As a result, polyurethane resin solutions PU-05 to PU-C8 of Comparative Examples of 5 to 8 were each obtained. Table 4 shows the combinations and characteristics of the polyurethane resin solutions PU-05 to PU-C8 obtained above.

TABLE-US-00005 TABLE 3 Raw material compositions and characteristics of polyester diols used in Comparative Examples Polyester diol No. PE (13) PE (14) PE (15) PE (16) PE (17) Dicarboxylic acid Adipic acid 100 component Bio-succinic acid 100 (molar ratio) Bio-dimer acid 100 100 Bio-sebacic acid 100 Diol NPG 50 component 1,6-HD 100 50 (molar ratio) Bio-1,3-PD 100 100 100 Hydroxyl value (mgKOH/g) 37.3 37.3 57.0 37.4 37.4 Acid value (mgKOH/g) 0.3 0.3 0.4 0.3 0.3 Number average molecular weight 3000 3000 2000 3000 3000 Bio % 100 100 81.1 0 100

[0131] The abbreviations in Table 3 are as described below.

[0132] NPG: Neopentyl glycol

[0133] 1,6-HD: 1,6-Hexanediol

[0134] 1,3-PD: 1,3-Propanediol

TABLE-US-00006 TABLE 4 Combinations and characteristics of urethane resin solutions of Comparative Examples Polyurethane Comparative Example resin 1 2 3 4 5 6 7 8 solution No. PU-C1 PU-C2 PU-C3 PU-C4 PU-05 PU-C6 PU-C7 PU-C8 Urethane No. (C1) (C2) (C3) (C4) (C5) (C6) (C7) (C8) prepolymer PE (2) 180 solution PE (4) 320 PE (6) 500 500 PE (13) 500 PE (14) 500 PE (15) 500 PE (16) 500 PE (17) 500 IPDI 66.4 62.7 59.0 111.0 72.2 59.2 66.6 66.6 NCO % 1.87 1.65 1.42 3.36 2.20 1.42 1.87 1.87 Ethyl 188.8 187.6 186.4 203.7 190.7 186.4 188.9 188.9 acetate IPDA 23.8 20.9 18.2 38.8 32.0 16.5 23.5 23.5 Ethyl aetate 981.9 969.9 958.5 1100.6 1007.3 955.6 981.1 981.1 IPA 206.6 204.3 202.0 230.2 211.5 201.5 206.5 206.5 Solid content (%) 30 30 30 30 30 30 30 30 Viscosity/mPas 1090 1180 1100 1020 800 1700 1180 1200 (25° C.) Amino group 47.1 41.7 42.7 42.5 127.0 8.8 41.0 41.0 equivalent (μeq/g) Bio % 84.7 85.7 31.2 61.6 82.3 86.9 0 84.7

[0135] The abbreviations in Table 4 are as described below.

[0136] IPDI: Isophorone diisocyanate

[0137] IPDA: Isophorone diamine

[0138] IPA: Isopropyl alcohol

[0139] <Evaluation>

[0140] A printing ink in which each resin solution was blended therein was prepared in the manner as described below, and evaluation of the performance of each polyurethane resin solution of Examples and Comparative Examples was performed using the obtained printing ink.

[0141] [Preparation of Printing Ink: Examples 1-I to 13-I and Comparative Examples 1-I to 8-I]

[0142] Printing inks of Examples and Comparative Examples were each prepared using 40 parts of respective polyurethane resin solutions of Examples 1 to 13 and Comparative Examples 1 to 8 in the manner as described below. Specifically, a mixture having a composition composed of 30 parts of titanium oxide white as a pigment, 40 parts of each polyurethane resin solution, 15 parts of n-propyl acetate, and 15 parts of isopropyl alcohol was kneaded with a paint shaker for 1 hour to prepare each white ink. Further, the viscosity of the obtained white ink was adjusted with a mixed solvent of ethyl acetate/IPA (mass ratio of 50/50) for dilution so as to be 18 seconds when measured with a Zahn cup #3 to obtain each of the printing inks of Examples 1-I to 13-I and Comparative Examples 1-I to 8-I. It is to be noted that the printing inks prepared using respective polyurethane resin solutions of Examples 1 to 13 and Comparative Examples 1 to 8 were each denoted with “-I” attached to the number for the Example or the Comparative Example.

[0143] (Method for Evaluating Printing Ink and Evaluation Criteria)

[0144] Printing inks of Examples 1-I to 13-I and Comparative Examples of 1-I to 8-I prepared above were each used and evaluated according to the testing methods and criteria described below, and the results are shown together in Table 5.

[0145] (1) Amount of Biomass Components

[0146] The content (% by mass) of the biomass components in the biomass urethane resin in the solid content of each printing ink of Examples and Comparative Examples was determined by calculation and evaluated according to the following criteria.

(Evaluation Criteria)

[0147] Good: The amount of the biomass components is 10% or more.

[0148] Poor: The amount of the biomass components is less than 10%.

[0149] (2) Compatibility

[0150] A standard ink was prepared for evaluation in the manner as described below in order to evaluate the compatibility with a petroleum-derived, standard printing ink. Firstly, 500 parts of the polyester diol PE (4) having 100% of the petroleum-derived components and 66.4 parts of IPDI were loaded in a reaction container and reacted at 100° C. for 5 hours in a nitrogen gas stream to obtain a urethane prepolymer having an NCO group content of 1.87%. Next, the obtained urethane prepolymer was dissolved in 188.8 parts of ethyl acetate, which is an organic solvent for dilution, to make a urethane prepolymer solution having a non-volatile content of 75%. Subsequently, a mixture (diamine solution) of 23.6 parts of IPDA, 981.4 parts of ethyl acetate, and 206.5 parts of IPA was blended, 755.2 parts of the urethane prepolymer solution obtained above was dropped in the mixture under stirring, and a resultant mixture was reacted at 40° C. for 1 hour. As a result, a polyurethane resin solution having a non-volatile content of 30%, a viscosity of 1150 mPa.Math.s (25° C.), and a terminal amino group concentration of 42.8μ equivalent per 1 g of the solid content of the resin, and not having a plant-derived component in the solid content of the resin was obtained.

[0151] A mixture having a composition composed of 40 parts of the obtained polyurethane resin solution, 30 parts of titanium oxide white, 15 parts of n-propyl acetate, and 15 parts of IPA was kneaded with a paint shaker for 1 hour to prepare a white ink. Further, the viscosity of the obtained white ink was adjusted with a mixed solvent of ethyl acetate/isopropyl alcohol (mass ratio of 50/50) for dilution so as to be 18 seconds when measured with a Zahn cup #3 to obtain a standard printing ink (100% derived from petroleum) for evaluating compatibility.

[0152] Into a cup, 100 parts of the standard printing ink for evaluating compatibility prepared above was taken out, and 100 parts of each of the inks 1-I to 13-I of Examples and the inks 1-I to 8-I of Comparative Examples was taken out into a cup and was poured into the standard printing ink to observe the state on that occasion visually and evaluate the compatibility with the standard printing ink according to the criteria described below.

[0153] (Evaluation Criteria)

[0154] Excellent: The resultant mixture becomes uniform by only mixing.

[0155] Good: The resultant mixture is ununiform by only mixing, but becomes uniform when stirred.

[0156] Poor: The resultant mixture does not become uniform even if it is stirred.

[0157] (3) Pigment Dispersibility

[0158] A small amount of each printing ink of Examples and Comparative Examples was dropped on white paper with a black band printed thereon, and the dropped ink was spread with a metal spatula to observe the uniformity of pigment dispersion and the color developability visually and evaluate them according to the following criteria.

[0159] (Evaluation Criteria)

[0160] Good: The pigment dispersion is uniform, and the color development is favorable.

[0161] Fair: The pigment dispersion is somewhat ununiform, and the color development is somewhat unfavorable.

[0162] Poor: The pigment dispersion is ununiform, and the color development is clearly inferior.

[0163] (4) Printability

[0164] The printing inks of Examples and Comparative Examples were separately set in a gravure printing machine with a gravure plate having a plate depth of 35 μm installed therein, and a change in the color development on the first printed matter before and after rotating the plate for 30 minutes under an environment of 25° C. with a doctor blade being in contact with the plate was observed visually and evaluated according to the following criteria. The base material of the printed matter was a corona discharge-treated, biaxially stretched biomass PET having a thickness of 12 μm.

[0165] (Evaluation Criteria)

[0166] Good: There is no difference in the color development of printing before and after the rotation in the gravure printing machine for 30 minutes.

[0167] Fair: The color development after the rotation in the gravure printing machine for 30 minutes is somewhat inferior to the color development at the time when the rotation is started.

[0168] Poor: The color development after the rotation in the gravure printing machine for 30 minutes is clearly inferior to the color development at the time when the rotation is started.

[0169] (5) Adhesion Property (Tape Adhesion Test)

[0170] The printing inks of Examples and Comparative Examples were separately set in a gravure printing machine with a gravure plate having a plate depth of 35 μm installed therein, and printing was performed twice so as to be overlaid on a corona discharge-treated, biaxially stretched biomass PET film base material having a thickness of 12 μm to obtain each white-printed film for evaluation after drying at 50° C.

[0171] The adhesiveness of each ink after each of the obtained white-printed films was left to stand for 1 day was evaluated by a tape adhesion test performed using a cellophane tape (CELLOTAPE (R), 24 mm, manufactured by Nichiban Co., Ltd.). Specifically, the cellophane tape was stuck to a printed face of each white-printed film, the state of the printed film at the time when the cellophane tape was peeled at an angle of 90° without stopping was observed visually, and the quality of the adhesion property of the printing ink was decided by the residual rate of the ink left on the printed face. In the tape adhesion test, when the residual rate of a printing ink is 90% or more, the printing ink has sufficient practicability.

TABLE-US-00007 TABLE 5 Evaluation results of printing inks Amount of biomass Adhesion property Printing ink Resin components Pigment Visual Residual No. component Evaluation (%) Compatibility dispersibility Printability evaluation ink (%) Ex. 1-I PU1 Good 24.2 Good Good Good Good 100 Ex. 2-I PU2 Good 23.2 Good Good Good Good 100 Ex. 3-I PU3 Good 24.7 Good Good Good Good 100 Ex. 4-I PU4 Good 12.0 Good Good Good Good 100 Ex. 5-I PU5 Good 10.5 Good Good Good Good 100 Ex. 6-I PU6 Good 24.2 Good Good Good Good 100 Ex. 7-I PU7 Good 24.2 Good Good Good Good 100 Ex. 8-I PU8 Good 24.2 Good Good Good Good 100 Ex. 9-I PU9 Good 15.1 Excellent Good Good Good 100 Ex. 10-I PU10 Good 11.7 Excellent Good Good Good 100 Ex. 11-I PU11 Good 11.6 Excellent Good Good Good 100 Ex. 12-I PU12 Good 13.4 Excellent Good Good Good 100 Ex. 13-I PU13 Good 24.4 Excellent Good Good Good 100 C.Ex. 1-I PU-C1 Good 24.2 Good Fair Poor Good 100 C.Ex. 2-I PU-C2 Good 24.5 Good Fair Poor Poor 0 C.Ex. 3-I PU-C3 Poor 8.9 Good Good Good Good 100 C.Ex. 4-I PU-C4 Good 17.6 Good Fair Poor Good 100 C.Ex. 5-I PU-C5 Good 23.7 Good Fair Fair Poor 0 C.Ex. 6-I PU-C6 Good 24.8 Good Fair Poor Poor 0 C.Ex. 7-I PU-C7 Poor 0 Excellent Good Good Good 100 C.Ex. 8-I PU-C8 Good 24.2 Good Fair Poor Poor 0 Ex. represents Example C.Ex. represents Comparative Example