Dope additive and fiber

Abstract

To provide an additive and the like.SOLUTION: The additive is composed of a polyurethane (A) having a V2 / V1 value of 1 or more, where V1 is a viscosity at 40°C when the additive is dissolved in dimethylacetamide (DMAc) at a concentration of 20 mass%, and V2 is a viscosity at 40°C after 24 hours have elapsed following the dissolution.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an additive for a dope, a dope, a fiber (such as a polyurethane fiber), and the like. [Background technology]

[0002] Solution molding is often used in the molding (shaping) of polyurethane, for example, solution spinning and solution cast film (Patent Document 1, etc.). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2015 / 056763 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a novel additive (additive for dope), dope, polyurethane fiber (elastic polyurethane fiber), and the like. [Means for solving the problem]

[0005] As mentioned above, solution casting is often used to mold (cast) polyurethane. Under these circumstances, the present inventors have conducted extensive research and found that by selecting specific components as components (additives) to be blended into a solution (dope), it is possible to realize efficient molding of polyurethane (e.g., polyurethane fiber (elastic fiber)) and production of polyurethane (e.g., polyurethane fiber (elastic fiber)) with good physical properties, and have completed the present invention.

[0006] That is, the present invention relates to the following inventions. [1] An additive for a dope, comprising a polyurethane (A), wherein V2 / V1 is a value of 1 or more, where V1 is the viscosity when the polyurethane is dissolved (or dispersed) in dimethylacetamide (DMAc) at 40°C at 20% by mass (at a concentration of 20% by mass), and V2 is the viscosity after 24 hours from the dissolution (or dispersion) (where V1 is the viscosity when the polyurethane is dissolved (or dispersed) in dimethylacetamide (DMAc) at 40°C at 20% by mass (at a concentration of 20% by mass), and V2 is the viscosity after 24 hours from the dissolution (or dispersion) at 40°C (where V2 is the viscosity after 24 hours from the dissolution (or dispersion) at 40°C). [2] The additive according to [1], wherein the polyurethane (A) has a V2 / V1 value of 1.01 or more. [3] The additive according to [1] or [2], wherein the polyurethane (A) has a V2 / V1 value of 5 or less (e.g., 4.3 or less, 4.1 or less). [4] The additive according to any one of [1] to [3], wherein the polyurethane (A) has a V2 / V1 value of 1.02 to 3.5. [5] The additive according to any one of [1] to [4], wherein V2 of the polyurethane (A) is 1000 poise or more. [6] The additive according to any one of [1] to [5], wherein the polyurethane (A) satisfies the following (i) or (ii): (i) V2 is 1000 to 5000 poise, and the value of V2 / V1 is 1.05 or more. (ii) V2 is greater than 5,000 poise and the V2 / V1 value is 3.5 or less. [7] The additive according to any one of [1] to [6], wherein the polyurethane (A) has a number average molecular weight of 10,000 or more. [8] The additive according to any one of [1] to [7], wherein the polyurethane (A) has a peak in a region of molecular weight (number average molecular weight) of 1,000,000 or more in GPC. [9] The additive according to any one of [1] to [8], wherein the polyurethane (A) has an amino group.

[10] The additive according to any one of [1] to [9], wherein the polyurethane (A) has amino groups in a proportion of 0.1 meq / kg or more.

[11] The additive according to any one of [1] to

[10] , wherein the polyurethane (A) has amino groups in a proportion of 50 meq / kg or less.

[12] The additive according to any one of [1] to

[11] , wherein the polyurethane (A) has amino groups in a proportion of 0.1 to 50 meq / kg.

[13] The additive according to any one of [1] to

[12] , wherein the polyurethane (A) has amino groups in a proportion of 1 to 30 meq / kg (for example, 2 to 25 meq / kg).

[14] The additive according to any one of [1] to

[13] , wherein the polyurethane (A) contains a metal soap (for example, the metal soap is contained in a proportion of 0.003 to 3% by mass).

[15] The additive according to any one of [1] to

[14] , wherein the polyurethane (A) contains at least one selected from a surfactant, an antioxidant, a tertiary amine compound, and a crosslinking structure modifier (for example, the polyurethane (A) contains a surfactant in a proportion of 0.003 to 3 mass % and / or contains an antioxidant in a proportion of 0.002 to 5 mass %).

[0007]

[16] The additive according to any one of [1] to

[15] , wherein the polyurethane (A) is fibrous.

[17] The additive according to any one of [1] to

[16] , wherein the polyurethane (A) is (or is derived from) at least one selected from a molded product [e.g., fiber (yarn)] that has been stored for one month or more after production, molding waste, and a post-consumer product [e.g., fiber (yarn)].

[18] The additive according to any one of [1] to

[17] , which is a viscosity modifier (viscosity control agent, viscosity increase agent, thickener).

[19] The additive according to any one of [1] to

[18] , wherein the dope is a polyurethane dope.

[20] An additive for a dope, which is composed of a polyurethane (A) having an amino group (for example, having an amino group at a ratio of 0.1 to 50 meq / kg). [twenty one] An additive for a dope, which is composed of a polyurethane (A) having an amino group in a proportion of 1 to 30 meq / kg (for example, 2 to 25 meq / kg). [twenty two] A dope comprising the polyurethane (A) according to any one of [1] to

[21] . [twenty three] The dope according to

[22] , wherein the proportion of the polyurethane (A) is 1% by mass or more. [twenty four] The dope according to

[22] or

[23] , further comprising a resin (B). [twenty five] The dope according to any one of

[22] to

[24] , further comprising a resin (B), wherein the resin (B) comprises a polyurethane (B).

[26] Further, it contains a resin (B), The dope according to any one of

[22] to

[26] , wherein the proportion of the polyurethane (A) to the total amount of the polyurethane (A) and the resin (B) is 3 mass % or more.

[27] Further, it contains a resin (B), The resin (B) contains polyurethane (B), The dope according to any one of

[22] to

[26] , wherein the proportion of polyurethane (A) to the total amount of polyurethane (A) and polyurethane (B) is 5% by mass or more (for example, 10 to 90% by mass).

[0008]

[28] The dope according to any one of

[22] to

[27] , wherein the resin constituting the dope has a number average molecular weight of 10,000 or more.

[29] The dope according to any one of

[22] to

[28] , wherein the resin constituting the dope has a peak in a region of molecular weight (number average molecular weight) of 1,000,000 or more in GPC.

[30] The dope according to any one of

[22] to

[29] , which contains a solvent (for example, a solvent containing at least one selected from an amide-based solvent and a sulfur-based solvent).

[31] The dope according to any one of

[22] to

[30] , which contains a solvent and has a solid content of 5 to 80 mass %.

[32] The dope according to any one of

[22] to

[31] , wherein the value of V2 / V1 is 0.8 or more, where V1 is the viscosity at the time of preparation at 40°C and V2 is the viscosity after 24 hours from the preparation (where V2 is the viscosity after 24 hours at 40°C (the viscosity after 24 hours at 40°C after dissolving at 40°C)).

[33] The dope according to any one of

[22] to

[32] , wherein the value of V2 / V1 is 1 or more (for example, 1 to 5), where V1 is the viscosity at the time of preparation at 40°C and V2 is the viscosity after 24 hours from the preparation (where V2 is the viscosity after 24 hours at 40°C (the viscosity after 24 hours at 40°C after dissolving at 40°C)).

[34]

[0033] The dope according to any one of

[22] to

[33] , wherein the viscosity at 40°C is V1 when the viscosity is prepared and V2 after 24 hours (the viscosity after 24 hours at 40°C (the viscosity after dissolving at 40°C and then maintaining at 40°C for 24 hours)), the value of V2 / V1 is 1.01 to 3.5, and the viscosity is 1000 to 10000 poises.

[35] A method for producing a molded article using the dope according to any one of

[22] to

[34] {for example, a method for producing a fiber [yarn, for example, a polyurethane fiber (yarn)] by spinning the dope according to any one of

[22] to

[34] }.

[36] A molded article obtained by using the dope according to any one of

[22] to

[34] .

[37] A molded article comprising the polyurethane (A) according to any one of [1] to

[21] .

[38] The molded article according to

[36] or

[37] , which is a fiber [yarn, for example, polyurethane fiber (yarn)].

[39] The molded article according to any one of

[36] to

[38] , wherein the resin constituting the molded article has a peak in a region of molecular weight (number average molecular weight) of 1,000,000 or more in GPC.

[40] The molded article according to any one of

[36] to

[39] , which contains at least one selected from a metal soap, a surfactant, an antioxidant, a tertiary amine compound, and a crosslinking structure modifier.

[41] The molded article according to any one of

[36] to

[40] , wherein the resin constituting the molded article is a fiber [yarn, for example, polyurethane fiber (yarn)] that has a peak in a region of molecular weight (number average molecular weight) of 1 million or more in GPC and contains a metal soap in a proportion of 0.003 to 3 mass%. [Effects of the Invention]

[0009] According to the present invention, a novel additive can be provided. Such additives are contained in specific polyurethanes and can improve the molding and physical properties (particularly both the molding and physical properties) of the polyurethanes.

[0010] For example, in one embodiment of the additive of the present invention, fiber breakage during spinning can be suppressed or prevented, enabling efficient production of polyurethane fibers. Despite the use of the additive, such efficient molding can be equivalent to or even superior to the case where dope production (polymerization) and spinning are simply performed.

[0011] In another embodiment of the additive of the present invention, good or improved physical properties {for example, at least one selected from strength (such as breaking strength), elongation (such as breaking elongation), heat resistance, durability [for example, maintenance of strength, etc. (for example, maintenance when exposed to an environment such as ultraviolet light, NOx, chlorine, etc. (particularly a complex environment combining these))], and yellowing resistance (for example, at least one selected from strength, elongation, heat resistance, and durability)} can be realized. DETAILED DESCRIPTION OF THE INVENTION

[0012] <Additives> The additive of the present invention is composed of a specific polyurethane (which may be referred to as polyurethane (A) etc.). Such an additive may be, for example, an additive for a dope.

[0013] [Polyurethane (A)] The polyurethane (A) may exhibit a particular viscosity behavior in a solvent (polar solvent).

[0014] Specifically, the polyurethane (A) has a viscosity (initial viscosity, V1) when dissolved (dispersed) (mixed) at a concentration of 20 mass % in dimethylacetamide (N,N-dimethylacetamide, DMAc) at 40°C, and a viscosity (viscosity after 24 hours, V2) after 24 hours have elapsed (left to stand) after dissolution (mixing) [the viscosity after 24 hours has elapsed (left to stand) at 40°C (after dissolving at 40°C and then leaving it at 40°C for 24 hours)], the ratio (ratio, proportion, viscosity ratio, viscosity after 24 hours / initial viscosity, V2 / V1) being selected from a range of 1 or more (for example, more than 1, 1.001 or more, 1.005 or more). For example, it may be 1.01 or more (e.g., 1.02 or more), preferably 1.03 or more (e.g., 1.04 or more), and more preferably 1.05 or more (e.g., 1.06 or more), and may be 1.08 or more (e.g., 1.1 or more, 1.15 or more, 1.2 or more, 1.25 or more, 1.3 or more, 1.35 or more, 1.4 or more, 1.45 or more, 1.5 or more, 1.55 or more, 1.6 or more, 1.7 or more, 1.8 or more, 1.9 or more, 2 or more, 2.1 or more, 2.2 or more, 2.3 or more, 2.4 or more, 2.5 or more, 2.6 or more, 2.7 or more, 2.8 or more, 2.9 or more, 3 or more, 3.1 or more, 3.2 or more, etc.).

[0015] The 24-hour viscosity / initial viscosity (V2 / V1) (upper limit) is not particularly limited and may be selected, for example, from a range of about 20 or less (e.g., 15 or less), for example, 10 or less (e.g., 8 or less), preferably 7 or less (e.g., 6 or less), more preferably 5 or less (e.g., 4.5 or less, 4.4 or less, 4.3 or less, 4.2 or less, 4.1 or less), particularly 4 or less (e.g., 3.8 or less, 3.7 or less, 3.6 or less, 3.5 or less, 3.4 or less), and may also be about 3.3 or less (e.g., 3.2 or less, 3.1 or less, 3 or less, 2.9 or less, 2.8 or less, 2.7 or less, 2.6 or less, 2.5 or less, 2.4 or less, 2.3 or less, 2.2 or less, 2.1 or less, 2 or less, 1.9 or less, 1.8 or less, 1.7 or less, 1.6 or less, 1.5 or less, 1.4 or less, 1.3 or less).

[0016] These ranges (upper and lower limits) may be combined appropriately to select a range (for example, 1 to 10, 1.01 to 5, etc.; the same applies to the ranges hereinafter).

[0017] Specific examples of the 24-hour viscosity / initial viscosity (V2 / V1) include 1 to 10, 1.01 to 5, 1.05 to 4, 1.03 to 3.5, 1.1 to 3.3, 1.2 to 3.5, 1.05 to 3, and 1.05 to 1.2.

[0018] Such a 24-hour viscosity / initial viscosity (V2 / V1) ratio makes it easier to achieve efficient molding of polyurethane (e.g., good spinnability) and to obtain polyurethane with good physical properties. The reasons for this are thought to be, for example, as follows.

[0019] First, as mentioned above, polyurethane is molded in a molten state (particularly solution molding), and the inventors' investigations have revealed that viscosity is important in such molding.

[0020] Specifically, if the viscosity is insufficient or inappropriate (or if such viscosity cannot be maintained or maintained over time), it may impair moldability (spinnability, etc.), such as making the yarn more susceptible to breakage, or it may impair the physical properties (e.g., strength, elongation, heat resistance, durability, etc.) of the resulting molded product.

[0021] Although the reason for this is not clear, it is believed that the viscosity of polyurethane is largely due to associations caused by strong hydrogen bonds in polyurethane, and if such associations are insufficient, it is thought that sufficient viscosity will be difficult to obtain.

[0022] If such association (viscosity) is insufficient, sufficient strength cannot be obtained during molding, and molding defects such as thread breakage are likely to occur. In addition, the insufficient association, which is thought to affect the manifestation of physical properties, will have an impact (reflect) on the obtained molded product (for example, the molded product will tend to have little or non-uniform association), and it is predicted that the physical properties will be impaired.

[0023] On the other hand, the above-mentioned V2 / V1 (change in viscosity over time) is thought to be related to the ease of thickening (and further, the ease of maintaining or continuing the thickened state), and ultimately the ease of association. In other words, polyurethanes with the above-mentioned V2 / V1 maintain or increase (maintain or increase over time) their viscosity (association), and when used alone or when blended with resins or their polymerization systems (e.g., polyurethanes or their polymerization systems), they exhibit or induce sufficient viscosity or association, minimizing viscosity decline over time and, depending on the combination and blend ratio, are thought to further increase viscosity, which in turn is thought to lead to good moldability and the physical properties of molded products.

[0024] However, if the viscosity becomes too high, spinnability and physical properties may be impaired. Therefore, the value of V2 / V1 and the use ratio (blending ratio) of the polyurethane (A) may be selected depending on the viscosity of the object (for example, polyurethane) to be blended (combined) with it.

[0025] For example, when the viscosity of the compounded object is relatively high, it is possible to select a polyurethane (A) whose V2 / V1 value is not too large, or to reduce the compounding ratio.

[0026] The initial viscosity (V1) of the polyurethane (A) is not limited, and may be selected from a range of about 10 poise (=1 Pa·s=1000 mPa·s) or more, and may be about 100 poise or more (e.g., 200 poise or more, 300 poise or more, 400 poise or more), preferably 500 poise or more (e.g., 600 poise or more, 700 poise or more, 800 poise or more), more preferably 1000 poise or more (e.g., 1100 poise or more, 1200 poise or more), and may be about 1300 poise or more (e.g., 1400 poise or more, 1500 poise or more, 1600 poise or more, 1700 poise or more). 100 poise or more, 1750 poise or more, 1800 poise or more, 1900 poise or more, 2000 poise or more, 2100 poise or more, 2200 poise or more, 2300 poise or more, 2400 poise or more, 2500 poise or more, 2600 poise or more, 2700 poise or more, 2800 poise or more, 2900 poise or more, 3000 poise or more, 3100 poise or more, 3200 poise or more, 3300 poise or more, 3400 poise or more, 3500 poise or more, 3600 poise or more, 3700 poise or more, 3800 poise or more, 3900 poise or more, 4000 poise or more), etc.

[0027] By satisfying the V2 / V1 ratio as described above, sufficient viscosity, etc. can be achieved; however, if the initial viscosity is too small, it may be difficult to efficiently achieve sufficient viscosity, etc. (for example, it may take an excessive amount of time to reach sufficient viscosity), although this depends on the blending target, blending ratio, and value of V2, and therefore it is acceptable to use an initial viscosity that is not too small as described above.

[0028] The initial viscosity (V1) (the upper limit value) of the polyurethane (A) is not limited, and may be selected from a range of about 100,000 poise or less, and may be about 80,000 poise or less (e.g., 60,000 poise or less, 50,000 poise or less, 40,000 poise or less), preferably 30,000 poise or less (e.g., 20,000 poise or less, 15,000 poise or less, 12,000 poise or less), more preferably 10,000 poise or less (e.g., 9,000 poise or less, 8,000 poise or less), and may be about 7,000 poise or less (e.g., 6,500 poise or less, 6,000 poise or less, 5,500 poise or less, 5,000 poise or less, 4,500 poise or less, 4,400 poise or less). 100 poise or less, 4300 poise or less, 4200 poise or less, 4100 poise or less, 4000 poise or less, 3900 poise or less, 3800 poise or less, 3700 poise or less, 3600 poise or less, 3500 poise or less, 3400 poise or less, 3300 poise or less, 3200 poise or less, 3100 poise or less, 3000 poise or less or less, 2900 poise or less, 2800 poise or less, 2700 poise or less, 2600 poise or less, 2500 poise or less, 2400 poise or less, 2300 poise or less, 2200 poise or less, 2100 poise or less, 2000 poise or less, 1900 poise or less, 1850 poise or less, 1800 poise or less), etc.

[0029] By satisfying the above-mentioned V2 / V1, sufficient viscosity, etc. can be achieved, but if the initial viscosity is too high, excessive viscosity may be exhibited, although this depends on the blending target, blending ratio, and value of V2, so it is also acceptable to set the initial viscosity to be not too high as described above.

[0030] The viscosity (V2) of the polyurethane (A) after 24 hours may be selected from a range of, for example, about 50 poise (=5 Pa·s=5000 mPa·s) or more, and may be about 300 poise or more (e.g., 400 poise or more, 500 poise or more, 600 poise or more), preferably 700 poise or more (e.g., 800 poise or more, 900 poise or more, 1000 poise or more), more preferably about 1100 poise or more (e.g., 1200 poise or more, 1300 poise or more), or about 1400 poise or more (e.g., 1500 poise or more, 1600 poise or more, 1700 poise or more, 1800 poise or more, 1900 poise or more, 1950 poise or more, 2000 poise or more, 2100 poise or more). , 2200 poise or more, 2300 poise or more, 2400 poise or more, 2500 poise or more, 2600 poise or more, 2700 poise or more, 2800 poise or more, 2900 poise or more, 3000 poise or more, 3100 poise or more, 3200 poise or more, 3300 poise or more, 3400 poise or more, 3500 poise or more, 3600 poise or more, 3700 poise or more, 3800 poise or more, 3900 poise or more, 4000 poise or more, 4200 poise or more, 4500 poise or more, 5000 poise or more, 5500 poise or more, 6000 poise or more, 6500 poise or more, 7000 poise or more, 7500 poise or more, 8000 poise or more, 8500 poise or more), etc.

[0031] By satisfying V2 / V1 as described above, sufficient viscosity, etc. can be achieved, but if V2 is too small, it may be difficult to efficiently achieve sufficient viscosity, etc. (for example, it may take an excessive amount of time to reach sufficient viscosity), although this depends on the blending target and blending ratio, and therefore V2 may not be too small as described above.

[0032] The viscosity (V2) (upper limit) of the polyurethane (A) after 24 hours may be selected from a range of about 1,000,000 poises or less, and is preferably 500,000 poises or less (e.g., 400,000 poises or less, 300,000 poises or less, 200,000 poises or less), and more preferably 100,000 poises or less (e.g., 80,000 poises or less, 70,000 poises or less, The viscosity may be about 60,000 poise or less, more preferably about 50,000 poise or less (for example, 40,000 poise or less, 30,000 poise or less), and may be about 25,000 poise or less (for example, 22,000 poise or less, 20,000 poise or less, 18,000 poise or less, 15,000 poise or less, 14,000 poise or less, 13,000 poise or less, 12,000 poise or less). poises or less, 11,500 poises or less, 11,000 poises or less, 10,500 poises or less, 10,000 poises or less, 9,500 poises or less, 9,000 poises or less, 8,800 poises or less, 8,500 poises or less, 8,000 poises or less, 7,500 poises or less, 7,000 poises or less, 6,800 poises or less, 6,500 poises or less, 5,000 poises or less, 4,500 poises poise or less, 4000 poise or less, 3500 poise or less, 3200 poise or less, 3000 poise or less, 2900 poise or less, 2800 poise or less, 2700 poise or less, 2600 poise or less, 2500 poise or less, 2400 poise or less, 2300 poise or less, 2200 poise or less, 2100 poise or less, 2000 poise or less), etc.

[0033] By satisfying the above-mentioned V2 / V1, sufficient viscosity etc. can be achieved, but if V2 is too large, excessive viscosity may be exhibited, although this depends on the blending target and blending ratio, so it is also acceptable to set V2 to be not too large as described above.

[0034] The viscosities (V1, V2) can be measured (for example, according to the method of ASTM D1343-69) using a viscometer (for example, a falling ball viscometer) starting from a state where the composition is sufficiently dissolved (dispersed) in DMAc at a concentration (ratio) of 20% by mass at 40°C (initial viscosity (V1)), and ending 24 hours from this starting point (viscosity after 24 hours (V2)). For example, they can be measured by the method described below.

[0035] The number average molecular weight of the polyurethane (A) may be selected from a range of about 2000 or more (e.g., 3000 or more, 4000 or more), for example, about 5000 or more (e.g., 6000 or more, 7000 or more), preferably 8000 or more (e.g., 9000 or more), more preferably about 10000 or more (e.g., 11000 or more, 12000 or more, 13000 or more, 14000 or more), or about 15000 or more (e.g., 16000 or more, 17000 or more, 18000 or more, 19000 or more, 20000 or more, 21000 or more, 22000 or more, 23000 or more, 24000 or more, 25000 or more, 26000 or more, 27000 or more, 28000 or more).

[0036] By satisfying the above-mentioned V2 / V1, sufficient viscosity etc. can be realized, but if the number average molecular weight is too small, it may be difficult to efficiently achieve sufficient viscosity etc. (for example, it may take an excessive amount of time to reach sufficient viscosity, etc.), although this depends on the compounding target, compounding ratio, and value of V2 / V1, so a number average molecular weight that is not too small as described above may be used. Also, in terms of physical properties such as strength and durability, it is preferable to use a number average molecular weight that is not too small.

[0037] The number average molecular weight (upper limit) of the polyurethane (A) is not limited, and may be selected from a range of about 2,000,000 or less (e.g., 1,500,000 or less, 1,200,000 or less), for example, about 1,000,000 or less (e.g., 800,000 or less, 700,000 or less), preferably 500,000 or less (e.g., 300,000 or less), more preferably about 200,000 or less (e.g., 180,000 or less, 150,000 or less, 120,000 or less), or about 100,000 or less (e.g., 90,000 or less, 80,000 or less, 70,000 or less, 60,000 or less, 55,000 or less, 50,000 or less, 45,000 or less, 40,000 or less, 35,000 or less).

[0038] Specific examples of the number average molecular weight of polyurethane include 10,000 to 300,000, 20,000 to 200,000, and 30,000 to 150,000.

[0039] In particular, the polyurethane (A) may have a peak derived from a high molecular weight component in a GPC (GPC chart) [for example, a peak generally in a region of a molecular weight (number average molecular weight) of 1 million or more (for example, 1 million to 50 million, 1 million to 30 million, 2 million to 15 million, 3 million to 10 million)].

[0040] According to the investigations of the present inventors, such a high-molecular-weight component appears to function as a component that induces or promotes association (for example, functions as a spreader), and therefore may contribute to an increase in viscosity (an increase over time). Depending on the compounding target, compounding ratio, value of V2 / V1, desired viscosity (degree of viscosity), and the like, a polyurethane (A) containing a high-molecular-weight component may be preferably used in combination with (in addition to) satisfying the above-mentioned value of V2 / V1. On the other hand, when a polyurethane (A) that does not contain high molecular weight components can achieve the desired functions and physical properties, or when the polyurethane (A) is to be used in an application that does not contain high molecular weight components, the polyurethane (A) that does not contain high molecular weight components may be obtained by subjecting the polyurethane (A) that contains high molecular weight components to a process that allows the high molecular weight components to be separated (for example, by dissolving or dispersing the polyurethane (A) in an appropriate solvent and then filtering the resultant mixture).

[0041] The polyurethane (A) having such a high molecular weight component is not particularly limited and may be obtained by separately blending a high molecular weight component with polyurethane, or the like. However, polyurethanes formed by various molding methods (e.g., solution molding) may also contain high molecular weight components, and polyurethanes that originally contain such high molecular weight components may be used as they are.

[0042] The molecular weight (number average molecular weight) and the presence or absence of high molecular weight components can be confirmed (measured), for example, by GPC (polystyrene equivalent, etc.), and specifically, they may be confirmed (measured) by the method described below (the same applies hereinafter).

[0043] The polyurethane (A) may have an amino group (terminal amino group). In such polyurethane (A) (polyurethane (A) having amino groups), the proportion of amino groups (concentration, lower limit of proportion) may be selected from a range of, for example, about 0.01 meq / kg [millimolar equivalent / kg, millimole / kg, millimoles (millimolar equivalents) / kg as amino groups] or more (e.g., 0.03 meq / kg or more, 0.05 meq / kg or more), and may be 0.1 meq / kg or more (e.g., 0.2 meq / kg or more, 0.3 meq / kg or more, 0.4 meq / kg or more, 0.5 meq / kg or more). / kg or more, 0.6 meq / kg or more, 0.7 meq / kg or more, 0.8 meq / kg or more, 0.9 meq / kg or more), preferably 1 meq / kg or more (e.g., 1.1 meq / kg or more, 1.2 meq / kg or more, 1.3 meq / kg or more, 1.4 meq / kg or more), more preferably 1.5 meq / kg or more (e.g., 1.6 meq / kg or more, 1.7 meq / kg or more, 1.8 meq / kg or more, 1.9 meq / kg or more), and may be 2 meq / kg or more (e.g., 2.2 meq / kg or more, 2.5 meq / kg or more, 3 meq / kg or more, 3.5 meq / kg or more, 4 meq / kg or more, 4.5 meq / kg or more, 5 meq / kg or more, 5.5 meq / kg or more, 6 meq / kg or more, 6.5 meq / kg or more, 7 meq / kg or more, 7.5 meq / kg or more, 8 meq / kg or more, 8.5 meq / kg or more, 9 meq / kg or more, 9.5 meq / kg or more, 10 meq / kg or more, 10.5 meq / kg or more, 11 meq / kg or more, 12 meq / kg or more, 13 meq / kg or more, 14 meq / kg or more, 15 meq / kg or more, 16 meq / kg or more, 17 meq / kg or more, 18 meq / kg or more, 19 meq / kg or more, 20 meq / kg or more, 21 meq / kg or more, 22 meq / kg or more, 23 meq / kg or more, 24 meq / kg or more, 25 meq / kg or more, 26 meq / kg or more, 27 meq / kg or more, 28 meq / kg or more, 29 meq / kg or more, 30 meq / kg or more, 31 meq / kg or more, 32 meq / kg or more, 33 meq / kg or more, 34 meq / kg or more, 35 meq / kg or more, 36 meq / kg or more, 37 meq / kg or more, 38 meq / kg or more, 39 meq / kg or more, 40 meq / kg or more, 41 meq / kg or more, 42 meq / kg or more, It may be 5 meq / kg or more, 12 meq / kg or more, 12.5 meq / kg or more, 13 meq / kg or more, 13.5 meq / kg or more, 14 meq / kg or more, 14.5 meq / kg or more, 15 meq / kg or more, 15.5 meq / kg or more, 16 meq / kg or more, 16.5 meq / kg or more, 17 meq / kg or more, 17.5 meq / kg or more, 18 meq / kg or more, 18.5 meq / kg or more, 19 meq / kg or more, 19.5 meq / kg or more, 20 meq / kg or more).

[0044] In the polyurethane (A) (polyurethane (A) having amino groups), the proportion of amino groups (concentration, upper limit of proportion) may be selected from a range of, for example, about 100 meq / kg or less (e.g., 80 meq / kg or less, 70 meq / kg or less, 60 meq / kg or less), 50 meq / kg or less (e.g., 45 meq / kg or less), preferably 40 meq / kg or less (e.g., 35 meq / kg or less), more preferably 30 meq / kg or less (e.g., 29 meq / kg or less, 28 meq / kg or less, 27 meq / kg or less, 26 meq / kg or less, 25 meq / kg or less, 24 meq / kg or less, 23 meq / kg or less, 22 meq / kg or less, 21 meq / kg or less), particularly 20 meq / kg or less ( For example, it may be less than 20 meq / kg, 19 meq / kg or less, 18.5 meq / kg or less, 18 meq / kg or less, 17.5 meq / kg or less, 17 meq / kg or less, 16.5 meq / kg or less, 16 meq / kg or less, 15.5 meq / kg or less, 15 meq / kg or less, 14.5 meq / kg or less, 14 meq / kg or less, 13.5 meq / kg or less, 13 meq / kg or less, 12.5 meq / kg or less, 12 meq / kg or less, 11.5 meq / kg or less, 11 meq / kg or less, 10.5 meq / kg or less, 10 meq / kg or less, 9.5 meq / kg or less, 9 meq / kg or less, 8.5 meq / kg or less, 8 meq / kg or less, 7.5 meq / kg or less, 7 meq / kg or less, etc.

[0045] In particular, it is preferable that the amino group concentration of the polyurethane (A) is not too small or not too large (furthermore, not too small or not too large).

[0046] From this viewpoint, the amino group concentration of the polyurethane (A) may be, for example, 0.1 meq / kg or more (e.g., 0.3 meq / kg or more, 0.5 meq / kg or more, 1 meq / kg or more, 1.5 meq / kg or more, 2 meq / kg or more), or 50 meq / kg or less (e.g., 45 meq / kg or less, 40 meq / kg or less, 35 meq / kg or less, 30 meq / kg or less, 25 meq / kg or less, 20 meq / kg or less, 18 meq / kg or less, 15 meq / kg or less, 12 meq / kg or less, 10 meq / kg or less), and preferably 0 It may be 1 to 50 meq / kg (e.g., 0.3 to 40 meq / kg, 0.3 to 35 meq / kg, 0.3 to 30 meq / kg, 0.5 to 28 meq / kg), more preferably 1 to 30 meq / kg (e.g., 1 to 28 meq / kg, 1.2 to 25 meq / kg, 1.2 to 22 meq / kg, 1.5 to 26 meq / kg, 1.5 to 25 meq / kg, 1.5 to 20 meq / kg, 1.8 to 10 meq / kg, 2 to 8 meq / kg, 3 to 22 meq / kg, 4 to 20 meq / kg, 5 to 20 meq / kg, 2 to 26 meq / kg, 2 to 22 meq / kg), etc.

[0047] According to the inventors' investigations, such amino groups appear to be able to contribute to the induction or promotion of association and to an increase in viscosity (increase over time), and selection of the amino group concentration [particularly in combination with (in addition to) satisfying the aforementioned V2 / V1 value] appears to facilitate efficient impartment of sufficient viscosity and control of viscosity increase. Therefore, in terms of efficient molding of polyurethane and production of polyurethane with good physical properties, polyurethane (A) having amino groups [particularly, as described above, having a proportion of amino groups that is not too small and / or not too large (particularly not too small and not too large)] may be preferably used. Such an amino group-containing polyurethane (A) may or may not contain the high-molecular-weight component described above. In particular, when the polyurethane (A) contains amino groups in the above proportions, it is easy to realize efficient molding of the polyurethane and production of polyurethane with good physical properties, even if it does not contain a high-molecular-weight component.

[0048] The presence or absence of amino groups and the proportion thereof can be confirmed (measured) by a conventional method (for example, potentiometric titration), and specifically, may be confirmed (measured) by the method described below.

[0049] If the raw material polyurethane does not have the desired amino group ratio as described above, it can be adjusted to the desired amino group ratio. For example, the amino group ratio can be reduced by contacting (reacting) the raw material polyurethane with a secondary amine (e.g., diethylamine, etc.), and the amino group ratio can be increased by contacting (reacting) the raw material polyurethane with a primary amine (e.g., ethylenediamine, etc.).

[0050] In addition, the proportion of amino groups in the polyurethane can be adjusted (e.g., increased) by treatments that can cause partial cleavage or recombination of polyurethane chains (e.g., heat treatment, stirring treatment using a stirring means, etc.).

[0051] The shape (form) of the polyurethane (A) is not particularly limited, and may be any of fibrous and non-fibrous (granular, powdery, coarsely ground molded product (non-fibrous chunks), etc.).

[0052] The fiber diameter (average fiber diameter) of the fibrous polyurethane (A) is not particularly limited, but may be, for example, about 1 to 10,000 μm, preferably about 10 to 5,000 μm, and more preferably about 20 to 2,000 μm.

[0053] The size (length of the fiber) of the polyurethane (A) is not particularly limited, but may be a relatively small size, such as an average diameter (maximum diameter) of 10 mm or less [for example, 5 mm or less (e.g., 3 mm or less), preferably 1 mm or less, and more preferably 0.5 mm or less], taking into consideration handleability, blending, usage, and the like.

[0054] The polyurethane (A) having such a size can be obtained, for example, by a general-purpose crushing process, although this depends on the type of polyurethane used as a raw material.

[0055] The fiber diameter and size can be measured, for example, by a scanning electron microscope (SEM). Specifically, the measurement may be carried out by the method described in the Examples below.

[0056] In particular, the polyurethane (A) may be suitably in the form of a fiber, which makes it easier to efficiently (e.g., quickly) realize or exhibit increased viscosity.

[0057] The polyurethane (A) [the resin component (polyurethane) constituting (contained in) the polyurethane (A)] is not particularly limited and may be, for example, any component having a structure derived from a polymer diol and a diisocyanate as starting materials, and is not particularly limited.

[0058] The synthesis method is not particularly limited. For example, it may be a polyurethane urea made from a polymer diol, a diisocyanate, and a low-molecular-weight diamine as a chain extender, or a polyurethane urethane made from a polymer diol, a diisocyanate, and a low-molecular-weight diol as a chain extender. It may also be a polyurethane urea using a compound having a hydroxyl group and an amino group in the molecule as a chain extender. It is also preferable to use a polyfunctional glycol or isocyanate having three or more functionalities as needed (within the range that does not impair the effects of the present invention).

[0059] The polymer diol is preferably a polyether-based diol, a polyester-based diol, a polycarbonate diol, etc. From the viewpoint of imparting flexibility and elongation to a molded article (such as thread), it is preferable to use a polyether-based diol.

[0060] Preferred examples of polyether diols include polyethylene oxide, polyethylene glycol, polyethylene glycol derivatives, polypropylene glycol, polytetramethylene ether glycol (hereinafter sometimes abbreviated as PTMG), modified PTMG which is a copolymer of tetrahydrofuran (hereinafter sometimes abbreviated as THF) and 3-methyltetrahydrofuran, modified PTMG which is a copolymer of THF and 2-methyltetrahydrofuran, modified PTMG which is a copolymer of THF and 2,3-dimethylTHF, polyols having side chains on both sides as disclosed in Japanese Patent No. 2615131, and random copolymers in which THF and ethylene oxide and / or propylene oxide are irregularly arranged. These polyether diols may be used alone or in combination or copolymerized with two or more.

[0061] Furthermore, from the viewpoint of obtaining abrasion resistance and light resistance as polyurethane elastic fibers, polyester diols such as butylene adipate, polycaprolactone diol, and polyester polyols having side chains as disclosed in JP-A-61-26612, and polycarbonate diols as disclosed in JP-B-2-289516 are preferably used.

[0062] These polymer diols may be used alone or in combination or copolymerized form.

[0063] From the viewpoint of obtaining elongation, strength, heat resistance, etc. when made into a thread, the molecular weight of the polymer diol is preferably a number average molecular weight of 1,000 or more and 8,000 or less, more preferably 1,500 or more and 6,000 or less. By using a polyol with a molecular weight in this range, a thread (elastic thread) excellent in elongation, strength, elastic recovery, heat resistance, etc. can be easily obtained.

[0064] Next, as diisocyanates, aromatic diisocyanates such as diphenylmethane diisocyanate (hereinafter sometimes abbreviated as MDI), tolylene diisocyanate, 1,4-diisocyanatobenzene, xylylene diisocyanate, and 2,6-naphthalene diisocyanate are particularly suitable for synthesizing polyurethanes with high heat resistance and strength. Furthermore, as alicyclic diisocyanates, for example, methylenebis(cyclohexyl isocyanate), isophorone diisocyanate, methylcyclohexane 2,4-diisocyanate, methylcyclohexane 2,6-diisocyanate, cyclohexane 1,4-diisocyanate, hexahydroxylylene diisocyanate, hexahydrotolylene diisocyanate, and octahydro-1,5-naphthalene diisocyanate are preferred. Alicyclic diisocyanates are particularly effective in suppressing yellowing of polyurethane elastic yarns. These diisocyanates may be used alone or in combination.

[0065] The chain extender used in synthesizing the polyurethane is preferably at least one of a low molecular weight diamine and a low molecular weight diol, although it may also be one having both a hydroxyl group and an amino group in one molecule, such as ethanolamine.

[0066] Preferred low-molecular-weight diamines include, for example, ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, hexamethylenediamine, p-phenylenediamine, p-xylylenediamine, m-xylylenediamine, p,p'-methylenedianiline, 1,3-cyclohexyldiamine, hexahydrometaphenylenediamine, 2-methylpentamethylenediamine, and bis(4-aminophenyl)phosphine oxide. It is preferable to use one or more of these. Ethylenediamine is particularly preferred. The use of ethylenediamine facilitates the production of yarns with excellent elongation, elastic recovery, and heat resistance. A triamine compound capable of forming a crosslinked structure, such as diethylenetriamine, may be added to these chain extenders to an extent that the effect is not lost.

[0067] Representative low-molecular-weight diols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, bishydroxyethoxybenzene, bishydroxyethylene terephthalate, and 1-methyl-1,2-ethanediol. It is preferable to use one or more of these. Ethylene glycol, 1,3-propanediol, and 1,4-butanediol are particularly preferred. The use of these diol-extended polyurethanes results in higher heat resistance and allows for the production of stronger yarns.

[0068] It is also preferable to use one or more types of terminal blocking agents in combination for the polyurethane. Preferred terminal blocking agents include monoamines such as dimethylamine, diisopropylamine, ethylmethylamine, diethylamine, methylpropylamine, isopropylmethylamine, diisopropylamine, butylmethylamine, isobutylmethylamine, isopentylmethylamine, dibutylamine, and diamylamine, monools such as ethanol, propanol, butanol, isopropanol, allyl alcohol, and cyclopentanol, and monoisocyanates such as phenyl isocyanate.

[0069] The polyurethane (A) may contain components (other components) other than the resin component (polyurethane). Such components can be appropriately selected depending on the molding method of the polyurethane (A) and the form of the molded product, and are not particularly limited.

[0070] Examples of other components include metal soaps, surfactants, antioxidants, tertiary amine compounds, crosslinking structure modifiers, silicones (e.g., silicone oil, modified silicone), fine particles (e.g., talc, silica, alumina, zinc oxide, titanium dioxide), higher aliphatic alcohols, waxes, colorants, rosin, dyes, pigments, oils (mineral oil, silicone oil, etc.), inorganic substances and inorganic porous substances (e.g., bamboo charcoal, charcoal, carbon black, porous mud, clay, diatomaceous earth, coconut shell activated carbon, coal-based activated carbon, zeolite, perlite, etc.), and catalysts (catalytic components, e.g., polyurethane amine catalysts, organometallic catalysts).

[0071] The polyurethane (A) may contain one or more other components.

[0072] When polyurethane (A) contains other components, the proportion (total proportion) of the other components can be selected from a range of about 50% by mass or less, and may be 40% by mass or less (for example, 30% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, etc.), relative to the total amount of polyurethane (A).

[0073] In particular, it is preferable that the polyurethane (A) contains a metal soap. The inclusion of a metal soap, coupled with the aforementioned satisfaction of V2 / V1, makes it easier to efficiently impart sufficient viscosity and control viscosity increase, which can be advantageous in terms of moldability (spinnability, etc.) and physical properties. While the reason for this is unclear, it is thought that the metal soap promotes hydrogen bonding while suppressing excessive promotion of hydrogen bonding, thereby stabilizing association and efficiently adjusting viscosity.

[0074] Examples of metal soaps include salts of acids and metals.

[0075] Examples of acids include organic acids (fatty acids, aromatic carboxylic acids, resin acids, etc.) such as octylic acid, lauric acid, stearic acid, palmitic acid, ricinoleic acid, abietic acid, neoabietic acid, d-pimaric acid, iso-d-pimaric acid, podocarpic acid, agathenedicarboxylic acid, benzoic acid, cinnamic acid, p-oxycinnamic acid, diterpene acid, and naphthenic acid.

[0076] Representative acids include fatty acids [for example, fatty acids having 6 or more carbon atoms (for example, 8 or more, 8 to 40, 8 to 30, etc.), such as octylic acid, lauric acid, stearic acid, palmitic acid, and ricinoleic acid].

[0077] Examples of metals include alkali metals other than sodium and potassium (e.g., lithium), alkaline earth metals (e.g., beryllium, magnesium, calcium, barium, etc.), and other metals (e.g., aluminum, zinc, cadmium, cobalt, chromium, copper, silver, iron, mercury, manganese, nickel, lead, tin, titanium), and other metals other than sodium and potassium.

[0078] Specific examples of metal soaps include metal octylates (e.g., zinc octylate), metal laurates (e.g., calcium laurate, barium laurate, zinc laurate), metal stearates (lithium stearate, magnesium stearate, calcium stearate, barium stearate, zinc stearate), and metal ricinoleates (e.g., calcium ricinoleate, barium ricinoleate, zinc ricinoleate).

[0079] The polyurethane (A) may contain one or more metal soaps.

[0080] When polyurethane (A) contains a metal soap, the proportion of the metal soap can be selected from a range of, for example, about 0.0001 mass% or more relative to the entire polyurethane (A), and may be about 0.0005 mass% or more, preferably 0.001 mass% or more, and more preferably about 0.003 mass% or more, or may be 20 mass% or less [for example, 15 mass% or less (e.g., 12 mass% or less), preferably 10 mass% or less (e.g., 8 mass% or less), and more preferably 5 mass% or less (e.g., 3 mass% or less)].

[0081] Specific examples of the proportion of the metal soap include 0.0001 to 10% by mass, preferably 0.001 to 5% by mass, and more preferably 0.003 to 3% by mass, based on the total amount of polyurethane (A).

[0082] The polyurethane (A) also preferably contains at least one selected from a surfactant, an antioxidant, a tertiary amine compound, and a crosslinking structure modifier. Like metal soaps, these components also participate in hydrogen bonding to stabilize association and efficiently adjust viscosity, which, combined with the aforementioned satisfaction of V2 / V1, makes it easier to efficiently impart sufficient viscosity and control viscosity increase, which can be advantageous in terms of moldability (spinnability, etc.) and physical properties.

[0083] Examples of surfactants include nonionic surfactants, anionic surfactants, and cationic surfactants.

[0084] Examples of nonionic surfactants include polyoxyethylene alkyl ethers, alkyl monoglyceryl ethers, polyoxyethylene alkylamines, fatty acid sorbitan esters, fatty acid diethanolamides, etc. Among these, the hydrophilic portion of the surfactant is preferably an ether type, and is preferably at least one of, for example, an ethylene oxide polymer, a propylene oxide polymer, and a copolymer of ethylene oxide and propylene oxide.

[0085] By including at least one of a terminally modified derivative of an ethylene oxide polymer, a terminally modified derivative of a propylene oxide polymer, and a terminally modified derivative of a copolymer of ethylene oxide and propylene oxide as a nonionic surfactant, it is possible to improve spinnability while also providing, for example, good antibacterial properties.

[0086] The so-called hydrophobic portion of the surfactant is the aforementioned terminally modified structure, and is preferably an alkyl group, a phenyl group, or a styrenated phenyl group. Specific examples of nonionic surfactants include polyoxyethylene stearyl ether, polyoxyethylene lauryl ether, polyoxyethylene ethylphenol ether, polyoxyethylene propylphenol ether, polyoxyethylene styrenated phenyl ether, and polyoxyethylene sorbitol tetraoleate. More preferred is polyoxyethylene styrenated phenyl ether, and examples thereof include polyoxyethylene oxypropylene tristyrenated phenyl ether, polyoxyethylene oxypropylene distyrenated phenyl ether, polyoxyethylene oxypropylene monostyrenated phenyl ether, polyoxyethylene oxypropylene-2,4,6-tris(α,α-dimethylbenzyl)phenyl ether, polyoxyethylene oxypropylene-2,4-bis(α,α-dimethylbenzyl)phenyl ether, polyoxyethylene oxypropylene-2-mono(α,α-dimethylbenzyl)phenyl ether, polyoxyethylene oxypropylene-4-mono(α,α-dimethylbenzyl)phenyl ether, etc. Most preferred is when the number of moles of these styrene groups added has a distribution and a mixture of these is used.

[0087] Examples of cationic surfactants include quaternary ammonium salts (quaternary ammonium ions). Among quaternary ammonium salts, the antibacterial activity varies depending on the chain length of the alkyl group in the ammonium ion, and those with strong antibacterial activity are desirable. However, from the viewpoint of inhibiting thermal decomposition, it is preferable to select the chain type of alkyl group, etc., with a long chain length, i.e., an alkyl group with a large number of carbon atoms. Furthermore, from the viewpoint of hygiene, it is preferable that the surfactant contains an antibacterial agent (has antibacterial properties).

[0088] Particularly preferred ammonium ions from this viewpoint are didecyldimethylammonium ion, oleyltrimethylammonium ion, etc. These are usually supplied by inorganic salts such as chlorides, bromides, and iodides, or organic salts such as sulfonates, carboxylates, and phosphates, and among these, sulfonates and carboxylates are preferred from the viewpoint of stability such as discoloration and heat resistance.

[0089] Specific examples of salts having the above structure include didecyldimethylammonium trifluoride methylsulfonate, di-n-decyldimethylammonium trifluoromethanesulfonate, di-n-decyldimethylammonium pentafluoroethanesulfonate, n-hexadecyltrimethylammonium trifluoromethanesulfonate, and benzyldimethylcocoalkylammonium pentafluoroethanesulfonate.

[0090] The antioxidant is not particularly limited, but examples thereof include phenol compounds. The phenol compounds may be hindered phenol compounds, and hindered phenols may be particularly preferably used.

[0091] Phenol compounds (hindered phenol compounds, etc.) include 3,5-di-t-butyl-4-hydroxytoluene, n-octadecyl-β-(4'-hydroxy-3',5'-di-t-butylphenyl)propionate, tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, 1,3,5-trimethyl-2,4,6'-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, calcium(3,5-di-t-butyl-4-hydroxybenzyl-monoethyl- phosphate), triethylene glycol bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 3,9-bis[1,1-dimethyl-2-{β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]2,4,8,10-tetraoxaspiro[5,5]undecane, tocopherol, 2,2'-ethylidenebis(4,6-di-t-butylphenol), N,N'-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyl]hydrazine, 2,2'- Oxamide bis[ethyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, ethylene-1,2-bis(3,3-bis[3-t-butyl-4-hydroxyphenyl]butyrate), ethylene-1,2-bis(3-[3-t-butyl-4-hydroxyphenyl]butyrate), 1,1-bis(2-methyl-5-t-butyl-4-hydroxyphenyl)butane, 1,1,3-tris(2-methyl-5-t-butyl-4-hydroxyphenyl) phenyl)butane, 1,3,5-tris(3',5'-di-t-butyl-4'-hydroxybenzyl)-S-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris(3'-t-butyl-4'-hydroxy-5-methylbenzyl)-S-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and other high molecular weight hindered phenol compounds.

[0092] Preferred examples of such high-molecular-weight hindered phenol compounds include addition polymers of divinylbenzene and cresol, addition polymers of dicyclopentadiene and cresol, isobutylene adducts, and polymers of chloromethylstyrene and compounds such as cresol, ethylphenol, and t-butylphenol. Here, divinylbenzene and chloromethylstyrene may be either p- or m-. Furthermore, cresol, ethylphenol, and t-butylphenol may be any of o-, m-, and p-.

[0093] Among these, compounds with a molecular weight of 300 or more are preferred from the viewpoint of stabilizing viscosity and facilitating good spinnability. Furthermore, in order to efficiently exhibit high spinning speed, heat resistance during dyeing, resistance to unsaturated fatty acids, and resistance to heavy metals, any one of 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], ethylene-1,2-bis(3,3-bis[3-t-butyl-4-hydroxyphenyl]butyrate), and a polymer of an adduct of divinylbenzene and p-cresol having a repeat number of 6 to 12 may be used, or a combination of these may be used. Among these, 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione may be preferably used.

[0094] As the phenol compound, a singly hindered phenol compound is also preferred. Examples of the singly hindered phenol compound include ethylene-1,2-bis(3,3-bis[3-t-butyl-4-hydroxyphenyl]butyrate) (the compound shown below), which has a structure in which a singly hindered hydroxyphenyl group is covalently bonded to a bisester skeleton.

[0095] [ka]

[0096] Specifically, hindered phenol compounds having a molecular weight of 1,000 or more are preferred. There are no particular limitations on the molecular weight other than the relatively high molecular weight of 1,000 or more, and preferred examples of such high-molecular-weight hindered phenol compounds include addition polymers of divinylbenzene and cresol, addition polymers of dicyclopentadiene and cresol, isobutylene adducts, and polymers of chloromethylstyrene and compounds such as cresol, ethylphenol, and t-butylphenol. Here, divinylbenzene and chloromethylstyrene may be either p- or m-. Furthermore, cresol, ethylphenol, and t-butylphenol may be any of o-, m-, and p-.

[0097] Among these, a polymeric hindered phenol compound derived from cresol is preferred from the viewpoints of stabilizing viscosity, obtaining good spinnability, etc. Furthermore, in order to efficiently exhibit a high spinning speed, heat resistance during dyeing, resistance to unsaturated fatty acids, and resistance to heavy metals, it is preferable to contain a certain amount of this high-molecular-weight hindered phenol compound, but from the viewpoint of obtaining better basic physical properties as a polyurethane yarn, it is preferable that the amount is not too much.

[0098] The tertiary amine compound is not particularly limited as long as it has an amino group in its structure, but from the viewpoint of the chlorine degradation resistance and yellowing of the polyurethane elastic yarn, it is particularly preferred that the compound have only a tertiary amino group in the molecule out of the primary to tertiary amino groups.

[0099] The tertiary amine compound may preferably have a relatively large molecular weight. The number average molecular weight of such a tertiary amine compound is preferably in the range of 2,000 to 10,000, and more preferably in the range of 2,000 to 4,000.

[0100] More specifically, examples of tertiary amine compounds include linear polymeric compounds having a number-average molecular weight of 2,000 or more obtained by reacting t-butyldiethanolamine with methylene-bis-(4-cyclohexylisocyanate), polyethyleneimine, and high-molecular-weight compounds having a branched structure containing a primary amino group, a secondary amino group, and a tertiary amino group in the molecular skeleton.

[0101] Examples of crosslinking structure regulators include monoamines and diamines. More specifically, monoamines (e.g., dimethylamine, diethylamine, cyclohexylamine, etc.) and diamines (e.g., ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, hexamethylenediamine, p-phenylenediamine, p-xylylenediamine, m-xylylenediamine, 1,3-cyclohexyldiamine, hexahydrometaphenylenediamine, 2-methylpentamethylenediamine) can be mentioned. Particularly preferred is the use of a mixture of monoamines and diamines.

[0102] When polyurethane (A) contains a surfactant, the proportion of the surfactant can be selected from a range of, for example, about 0.0001% by mass or more, and may be about 0.0005% by mass or more, preferably 0.001% by mass or more, and more preferably 0.003% by mass or more, relative to the total polyurethane (A), or may be 20% by mass or less [for example, 15% by mass or less (e.g., 12% by mass or less), preferably 10% by mass or less (e.g., 8% by mass or less), and more preferably 5% by mass or less (e.g., 3% by mass or less)].

[0103] Specific examples of the proportion of the surfactant include 0.0001 to 10% by mass, preferably 0.001 to 5% by mass, and more preferably 0.003 to 3% by mass, based on the total amount of polyurethane (A).

[0104] When the polyurethane (A) contains an antioxidant, the proportion of the antioxidant can be selected from the range of, for example, about 0.0001% by mass or more, and may be about 0.0005% by mass or more, preferably 0.001% by mass or more, and more preferably 0.002% by mass or more, relative to the entire polyurethane (A), and may be 20% by mass or less [for example, 15% by mass or less (e.g., 12% by mass or less), preferably 10% by mass or less (e.g., 8% by mass or less), and more preferably 7% by mass or less (e.g., 5% by mass or less)].

[0105] Specific examples of the proportion of the antioxidant include 0.0001 to 10% by mass, preferably 0.001 to 7% by mass, and more preferably 0.002 to 5% by mass, based on the total amount of the polyurethane (A).

[0106] From the viewpoint of moldability (e.g., spinnability) and physical properties (strength, yellowing resistance, durability, etc.), the polyurethane (A) may contain decomposition products of antioxidants (phenolic compounds, etc.) in an amount of 1% by mass or less, and preferably 0.5% by mass or less, based on the total mass of the polyurethane (A).

[0107] When the polyurethane (A) contains a tertiary amine compound, the proportion of the tertiary amine compound can be selected from a range of, for example, about 0.01% by mass or more relative to the entire polyurethane (A), and may be about 0.05% by mass or more, preferably 0.1% by mass or more, and more preferably about 0.2% by mass or more, or may be 30% by mass or less [for example, 20% by mass or less (e.g., 15% by mass or less), preferably 12% by mass or less (e.g., 10% by mass or less), and more preferably 7% by mass or less (e.g., 5% by mass or less)].

[0108] Specific examples of the proportion of the tertiary amine compound include 0.01 to 20 mass %, preferably 0.1 to 10 mass %, and more preferably 0.2 to 5 mass %, based on the total amount of polyurethane (A).

[0109] From the viewpoint of moldability (e.g., spinnability) and physical properties (strength, yellowing resistance, durability, etc.), the polyurethane (A) may contain decomposition products of tertiary amine compounds in an amount of 1% by mass or less, preferably 0.5% by mass or less, based on the total amount of polyurethane (A).

[0110] When the polyurethane (A) contains a crosslinking structure modifier, the proportion of the crosslinking structure modifier can be selected from a range of, for example, about 0.0001% by mass or more relative to the entire polyurethane (A), and may be about 0.0005% by mass or more, preferably 0.001% by mass or more, and more preferably about 0.002% by mass or more, or may be 20% by mass or less [for example, 15% by mass or less (e.g., 12% by mass or less), preferably 10% by mass or less (e.g., 8% by mass or less), and more preferably 5% by mass or less (e.g., 2% by mass or less)].

[0111] Specific examples of the proportion of the crosslinking structure regulator include 0.0001 to 10% by mass, preferably 0.001 to 5% by mass, and more preferably 0.002 to 2% by mass, based on the total amount of polyurethane (A).

[0112] The polyurethane (A) is not particularly limited, and a commercially available product (distributed product) may be used, or one produced or molded by a conventional method may be used.

[0113] The production method or molding method for such polyurethane (A) is also not particularly limited and can be appropriately selected depending on the type and form of the molded product, etc. For example, the fibrous polyurethane (A) may be obtained by a conventional spinning method (e.g., melt spinning, wet spinning, dry spinning, etc.).

[0114] In addition, the polyurethane (A) may be a virgin product or a used product.

[0115] The polyurethane (A) may be one that has been left or stored (for example, left or stored for one month or more (for example, six months or more, one year or more)) after production without being used (for sale, use in various applications, etc.) {for example, the fiber itself, a wound body [for example, a warp wound body (beam) that is an intermediate product in knitting and weaving processing], processed yarn, etc.}, or molding waste [for example, waste that has been cut when obtaining a wound body through various spinning methods (waste that has not been formed into a wound body)]. Also, it may be a used product (post-consumer product).

[0116] By utilizing such abandoned or stored items (for example, items that are to be disposed of due to excess inventory, etc.), molding scraps, used products, etc., polyurethane can be efficiently reused (recycled).

[0117] In addition, as for the polyurethane satisfying the above-mentioned properties, if it is a commercially available product, it may be selected from among the commercially available products that satisfy the above-mentioned properties, or if it is a manufactured product, it may be manufactured so as to satisfy the above-mentioned properties. For example, the viscosity (ease of thickening) of polyurethane is recognized to be affected by association as described above, and can be efficiently adjusted by adjusting the ease of association. To give a specific example, with regard to the resin component (polyurethane) itself, the ease of association can be efficiently adjusted by the degree of progress of the reaction [for example, by using polyurethane in which the reaction of the polymerization components has progressed sufficiently (and thus which is likely to produce crystal nuclei that can serve as association nuclei)]. Furthermore, the ease of association can also be efficiently adjusted by the presence or absence of the high-molecular-weight component described above, the blending of other components (and even their amounts), and the like.

[0118] The polyurethane (A) containing other components may be produced by adding or blending the other components to a base resin component (polyurethane) by a conventional method, or a commercially available product or recycled product that already contains other components may be used as is.

[0119] [Additive applications] The additive of the present invention is composed of a polyurethane (A).

[0120] The target of such an additive (target to be added, target to be blended) is not limited, but may be a dope in particular. That is, the additive of the present invention may be an additive for a dope (an agent to be added to a dope).

[0121] Furthermore, as described above, the additive (polyurethane (A)) can increase or adjust the viscosity (maintain the viscosity or prevent a decrease in viscosity), and can also improve the moldability (spinnability) and physical properties.

[0122] Therefore, the additive (polyurethane (A)) may be used in applications corresponding to such functions. For example, the additive (polyurethane (A)) may be (or may be used in applications such as) a viscosity (viscosity) adjuster [viscosity (viscosity) control agent, viscosity (viscosity) increaser, thickener, viscosity (viscosity) retention agent], a moldability (spinnability, etc.) improver (enhancement agent), and / or a physical property (for example, at least one physical property selected from strength, elongation, heat resistance, and durability) improver (enhancement agent), etc.

[0123] In particular, the additive (polyurethane (A)) is suitable for use in dopes (and for improving the viscosity and physical properties as described above), and therefore, the use in dopes will be described in detail below.

[0124] <Dope, etc.> The dope is a liquid (liquid substance, liquid-like substance) containing a resin (resin component), and may not contain a solvent (bulk dope), but may usually contain a resin and a solvent {particularly, it may be a solution [or dispersion, or a solution (or dispersion) in which at least a resin is dissolved (or dispersed)] containing a resin}.

[0125] Since the polyurethane (A) is also a resin, when it is blended into the dope, it becomes a resin constituting the dope.

[0126] The resin component (such as polyurethane) constituting (contained in) such a dope may be composed of polyurethane (A) alone, or may contain polyurethane (A) and another resin (B) (a resin component different from polyurethane (A)).

[0127] That is, the dope may be a dope containing only polyurethane (A) as a resin, or a dope containing polyurethane (A) and resin (B) as resins.

[0128] The dope containing the polyurethane (A) and the resin (B) may be obtained by mixing the polyurethane (A) and the resin (B), or by mixing the polyurethane (A) in a system (dope) containing the resin (B) in advance.

[0129] In particular, polyurethane (A) is preferably used in combination with resin (B) in view of its functions of controlling viscosity, improving moldability (spinnability) and physical properties.

[0130] The resin (B) may be either a non-polyurethane or a polyurethane, but since the additive (polyurethane (A)) is polyurethane, it is preferable that the resin (B) contains at least polyurethane. In other words, the dope may be a polyurethane dope (a dope containing polyurethane as the resin (B)).

[0131] Such polyurethane (sometimes referred to as polyurethane as resin (B), polyurethane (B), etc.) is not particularly limited, but examples thereof include the same polyurethanes as those described in the section on polyurethane (A). Preferred aspects of polyurethane (B) are also the same as those described for polyurethane (A).

[0132] In particular, polyurethane (B) and polyurethane (A) may be the same type or type of polyurethane (for example, both polyurethanes (A) and (B) may be polyurethaneurea).

[0133] When the dope contains a resin (B), the proportion of polyurethane (A) relative to the total amount of polyurethane (A) and resin (B) (e.g., polyurethane (B)) can be appropriately selected depending on the object to be improved or improved [e.g., moldability (spinnability, etc.), physical properties (strength, elongation, heat resistance, etc.)] and the degree thereof, and for example, it may be about 0.1% by mass or more (e.g., 0.5% by mass or more), preferably 1% by mass or more (e.g., 2% by mass or more), more preferably 3% by mass or more (e.g., 5% by mass or more), or it can also be 8% by mass or more (e.g., 10% by mass or more, 12% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, 30% by mass or more, 40% by mass or more, 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more), etc.

[0134] The proportion (upper limit of the proportion) of polyurethane (A) relative to the total amount of polyurethane (A) and resin (B) (e.g., polyurethane (B)) may be selected from a range of about 99.9% by mass or less (e.g., 99.5% by mass or less), and may be about 99% by mass or less (e.g., 98% by mass or less), preferably about 97% by mass or less (e.g., 95% by mass or less), or may be 90% by mass or less (e.g., 88% by mass or less, 85% by mass or less, 80% by mass or less, 75% by mass or less, 70% by mass or less, 60% by mass or less, 50% by mass or less, 45% by mass or less, 40% by mass or less, 35% by mass or less, 30% by mass or less), etc.

[0135] Specific examples of the proportion of polyurethane (A) relative to the total amount of polyurethane (A) and resin (B) (e.g., polyurethane (B)) include 0.1 to 99.9 mass% (e.g., 0.5 to 99 mass%), 1 to 99 mass% (e.g., 3 to 97 mass%), 5 to 95 mass% (e.g., 10 to 90 mass%), 1 to 50 mass%, 3 to 40 mass%, 50 to 99 mass%, and 60 to 95 mass%.

[0136] The proportion of polyurethane (A) relative to the total amount of polyurethane (A) and resin (B) (for example, polyurethane (B)) (100) can be appropriately selected so as to achieve the viscosity and viscosity ratio described below.

[0137] The molecular weight of the resin constituting the dope depends on the type of resin (B) (for example, polyurethane (B)) and the mixing ratio with polyurethane (A), but for example, the number average molecular weight of the resin [for example, polyurethane (A) alone, a mixed resin () of polyurethane (A) and resin (B) (polyurethane (B) etc.)] may be selected from the range of about 2000 or more (for example, 3000 or more, 4000 or more), for example, 5000 or more (for example, 6000 or more, 7000 or more), preferably 8000 or more. It may be about 10,000 or more (e.g., 9,000 or more), more preferably about 10,000 or more (e.g., 11,000 or more, 12,000 or more, 13,000 or more, 14,000 or more), or about 15,000 or more (e.g., 16,000 or more, 17,000 or more, 18,000 or more, 19,000 or more, 20,000 or more, 21,000 or more, 22,000 or more, 23,000 or more, 24,000 or more, 25,000 or more, 26,000 or more, 27,000 or more, 28,000 or more).

[0138] The number average molecular weight (upper limit) of the resin constituting the dope is not limited, but may be selected from a range of about 2,000,000 or less (e.g., 1,500,000 or less, 1,200,000 or less), for example, about 1,000,000 or less (e.g., 800,000 or less, 700,000 or less), preferably 500,000 or less (e.g., 300,000 or less), more preferably about 200,000 or less (e.g., 180,000 or less, 150,000 or less, 120,000 or less), or about 100,000 or less (e.g., 90,000 or less, 80,000 or less, 70,000 or less, 60,000 or less, 55,000 or less, 50,000 or less, 45,000 or less, 40,000 or less, 35,000 or less).

[0139] Specific examples of the number average molecular weight of the resin constituting the dope include 10,000 to 300,000, 20,000 to 200,000, and 30,000 to 150,000.

[0140] In particular, the resin constituting the dope may have a peak derived from a high molecular weight component in GPC (GPC chart) [for example, a peak in a region of a molecular weight (number average molecular weight) of 1 million or more (for example, 1 million to 50 million, 1 million to 30 million, 2 million to 15 million, 3 million to 10 million)].

[0141] The peak derived from such a high molecular weight component may be generated in the system (polymerization in the dope) or may be derived from the high molecular weight component contained in the polyurethane (A).Usually, by using the polyurethane (A) containing a high molecular weight component, a peak derived from the high molecular weight component can be found in the resin constituting the dope.

[0142] If the polymer has the above-mentioned molecular weight range or a peak derived from a high molecular weight component, it is likely to be advantageous in terms of, for example, moldability (spinnability, etc.) and physical properties.

[0143] The resin (B) may be contained in the dope from the stage of a raw material (monomer) as long as it can constitute a resin together with the polyurethane (A) in the dope (during use as the dope). For example, a dope containing the polyurethane (A) and the raw materials of the resin (B) (e.g., monomers that are raw materials for polyurethane) may be polymerized in the system (in the dope) to obtain a dope containing the polyurethane (A) and the resin (B).

[0144] The dope may contain other components (components other than the resin). Examples of such other components depend on the resin constituting the dope and the application of the dope, but include, for example, metal soaps, surfactants, antioxidants, tertiary amine compounds, crosslinking structure modifiers, silicones (e.g., silicone oil, modified silicone), fine particles (e.g., talc, silica, alumina, zinc oxide, titanium dioxide), higher aliphatic alcohols, waxes, colorants, rosin, dyes, pigments, oils (mineral oil, silicone oil, etc.), inorganic substances and inorganic porous materials (e.g., bamboo charcoal, charcoal, carbon black, porous mud, clay, diatomaceous earth, coconut shell activated carbon, coal-based activated carbon, zeolite, perlite, etc.), and catalysts (catalytic components, e.g., polyurethane amine catalysts, organometallic catalysts), etc.

[0145] Such other components may be contained in the polyurethane (A) in advance, may be added separately to the dope, or may be a combination of those contained in the polyurethane (A) and those added separately.

[0146] The preferred embodiments of the other components (preferable components, proportions contained in the resin) are also the same as those described above for the polyurethane (A).

[0147] When the dope contains other components, the proportion (proportion of the total amount) of the other components can be selected from a range of, for example, about 50% by mass or less, and may be 40% by mass or less (for example, 30% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, etc.) relative to the total amount of the resin and other components (for example, polyurethane (A) containing other components; the total amount of polyurethane (A) containing other components and resin (B) and resin (B); the total amount of polyurethane (A) which may contain other components, resin (B) and other components separately blended into the dope, etc.).

[0148] When the dope contains a metal soap, the proportion of the metal soap can be selected from a range of, for example, about 0.0001 mass% or more relative to the total amount of the resin and the metal soap (for example, the total amount of polyurethane (A) containing a metal soap; the total amount of polyurethane (A) containing a metal soap and resin (B); the total amount of polyurethane (A) which may contain a metal soap, resin (B) and the metal soap separately blended into the dope, etc.), and may be about 0.0005 mass% or more, preferably 0.001 mass% or more, more preferably about 0.003 mass% or more, or may be 20 mass% or less [for example, 15 mass% or less (for example, 12 mass% or less), preferably 10 mass% or less (for example, 8 mass% or less), more preferably 5 mass% or less (for example, 3 mass% or less)].

[0149] Specific examples of the proportion of the metal soap include 0.0001 to 10% by mass, preferably 0.001 to 5% by mass, and more preferably 0.003 to 3% by mass, based on the total amount of the resin and the metal soap.

[0150] When the dope contains a surfactant, the proportion of the surfactant can be selected from a range of, for example, about 0.0001% by mass or more, and may be 0.0005% by mass or more, preferably 0.001% by mass or more, more preferably 0.003% by mass or more, based on the total amount of the resin and surfactant (e.g., polyurethane (A) containing a surfactant; the total amount of polyurethane (A) containing a surfactant and resin (B); the total amount of polyurethane (A) which may contain a surfactant, resin (B) and a surfactant separately blended into the dope, etc.), and may be 20% by mass or less [e.g., 15% by mass or less (e.g., 12% by mass or less), preferably 10% by mass or less (e.g., 8% by mass or less), more preferably 5% by mass or less (e.g., 3% by mass or less)].

[0151] Specific examples of the proportion of the surfactant include 0.0001 to 10% by mass, preferably 0.001 to 5% by mass, and more preferably 0.003 to 3% by mass, based on the total amount of the resin and surfactant.

[0152] When the dope contains an antioxidant, the proportion of the antioxidant can be selected from a range of, for example, about 0.0001% by mass or more, and may be 0.0005% by mass or more, preferably 0.001% by mass or more, more preferably 0.002% by mass or more, based on the total amount of the resin and the antioxidant (e.g., polyurethane (A) containing an antioxidant; the total amount of polyurethane (A) containing an antioxidant and resin (B); the total amount of polyurethane (A), resin (B), and the antioxidant separately blended into the dope, etc.), and may be 20% by mass or less [e.g., 15% by mass or less (e.g., 12% by mass or less), preferably 10% by mass or less (e.g., 8% by mass or less), more preferably 7% by mass or less (e.g., 5% by mass or less)].

[0153] Specific examples of the proportion of the antioxidant include 0.0001 to 10% by mass, preferably 0.001 to 7% by mass, and more preferably 0.002 to 5% by mass, based on the total amount of the resin and the antioxidant.

[0154] From the viewpoint of moldability (e.g., spinnability) and physical properties (strength, yellowing resistance, durability, etc.), the proportion of decomposition products of the antioxidant (e.g., phenolic compounds) may be 1% by mass or less, preferably 0.5% by mass or less, based on the total amount of the resin and the decomposition products of the antioxidant.

[0155] When the dope contains a tertiary amine compound, the proportion of the tertiary amine compound can be selected from a range of, for example, about 0.01% by mass or more, and may be 0.05% by mass or more, preferably 0.1% by mass or more, more preferably 0.2% by mass or more, or 30% by mass or less [for example, 20% by mass or less (e.g., 15% by mass or less), preferably 12% by mass or less (e.g., 10% by mass or less), more preferably 7% by mass or less (e.g., 5% by mass or less)], based on the total amount of the resin and the tertiary amine compound (e.g., the total amount of polyurethane (A) containing a tertiary amine compound and polyurethane (A) containing a tertiary amine compound and resin (B); the total amount of polyurethane (A), resin (B), and the tertiary amine compound separately blended into the dope).

[0156] Specific examples of the proportion of the tertiary amine compound include 0.01 to 20% by mass, preferably 0.1 to 10% by mass, and more preferably 0.2 to 5% by mass, based on the total amount of the resin and the tertiary amine compound.

[0157] From the viewpoint of moldability (e.g., spinnability) and physical properties (strength, yellowing resistance, durability, etc.), the proportion of the decomposition products of the tertiary amine compound may be 1% by mass or less, preferably 0.5% by mass or less, based on the total amount of the resin and the decomposition products of the tertiary amine compound.

[0158] When the dope contains a crosslinking structure modifier, the proportion of the crosslinking structure modifier relative to the total amount of the resin and the crosslinking structure modifier (for example, polyurethane (A) containing a crosslinking structure modifier; the total amount of polyurethane (A) containing a crosslinking structure modifier and resin (B); the total amount of polyurethane (A) which may contain a crosslinking structure modifier, resin (B) and the crosslinking structure modifier separately blended into the dope, etc.) can be selected from a range of, for example, about 0.0001 mass% or more, and may be 0.0005 mass% or more, preferably 0.001 mass% or more, more preferably about 0.002 mass% or more, or may be 20 mass% or less [for example, 15 mass% or less (for example, 12 mass% or less), preferably 10 mass% or less (for example, 8 mass% or less), more preferably 5 mass% or less (for example, 2 mass% or less)].

[0159] Specific examples of the proportion of the crosslinking structure modifier include 0.0001 to 10 mass %, preferably 0.001 to 5 mass %, and more preferably 0.002 to 2 mass %, based on the total amount of the resin and the crosslinking structure modifier.

[0160] The dope may contain a solvent.

[0161] The solvent may vary depending on the type of resin (B), the molding method, the form of the molded product, etc., but examples thereof include organic solvents {e.g., amide-based solvents [e.g., chain aliphatic amides such as N,N-dimethylformamide and N,N-dimethylacetamide (DMAc); cyclic aliphatic amides such as N-methyl-2-pyrrolidone and N-vinylpyrrolidone], halogen-based solvents (e.g., 1,1-difluorotetrachloroethane and dichloromethane), ether-based solvents (e.g., cyclic ethers such as 1,4-dioxane, 1,3-dioxolane and tetrahydrofuran), esters, etc. Examples of the solvent include nitrile-based solvents (e.g., fatty acid esters such as ethyl acetate), ketone-based solvents (e.g., chain ketones such as acetone and methyl ethyl ketone; cyclic ketones such as cyclohexanone), nitrile-based solvents (e.g., acetonitrile), sulfur-based solvents (e.g., sulfone-based solvents such as diethyl sulfone; sulfoxide-based solvents such as dimethyl sulfoxide), alcohol-based solvents (e.g., alkanols such as methanol, ethanol, and isopropanol), amine oxide-based solvents (e.g., N-methylmorpholine N-oxide), and water.

[0162] The solvents may be used alone or in combination of two or more.

[0163] Among these, polar solvents (e.g., aprotic polar solvents or protic polar solvents, particularly aprotic polar solvents) such as amide-based solvents (e.g., DMAc, dimethylformamide, dimethyl sulfoxide, vinylpyrrolidone, etc.) and sulfur-based solvents (e.g., dimethyl sulfoxide, etc.) can be preferably used. The SP value of such a solvent (e.g., a polar solvent) [(cal / cm 1 / 2 ] may be, for example, about 5 to 16, preferably about 6 to 15, and more preferably about 6.5 to 14 (for example, about 7 to 13).

[0164] The SP value may be, for example, the Hansen solubility parameter (method by Hansen). Such a Hansen solubility parameter can be measured or calculated, for example, by the Hansen sphere method.

[0165] In the dope containing a solvent, the concentration of solids (or components other than the solvent, resin, other components, etc.) may vary depending on the molding mode, etc., but may be, for example, 1 to 90 mass % (e.g., 3 to 95 mass %), preferably 5 to 80 mass % (e.g., 10 to 70 mass %), more preferably 15 to 60 mass % (e.g., 20 to 50 mass %), etc.

[0166] In particular, when the dope is used as a spinning solution (spinning liquid), the solid content may be, for example, about 5 to 80 mass%, preferably 8 to 70 mass%, and more preferably about 10 to 60 mass% (e.g., 15 to 55 mass%, 20 to 50 mass%, 25 to 45 mass%, 35 to 55 mass%, 30 to 60 mass%).

[0167] In the dope (e.g., dope containing a solvent), the proportion of polyurethane (A) may be, for example, 0.1% by mass or more (e.g., 0.5% by mass or more), preferably 1% by mass or more (e.g., 2% by mass or more), and more preferably 3% by mass or more (e.g., 5% by mass or more), and can also be 8% by mass or more (e.g., 10% by mass or more, 12% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, 30% by mass or more, 40% by mass or more, 50% by mass or more), etc.

[0168] The upper limit of the proportion of polyurethane (A) in the dope can be appropriately selected depending on whether or not a solvent is contained. In particular, in a dope containing a solvent, the proportion (upper limit of the proportion) of polyurethane (A) can be selected from a range of about 99% by mass or less (e.g., 97% by mass or less), and can also be 95% by mass or less (e.g., 90% by mass or less), preferably 85% by mass or less (e.g., 80% by mass or less), more preferably 75% by mass or less (e.g., 70% by mass or less, 65% by mass or less, 60% by mass or less, 55% by mass or less, 50% by mass or less, 45% by mass or less, 40% by mass or less, 35% by mass or less).

[0169] The viscosity of the dope depends on the molding mode (for example, whether it is used as a spinning solution) and the solid content concentration (for example, whether it is a suitable concentration in the spinning solution as described above), but may be selected from a range of about 10 poise (=1 Pa·s=1000 mPa·s) or more at 40°C, for example, 100 poise or more (for example, 200 poise or more, 300 poise or more, 400 poise or more), preferably 500 poise or more (for example, 600 poise or more, 700 poise or more, 800 poise or more), more preferably 1000 poise or more (for example, 1100 poise or more, 1200 poise or more), or about 1300 poise or more (for example, 1400 poise or more). poise or more, 1500 poise or more, 1600 poise or more, 1700 poise or more, 1750 poise or more, 1800 poise or more, 1900 poise or more, 2000 poise or more, 2100 poise or more, 2200 poise or more, 2300 poise or more, 2400 poise or more, 2500 poise or more, 2600 poise or more, 2700 poise or more 2800 poise or more, 2900 poise or more, 3000 poise or more, 3100 poise or more, 3200 poise or more, 3300 poise or more, 3400 poise or more, 3500 poise or more, 3600 poise or more, 3700 poise or more, 3800 poise or more, 3900 poise or more, 4000 poise or more), etc.

[0170] The viscosity (upper limit) of the dope is not limited, but may be selected from a range of about 100,000 poise or less at 40°C, and may be about 80,000 poise or less (e.g., 60,000 poise or less, 50,000 poise or less, 40,000 poise or less), preferably 30,000 poise or less (e.g., 20,000 poise or less, 15,000 poise or less, 12,000 poise or less), more preferably 10,000 poise or less (e.g., 9,000 poise or less, 8,000 poise or less), and may be about 7,000 poise or less (e.g., 6,500 poise or less, 6,000 poise or less, 5,500 poise or less, 5,000 poise or less, 4,500 poise or less, 4,400 poise or less). or less, 4300 poise or less, 4200 poise or less, 4100 poise or less, 4000 poise or less, 3900 poise or less, 3800 poise or less, 3700 poise or less, 3600 poise or less, 3500 poise or less, 3400 poise or less, 3300 poise or less, 3200 poise or less, 3100 poise or less, 3000 poise or less , 2900 poise or less, 2800 poise or less, 2700 poise or less, 2600 poise or less, 2500 poise or less, 2400 poise or less, 2300 poise or less, 2200 poise or less, 2100 poise or less, 2000 poise or less, 1900 poise or less, 1850 poise or less, 1800 poise or less), etc.

[0171] The viscosity of the dope may change over time, but may be maintained (retained) within the above range when used as a dope.

[0172] The viscosity of the dope may change over time, but it is preferable that the change is small, and more preferably that the viscosity increases over time.

[0173] For example, at 40°C, the ratio (ratio, proportion, viscosity ratio, viscosity after 24 hours / initial viscosity, V2 / V1) of the viscosity (initial viscosity, V1) when the polyurethane (A) is prepared (for example, dissolved (mixed)) to the viscosity after 24 hours (left standing) after preparation (for example, dissolving (mixing)) of the dope can be selected from the range of 0.7 or more (for example, 0.75 or more), for example, 0.8 or more (for example, 0.85 or more, 0.9 or more), preferably 0.95 or more (for example, It may be 0.98 or more, 0.99 or more), more preferably 1 or more (for example, greater than 1, 1.001 or more, 1.005 or more), particularly 1.01 or more (for example, 1.02 or more, 1.03 or more, 1.04 or more, 1.05 or more, 1.06 or more), and may be 1.08 or more (for example, 1.1 or more, 1.15 or more, 1.2 or more, 1.25 or more, 1.3 or more, 1.35 or more, 1.4 or more, 1.45 or more, 1.5 or more, 1.55 or more, 1.6 or more, 1.7 or more, 1.8 or more, 1.9 or more, etc.).

[0174] The (upper limit of) the 24-hour viscosity / initial viscosity (V2 / V1) is not particularly limited and may be selected, for example, from a range of about 20 or less (e.g., 15 or less), and can be, for example, about 10 or less (e.g., 8 or less, 7 or less, 6 or less), preferably 5 or less (e.g., 4.5 or less, 4 or less), and more preferably 3.5 or less (e.g., 3.3 or less, 3.2 or less, 3.1 or less, 3 or less, 2.9 or less, 2.8 or less, 2.7 or less, 2.6 or less, 2.5 or less, 2.4 or less, 2.3 or less, 2.2 or less, 2.1 or less, 2 or less, 1.9 or less, 1.8 or less, 1.7 or less, 1.6 or less, 1.5 or less, 1.4 or less, 1.3 or less).

[0175] Specific examples of the 24-hour viscosity / initial viscosity (V2 / V1) include 0.7 to 10, 1 to 5, 1.01 to 4, 1.03 to 3.5, 1.1 to 3.3, 1.2 to 3.5, 1.05 to 3, and 1.05 to 1.2.

[0176] Within such a range, the viscosity can be efficiently prevented from decreasing or can be increased appropriately, which is likely to be advantageous in terms of moldability (spinnability, etc.) and physical properties.

[0177] The viscosity (V1, V2) of the dope can be measured at 40°C using a viscometer (e.g., a falling ball viscometer) (e.g., according to the method of ASTM D1343-69) by setting the starting point (initial viscosity (V1)) when the solid components (polyurethane resin (A), resin (B), etc.) are fully dissolved (dispersed) and the end point (viscosity after 24 hours (V2)) 24 hours after the starting point.

[0178] The dope can be produced by mixing the components that make up the dope. In such mixing, the method of mixing (adding) the polyurethane (A) is not particularly limited. For example, a dope containing a solvent and a resin (B) may be obtained by mixing the polyurethane (A) into a system containing the resin (B) (or a raw material thereof) and a solvent, or by mixing the polyurethane (A), the resin (B), and the solvent all at once.

[0179] During mixing, heating and stirring may be carried out as appropriate for the purpose of promoting melting (dissolution) or dispersion of the polyurethane (A), and various components may be mixed.

[0180] The dope can be used for purposes depending on the shape of the molded product, and may be suitably used, for example, for producing fibers (yarn).

[0181] Specifically, the dope can be spun to produce fibers (yarn).

[0182] The fiber contains polyurethane (A) as a resin, and may typically be a polyurethane fiber (yarn) {for example, a polyurethane fiber (e.g., polyurethane elastic fiber) containing polyurethane as the main resin [for example, mainly containing polyurethane (A), or mainly containing polyurethane (A) and polyurethane (B)]}.

[0183] The spinning method is not particularly limited as long as it is a method using a dope, and for example, a solution spinning method (eg, a dry spinning method) may be suitably used.

[0184] In such a spinning method (for example, a dry spinning method), known or conventional spinning conditions can also be used and are not particularly limited. The obtained fiber (yarn) may be treated (or surface-treated) with a conventional additive (a fiber treatment agent or finishing agent, such as silicones, oils, or the aforementioned components such as inorganic substances and inorganic porous materials) at an appropriate timing (for example, when winding, etc.) (the conventional additive may be applied, adhered, or incorporated).

[0185] The dope (or polyurethane (A)) can be used to obtain molded articles (fibers (yarns) and the like), and therefore, such molded articles are also included in the present invention.

[0186] Such a molded article may generally reflect the characteristics of the polyurethane (A) or the dope. For example, when the polyurethane (A) or the dope contains a high-molecular-weight component or other components as described above, the molded article may also contain such components. [Example]

[0187] The present invention will be explained in more detail below by way of examples, but the present invention is not limited to these examples in any way.

[0188] First, we will show the measurement and evaluation methods for each physical property, etc. Unless otherwise specified, measurements were carried out under conditions of 23°C and a relative humidity of 60%.

[0189] <Viscosity> The viscosity was measured at 40° C. using a Model DV-8 falling ball viscometer (Duratech Corp., Waynesboro, VA) according to the method of ASTM D1343-69. The inner diameter of the viscosity tube used was 31.4 (±0.2) mm.

[0190] <Initial viscosity and viscosity after 24 hours in a 20% by mass DMAc solution>

[0191] The samples (polyurethane, polyurethane (A)) were thoroughly dried (in a vacuum dryer at approximately 40°C and a reduced pressure of 1 kPa or less for 8 hours), and then mixed with N,N-dimethylacetamide (DMAc) to a concentration of 20% by mass. The mixture was stirred at 23°C (ambient temperature) for 4 hours to prepare a 20% by mass DMAc solution.

[0192] A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0193] The obtained 20% by mass DMAc solution was left to stand at 40°C (the temperature of the thermostatic bath of the falling ball viscometer) for 2 hours to stabilize [dissolve (or disperse)], and then the initial viscosity at 40°C (the viscosity after standing for 2 hours to stabilize) and after standing for 24 hours (another 24 hours had passed) were measured using the method described in <Viscosity> above.

[0194] Then, from the obtained initial viscosity and viscosity after 24 hours, the viscosity ratio (initial viscosity / viscosity after 24 hours) was calculated.

[0195] <Viscosity ratio of dope at initial stage and after 24 hours> The dope (spinning solution) was left to stand at 40°C (the temperature of the thermostatic bath of the falling ball viscometer) for 2 hours to stabilize, and then the initial viscosity at 40°C (the viscosity after being left to stand for 2 hours to stabilize) and the viscosity after being left to stand for 24 hours (and after a further 24 hours had passed) were measured using the method described in <Viscosity> above.

[0196] Then, the viscosity ratio (initial viscosity / viscosity after 24 hours) was calculated from the initial viscosity and the viscosity after 24 hours.

[0197] <Molecular weight> The molecular weight measurement by GPC was carried out under the following conditions. Column: Showa Denko SHODEX KF-806M (2 units) Solvent: N,N-dimethylacetamide (DMAc) 1 ml / min Temperature: 40℃ Detector: Differential refractometer (RI detector) Standard material: polystyrene

[0198] <Amino group concentration> A 20% by mass DMAc solution of the sample (polyurethane, polyurethane (A)) prepared by the above-mentioned method was diluted with DMAc to prepare a 2% by mass DMAc solution, and this DMAc solution was subjected to potentiometric titration with p-toluenesulfonic acid (0.01 N) at room temperature (18 to 28°C) using an automatic titrator (COM-1760) manufactured by Hiranuma Corporation to measure the amount of end groups (the total of end groups derived from primary amines and secondary amines) (X) (meq / kg).

[0199] Separately, a 20% by mass DMAc solution of the sample (polyurethane, polyurethane (A)) prepared by the above-mentioned method was diluted with DMAc to prepare a 2% by mass DMAc solution. To this DMAc solution, salicylaldehyde (20% by mass isopropyl alcohol solution) was added to block the terminal groups derived from the primary amine (to react with the terminal groups derived from the primary amine). After that, the solution was subjected to potentiometric titration with p-toluenesulfonic acid (0.01 N) at room temperature (18 to 28°C) using an automatic titrator (COM-1760) manufactured by Hiranuma Corporation, and the amount of terminal groups (secondary amine-derived terminal groups) (Y) (meq / kg) was measured.

[0200] Then, using these measured values, the amino group concentration was calculated according to the following formula. Proportion (concentration) of amino groups (terminal amino groups) = (X) - (Y) (meq / kg)

[0201] <Fiber diameter / size> The fibers were embedded in an embedding agent (paraffin resin or epoxy resin), and images of the fiber cross section perpendicular to the fiber axis were taken with an SEM at a magnification that allowed the filaments to be observed. The area of ​​a randomly selected fiber was measured within each image, and the diameter calculated as a perfect circle was measured in μm units to the first decimal place. This was done for 10 filaments, and the simple number average was calculated, and the value rounded to the first decimal place was taken as the fiber diameter (μm). When hollows or gaps exist in the cross section of the fiber perpendicular to the fiber axis, the area of ​​the hollows was added to the area of ​​the fiber. The length and size were also measured using SEM in the same manner.

[0202] <Spinnability> In dry spinning, the number of times that yarn breakage occurred when a 22 dtex, 3 filament yarn (fiber) was spun continuously for 96 hours was counted and the following evaluation was made. Number of thread breaks: 0 = Very good ◎ Number of thread breaks: 1-2 times = Good Number of thread breaks: 3-4 times = Acceptable Number of thread breaks: 5 or more = defective ×

[0203] <Breaking elongation, breaking strength> The breaking elongation and breaking strength were measured by subjecting the sample to a tensile test using an Instron 5564 tensile tester. A sample with a length of 5 cm (L1) was stretched 300% five times at a tensile speed of 50 cm / min. The stress at 300% stretch was defined as (G1). The sample length was then held at 300% stretch for 30 seconds. The stress after 30 seconds was defined as (G2). The sample was then allowed to recover, and the length of the sample when the stress returned to 0 was defined as (L2). This cycle of 300% stretching, holding, and recovery was repeated until the sample broke on the sixth stretch. The stress at break was defined as (G3), and the sample length at break was defined as (L3). Hereinafter, the above properties are calculated using the following formulas. Breaking strength (cN) = (G3) 20 or more: ◎, 17 or more but less than 20: 〇, 14 or more but less than 17: △, less than 14: × Breaking elongation (%) = 100 × ((L3) - (L1)) / (L1) 480 or more: ◎, 460 or more but less than 480: 〇, 430 or more but less than 460: △, less than 430: ×

[0204] <Heat resistance> A two-way half tricot consisting of 85% by weight of nylon filament (24 dtex, 7 filaments) and 15% by weight of the sample (fiber, 44 dtex) with an on-machine well count of 9 per inch and an on-machine course count of 18 per inch was produced by a conventional knitting method to form a raw knitted fabric. The resulting raw knit fabric was preset at 170°C for 60 seconds under 3% elongation, and 0.1 ml of Chemical 1 was applied. Subsequently, 0.1 ml of Chemical 2 was applied (almost simultaneously or within 1 minute). The fabric was then dry-heated (at 175°C for 60 seconds, then removed and cooled to room temperature, and then dry-heated at 180°C for 60 seconds). The fabric was then subjected to a bending test at a maximum elongation of 20% alternating between the longitudinal and transverse directions, at 2 times per second. Chemical 1 was a mineral oil-based nylon spinning oil containing 1% oleic acid. Chemical 2 was a copper acetate aqueous solution (copper concentration 100 ppm). The raw knitted fabric to which chemicals 1 and 2 had been applied in this way was a model that reproduced the situation in which trace amounts of machine oil (containing metals) and nylon spinning oil agent had adhered to a nylon stretch raw knitted fabric before dyeing.The amount of chemical 1 adhered to 0.9 g of raw knitted fabric was 3.0 mg, and the amount of chemical 2 adhered to 0.9 g of raw knitted fabric was 3.0 mg. The resulting stretch fabric was dyed in a conventional manner. The degree of damage to the sample (polyurethane) tissue in the resulting dyed stretch fabric was observed visually or under magnification and judged according to the following criteria. The judgement was made by five people, and the mode (the judgement that appeared most frequently) was used. When the judgements were split between two people, two people, and one person, the judgement was given as "△". ◎: No damage and the knitting structure is uniform. ○: No damage. △: The fabric is worn and dented, and under magnification the sample (polyurethane elastic fiber) is found to be brittle. ×: There are holes in the fabric.

[0205] <Composite durability, yellowing resistance> The composite durability was evaluated by stretching the sample yarn by 100% and determining the retention of breaking strength after the following exposure treatments (a), (b), and (c). The sample shape and measurement method for yellowing resistance (yellowing resistance) were as follows: the sample yarn was wound tightly onto a 5 x 5 cm sample plate with minimal load, so as not to affect the color of the sample plate. The front of the sample and the standard white surface (JIS Z 8722, 4.3.4) were tightly covered with a uniform, flat, transparent glass plate approximately 1 mm thick. The b value was measured using a Hunter color difference meter in accordance with JIS L 1013, Method C (Hunter's method), and calculated using the following formula. Five measurements were made, and the average value was used. b=7.0(Y-0.847Z) / Y 1 / 2 (X, Y, and Z were calculated according to JIS Z 8701) Yellowing resistance (yellowing) was evaluated by the degree of yellowing (hereinafter abbreviated as Δb) after the samples were exposed to the exposure conditions (a) and (b). The degree of yellowing after each exposure was calculated as follows: Δb = b value after exposure treatment - b value before exposure treatment Each exposure treatment was carried out as follows: (A) Ultraviolet (UV) exposure treatment Using a carbon arc weather meter manufactured by Suga Test Instruments Co., Ltd., the samples were exposed to a temperature and humidity of 63°C and 60% RH for 25 hours. (a) Nitrogen oxide (NOx) exposure treatment Using a closed container (Scott Tester) with a rotating sample stand, the sample was exposed to 10 ppm NO2 gas at 40°C and 60% RH for 20 hours. (c) Chlorine bleach (Cl2) exposure treatment The sample was exposed to a 500 ppm aqueous solution of Kao Haiter (manufactured by Kao Corporation) in a thermostatic chamber at 40°C for 30 minutes, and then washed with water for 10 minutes. This cycle was repeated eight times. The criteria for judgment are as follows:

[0206] ·Composite durability ◎ for 60% or more, 〇 for 40% to less than 60%, △ for 20% to less than 40%, and × for less than 20%

[0207] ·Yellowing degree Less than 3 is ◎, 3 to less than 6 is 〇, 6 to less than 10 is △, 10 or more is ×

[0208] [Reference example 1] A 35% by mass solution of N,N'-dimethylacetamide (hereinafter sometimes abbreviated as DMAc) containing tetramethylene ether glycol (PTMG) with a molecular weight of 2,000, 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI), and ethylenediamine (EDA) was polymerized to obtain the polymer solution PUUV. The molar ratio of 4,4'-MDI to 2,4'-MDI was 97:3, and diethylamine was used as the polymerization terminator, with the molar ratio of ethylenediamine to diethylamine being 8:1. Next, a 1:1 (mass ratio) mixture of polyurethane (DuPont's "Methachlor" (registered trademark) 2462) produced by the reaction of t-butyldiethanolamine with methylene-bis-(4-cyclohexylisocyanate) and a condensation polymer of p-cresol and divinylbenzene (DuPont's "Methachlor" (registered trademark) 2390) was used as an antioxidant. A DMAc solution (35 mass %) of this mixture was prepared to serve as an antioxidant solution.

[0209] The above-mentioned PUUV solution, antioxidant solution, and ethylenediamine were uniformly mixed in proportions of 99.5 parts by mass, 0.5 parts by mass, and 0.1 parts by mass, respectively, to prepare a spinning dope (spinning solution, dope) with a concentration of 35% by mass.

[0210] The initial viscosity of the spinning solution was 1900 P (poise) (= 190,000 mPa·s), and the viscosity after 24 hours was 1850 P, and the viscosity ratio between these was calculated to be 0.97.

[0211] The spinning solution thus obtained was used as a dope as it was, and dry-spun at a dry nitrogen temperature of 300°C or higher so that the DMAc and floating ethylenediamine in the spinning solution were 1 / 100 or less of the contents in the spinning solution.

[0212] At this time, the speed ratio of the godet roller to the winder was set to 1:1.20, and a 22 dtex / 3fil multifilament fiber (polyurethane elastic fiber) was spun. A treatment agent (oil) described below was applied to the spinning surface using an oiling roller before winding. The spinning speed was set to 600 m / min, and the spinning was carried out on a 58 mm long cylindrical paper tube via a traverse guide that gave a winding width of 38 mm. A 500 g wound body of dry-spun fiber (polyurethane elastic fiber) was obtained.

[0213] The resulting fiber was a fused yarn made by fusing three filaments. The rotation speed of the oiling roller was adjusted so that the amount of treatment agent applied to the yarn was the predetermined amount. The amount of treatment agent applied was measured in accordance with JIS-L1073 (Testing Method for Synthetic Fiber Filament Yarns) using n-hexane as the extraction solvent.

[0214] The composition of the treatment agent used here was 1 x 10 -5 m 2 80 parts by weight of polydimethylsiloxane having a viscosity of 1.2 x 10 / s at 25°C -5 m 2 The mixture is 15 parts by mass of mineral oil having a viscosity of 1000000000 / s and 5 parts by mass of magnesium distearate having an average particle size of 0.5 μm.

[0215] The number average molecular weight of the polymer constituting the fiber (or thread) was 20,000.

[0216] The results, including various evaluations, are shown in the table.

[0217] [Reference example 2] In Reference Example 1, the prepared solution PUUV was used as it was as a spinning solution (a spinning solution with a concentration of 35% by mass).

[0218] The initial viscosity of the spinning dope was 2200P, and the viscosity after 24 hours was 2000P, and the viscosity ratio between these was calculated to be 0.91.

[0219] This spinning solution was used as a dope as it was, and the same procedure as in Reference Example 1 was carried out to obtain dry-spun fibers.

[0220] The number average molecular weight of the polymer constituting the fiber (or thread) was 27,000.

[0221] The results, including various evaluations, are shown in the table. As is clear from the table, when the above dope (spinning solution) was used, the resulting fibers were inferior in physical properties (breaking strength, breaking elongation, heat resistance, and yellowing resistance) compared to when the dope (spinning solution) obtained in Reference Example 1 was used.

[0222] [Reference example 3] A spinning solution (a spinning solution with a concentration of 35% by mass) was obtained in the same manner as in Reference Example 2, except that the molar ratio of 4,4'-MDI to 2,4'-MDI was 98:1 and the molar ratio of ethylenediamine to diethylamine was 12:1.

[0223] The initial viscosity of the spinning dope was 3000P, and the viscosity after 24 hours was 2450P, and the viscosity ratio between these was calculated to be 0.82.

[0224] This spinning solution was used as a dope as it was, and the same procedure as in Reference Example 1 was carried out to obtain dry-spun fibers.

[0225] The number average molecular weight of the polymer constituting the fiber (or thread) was 30,000.

[0226] The results, including various evaluations, are shown in the table.

[0227] As is clear from the table, when the above dope (spinning solution) was used, the resulting fibers were inferior in physical properties (breaking strength, heat resistance, yellowing resistance) compared to when the dope (spinning solution) obtained in Reference Example 1 was used.

[0228] [Reference example 4] A fibrous polyurethane [polyurethane composition (PTMG, MDI, BDO (butanediol)), crushed post-consumer yarn produced by melt spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 244 μm)] was prepared. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0229] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 2200 P, and the viscosity after 24 hours was measured to be 1975 P, and the viscosity ratio between these values ​​was calculated to be 0.90.

[0230] Furthermore, the number average molecular weight of this polyurethane was 23,000, and there was no peak (peak top) in the region of molecular weights (number average molecular weights) of 1 million or more (the region on the GPC chart corresponding to a molecular weight (number average molecular weight) of 1 million or more).

[0231] Next, the polyurethane, the spinning dope obtained in Reference Example 1, and DMAc were mixed and stirred at 23° C. (ambient temperature) for 4 hours to prepare a solution.

[0232] A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0233] The resulting solution was then further concentrated to obtain a dope. The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0234] The initial viscosity of this dope was 2200P, and the viscosity after 24 hours was 1700P, and the viscosity ratio between these was calculated to be 0.77.

[0235] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0236] The number average molecular weight of the polymer constituting the fiber (or thread) was 20,000.

[0237] The results, including various evaluations, are shown in the table.

[0238] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the resulting fibers had poorer physical properties (yellowing resistance) than when the dope (spinning solution) obtained in Reference Example 1 was used.

[0239] [Example 1] A fibrous polyurethane [polyurethane composition (PTMG, MDI, BDO), ground post-consumer yarn produced by the dry spinning method (length approximately 2 mm, fiber diameter (average fiber diameter) 260 μm)] was prepared. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0240] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 1800P, and the viscosity after 24 hours was measured to be 2000P, and the viscosity ratio between these values ​​was calculated to be 1.11.

[0241] Furthermore, the number average molecular weight of this polyurethane was 30,000, and there was (existed) a peak in the range of molecular weights (number average molecular weights) of 1 million or more.

[0242] Then, using this polyurethane, a dope was obtained in the same manner as in Reference Example 4.

[0243] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0244] The initial viscosity of this dope was 2600P, and the viscosity after 24 hours was 2600P, and the viscosity ratio between these was calculated to be 1.00.

[0245] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0246] The number average molecular weight of the polymer constituting the fiber (or thread) was 29,000.

[0247] The results, including various evaluations, are shown in the table.

[0248] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the spinnability was significantly improved compared to when the dope (spinning solution) obtained in Reference Example 1 was used, and the physical properties (elongation at break, heat resistance, and composite durability) of the obtained fiber were significantly superior.

[0249] As mentioned above, the dope (spinning solution) obtained in Reference Example 1 is a dope that can achieve superior physical properties compared to the dopes of Reference Examples 2 and 3 produced separately from Reference Example 1. However, even compared to the dope obtained in Reference Example 1, such a significant improvement in spinnability and further significant improvements in physical properties were achieved.

[0250] [Example 2] A dope (dope with a concentration of 35% by mass) was obtained in the same manner as in Example 1, except that the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 60% by mass.

[0251] The initial viscosity of this dope was 1950P, and the viscosity after 24 hours was 2600P, and the viscosity ratio between these was calculated to be 1.33.

[0252] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1. The number average molecular weight of the polymer constituting the fiber (or thread) was 29,500.

[0253] The results, including various evaluations, are shown in the table.

[0254] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the spinnability was significantly improved compared to when the dope (spinning solution) obtained in Reference Example 1 was used, and the physical properties (breaking strength, breaking elongation, heat resistance, and composite durability) of the obtained fiber were significantly superior.

[0255] The physical properties (breaking strength) were significantly better than those of Example 1, which had a lower addition ratio.

[0256] [Example 3] A dope was obtained in the same manner as in Example 1, except that a DMAc dispersion (35% by mass) of a metal soap (magnesium stearate) and a DMAc dispersion (35% by mass) of a surfactant (polyoxyethylene lauryl ether) were uniformly mixed (blended) with the dope (35% by mass) so that each amount was 1 part by mass per 98 parts by mass of the dope.

[0257] The initial viscosity of this dope was 1900P, and the viscosity after 24 hours was 2700P, and the viscosity ratio between these was calculated to be 1.42.

[0258] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0259] The number average molecular weight of the polymer constituting the fiber (or thread) was 30,000.

[0260] The results, including various evaluations, are shown in the table.

[0261] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the spinnability was significantly improved compared to when the dope (spinning solution) obtained in Reference Example 1 was used, and the physical properties (breaking strength, breaking elongation, heat resistance, and composite durability) of the obtained fiber were significantly excellent.

[0262] The spinnability and physical properties (breaking strength, breaking elongation) were significantly superior to those of Example 1 in which no metal soap or surfactant was blended.

[0263] Therefore, similar results can be obtained even if a polyurethane containing metal soap (or even a surfactant) is used.

[0264] To confirm this, the same amount of metal soap (and surfactant) was added to the polyurethane in advance, and dry-spun fibers were obtained in the same manner as above. The spinnability and physical properties showed similar trends. For the polyurethane that had previously contained metal soap (and surfactant), the initial viscosity in a 20% by mass DMAc solution was measured to be 1760P, and the viscosity after 24 hours was measured to be 1970P, and the viscosity ratio between these values ​​was calculated to be 1.12.

[0265] [Example 4] A dope was obtained in the same manner as in Example 1, except that a DMAc solution (35 mass%) of an antioxidant (ethylene-1,2-bis(3,3-bis[3-t-butyl-4-hydroxyphenyl]butyrate)) was uniformly mixed (blended) with the dope (35 mass%) so that the amount of the DMAc solution was 3 parts by mass relative to 97 parts by mass of the dope.

[0266] The initial viscosity of this dope was 1800P, and the viscosity after 24 hours was 2600P, and the viscosity ratio between these was calculated to be 1.44.

[0267] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0268] The number average molecular weight of the polymer constituting the fiber (or thread) was 31,000.

[0269] The results, including various evaluations, are shown in the table.

[0270] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the spinnability was significantly improved compared to when the dope (spinning solution) obtained in Reference Example 1 was used, and the physical properties (breaking strength, breaking elongation, heat resistance, and composite durability) of the obtained fiber were significantly excellent.

[0271] The spinnability and physical properties (breaking strength, heat resistance, and composite durability) were significantly superior to those of Example 1, which did not contain any antioxidant.

[0272] Therefore, similar results can be obtained even if a polyurethane containing an antioxidant is used.

[0273] To confirm this, the same amount of antioxidant was added to the polyurethane in advance, and dry-spun fibers were obtained in the same manner as above. The spinnability and physical properties showed similar trends. The polyurethane to which an antioxidant had been added beforehand had an initial viscosity of 1710 P in a 20% by mass DMAc solution, and a viscosity of 1900 P after 24 hours, and the viscosity ratio between these values ​​was calculated to be 1.11.

[0274] [Example 5] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground post-consumer yarn produced by the dry spinning method (length approximately 2 mm, fiber diameter (average fiber diameter) 220 μm)] was prepared.

[0275] The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0276] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 2900 P, and the viscosity after 24 hours was measured to be 3050 P, and the viscosity ratio between these values ​​was calculated to be 1.05.

[0277] The number average molecular weight of this polyurethane was 30,000, with a peak in the range of number average molecular weights of 1,000,000 or more.

[0278] Then, using this polyurethane, a dope was obtained in the same manner as in Reference Example 4.

[0279] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0280] The initial viscosity of this dope was 2600P, and the viscosity after 24 hours was 2800P, and the viscosity ratio between these was calculated to be 1.08.

[0281] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0282] The number average molecular weight of the polymer constituting the fiber (or thread) was 30,000.

[0283] The results, including various evaluations, are shown in the table.

[0284] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the spinnability was significantly improved compared to when the dope (spinning solution) obtained in Reference Example 1 was used, and the physical properties (breaking strength, breaking elongation, heat resistance, and composite durability) of the obtained fiber were significantly excellent.

[0285] Although the polyurethane used was different from that used in Example 1, it was found to show a similar tendency.

[0286] [Example 6] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground wound yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 225 μm)] was prepared.

[0287] The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0288] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 3000 P, and the viscosity after 24 hours was measured to be 3900 P, and the viscosity ratio between these was calculated to be 1.30.

[0289] The number average molecular weight of this polyurethane was 30,500, with a peak in the molecular weight (number average molecular weight) range of 1,000,000 or more.

[0290] Then, using this polyurethane, a dope was obtained in the same manner as in Reference Example 4. The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0291] The initial viscosity of this dope was 2900P, and the viscosity after 24 hours was 3200P, and the viscosity ratio between these was calculated to be 1.10.

[0292] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0293] The number average molecular weight of the polymer constituting the fiber (or thread) was 33,000.

[0294] The results, including various evaluations, are shown in the table.

[0295] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the spinnability was significantly improved compared to when the dope (spinning solution) obtained in Reference Example 1 was used, and the physical properties (breaking strength, breaking elongation, heat resistance, and composite durability) of the obtained fiber were significantly excellent.

[0296] Although the polyurethane used was different from that used in Example 1, it was found to show a similar tendency.

[0297] In particular, the viscosity ratio after 24 hours in a 20% by mass DMAc solution was greater than that of the polyurethane used in Example 1, and the improvement in spinnability was particularly remarkable.

[0298] [Example 7] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground wound yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 560 μm)] was prepared.

[0299] The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0300] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 4200 P, and the viscosity after 24 hours was measured to be 6500 P, and the viscosity ratio between these values ​​was calculated to be 1.55.

[0301] The number average molecular weight of this polyurethane was 30,000, with a peak in the molecular weight (number average molecular weight) range of 1,000,000 or more.

[0302] Next, the 20% by mass DMAc solution of the polyurethane was concentrated under reduced pressure at 60°C to a 35% by mass DMAc solution, and the concentrated solution was mixed with the spinning solution obtained in Reference Example 1 and stirred for 2 hours to prepare a solution (dope).

[0303] A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0304] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0305] The initial viscosity of this dope was 2900P, and the viscosity after 24 hours was 4200P, and the viscosity ratio was calculated to be 1.45.

[0306] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0307] The number average molecular weight of the polymer constituting the fiber (or thread) was 30,000.

[0308] The results, including various evaluations, are shown in the table.

[0309] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the spinnability was significantly improved compared to when the dope (spinning solution) obtained in Reference Example 1 was used, and the physical properties (breaking strength, breaking elongation, heat resistance, composite durability, and yellowing resistance) of the obtained fiber were significantly excellent.

[0310] Although a different polyurethane was used than that used in Example 1 and the dope preparation method was also changed, it was found that the same tendency was observed.

[0311] [Example 8] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 1265 μm)] was prepared. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0312] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 2900 P, and the viscosity after 24 hours was measured to be 8600 P, and the viscosity ratio between these values ​​was calculated to be 2.97.

[0313] The number average molecular weight of this polyurethane was 29,000, with a peak in the molecular weight (number average molecular weight) range of 1,000,000 or more.

[0314] Next, the 20% by mass DMAc solution of the polyurethane was concentrated under reduced pressure at 80° C. to a 35% by mass DMAc solution, and mixed with the spinning dope obtained in Reference Example 1 to prepare a solution (dope). A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0315] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0316] The initial viscosity of this dope was 2680P, and the viscosity after 24 hours was 3800P, and the viscosity ratio was calculated to be 1.42.

[0317] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0318] The number average molecular weight of the polymer constituting the fiber (or thread) was 29,000.

[0319] The results, including various evaluations, are shown in the table.

[0320] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the spinnability was significantly improved compared to when the dope (spinning solution) obtained in Reference Example 1 was used, and the physical properties (breaking strength, breaking elongation, heat resistance, composite durability, and yellowing resistance) of the obtained fiber were significantly excellent.

[0321] Although a different polyurethane was used than that used in Example 1 and the dope preparation method was also changed, it was found that the same tendency was observed.

[0322] [Example 9] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground wound yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 1205 μm)] was prepared. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0323] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 4200 P, and the viscosity after 24 hours was measured to be 10500 P, and the viscosity ratio between these values ​​was calculated to be 2.50.

[0324] The number average molecular weight of this polyurethane was 28,000, with a peak in the molecular weight (number average molecular weight) range of 1,000,000 or more.

[0325] Next, the polyurethane, the spinning dope obtained in Reference Example 1, and diethylamine were mixed and stirred for 2 hours to prepare a solution (dope).

[0326] A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0327] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass, and the proportion of diethylamine was 0.2% by mass.

[0328] The initial viscosity of this dope was 3300P, and the viscosity after 24 hours was 4300P, and the viscosity ratio between these was calculated to be 1.30.

[0329] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0330] The number average molecular weight of the polymer constituting the fiber (or thread) was 44,000.

[0331] The results, including various evaluations, are shown in the table.

[0332] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the spinnability was significantly improved compared to when the dope (spinning solution) obtained in Reference Example 1 was used, and the physical properties (breaking strength, breaking elongation, heat resistance, and composite durability) of the obtained fiber were significantly excellent.

[0333] Although a different polyurethane was used than that used in Example 1 and the dope preparation method was also changed, it was found that the same tendency was observed.

[0334] [Example 10] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground wound yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 1245 μm)] was prepared. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0335] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 4200 P, and the viscosity after 24 hours was measured to be 6600 P, and the viscosity ratio between these values ​​was calculated to be 1.57.

[0336] The number average molecular weight of this polyurethane was 30,000, with a peak in the molecular weight (number average molecular weight) range of 1,000,000 or more.

[0337] Next, 98 parts by mass of a 20% by mass DMAc solution of the polyurethane was mixed with 2 parts by mass of a 20% by mass DMAc solution of a surfactant (polyoxyethylene styrenated phenyl ether) to prepare a solution, which was then mixed with the spinning dope obtained in Reference Example 1.

[0338] A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0339] The resulting solution was then further concentrated to obtain a dope.

[0340] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass, and the proportion of the surfactant was 0.6% by mass.

[0341] The initial viscosity of this dope was 3300P, and the viscosity after 24 hours was 4300P, and the viscosity ratio between these was calculated to be 1.30.

[0342] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0343] The number average molecular weight of the polymer constituting the fiber (or thread) was 40,000.

[0344] The results, including various evaluations, are shown in the table.

[0345] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the spinnability was significantly improved compared to when the dope (spinning solution) obtained in Reference Example 1 was used, and the physical properties (breaking strength, breaking elongation, heat resistance, and composite durability) of the obtained fiber were significantly excellent.

[0346] Although a different polyurethane was used than that used in Example 1 and the dope preparation method was also changed, it was found that the same tendency was observed.

[0347] [Example 11] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground wound yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 1222 μm)] was prepared.

[0348] The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0349] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 2800 P, and the viscosity after 24 hours was measured to be 9000 P, and the viscosity ratio between these values ​​was calculated to be 3.21.

[0350] The number average molecular weight of this polyurethane was 33,000, with a peak in the molecular weight (number average molecular weight) range of 1,000,000 or more.

[0351] Next, the polyurethane, the spinning dope obtained in Reference Example 1, and a 20 mass % DMAc solution of a hindered phenol-based antioxidant {ethylene-1,2-bis(3,3-bis[3-t-butyl-4-hydroxyphenyl]butyrate)} were mixed to prepare a solution.

[0352] A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0353] The resulting solution was then further concentrated to obtain a dope.

[0354] The concentration of this dope was 35% by mass, with the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope being 30% by mass and the proportion of the hindered phenol-based antioxidant being 1.0% by mass.

[0355] The initial viscosity of this dope was 4200P, and the viscosity after 24 hours was 8080P, and the viscosity ratio was calculated to be 1.92.

[0356] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0357] The number average molecular weight of the polymer constituting the fiber (or thread) was 34,000.

[0358] The results, including various evaluations, are shown in the table.

[0359] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the spinnability was significantly improved compared to when the dope (spinning solution) obtained in Reference Example 1 was used, and the physical properties (breaking strength, breaking elongation, heat resistance, and composite durability) of the obtained fiber were significantly excellent.

[0360] Although a different polyurethane was used than that used in Example 1 and the dope preparation method was also changed, it was found that the same tendency was observed.

[0361] [Example 12] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground wound yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 660 μm)] was prepared.

[0362] The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0363] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 2800 P, and the viscosity after 24 hours was measured to be 9000 P, and the viscosity ratio between these values ​​was calculated to be 3.21.

[0364] The number average molecular weight of this polyurethane was 33,000, with a peak in the molecular weight (number average molecular weight) range of 1,000,000 or more.

[0365] Next, a hindered phenol-based antioxidant {ethylene-1,2-bis(3,3-bis[3-t-butyl-4-hydroxyphenyl]butyrate)} and a 20% by mass solution of ethylenediamine in DMAc were mixed with the polyurethane to prepare a solution (dope). A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0366] The concentration of this dope was 35% by mass (including 0.7% by mass of the hindered phenol-based antioxidant and 0.07% by mass of the ethylenediamine).

[0367] The initial viscosity of this dope was 7200P, and the viscosity after 24 hours was 12100P, and the viscosity ratio between these was calculated to be 1.68.

[0368] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0369] The number average molecular weight of the polymer constituting the fiber (or thread) was 53,000.

[0370] The results, including various evaluations, are shown in the table.

[0371] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the spinnability was significantly improved compared to when the dope (spinning solution) obtained in Reference Example 1 was used, and the physical properties (breaking strength, composite durability) of the obtained fiber were also significantly superior.

[0372] The polyurethane used was different from that used in Example 1, and the proportion of polyurethane in the dope was also changed from that in Example 12 (the polyurethane in the dope was the same as above), but it was found that the same tendency was observed.

[0373] Comparison with other examples suggests that the dope prepared by combining the polyurethane with a separate polyurethane polymerization component is more advantageous in terms of physical properties.

[0374] [Example 13] A polyurethane urea resin molded product (RIM molded product) [a pulverized product (granular, particle diameter of approximately 0.1 to 2 mm) of a polyurethane urea composition (PTMG, MDI, EDA)] was prepared. The crushing was carried out using a three-blade helical cutting type crusher.

[0375] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 2900 P, and the viscosity after 24 hours was measured to be 3200 P, and the viscosity ratio between these values ​​was calculated to be 1.10.

[0376] Next, the polyurethane, the spinning dope obtained in Reference Example 1, diethylamine, and DMAc were mixed and stirred at 40° C. (ambient temperature) for 2 hours to prepare a solution.

[0377] A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0378] The resulting solution was then further concentrated to obtain a dope. The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass, and the proportion of diethylamine was 0.06% by mass.

[0379] The initial viscosity of this dope was 3000P, and the viscosity after 24 hours was 2800P, and the viscosity ratio between these was calculated to be 0.93.

[0380] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1. The number average molecular weight of the polymer constituting the fiber (or thread) was 12,000.

[0381] The results, including various evaluations, are shown in the table.

[0382] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the spinnability was significantly improved compared to when the dope (spinning solution) obtained in Reference Example 1 was used, and the physical properties (heat resistance) of the obtained fiber were also significantly superior.

[0383] Although this polyurethane was different from that used in Example 1, it was found to show similar trends. Furthermore, comparison with other Examples suggests that polyurethane in a fibrous form is more advantageous in terms of spinnability and physical properties.

[0384] [Example 14] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), wound body of post-consumer yarn produced by wet spinning method (length approximately 2 mm, fiber diameter (average fiber diameter) 660 μm)] was prepared.

[0385] The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0386] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 2800 P, and the viscosity after 24 hours was measured to be 12000 P, and the viscosity ratio between these values ​​was calculated to be 4.29.

[0387] The number average molecular weight of this polyurethane was 33,000, and there was no peak in the range of molecular weights (number average molecular weight) of 1,000,000 or more.

[0388] Next, the polyurethane and DMAc were mixed and stirred at 23°C (ambient temperature) for 2 hours to prepare a solution. A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0389] The resulting solution was then further concentrated to obtain a dope.

[0390] The concentration of this dope was 35% by mass. The initial viscosity of this dope was 6600P, and the viscosity after 24 hours was 13400P, and the viscosity ratio between these was calculated to be 2.03.

[0391] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0392] The number average molecular weight of the polymer constituting the fiber (or thread) was 34,000.

[0393] The results, including various evaluations, are shown in the table.

[0394] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the physical properties of the resulting fibers were comparable to those of the dope (spinning solution) obtained in Reference Example 1, or were significantly superior in some physical properties (composite durability).

[0395] Comparison with other examples suggests that when the viscosity ratio after 24 hours in a 20% by mass DMAc solution is not too large or when a high molecular weight component is included, it is more advantageous in terms of spinnability and physical properties.

[0396] [Example 15] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), wound body of post-consumer yarn produced by wet spinning method (length approximately 2 mm, fiber diameter (average fiber diameter) 1290 μm)] was prepared. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0397] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 2200 P, and the viscosity after 24 hours was measured to be 8850 P, and the viscosity ratio between these values ​​was calculated to be 4.02.

[0398] The number average molecular weight of this polyurethane was 33,000, with a peak in the molecular weight (number average molecular weight) range of 1,000,000 or more.

[0399] Next, the polyurethane and DMAc were mixed and stirred at 23°C (ambient temperature) for 2 hours to prepare a solution. A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0400] The resulting solution was then further concentrated to obtain a dope.

[0401] The concentration of this dope was 35% by mass. The initial viscosity of this dope was 3020P, and the viscosity after 24 hours was 6450P, and the viscosity ratio was calculated to be 2.14.

[0402] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0403] The number average molecular weight of the polymer constituting the fiber (or thread) was 42,000.

[0404] The results, including various evaluations, are shown in the table.

[0405] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the spinnability was significantly improved compared to when the dope (spinning solution) obtained in Reference Example 1 was used, and the physical properties of the obtained fibers were comparable to those of the dope (spinning solution) or were significantly superior in some physical properties (composite durability).

[0406] Furthermore, comparison with other examples suggests that if the viscosity ratio after 24 hours in a 20% by mass DMAc solution is not too large, it is more advantageous in terms of spinnability and physical properties.

[0407] [Table 1]

[0408] [Example 16] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground post-consumer yarn produced by the dry spinning method (length approximately 2 mm, fiber diameter (average fiber diameter) 220 μm)] was prepared.

[0409] The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0410] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 2900 P, and the viscosity after 24 hours was measured to be 3050 P, and the viscosity ratio between these values ​​was calculated to be 1.05.

[0411] The number-average molecular weight of this polyurethane was 30,000, with a peak in the region of number-average molecular weights of over 1,000,000. The amino group concentration of this polyurethane was 2.2 meq / kg.

[0412] Then, using this polyurethane, a dope was obtained in the same manner as in Reference Example 4.

[0413] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0414] The initial viscosity of this dope was 2600P, and the viscosity after 24 hours was 2800P, and the viscosity ratio between these was calculated to be 1.08.

[0415] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0416] The number average molecular weight of the polymer constituting the fiber (or thread) was 30,000.

[0417] The results, including various evaluations, are shown in the table.

[0418] [Example 17] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground post-consumer yarn produced by the dry spinning method (length approximately 2 mm, fiber diameter (average fiber diameter) 220 μm)] was prepared.

[0419] The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm. The resulting pulverized product was then dissolved (or dispersed) in DMAc and filtered to obtain polyurethane.

[0420] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 2400 P, and the viscosity after 24 hours was measured to be 3070 P, and the viscosity ratio between these values ​​was calculated to be 1.54.

[0421] The number average molecular weight of this polyurethane was 30,000, and there was no peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 0.9 meq / kg.

[0422] Then, using this polyurethane, a dope was obtained in the same manner as in Reference Example 4.

[0423] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0424] The initial viscosity of this dope was 2900P, and the viscosity after 24 hours was 2950P, and the viscosity ratio between these was calculated to be 1.02.

[0425] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0426] The number average molecular weight of the polymer constituting the fiber (or thread) was 28,000.

[0427] The results, including various evaluations, are shown in the table.

[0428] [Example 18] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground wound yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 225 μm)] was prepared.

[0429] The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0430] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 3000 P, and the viscosity after 24 hours was measured to be 3900 P, and the viscosity ratio between these was calculated to be 1.30.

[0431] The number average molecular weight of this polyurethane was 30,500, with a peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 5.5 meq / kg.

[0432] Then, using this polyurethane, a dope was obtained in the same manner as in Reference Example 4. The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0433] The initial viscosity of this dope was 2900P, and the viscosity after 24 hours was 3200P, and the viscosity ratio between these was calculated to be 1.10.

[0434] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0435] The number average molecular weight of the polymer constituting the fiber (or thread) was 33,000.

[0436] The results, including various evaluations, are shown in the table.

[0437] [Example 19] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground wound yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 560 μm)] was prepared.

[0438] The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0439] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 4200 P, and the viscosity after 24 hours was measured to be 6500 P, and the viscosity ratio between these values ​​was calculated to be 1.55.

[0440] The number average molecular weight of this polyurethane was 30,000, with a peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 6.8 meq / kg.

[0441] Next, the 20% by mass DMAc solution of the polyurethane was concentrated under reduced pressure at 60°C to a 35% by mass DMAc solution, and the concentrated solution was mixed with the spinning solution obtained in Reference Example 1 and stirred for 2 hours to prepare a solution (dope).

[0442] A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0443] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0444] The initial viscosity of this dope was 2900P, and the viscosity after 24 hours was 4200P, and the viscosity ratio was calculated to be 1.45.

[0445] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0446] The number average molecular weight of the polymer constituting the fiber (or thread) was 30,000.

[0447] The results, including various evaluations, are shown in the table.

[0448] [Example 20] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground wound yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 560 μm)] was prepared.

[0449] The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0450] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 4100 P, and the viscosity after 24 hours was measured to be 5300 P, and the viscosity ratio between these values ​​was calculated to be 1.29.

[0451] The number average molecular weight of this polyurethane was 30,000, and there was no peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 2.0 meq / kg.

[0452] Next, the 20% by mass DMAc solution of the polyurethane was concentrated under reduced pressure at 60°C to a 35% by mass DMAc solution, and the concentrated solution was mixed with the spinning solution obtained in Reference Example 1 and stirred for 2 hours to prepare a solution (dope).

[0453] A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0454] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0455] The initial viscosity of this dope was 2900P, and the viscosity after 24 hours was 3000P, and the viscosity ratio between these was calculated to be 1.03.

[0456] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0457] The number average molecular weight of the polymer constituting the fiber (or thread) was 29,000.

[0458] The results, including various evaluations, are shown in the table.

[0459] [Example 21] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground wound yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 560 μm)] was prepared.

[0460] The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0461] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 4100 P, and the viscosity after 24 hours was measured to be 6500 P, and the viscosity ratio between these values ​​was calculated to be 1.59.

[0462] The number average molecular weight of this polyurethane was 30,000, and there was no peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 6.8 meq / kg.

[0463] Next, the 20% by mass DMAc solution of the polyurethane was concentrated under reduced pressure at 60°C to a 35% by mass DMAc solution, and the concentrated solution was mixed with the spinning solution obtained in Reference Example 1 and stirred for 2 hours to prepare a solution (dope).

[0464] A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0465] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0466] The initial viscosity of this dope was 2900P, and the viscosity after 24 hours was 3000P, and the viscosity ratio between these was calculated to be 1.03.

[0467] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0468] The number average molecular weight of the polymer constituting the fiber (or thread) was 29,000.

[0469] The results, including various evaluations, are shown in the table.

[0470] [Example 22] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground wound yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 560 μm)] was prepared.

[0471] The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0472] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 4100 P, and the viscosity after 24 hours was measured to be 6500 P, and the viscosity ratio between these values ​​was calculated to be 1.59.

[0473] The number average molecular weight of this polyurethane was 30,000, and there was no peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 19.8 meq / kg.

[0474] Next, the 20% by mass DMAc solution of the polyurethane was concentrated under reduced pressure at 60°C to a 35% by mass DMAc solution, and the concentrated solution was mixed with the spinning solution obtained in Reference Example 1 and stirred for 2 hours to prepare a solution (dope).

[0475] A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0476] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0477] The initial viscosity of this dope was 3050P, and the viscosity after 24 hours was 4300P, and the viscosity ratio was calculated to be 1.41.

[0478] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0479] The number average molecular weight of the polymer constituting the fiber (or thread) was 29,000.

[0480] The results, including various evaluations, are shown in the table.

[0481] [Example 23] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground wound yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 560 μm)] was prepared.

[0482] The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0483] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 4100 P, and the viscosity after 24 hours was measured to be 6500 P, and the viscosity ratio between these values ​​was calculated to be 1.59.

[0484] The number average molecular weight of this polyurethane was 30,000, and there was no peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 28.5 meq / kg.

[0485] Next, the 20% by mass DMAc solution of the polyurethane was concentrated under reduced pressure at 60°C to a 35% by mass DMAc solution, and the concentrated solution was mixed with the spinning solution obtained in Reference Example 1 and stirred for 2 hours to prepare a solution (dope).

[0486] A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0487] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0488] The initial viscosity of this dope was 3500P, and the viscosity after 24 hours was 4400P, and the viscosity ratio was calculated to be 1.26.

[0489] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0490] The number average molecular weight of the polymer constituting the fiber (or thread) was 29,000.

[0491] The results, including various evaluations, are shown in the table.

[0492] [Example 24] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 1265 μm)] was prepared. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0493] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 2900 P, and the viscosity after 24 hours was measured to be 8600 P, and the viscosity ratio between these values ​​was calculated to be 2.97.

[0494] The number average molecular weight of this polyurethane was 29,000, with a peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 7.2 meq / kg.

[0495] Next, the 20% by mass DMAc solution of the polyurethane was concentrated under reduced pressure at 80° C. to a 35% by mass DMAc solution, and mixed with the spinning dope obtained in Reference Example 1 to prepare a solution (dope). A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0496] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0497] The initial viscosity of this dope was 2680P, and the viscosity after 24 hours was 3800P, and the viscosity ratio was calculated to be 1.42.

[0498] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0499] The number average molecular weight of the polymer constituting the fiber (or thread) was 29,000.

[0500] The results, including various evaluations, are shown in the table.

[0501] [Example 25] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 1265 μm)] was prepared. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0502] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 2900 P, and the viscosity after 24 hours was measured to be 8300 P, and the viscosity ratio between these was calculated to be 2.86.

[0503] The number average molecular weight of this polyurethane was 29,000, and there was no peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 0.5 meq / kg.

[0504] Next, the 20% by mass DMAc solution of the polyurethane was concentrated under reduced pressure at 80° C. to a 35% by mass DMAc solution, and mixed with the spinning dope obtained in Reference Example 1 to prepare a solution (dope). A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0505] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0506] The initial viscosity of this dope was 2680P, and the viscosity after 24 hours was 3800P, and the viscosity ratio was calculated to be 1.42.

[0507] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0508] The number average molecular weight of the polymer constituting the fiber (or thread) was 29,000.

[0509] The results, including various evaluations, are shown in the table.

[0510] [Example 26] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 1265 μm)] was prepared. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0511] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 3000 P, and the viscosity after 24 hours was measured to be 8600 P, and the viscosity ratio between these values ​​was calculated to be 2.87.

[0512] The number average molecular weight of this polyurethane was 29,000, and there was no peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 2.0 meq / kg.

[0513] Next, the 20% by mass DMAc solution of the polyurethane was concentrated under reduced pressure at 80° C. to a 35% by mass DMAc solution, and mixed with the spinning dope obtained in Reference Example 1 to prepare a solution (dope). A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0514] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0515] The initial viscosity of this dope was 2750P, and the viscosity after 24 hours was 3800P, and the viscosity ratio between these was calculated to be 1.38.

[0516] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0517] The number average molecular weight of the polymer constituting the fiber (or thread) was 29,000.

[0518] The results, including various evaluations, are shown in the table.

[0519] [Example 27] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 1265 μm)] was prepared. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0520] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 3100 P, and the viscosity after 24 hours was measured to be 8600 P, and the viscosity ratio between these was calculated to be 2.77.

[0521] The number average molecular weight of this polyurethane was 29,000, and there was no peak in the range of molecular weights (number average molecular weights) of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 12.4 meq / kg.

[0522] Next, the 20% by mass DMAc solution of the polyurethane was concentrated under reduced pressure at 80° C. to a 35% by mass DMAc solution, and mixed with the spinning dope obtained in Reference Example 1 to prepare a solution (dope). A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0523] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0524] The initial viscosity of this dope was 2800P, and the viscosity after 24 hours was 3800P, and the viscosity ratio was calculated to be 1.36.

[0525] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0526] The number average molecular weight of the polymer constituting the fiber (or thread) was 29,000.

[0527] The results, including various evaluations, are shown in the table.

[0528] [Example 28] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 1265 μm)] was prepared. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0529] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 3100 P, and the viscosity after 24 hours was measured to be 8750 P, and the viscosity ratio between these values ​​was calculated to be 2.82.

[0530] The number average molecular weight of this polyurethane was 29,000, and there was no peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 20.2 meq / kg.

[0531] Next, the 20% by mass DMAc solution of the polyurethane was concentrated under reduced pressure at 80° C. to a 35% by mass DMAc solution, and mixed with the spinning dope obtained in Reference Example 1 to prepare a solution (dope). A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0532] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0533] The initial viscosity of this dope was 2900P, and the viscosity after 24 hours was 3800P, and the viscosity ratio between these was calculated to be 1.31.

[0534] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0535] The number average molecular weight of the polymer constituting the fiber (or thread) was 29,000.

[0536] The results, including various evaluations, are shown in the table.

[0537] [Example 29] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 1265 μm)] was prepared. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0538] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 3200 P, and the viscosity after 24 hours was measured to be 8800 P, and the viscosity ratio between these values ​​was calculated to be 2.75.

[0539] The number average molecular weight of this polyurethane was 29,000, and there was no peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 25.9 meq / kg.

[0540] Next, the 20% by mass DMAc solution of the polyurethane was concentrated under reduced pressure at 80° C. to a 35% by mass DMAc solution, and mixed with the spinning dope obtained in Reference Example 1 to prepare a solution (dope). A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0541] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0542] The initial viscosity of this dope was 2850P, and the viscosity after 24 hours was 3800P, and the viscosity ratio between these was calculated to be 1.33.

[0543] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0544] The number average molecular weight of the polymer constituting the fiber (or thread) was 29,000.

[0545] The results, including various evaluations, are shown in the table.

[0546] [Example 30] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground wound yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 1205 μm)] was prepared. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0547] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 4200 P, and the viscosity after 24 hours was measured to be 10500 P, and the viscosity ratio between these values ​​was calculated to be 2.50.

[0548] The number average molecular weight of this polyurethane was 28,000, with a peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 7.7 meq / kg.

[0549] Next, the polyurethane, the spinning dope obtained in Reference Example 1, and diethylamine were mixed and stirred for 2 hours to prepare a solution (dope).

[0550] A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0551] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass, and the proportion of diethylamine was 0.2% by mass.

[0552] The initial viscosity of this dope was 3300P, and the viscosity after 24 hours was 4300P, and the viscosity ratio between these was calculated to be 1.30.

[0553] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0554] The number average molecular weight of the polymer constituting the fiber (or thread) was 44,000.

[0555] The results, including various evaluations, are shown in the table.

[0556] [Example 31] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground wound yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 1245 μm)] was prepared. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0557] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 4200 P, and the viscosity after 24 hours was measured to be 6600 P, and the viscosity ratio between these values ​​was calculated to be 1.57.

[0558] The number average molecular weight of this polyurethane was 30,000, with a peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 6.5 meq / kg.

[0559] Next, 98 parts by mass of a 20% by mass DMAc solution of the polyurethane was mixed with 2 parts by mass of a 20% by mass DMAc solution of a surfactant (polyoxyethylene styrenated phenyl ether) to prepare a solution, which was then mixed with the spinning dope obtained in Reference Example 1.

[0560] A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0561] The resulting solution was then further concentrated to obtain a dope.

[0562] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass, and the proportion of the surfactant was 0.6% by mass.

[0563] The initial viscosity of this dope was 3300P, and the viscosity after 24 hours was 4300P, and the viscosity ratio between these was calculated to be 1.30.

[0564] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0565] The number average molecular weight of the polymer constituting the fiber (or thread) was 40,000.

[0566] The results, including various evaluations, are shown in the table.

[0567] [Example 32] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground wound yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 1245 μm)] was prepared. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0568] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 4200P, and the viscosity after 24 hours was measured to be 9200P, and the viscosity ratio between these values ​​was calculated to be 2.19.

[0569] The number average molecular weight of this polyurethane was 30,000, and there was no peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 6.5 meq / kg.

[0570] Next, 98 parts by mass of a 20% by mass DMAc solution of the polyurethane was mixed with 2 parts by mass of a 20% by mass DMAc solution of a surfactant (polyoxyethylene styrenated phenyl ether) to prepare a solution, which was then mixed with the spinning dope obtained in Reference Example 1.

[0571] A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0572] The resulting solution was then further concentrated to obtain a dope.

[0573] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass, and the proportion of the surfactant was 0.6% by mass.

[0574] The initial viscosity of this dope was 3300P, and the viscosity after 24 hours was 4300P, and the viscosity ratio between these was calculated to be 1.30.

[0575] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0576] The number average molecular weight of the polymer constituting the fiber (or thread) was 40,000.

[0577] The results, including various evaluations, are shown in the table.

[0578] [Example 33] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground wound yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 1245 μm)] was prepared. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0579] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 4400 P, and the viscosity after 24 hours was measured to be 15200 P, and the viscosity ratio between these values ​​was calculated to be 3.45.

[0580] The number average molecular weight of this polyurethane was 30,000, and there was no peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 6.6 meq / kg.

[0581] Next, 98 parts by mass of a 20% by mass DMAc solution of the polyurethane was mixed with 2 parts by mass of a 20% by mass DMAc solution of a surfactant (polyoxyethylene styrenated phenyl ether) to prepare a solution, which was then mixed with the spinning dope obtained in Reference Example 1.

[0582] A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0583] The resulting solution was then further concentrated to obtain a dope.

[0584] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass, and the proportion of the surfactant was 0.6% by mass.

[0585] The initial viscosity of this dope was 3300P, and the viscosity after 24 hours was 4300P, and the viscosity ratio between these was calculated to be 1.30.

[0586] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0587] The number average molecular weight of the polymer constituting the fiber (or thread) was 40,000.

[0588] The results, including various evaluations, are shown in the table.

[0589] [Example 34] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground wound yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 1245 μm)] was prepared. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0590] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 4400 P, and the viscosity after 24 hours was measured to be 18400 P, and the viscosity ratio between these values ​​was calculated to be 4.18.

[0591] The number average molecular weight of this polyurethane was 30,000, and there was no peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 7.5 meq / kg.

[0592] Next, 98 parts by mass of a 20% by mass DMAc solution of the polyurethane was mixed with 2 parts by mass of a 20% by mass DMAc solution of a surfactant (polyoxyethylene styrenated phenyl ether) to prepare a solution, which was then mixed with the spinning dope obtained in Reference Example 1.

[0593] A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0594] The resulting solution was then further concentrated to obtain a dope.

[0595] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass, and the proportion of the surfactant was 0.6% by mass.

[0596] The initial viscosity of this dope was 3300P, and the viscosity after 24 hours was 4300P, and the viscosity ratio between these was calculated to be 1.30.

[0597] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0598] The number average molecular weight of the polymer constituting the fiber (or thread) was 40,000.

[0599] The results, including various evaluations, are shown in the table.

[0600] [Example 35] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground wound yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 1222 μm)] was prepared.

[0601] The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0602] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 2800 P, and the viscosity after 24 hours was measured to be 9000 P, and the viscosity ratio between these values ​​was calculated to be 3.21.

[0603] The number average molecular weight of this polyurethane was 33,000, with a peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 11.2 meq / kg.

[0604] Next, the polyurethane, the spinning dope obtained in Reference Example 1, and a 20 mass % DMAc solution of a hindered phenol-based antioxidant {ethylene-1,2-bis(3,3-bis[3-t-butyl-4-hydroxyphenyl]butyrate)} were mixed to prepare a solution.

[0605] A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0606] The resulting solution was then further concentrated to obtain a dope.

[0607] The concentration of this dope was 35% by mass, with the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope being 30% by mass and the proportion of the hindered phenol-based antioxidant being 1.0% by mass.

[0608] The initial viscosity of this dope was 4200P, and the viscosity after 24 hours was 8080P, and the viscosity ratio was calculated to be 1.92.

[0609] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0610] The number average molecular weight of the polymer constituting the fiber (or thread) was 34,000.

[0611] The results, including various evaluations, are shown in the table.

[0612] [Example 36] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground wound yarn produced by dry spinning (length approximately 2 mm, fiber diameter (average fiber diameter) 660 μm)] was prepared.

[0613] The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0614] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 2800 P, and the viscosity after 24 hours was measured to be 9000 P, and the viscosity ratio between these values ​​was calculated to be 3.21.

[0615] The number average molecular weight of this polyurethane was 33,000, with a peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 11.2 meq / kg.

[0616] Next, a hindered phenol-based antioxidant {ethylene-1,2-bis(3,3-bis[3-t-butyl-4-hydroxyphenyl]butyrate)} and a 20% by mass solution of ethylenediamine in DMAc were mixed with the polyurethane to prepare a solution (dope). A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0617] The concentration of this dope was 35% by mass (including 0.7% by mass of the hindered phenol-based antioxidant and 0.07% by mass of the ethylenediamine).

[0618] The initial viscosity of this dope was 7200P, and the viscosity after 24 hours was 12100P, and the viscosity ratio between these was calculated to be 1.68.

[0619] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0620] The number average molecular weight of the polymer constituting the fiber (or thread) was 53,000.

[0621] The results, including various evaluations, are shown in the table.

[0622] [Example 37] A polyurethane urea resin molded product (RIM molded product) [a pulverized product (granular, particle diameter of approximately 0.1 to 2 mm) of a polyurethane urea composition (PTMG, MDI, EDA)] was prepared. The crushing was carried out using a three-blade helical cutting type crusher.

[0623] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 2900 P, and the viscosity after 24 hours was measured to be 3200 P. The viscosity ratio was calculated to be 1.10. The amino group concentration of this polyurethane was also found to be 3.7 meq / kg.

[0624] Next, the polyurethane, the spinning dope obtained in Reference Example 1, diethylamine, and DMAc were mixed and stirred at 40° C. (ambient temperature) for 2 hours to prepare a solution.

[0625] A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0626] The resulting solution was then further concentrated to obtain a dope. The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass, and the proportion of diethylamine was 0.06% by mass.

[0627] The initial viscosity of this dope was 3000P, and the viscosity after 24 hours was 2800P, and the viscosity ratio between these was calculated to be 0.93.

[0628] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1. The number average molecular weight of the polymer constituting the fiber (or thread) was 12,000.

[0629] The results, including various evaluations, are shown in the table.

[0630] [Example 38] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), wound body of post-consumer yarn produced by wet spinning method (length approximately 2 mm, fiber diameter (average fiber diameter) 660 μm)] was prepared.

[0631] The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0632] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 2800 P, and the viscosity after 24 hours was measured to be 12000 P, and the viscosity ratio between these values ​​was calculated to be 4.29.

[0633] The number average molecular weight of this polyurethane was 33,000, with no peak in the region of number average molecular weights of 1,000,000 or more. The amino group concentration of this polyurethane was 14.8 meq / kg.

[0634] Next, the polyurethane and DMAc were mixed and stirred at 23°C (ambient temperature) for 2 hours to prepare a solution. A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0635] The resulting solution was then further concentrated to obtain a dope.

[0636] The concentration of this dope was 35% by mass. The initial viscosity of this dope was 6600P, and the viscosity after 24 hours was 13400P, and the viscosity ratio between these was calculated to be 2.03.

[0637] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0638] The number average molecular weight of the polymer constituting the fiber (or thread) was 34,000.

[0639] The results, including various evaluations, are shown in the table.

[0640] [Example 39] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), wound body of post-consumer yarn produced by wet spinning method (length approximately 2 mm, fiber diameter (average fiber diameter) 1290 μm)] was prepared. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm.

[0641] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 2200 P, and the viscosity after 24 hours was measured to be 8850 P, and the viscosity ratio between these values ​​was calculated to be 4.02.

[0642] The number average molecular weight of this polyurethane was 33,000, with a peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 7.1 meq / kg.

[0643] Next, the polyurethane and DMAc were mixed and stirred at 23°C (ambient temperature) for 2 hours to prepare a solution. A cylindrical vessel was used for stirring, and a helical ribbon stirring blade was used, which covered 85% of the projected outer diameter of the vessel bottom.

[0644] The resulting solution was then further concentrated to obtain a dope.

[0645] The concentration of this dope was 35% by mass. The initial viscosity of this dope was 3020P, and the viscosity after 24 hours was 6450P, and the viscosity ratio was calculated to be 2.14.

[0646] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0647] The number average molecular weight of the polymer constituting the fiber (or thread) was 42,000.

[0648] [Examples 40 to 52] A fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground post-consumer yarn produced by the dry spinning method (length approximately 2 mm, fiber diameter (average fiber diameter) 220 μm)] was prepared.

[0649] The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm. The resulting pulverized product was then dissolved (or dispersed) in DMAc and filtered to obtain polyurethane.

[0650] This polyurethane was further treated by dissolving (or dispersing) it in DMAc, followed by adding a predetermined amount of a primary amine, adding a predetermined amount of a secondary amine, heating (adjusting temperature and heating time), stirring (adjusting stirring speed and stirring time), or a combination of these, to obtain various polyurethanes (A) shown in the table. The physical properties of each polyurethane (A) are as shown in the table.

[0651] Using each of these polyurethanes (A), the dopes shown in the table were obtained in the same manner as in Reference Example 4.

[0652] The concentration of each dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass. The physical properties of each dope are as shown in the table.

[0653] Then, each dope was used to obtain dry-spun fibers in the same manner as in Reference Example 1. The number average molecular weights of the polymers constituting the fibers (or yarns) were as shown in the table.

[0654] The results, including various evaluations, are shown in the table.

[0655] [Table 2]

[0656] [Table 3]

[0657] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the spinnability was improved compared to when the dope (spinning solution) obtained in Reference Example 1 was used, and the physical properties of the obtained fibers were comparable to or even superior to those of the dope (spinning solution) obtained in Reference Example 1. This tendency can also be easily achieved by using a polyurethane (A) having amino groups, and is particularly notable in polyurethanes (A) having a specific proportion of amino groups [a proportion that is not too small and / or not too large (particularly, not too small and not too large)] (particularly, polyurethanes (A) having the above V2 / V1 combination). Furthermore, by using polyurethane (A) having such amino groups at a specific ratio, it is possible to significantly improve spinnability even if polyurethane (A) does not have a peak at a molecular weight of 1,000,000 or more, and it is possible to obtain exceptionally excellent results in terms of physical properties of the obtained fiber.

[0658] [Example 53] The dry-spun fibers (elastic polyurethane fibers) obtained in Reference Example 1 were pulverized within one week to obtain fibrous polyurethane [length: approximately 2 mm, fiber diameter (average fiber diameter): 52 μm]. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm. The resulting fibrous polyurethane was then dissolved in DMAc at 80°C for 6 hours. The dissolution equipment used was a torque meter, a spiral stirring blade, and a glass double tube equipped with an independent heat medium heater unit using a mixture of triethylene glycol and water as a heat medium, and a refrigerant chiller unit.

[0659] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 3200 P, and the viscosity after 24 hours was measured to be 2950 P, and the viscosity ratio between these values ​​was calculated to be 0.92.

[0660] The number average molecular weight of this polyurethane was 25,500, and there was no peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 25 meq / kg.

[0661] Then, using this polyurethane, a dope was obtained in the same manner as in Reference Example 4.

[0662] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0663] The initial viscosity of this dope was 2600P, and the viscosity after 24 hours was 2900P, and the viscosity ratio between these was calculated to be 1.12.

[0664] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0665] The number average molecular weight of the polymer constituting the fiber (or thread) was 30,000.

[0666] The results, including various evaluations, are shown in the table.

[0667] [Example 54] The dry-spun fiber (elastic polyurethane fiber) obtained in Reference Example 1 was placed in a thermo-hygrostat and aged at 50°C and 60% RH (relative humidity) for 4 weeks. Next, the dry-spun fibers after aging were crushed within one week to obtain fibrous polyurethane [length: approximately 2 mm, average fiber diameter: 55 μm]. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm. The resulting fibrous polyurethane was then dissolved in DMAc at 80°C for 6 hours. The dissolution equipment used was a torque meter, a spiral stirring blade, and a glass double tube equipped with an independent heat medium heater unit using a mixture of triethylene glycol and water as a heat medium, and a refrigerant chiller unit.

[0668] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 4000 P, and the viscosity after 24 hours was measured to be 4650 P, and the viscosity ratio between these values ​​was calculated to be 1.16.

[0669] The number average molecular weight of this polyurethane was 30,000, with a peak in the molecular weight (number average molecular weight) range of 1 million or more. Furthermore, the amino group concentration of this polyurethane was 11 meq / kg.

[0670] Then, using this polyurethane, a dope was obtained in the same manner as in Reference Example 4.

[0671] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0672] The initial viscosity of this dope was 2900P, and the viscosity after 24 hours was 4400P, and the viscosity ratio was calculated to be 1.52.

[0673] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0674] The number average molecular weight of the polymer constituting the fiber (or thread) was 30,000.

[0675] The results, including various evaluations, are shown in the table.

[0676] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the spinnability was significantly improved compared to when the dope (spinning solution) containing the polyurethane obtained in Example 53 was used, and the physical properties (breaking elongation, heat resistance, composite durability) of the obtained fiber were significantly superior.

[0677] [Example 55] The dry-spun fiber (elastic polyurethane fiber) obtained in Reference Example 1 was placed in a thermo-hygrostat and aged at 50°C and 60% RH (relative humidity) for 12 weeks. Next, the dry-spun fibers after aging were crushed within one week to obtain fibrous polyurethane [length: approximately 2 mm, average fiber diameter: 56 μm]. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm. The resulting fibrous polyurethane was then dissolved in DMAc at 80°C for 6 hours. The dissolution equipment used was a torque meter, a spiral stirring blade, and a glass double tube equipped with an independent heat medium heater unit using a mixture of triethylene glycol and water as a heat medium, and a refrigerant chiller unit.

[0678] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 3600 P, and the viscosity after 24 hours was measured to be 8500 P, and the viscosity ratio between these was calculated to be 2.36.

[0679] The number average molecular weight of this polyurethane was 31,000, with a peak in the molecular weight (number average molecular weight) range of 1 million or more. Furthermore, the amino group concentration of this polyurethane was 4 meq / kg.

[0680] Then, using this polyurethane, a dope was obtained in the same manner as in Reference Example 4.

[0681] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0682] The initial viscosity of this dope was 2800P, and the viscosity after 24 hours was 4500P, and the viscosity ratio was calculated to be 1.61.

[0683] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0684] The number average molecular weight of the polymer constituting the fiber (or thread) was 31,000.

[0685] The results, including various evaluations, are shown in the table.

[0686] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the spinnability was significantly improved compared to when the dope (spinning solution) containing the polyurethane obtained in Example 53 was used, and the physical properties (breaking strength, heat resistance, composite durability) of the obtained fibers were significantly superior.

[0687] [Example 56] The dry-spun fiber (elastic polyurethane fiber) obtained in Reference Example 1 was placed in a thermo-hygrostat and aged at 50°C and 60% RH (relative humidity) for 4 weeks. Next, the dry-spun fibers after aging were crushed within one week to obtain fibrous polyurethane [length: approximately 2 mm, average fiber diameter: 54 μm]. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm. The resulting fibrous polyurethane was dissolved in DMAc at 80°C for 6 hours, then rapidly cooled to 23°C, and stirred for 24 hours. The dissolution equipment used was a torque meter, a spiral stirring blade, and a glass double tube equipped with an independent heat medium heater unit using a mixture of triethylene glycol and water as a heat medium, and a refrigerant chiller unit.

[0688] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 4600 P, and the viscosity after 24 hours was measured to be 8800 P, and the viscosity ratio between these values ​​was calculated to be 1.91.

[0689] The number average molecular weight of this polyurethane was 30,000, with a peak in the molecular weight (number average molecular weight) range of 1 million or more. Furthermore, the amino group concentration of this polyurethane was 11 meq / kg.

[0690] Then, using this polyurethane, a dope was obtained in the same manner as in Reference Example 4.

[0691] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0692] The initial viscosity of this dope was 2900P, and the viscosity after 24 hours was 4400P, and the viscosity ratio was calculated to be 1.52.

[0693] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0694] The number average molecular weight of the polymer constituting the fiber (or thread) was 30,000.

[0695] The results, including various evaluations, are shown in the table.

[0696] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the spinnability was significantly improved compared to when the dope (spinning solution) containing the polyurethane obtained in Example 53 was used, and the physical properties (breaking strength, breaking elongation, heat resistance, and composite durability) of the obtained fiber were significantly superior.

[0697] [Example 57] The dry-spun fiber (elastic polyurethane fiber) obtained in Reference Example 1 was placed in a thermo-hygrostat and aged at 50°C and 60% RH (relative humidity) for 4 weeks. Next, the dry-spun fibers after aging were crushed within one week to obtain fibrous polyurethane [length: approximately 2 mm, average fiber diameter: 54 μm]. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm. The resulting fibrous polyurethane was dissolved in DMAc at 80°C for 6 hours, then rapidly cooled to 23°C, and stirring and circulating filtering (filtering conditions: controlled to have a pressure drop of 1 MPa, circulation conditions: flow rate controlled so that the replacement rate of the contents was 100% / hour) were continued for 24 hours. The dissolving and circulating filtering equipment is a triple pipe with a vertical agitator shaft equipped with a torque meter, a spiral agitator blade, and an independent heat medium heater unit and refrigerant chiller unit, each using a mixture of triethylene glycol and water as the heat medium. Furthermore, the triple pipe is equipped with a circulation piping (circulation filtering unit) outside the triple pipe. The circulation piping is equipped with a pump that circulates the material from the bottom of the pipe to the top of the pipe, and a sintered metal filter.

[0698] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 4000 P, and the viscosity after 24 hours was measured to be 6500 P, and the viscosity ratio between these values ​​was calculated to be 1.63.

[0699] The number average molecular weight of this polyurethane was 30,000, with a peak in the molecular weight (number average molecular weight) range of 1 million or more. Furthermore, the amino group concentration of this polyurethane was 11 meq / kg.

[0700] Then, using this polyurethane, a dope was obtained in the same manner as in Reference Example 4.

[0701] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0702] The initial viscosity of this dope was 3100P, and the viscosity after 24 hours was 4500P, and the viscosity ratio between these was calculated to be 1.45.

[0703] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0704] The number average molecular weight of the polymer constituting the fiber (or thread) was 30,000.

[0705] The results, including various evaluations, are shown in the table.

[0706] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the spinnability was significantly improved compared to when the dope (spinning solution) containing the polyurethane obtained in Example 53 was used, and the physical properties (breaking strength, breaking elongation, heat resistance, and composite durability) of the obtained fiber were significantly superior.

[0707] [Example 58] The dry-spun fiber (elastic polyurethane fiber) obtained in Reference Example 1 was placed in a thermo-hygrostat and aged at 50°C and 60% RH (relative humidity) for 4 weeks. Next, the dry-spun fibers after aging were crushed within one week to obtain fibrous polyurethane [length: approximately 2 mm, average fiber diameter: 55 μm]. The crushing was carried out using a three-blade helical cutting crusher until the size became 2 mm. The resulting fibrous polyurethane was then dissolved in DMAc, and an amine mixture (a mixture of ethylenediamine, diethylenetriamine, and diethylamine with a target amino group concentration of 25 meq) was added dropwise while monitoring the stirring shaft torque meter so that the target V2 / V1 value was set to 2.00. After 6 hours at 80°C, the mixture was rapidly cooled to 23°C, and stirring and circulation filtering (filtering conditions: controlled to have a pressure drop of 1 MPa, circulation conditions: flow rate controlled so that the replacement of the contents was 100% / hour) were continued for 24 hours. The dissolving, circulating filtering, and dripping equipment is a triple pipe with a vertical agitator shaft, equipped with an agitator shaft torque meter, a spiral agitator blade, and independent heat medium heater and refrigerant chiller units, each using a mixture of triethylene glycol and water as the heat medium. It also includes a circulation pipe (circulating filtering unit) outside the triple pipe, an amine mixture dripping unit, and a condenser at the top outside of the triple pipe to trap volatile substances (mainly added amines) inside the triple pipe. The circulation pipe is equipped with a pump that circulates the material from the bottom of the pipe to the ceiling, and a sintered metal filter. The condenser passes a -10°C refrigerant.

[0708] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 3900 P, and the viscosity after 24 hours was measured to be 8000 P, and the viscosity ratio between these values ​​was calculated to be 2.05.

[0709] The number average molecular weight of this polyurethane was 29,000, with a peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 24 meq / kg.

[0710] Then, using this polyurethane, a dope was obtained in the same manner as in Reference Example 4.

[0711] The concentration of this dope was 35% by mass, and the proportion of the polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass.

[0712] The initial viscosity of this dope was 2800P, and the viscosity after 24 hours was 4500P, and the viscosity ratio was calculated to be 1.61.

[0713] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0714] The number average molecular weight of the polymer constituting the fiber (or thread) was 28,500.

[0715] The results, including various evaluations, are shown in the table.

[0716] As is clear from the table, when the dope (spinning solution) containing the polyurethane was used, the spinnability was significantly improved compared to when the dope (spinning solution) containing the polyurethane obtained in Example 53 was used, and the physical properties of the resulting fibers (breaking strength, breaking elongation, heat resistance, composite durability, and yellowing resistance) were significantly superior.

[0717] [Example 59] Polyurethane, dope and dry-spun fiber (elastic polyurethane fiber) were obtained in the same manner as in Example 53, except that the molar ratio of 4,4'-MDI to 2,4'-MDI in Reference Example 1 was changed from 97:3 to 99:1.

[0718] The initial viscosity of the polyurethane in a 20% by mass DMAc solution was measured to be 5500 P, and the viscosity after 24 hours was measured to be 7000 P, and the viscosity ratio between these was calculated to be 1.27.

[0719] The number average molecular weight of the polyurethane was 27,000, and there was no peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 25 meq / kg.

[0720] The initial viscosity of the dope was 2800P, and the viscosity after 24 hours was 4500P, and the viscosity ratio between these was calculated to be 1.61.

[0721] Furthermore, the number average molecular weight of the polymer constituting the dry-spun fiber (or yarn) was 30,000.

[0722] The results, including various evaluations, are shown in the table.

[0723] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the spinnability and the properties of the resulting fiber were significantly superior to those when the dope (spinning solution) containing the polyurethane obtained in Example 53 was used.

[0724] [Example 60] Polyurethane, dope and dry-spun fiber (elastic polyurethane fiber) were obtained in the same manner as in Example 58, except that the molar ratio of 4,4'-MDI to 2,4'-MDI in Reference Example 1 was changed from 97:3 to 99:1.

[0725] The initial viscosity of the polyurethane in a 20% by mass DMAc solution was measured to be 3800P, and the viscosity after 24 hours was measured to be 7700P, and the viscosity ratio between these values ​​was calculated to be 2.03.

[0726] The number average molecular weight of the polyurethane was 29,000, and there was a peak in the molecular weight (number average molecular weight) range of 1 million or more. Furthermore, the amino group concentration of this polyurethane was 25 meq / kg.

[0727] The initial viscosity of the dope was 2800P, and the viscosity after 24 hours was 4300P, and the viscosity ratio between these was calculated to be 1.54.

[0728] Furthermore, the number average molecular weight of the polymer constituting the dry-spun fiber (or yarn) was 29,000.

[0729] The results, including various evaluations, are shown in the table.

[0730] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the spinnability and the properties of the resulting fiber were significantly superior to those when the dope (spinning solution) containing the polyurethane obtained in Example 53 was used.

[0731] [Example 61] Polyurethane, dope and dry-spun fiber (elastic polyurethane fiber) were obtained in the same manner as in Example 53, except that the molar ratio of 4,4'-MDI to 2,4'-MDI in Reference Example 1 was changed from 97:3 to 99.9:0.1.

[0732] The initial viscosity of the polyurethane in a 20% by mass DMAc solution was measured to be 11,000 P, and the viscosity after 24 hours was measured to be 12,500 P, and the viscosity ratio between these values ​​was calculated to be 1.14.

[0733] The number average molecular weight of the polyurethane was 27,000, and there was no peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 25 meq / kg.

[0734] The initial viscosity of the dope was 3000P, and the viscosity after 24 hours was 4200P, and the viscosity ratio was calculated to be 1.40.

[0735] Furthermore, the number average molecular weight of the polymer constituting the dry-spun fiber (or yarn) was 36,000.

[0736] The results, including various evaluations, are shown in the table.

[0737] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the spinnability and the properties of the resulting fiber were significantly superior to those when the dope (spinning solution) containing the polyurethane obtained in Example 53 was used.

[0738] [Example 62] Polyurethane, dope and dry-spun fiber (elastic polyurethane fiber) were obtained in the same manner as in Example 58, except that the molar ratio of 4,4'-MDI to 2,4'-MDI in Reference Example 1 was changed from 97:3 to 99.9:0.1.

[0739] The initial viscosity of the polyurethane in a 20% by mass DMAc solution was measured to be 6600 P, and the viscosity after 24 hours was measured to be 13500 P, and the viscosity ratio between these was calculated to be 2.05.

[0740] The number average molecular weight of the polyurethane was 29,000, and there was a peak in the molecular weight (number average molecular weight) range of 1 million or more. Furthermore, the amino group concentration of this polyurethane was 25 meq / kg.

[0741] The initial viscosity of the dope was 3000P, and the viscosity after 24 hours was 4500P, and the viscosity ratio between these was calculated to be 1.50.

[0742] Furthermore, the number average molecular weight of the polymer constituting the dry-spun fiber (or yarn) was 31,000.

[0743] The results, including various evaluations, are shown in the table.

[0744] As is clear from the table, when the dope (spinning solution) containing the above polyurethane was used, the spinnability and the properties of the resulting fiber were significantly superior to those when the dope (spinning solution) containing the polyurethane obtained in Example 53 was used.

[0745] [Example 63] We prepared DCY (double-covered yarn) by covering nylon yarn with polyurethane yarn [polyurethane composition (modified PTMG consisting of 3-methyltetrahydrofuran-tetrahydrofuran (THF) copolymer with a molecular weight of 3500, MDI, a mixed diamine consisting of EDA and 1,3-propanediamine (PDA)] that had been left at room temperature for two years.The DCY was removed from the paper tube and immersed in DMAc at a bath ratio of 50 to extract the polyurethane components. After measuring the solid content concentration, the solution was concentrated to obtain a polyurethane (solution). The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 12,000 P, and the viscosity after 24 hours was measured to be 11,600 P, and the viscosity ratio between these values ​​was calculated to be 0.97.

[0746] The number average molecular weight of this polyurethane was 92,000, and there was a peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 3 meq / kg.

[0747] Next, this polyurethane was further blended in a proportion of 10% by mass into the dope obtained in Example 45 to obtain a dope.

[0748] The initial viscosity of this dope was 3000P, and the viscosity after 24 hours was 3800P, and the viscosity ratio between these was calculated to be 1.28.

[0749] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0750] The number average molecular weight of the polymer constituting the fiber (or thread) was 33,000.

[0751] The results, including various evaluations, are shown in the table.

[0752] [Example 64] The polyurethane obtained in Example 62 was placed in the same triple-pipe apparatus as in Example 58 and dissolved in DMAc. An amine mixture (a mixture of monoethanolamine, diethylamine, and triethylenediamine with a target amino group concentration of 20 meq) was added dropwise at 100°C while monitoring the stirring shaft torque meter so that the target V2 / V1 value was set to 1.4. When the stirring shaft torque reached a value equivalent to 3000 P (40°C) (which took approximately 6 hours), the mixture was rapidly cooled to 23°C, and stirring and circulation filtering (filtering conditions: controlled to have a pressure drop of 1 MPa; circulation conditions: flow rate controlled so that the replacement of the contents was 100% / hour) were continued for 24 hours.

[0753] The initial viscosity of this polyurethane in a 20% by mass DMAc solution was measured to be 3100 P, and the viscosity after 24 hours was measured to be 4200 P, and the viscosity ratio between these values ​​was calculated to be 1.35.

[0754] The number average molecular weight of this polyurethane was 31,000, with no peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 20 meq / kg.

[0755] Next, this polyurethane was further blended in a proportion of 10% by mass into the dope obtained in Example 45 to obtain a dope.

[0756] The initial viscosity of this dope was 3000P, and the viscosity after 24 hours was 6500P, and the viscosity ratio was calculated to be 2.17.

[0757] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0758] The number average molecular weight of the polymer constituting the fiber (or thread) was 35,000.

[0759] The results, including various evaluations, are shown in the table.

[0760] [Example 65] The polyurethane obtained in Example 62 was placed in the same triple-pipe apparatus as in Example 58 and dissolved in DMAc. An amine mixture (a mixture of monoethanolamine, diethylamine, and triethylenediamine with a target amino group concentration of 30 meq) was added dropwise at 100°C while monitoring the stirring shaft torque meter so that the target V2 / V1 value was set to 1.4. When the stirring shaft torque reached a value equivalent to 3000 P (40°C) (which took approximately 6 hours), the mixture was rapidly cooled to 23°C, and stirring and circulation filtering (filtering conditions: controlled to have a pressure drop of 1 MPa; circulation conditions: flow rate controlled so that the replacement of the contents was 100% / hour) were continued for 24 hours.

[0761] The initial viscosity of this dried polyurethane in a 20% by mass DMAc solution was measured to be 3100 P, and the viscosity after 24 hours was measured to be 4600 P, and the viscosity ratio between these values ​​was calculated to be 1.48.

[0762] The number average molecular weight of this polyurethane was 31,000, with no peak in the molecular weight (number average molecular weight) range of 1,000,000 or more. Furthermore, the amino group concentration of this polyurethane was 30 meq / kg.

[0763] Next, this polyurethane was further blended in a proportion of 10% by mass into the dope obtained in Example 45 to obtain a dope.

[0764] The initial viscosity of this dope was 3000P, and the viscosity after 24 hours was 5800P, and the viscosity ratio between these was calculated to be 1.93.

[0765] Then, using this dope, dry spun fibers were obtained in the same manner as in Reference Example 1.

[0766] The number average molecular weight of the polymer constituting the fiber (or thread) was 34,000.

[0767] The results, including various evaluations, are shown in the table.

[0768] [Table 4]

[0769] [Example 66] Dopes were obtained in the same manner as in Reference Examples 1, 2, and 4 and Examples 1, 2, 16, 17, 40, 41, 42, 53, 54, 63, and 64, except that the PUUV was changed to that prepared as follows, and dry-spun fibers were obtained.

[0770] A mixed polymer diol of trimethylene ether glycol (sometimes abbreviated as PO3G) with a molecular weight of 2,000 and tetramethylene ether glycol (PTMG) with a molecular weight of 1,800, and a DMAc solution (35% by mass) containing 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI), and a mixed diamine of ethylenediamine (EDA) and 2-methylpentane-1,5-diamine were polymerized to produce the polymer solution PUUV.

[0771] The obtained dope and dry-spun fibers showed the same tendency as those in the respective Reference Examples and Examples.

[0772] [Example 67] Dopes were obtained in the same manner as in Reference Examples 1, 2, and 4 and Examples 1, 2, 16, 17, 40, 41, 42, 53, 54, 63, and 64, except that the PUUV was changed to that prepared as follows, and dry-spun fibers were obtained.

[0773] A modified PTMG consisting of a copolymer of 2-methyl-tetrahydrofuran and tetrahydrofuran (THF) with a molecular weight of 3,800, MDI, and a DMAc solution (35% by mass) containing a mixed diamine of ethylenediamine (EDA) and 2-methylpentane-1,5-diamine were polymerized to obtain the polymer solution PUUV.

[0774] The obtained dope and dry-spun fibers showed the same tendency as those in the respective Reference Examples and Examples. [Industrial Applicability]

[0775] According to the present invention, an additive can be provided. Such an additive can be suitably used as an additive for a dope.

Claims

1. The additive for a dope is composed of polyurethane (A), and the viscosity when the polyurethane (A) is dissolved in dimethylacetamide at 40°C at 20 mass % is V1, and the viscosity after further 24 hours at 40°C is V2, the value of V2 / V1 is 1 or more.

2. 2. The additive according to claim 1, wherein the polyurethane (A) has a V2 / V1 value of 1.01 or more.

3. 2. The additive according to claim 1, wherein the polyurethane (A) has a V2 / V1 value of 5 or less.

4. The additive according to claim 1, wherein the polyurethane (A) has a V2 / V1 value of 1.02 to 3.

5.

5. 2. The additive according to claim 1, wherein the polyurethane (A) has a V2 of 1,000 poise or more.

6. The additive according to claim 1, wherein the polyurethane (A) satisfies the following (i) or (ii): (i) V2 is 1000 to 5000 poise, and the value of V2 / V1 is 1.05 or more. (ii) V2 is more than 5000 poise and the value of V2 / V1 is 3.5 or less.

7. 2. The additive according to claim 1, wherein the polyurethane (A) has a number average molecular weight of 10,000 or more.

8. 2. The additive according to claim 1, wherein the polyurethane (A) has a peak in a molecular weight region of 1,000,000 or more in GPC.

9. The additive according to claim 1, wherein the polyurethane (A) has an amino group.

10. 2. The additive according to claim 1, wherein the polyurethane (A) has amino groups in a proportion of 0.1 meq / kg or more.

11. 2. The additive according to claim 1, wherein the polyurethane (A) has amino groups in a proportion of 50 meq / kg or less.

12. 2. The additive according to claim 1, wherein the polyurethane (A) has amino groups in a proportion of 0.1 to 50 meq / kg.

13. 2. The additive according to claim 1, wherein the polyurethane (A) has amino groups in a proportion of 1 to 30 meq / kg.

14. The additive according to claim 1, wherein the polyurethane (A) contains a metal soap in an amount of 0.003 to 3% by mass.

15. The additive according to claim 1, wherein the polyurethane (A) contains a surfactant in a proportion of 0.003 to 3% by mass and / or an antioxidant in a proportion of 0.002 to 5% by mass.

16. 2. The additive according to claim 1, wherein the polyurethane (A) is fibrous.

17. 2. The additive according to claim 1, wherein the polyurethane (A) is at least one selected from a molded product stored for one month or more after production, molding waste, and post-consumer products.

18. The additive of claim 1 which is a viscosity modifier.

19. 2. The additive of claim 1, wherein the dope is a polyurethane dope.

20. The additive for the dope is composed of a polyurethane (A) having an amino group in a proportion of 0.1 to 50 meq / kg.

21. The additive for the dope is composed of a polyurethane (A) having an amino group in a proportion of 1 to 30 meq / kg.

22. A dope comprising the polyurethane (A) according to any one of claims 1 to 21.

23. The dope according to claim 22, wherein the proportion of the polyurethane (A) is 1% by mass or more.

24. The dope according to claim 22, further comprising a resin (B).

25. The dope according to claim 22, further comprising a resin (B), wherein the resin (B) comprises a polyurethane (B).

26. Further, it contains a resin (B), 23. The dope according to claim 22, wherein the proportion of the polyurethane (A) is 3% by mass or more based on the total amount of the polyurethane (A) and the resin (B).

27. Further, it contains a resin (B), The resin (B) contains a polyurethane (B), 23. The dope according to claim 22, wherein the proportion of the polyurethane (A) to the total amount of the polyurethane (A) and the polyurethane (B) is 10 to 90% by mass.

28. 23. The dope according to claim 22, wherein the resin constituting the dope has a number average molecular weight of 10,000 or more.

29. 23. The dope according to claim 22, wherein the resin constituting the dope has a peak in a molecular weight region of 1,000,000 or more in GPC.

30. The dope according to claim 22, further comprising a solvent containing at least one selected from the group consisting of an amide-based solvent and a sulfur-based solvent.

31. The dope according to claim 22, which contains a solvent and has a solid content of 5 to 80% by mass.

32. 23. The dope according to claim 22, wherein V2 / V1 is a ratio of 0.8 or more, where V1 is the viscosity at the time of preparation at 40°C and V2 is the viscosity at 40°C for 24 hours after preparation.

33. 23. The dope according to claim 22, wherein V2 / V1 is a value of 1 to 5, where V1 is the viscosity at 40°C when the dope is prepared and V2 is the viscosity at 40°C after the preparation for 24 hours.

34. 23. The dope according to claim 22, wherein the viscosity at 40°C is V1 when the dope is prepared and V2 after 24 hours at 40°C, the value of V2 / V1 is 1.01 to 3.5, and the viscosity is 1,000 to 10,000 poise.

35. A method for producing fibers by spinning the dope according to claim 22.

36. Fibers obtained using the dope according to claim 22.

37. A fiber comprising the polyurethane (A) according to any one of claims 1 to 21.

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