Additives for doping and fibers

Abstract

To provide an additive and the like.SOLUTION: An additive comprises a polyurethane (A) having a value of V2 / V1 greater than or equal to 1, where, at 40°C, V1 refers to the viscosity when it is dissolved in dimethylacetamide (DMAc) at 20 mass%, and V2 refers to the viscosity 24 hours after the dissolution.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to additives for dope, dope, fibers (such as polyurethane fibers), etc.

Background Art

[0002] In the molding of polyurethane, solution molding is widely used. For example, solution spinning, solution cast film, etc. (Patent Document 1, etc.).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems 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 (polyurethane elastic fiber), etc.

Means for Solving the Problems

[0005] As described above, solution molding is widely used for the molding of polyurethane. Under such circumstances, as a result of intensive studies, the present inventor has found that by selecting specific components as the components (additives) to be blended in a solution (dope), efficient molding of polyurethane [for example, polyurethane fiber (elastic fiber)] and production of polyurethane [for example, polyurethane fiber (elastic fiber)] having good physical properties can be realized, and the present invention has been completed.

[0006] That is, the present invention relates to the following inventions, etc. [1] An additive for doping, which is composed of polyurethane (A) and has a viscosity V1 when dissolved (or dispersed) in dimethylacetamide (DMAc) at 20% by mass (at a concentration of 20% by mass) at 40°C, and a viscosity V2 after 24 hours have elapsed after dissolution (or dispersion). The value of V2 / V1 is 1 or more. [2] The additive according to [1], wherein the value of V2 / V1 of the polyurethane (A) is 1.01 or more. [3] The additive according to [1] or [2], wherein the value of V2 / V1 of the polyurethane (A) is 5 or less (for example, 4.3 or less, 4.1 or less). [4] The additive according to any one of [1] to [3], wherein the value of V2 / V1 of the polyurethane (A) is 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 more than 5000 poise and the value of V2 / V1 is 3.5 or less [7] The additive according to any one of [1] to [6], wherein the number average molecular weight of the polyurethane (A) is 10000 or more. [8] The additive according to any one of [1] to [7], wherein the polyurethane (A) has a peak in the region of a number average molecular weight of 1 million or more in GPC. [9] The additive according to any one of [1] to [8], wherein the polyurethane (A) contains a metal soap (for example, contains a metal soap at a ratio of 0.003 to 3% by mass).

[10] The polyurethane (A) contains at least one selected from a surfactant, an antioxidant, a tertiary amine compound, and a crosslinking structure regulator (for example, contains a surfactant at a ratio of 0.003 to 3% by mass and / or contains an antioxidant at a ratio of 0.002 to 5% by mass), the additive according to any one of [1] to [9].

[0007]

[11] The polyurethane (A) is fibrous, the additive according to any one of [1] to

[10] .

[12] The polyurethane (A) is at least one selected from (derived from) molded products [for example, fibers (yarns)], molding scraps, and post-consumer products [for example, fibers (yarns)] stored for one month or more after production, the additive according to any one of [1] to

[11] .

[13] It is a viscosity modifier (viscosity controller, viscosity increasing agent, thickener), the additive according to any one of [1] to

[12] .

[14] The dope is a polyurethane dope, the additive according to any one of [1] to

[13] .

[15] A dope containing the polyurethane (A) according to any one of [1] to

[14] .

[16] The proportion of the polyurethane (A) is 1% by mass or more, the dope according to

[15] .

[17] Furthermore, it contains a resin (B), the dope according to

[15] or

[16] .

[18] Furthermore, it contains a resin (B), and the resin (B) contains a polyurethane (B), the dope according to any one of

[15] to

[17] .

[19] Furthermore, it contains a resin (B), The proportion of the polyurethane (A) with respect to the total amount of the polyurethane (A) and the resin (B) is 3% by mass or more, the dope according to any one of

[15] to

[18] .

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

[15] to

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

[0008]

[21] The dope according to any one of

[15] to

[20] , wherein the number average molecular weight of the resin constituting the dope is 10,000 or more.

[22] The dope according to any one of

[15] to

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

[23] The dope according to any one of

[15] to

[22] , comprising a solvent (for example, a solvent containing at least one selected from amide solvents and sulfur solvents).

[24] The dope according to any one of

[15] to

[23] , comprising a solvent and having a solid content concentration of 5 to 80% by mass.

[25] When the viscosity at the time of preparation is V1 and the viscosity after 24 hours from the time of preparation is V2 at 40 ° C., the value of V2 / V1 is 0.8 or more, and the dope according to any one of

[15] to

[24] .

[26] When the viscosity at the time of preparation is V1 and the viscosity after 24 hours from the time of preparation is V2 at 40 ° C., the value of V2 / V1 is 1 or more (for example, 1 to 5), and the dope according to any one of

[15] to

[25] .

[27] When the viscosity at the time of preparation is V1 and the viscosity after 24 hours from the time of preparation is V2 at 40 ° C., the value of V2 / V1 is 1.01 to 3.5 and the viscosity is 1000 to 10,000 poises, and the dope according to any one of

[15] to

[26] .

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

[15] to

[27] {for example, a method for spinning the dope according to any one of

[15] to

[27] to produce a fiber [yarn, for example, a polyurethane fiber (yarn)]}.

[29] A molded article obtained using the dopant described in any one of

[15] to

[27] .

[30] A molded article containing the polyurethane (A) described in any one of [1] to

[14] .

[31] The molded article according to

[29] or

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

[32] The molded article according to any one of

[29] to

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

[33] The molded article according to any one of

[29] to

[32] , containing at least one selected from metal soaps, surfactants, antioxidants, tertiary amine compounds, and crosslinking structure regulators.

[34] The molded article according to any one of

[29] to

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

[0009] According to the present invention, a novel additive can be provided. Such an additive is composed of a specific polyurethane and can make the molding and physical properties of the polyurethane (particularly both molding and physical properties) good.

[0010] For example, in one aspect of the additive of the present invention, it is possible to suppress or prevent yarn breakage during spinning and efficiently produce polyurethane fibers. Such efficient molding can be made equivalent to or even more excellent than, for example, when simply producing (polymerizing) a dopant and spinning, even though it is an additive-like usage mode.

[0011] In another aspect of the additive of the present invention, at least one property selected from good or improved physical properties (for example, strength (breaking strength, etc.), elongation (breaking elongation, etc.), heat resistance, durability [for example, maintenance of strength, etc. (for example, maintenance when exposed to an environment such as ultraviolet rays, NOx, chlorine, etc., especially a combined composite environment of these)], and yellowing resistance) (for example, at least one selected from strength, elongation, heat resistance, and durability) can be achieved.

Mode for Carrying Out the Invention

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

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

[0014] Specifically, polyurethane (A) is in the ratio (ratio, rate, viscosity ratio, viscosity after 24 hours / initial viscosity, V2 / V1) of the viscosity (initial viscosity, V1) when dissolved (dispersed) (mixed) in N,N-dimethylacetamide (DMAc) at a concentration of 20% by mass at 40°C and the viscosity (viscosity after 24 hours, V2) after further 24 hours have elapsed (left standing) after being dissolved (mixed), and can be selected from the range of 1 or more (for example, more than 1, 1.001 or more, 1.005 or more), for example, 1.01 or more (for example, 1.02 or more), preferably 1.03 or more (for example, 1.04 or more), more preferably 1.05 or more (for example, 1.06 or more), and may satisfy 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, 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 upper limit of the viscosity after 24 hours / initial viscosity (V2 / V1) is not particularly limited, and may be selected, for example, from a range of about 20 or less (for example, 15 or less), for example, 10 or less (for example, 8 or less), preferably 7 or less (for example, 6 or less), more preferably 5 or less (for example, 4.5 or less, 4.4 or less, 4.3 or less, 4.2 or less, 4.1 or less), particularly 4 or less (for example, 3.8 or less, 3.7 or less, 3.6 or less, 3.5 or less, 3.4 or less), and may even be 3.3 or less (for example, 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] In addition, these ranges (upper limit and lower limit) may be appropriately combined to select a range (for example, 1 - 10, 1.01 - 5, etc., the same applies to the description of ranges hereinafter).

[0017] Specific viscosities after 24 hours / initial viscosities (V2 / V1) include, for example, 1 - 10, 1.01 - 5, 1.05 - 4, 1.03 - 3.5, 1.1 - 3.3, 1.2 - 3.5, 1.05 - 3, 1.05 - 1.2, etc.

[0018] With such a viscosity after 24 hours / initial viscosity (V2 / V1), it is easy to achieve efficient molding of polyurethane (for example, good spinnability) and obtain polyurethane with good physical properties. The reasons for this are considered to be, for example, as follows.

[0019] First, as described above, polyurethane is molded in a molten state (particularly, solution molding), but according to the study by the present inventor, it has been found that viscosity is important in such molding.

[0020] Specifically, if the viscosity is insufficient or inappropriate (or if such viscosity cannot be maintained or retained over time), problems such as easy yarn breakage may occur, which may impair the formability (such as spinnability), or may impair the physical properties of the resulting molded article (such as strength, elongation, heat resistance, durability, etc.).

[0021] Although the reason for this is not clear, it is considered that the viscosity in polyurethane is largely due to the strong hydrogen bond association in polyurethane. Then, if such an association is insufficient, it is considered difficult to obtain sufficient viscosity.

[0022] And if such an association (viscosity) is insufficient, sufficient strength cannot be obtained during molding, and molding defects such as yarn breakage are likely to occur. In addition, it is considered that the insufficient association that affects the expression of physical properties in the resulting molded article (for example, the association in the molded article is likely to be small or uneven) will affect (be reflected), and it is predicted that the physical properties will be impaired.

[0023] On the other hand, the above-mentioned V2 / V1 (viscosity change over time) is considered to be related to the ease of thickening (and further the ease of maintaining or continuing the thickened state), and thus the ease of association. That is, the polyurethane with the above-mentioned V2 / V1 maintains or increases (maintains or increases over time) the viscosity (association). When used alone, of course, when compounded with a resin or its polymerization system (for example, a polyurethane or its polymerization system), it exhibits or induces sufficient viscosity or association, and suppresses the decrease in viscosity over time as much as possible. In particular, depending on the combination target and its blending ratio, it is considered to increase the viscosity, and accordingly, it is considered to lead to good formability and physical properties of the molded article.

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

[0025] For example, when the viscosity of the target to be blended is relatively high, as the polyurethane (A), one with a V2 / V1 value not too large may be selected, or the blending ratio may be decreased, etc.

[0026] The initial viscosity (V1) of the polyurethane (A) is not limited, but may be selected from a range of about 10 poise (= 1 Pa·s = 1000 mPa·s) or more, 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 about 1000 poise or more (for example, 1100 poise or more, 1200 poise or more), and may also be 1300 poise or more (for example, 1400 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.

[0027] By satisfying V2 / V1 as described above, sufficient viscosity, etc. can be realized. However, if the initial viscosity is too small, although it also depends on the blending target, blending ratio, and the value of V2, it may become difficult to efficiently realize sufficient viscosity, etc. (for example, it may take an excessive amount of time to reach sufficient viscosity), and an initial viscosity not too small as described above may be used.

[0028] The initial viscosity (upper limit value) of the polyurethane (A) is not limited, but may be selected from the range of about 100,000 poises or less, preferably 80,000 poises or less (for example, 60,000 poises or less, 50,000 poises or less, 40,000 poises or less), more preferably 30,000 poises or less (for example, 20,000 poises or less, 15,000 poises or less, 12,000 poises or less), still more preferably about 10,000 poises or less (for example, 9,000 poises or less, 8,000 poises or less), and may also be 7,000 poises or less (for example, 6,500 poises or less, 6,000 poises or less, 5,500 poises or less, 5,000 poises or less, 4,500 poises or less, 4,400 poises or less, 4,300 poises or less, 4,200 poises or less, 4,100 poises or less, 4,000 poises or less, 3,900 poises or less, 3,800 poises or less, 3,700 poises or less, 3,600 poises or less, 3,500 poises or less, 3,400 poises or less, 3,300 poises or less, 3,200 poises or less, 3,100 poises or less, 3,000 poises or less, 2,900 poises or less, 2,800 poises or less, 2,700 poises or less, 2,600 poises or less, 2,500 poises or less, 2,400 poises or less, 2,300 poises or less, 2,200 poises or less, 2,100 poises or less, 2,000 poises or less, 1,900 poises or less, 1,850 poises or less, 1,800 poises or less), etc.

[0029] By satisfying V2 / V1 as described above, sufficient viscosity and the like can be achieved. However, if the initial viscosity is too high, although it also depends on the compounding target, compounding ratio, and the value of V2, excessive viscosity may be exhibited, and the initial viscosity that is not too large as described above may be used.

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

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

[0032] The upper limit of the viscosity (V2) of the polyurethane (A) after 24 hours may be selected from the range of about 1,000,000 poises or less, 500,000 poises or less (for example, 400,000 poises or less, 300,000 poises or less, 200,000 poises or less), preferably 100,000 poises or less (for example, 80,000 poises or less, 70,000 poises or less, 60,000 poises or less), more preferably about 50,000 poises or less (for example, 40,000 poises or less, 30,000 poises or less), and may also be 25,000 poises or less (for example, 22,000 poises or less, 20,000 poises or less, 18,000 poises or less, 15,000 poises or less, 14,000 poises or less, 13,000 poises or less, 12,000 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 or less, 4,000 poises or less, 3,500 poises or less, 3,200 poises or less, 3,000 poises or less, 2,900 poises or less, 2,800 poises or less, 2,700 poises or less, 2,600 poises or less, 2,500 poises or less, 2,400 poises or less, 2,300 poises or less, 2,200 poises or less, 2,100 poises or less, 2,000 poises or less), etc.

[0033] By satisfying V2 / V1 as described above, sufficient viscosity and the like can be realized. However, if V2 is too large, although it depends on the values of the blending target and blending ratio, excessive viscosity may be exhibited, and V2 that is not too large as described above may also be used.

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

[0035] The number average molecular weight of the polyurethane (A) may be selected from the range of about 2,000 or more (for example, 3,000 or more, 4,000 or more), and for example, 5,000 or more (for example, 6,000 or more, 7,000 or more), preferably 8,000 or more (for example, 9,000 or more), more preferably 10,000 or more (for example, 11,000 or more, 12,000 or more, 13,000 or more, 14,000 or more), and may be about 15,000 or more (for example, 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).

[0036] By satisfying V2 / V1 as described above, sufficient viscosity and the like can be realized. However, if the number average molecular weight is too small, although it depends on the compounding target, compounding ratio, and the value of V2 / V1, it becomes difficult to efficiently realize sufficient viscosity and the like (for example, it may take an excessive amount of time to reach sufficient viscosity). Therefore, the number average molecular weight may be not too small as described above. Also, from the viewpoint of physical properties such as strength and durability, it is preferable to have a number average molecular weight that is not too small.

[0037] Note that the upper limit of the number average molecular weight of the polyurethane (A) is not limited, but it may be selected from the range of about 2,000,000 or less (for example, 1,500,000 or less, 1,200,000 or less), and for example, 1,000,000 or less (for example, 800,000 or less, 700,000 or less), preferably 500,000 or less (for example, 300,000 or less), more preferably 200,000 or less (for example, 180,000 or less, 150,000 or less, 120,000 or less), and may be about 100,000 or less (for example, 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 the polyurethane include, for example, 10,000 to 300,000, 20,000 to 200,000, 30,000 to 150,000, and the like.

[0039] In particular, the polyurethane (A) may have a peak derived from a high molecular weight component [for example, generally, a peak in the region of a 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)] in a GPC (GPC chart).

[0040] According to the study by the present inventors, such a high molecular weight component seems to be able to contribute to an increase in viscosity (increase over time) because it functions as a component that induces or promotes association (for example, functions as a plasticizer), and depending on the blending target, blending ratio, value of V2 / V1, desired viscosity (degree of viscosity), etc., in combination with the fulfillment of the aforementioned value of V2 / V1 (in addition to the fulfillment), the polyurethane (A) containing a high molecular weight component may be preferably used.

[0041] The polyurethane (A) having such a high molecular weight component is not particularly limited, and it may be obtained by separately blending a high molecular weight component into the polyurethane, etc., but there are cases where polyurethanes formed by various molding methods (for example, solution molding) contain a high molecular weight component, and the polyurethane originally containing such a high molecular weight component may be used as it is.

[0042] The molecular weight (number average molecular weight) and the presence or absence of a high molecular weight component can be confirmed (measured) by, for example, GPC (polystyrene conversion, etc.), and specifically, it may be confirmed (measured) by the method described later (hereinafter).

[0043] The shape (aspect) of the polyurethane (A) is not particularly limited, and it may be any of fibrous, non-fibrous [granular, powdery, coarsely pulverized product of a molded article (non-fibrous mass), etc.].

[0044] The fiber diameter (average fiber diameter) of the fibrous polyurethane (A) is not particularly limited, but may be, for example, 1 to 10000 μm, preferably 10 to 5000 μm, and more preferably about 20 to 2000 μm.

[0045] The size (dimension, length in the case of fibers) of the polyurethane (A) is not particularly limited, but in view of handleability, compounding, usage mode, etc., it may be a relatively small size such as an average diameter (maximum diameter) of 10 mm or less [for example, 5 mm or less (for example, 3 mm or less), preferably 1 mm or less, more preferably 0.5 mm or less].

[0046] Incidentally, the polyurethane (A) of such a size can be obtained, for example, by a general-purpose grinding treatment, depending on the form of the polyurethane as a raw material.

[0047] Incidentally, the fiber diameter and size can be measured, for example, by a scanning electron microscope (SEM). Specifically, it may be measured by the method of the examples described later.

[0048] In particular, fibrous polyurethane (A) may be preferably used. When it is fibrous, it is easy to efficiently (for example, early) realize or exhibit an increase in viscosity or the like.

[0049] The polyurethane (A) [the resin component (polyurethane) constituting the polyurethane (A) and contained in the polyurethane (A)] is not particularly limited, and may be, for example, any one having a structure starting from a polymer diol and a diisocyanate, and is not particularly limited.

[0050] Also, the synthesis method is not particularly limited. For example, it may be a polyurethane urea composed of a polymer diol, a diisocyanate, and a low molecular weight diamine as a chain extender, or a polyurethane urethane composed of a polymer diol, a diisocyanate, and a low molecular weight diol as a chain extender. Further, it may 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 trifunctional or higher polyfunctional glycols, isocyanates, etc. as necessary (within a range not hindering the effects of the present invention).

[0051] Polymeric diols such as polyether-based, polyester-based diols, and polycarbonate diols are preferred. And in molded articles (such as threads), from the viewpoint of imparting flexibility and elongation, polyether-based diols are preferably used.

[0052] Examples of polyether-based diols include polyethylene oxide, polyethylene glycol, derivatives of polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol (hereinafter sometimes abbreviated as PTMG), tetrahydrofuran (hereinafter sometimes abbreviated as THF), and modified PTMG which is a copolymer of 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-dimethyl THF, polyols having side chains disclosed in Japanese Patent No. 2615131, etc., and random copolymers in which THF and ethylene oxide and / or propylene oxide are irregularly arranged, etc. are preferably used. These polyether-based diols may be used alone or in a mixture of two or more or copolymerized.

[0053] Also, from the viewpoint of obtaining abrasion resistance and light resistance as polyurethane elastic fibers, polyester-based diols such as butylene adipate, polycaprolactone diol, and polyester polyols having side chains disclosed in JP-A-61-26612, etc., and polycarbonate diols disclosed in Japanese Examined Patent Publication No. 2-289516, etc. are preferably used.

[0054] Also, such polymeric diols may be used alone or in a mixture of two or more or copolymerized.

[0055] From the viewpoint of obtaining elongation, strength, heat resistance, etc. when made into a thread, the number average molecular weight of the polymeric diol is preferably 1,000 or more and 8,000 or less, and more preferably 1,500 or more and 6,000 or less. By using a polyol having a molecular weight in this range, a thread (elastic thread) excellent in elongation, strength, elastic recovery force, heat resistance, etc. can be easily obtained.

[0056] Next, as the diisocyanate, aromatic diisocyanates such as diphenylmethane diisocyanate (hereinafter sometimes abbreviated as MDI), tolylene diisocyanate, 1,4-diisocyanate benzene, xylylene diisocyanate, and 2,6-naphthalene diisocyanate are particularly suitable for synthesizing polyurethanes with high heat resistance and strength. Further, as the alicyclic diisocyanate, for example, methylene bis(cyclohexyl isocyanate), isophorone diisocyanate, methylcyclohexane 2,4-diisocyanate, methylcyclohexane 2,6-diisocyanate, cyclohexane 1,4-diisocyanate, hexahydroxylylene diisocyanate, hexahydrotoluene diisocyanate, octahydro-1,5-naphthalene diisocyanate, etc. are preferable. Alicyclic diisocyanates can be effectively used particularly when suppressing the yellowing of polyurethane elastic fibers. And these diisocyanates may be used alone or in combination of two or more.

[0057] Next, when synthesizing polyurethane, it is preferable to use at least one of low molecular weight diamine and low molecular weight diol as the chain extender. In addition, those having both a hydroxyl group and an amino group in one molecule such as ethanolamine may also be used.

[0058] 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, bis(4-aminophenyl)phosphine oxide, and the like. It is preferable to use one or more of these. Particularly preferred is ethylenediamine. By using ethylenediamine, a yarn excellent in elongation, elastic recovery, and further heat resistance can be easily obtained. A triamine compound capable of forming a crosslinked structure with these chain extenders, such as diethylenetriamine, may be added to the extent that the effect is not lost.

[0059] Also, typical low molecular weight diols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, bishydroxyethoxybenzene, bishydroxyethylene terephthalate, 1-methyl-1,2-ethanediol, and the like. It is preferable to use one or more of these. Particularly preferred are ethylene glycol, 1,3-propanediol, and 1,4-butanediol. When these are used, the polyurethane with diol extension has higher heat resistance, and a yarn with higher strength can be obtained.

[0060] It is also preferable to use one or more kinds of end-capping agents in the polyurethane. Preferred end-capping 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.

[0061] Polyurethane (A) may contain components other than the resin component (polyurethane) (other components). Such components can be appropriately selected depending on the molding method of polyurethane (A), the form of the molded article, etc., and are not particularly limited.

[0062] Examples of other components include metallic soaps, surfactants, antioxidants, tertiary amine compounds, crosslinking structure regulators, 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.), catalysts (catalyst components, e.g., polyurethane amine-based catalysts, organometallic catalysts), and the like.

[0063] Polyurethane (A) may contain one or more other components.

[0064] When polyurethane (A) contains other components, the ratio of the other components (ratio of the total amount) can be selected from the range of about 50% by mass or less with respect to the whole polyurethane (A), and may be 40% by mass or less (e.g., 30% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, etc.).

[0065] Among them, it is preferable that polyurethane (A) contains a metallic soap. By containing a metallic soap, in combination with the fulfillment of V2 / V1 etc. described above, it becomes easier to efficiently impart sufficient viscosity and control the viscosity increase, and it can be advantageous in terms of moldability (spinnability, etc.) and physical properties. The reason for this is not clear, but it is considered that the metallic soap promotes hydrogen bonding while suppressing excessive promotion of hydrogen bonding, and as a result, stabilizes the association and efficiently functions to adjust the viscosity.

[0066] Examples of the metallic soap include salts of an acid and a metal.

[0067] Examples of the acid include organic acids (such as fatty acids, aromatic carboxylic acids, and resin acids) 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, agathic dicarboxylic acid, benzoic acid, cinnamic acid, p-hydroxycinnamic acid, diterpenic acid, naphthenic acid, etc.

[0068] Typical acids include fatty acids [such as fatty acids having 6 or more carbon atoms (such as 8 or more, 8 to 40, 8 to 30, etc.) like octylic acid, lauric acid, stearic acid, palmitic acid, ricinoleic acid, etc.].

[0069] Examples of the metal include metals other than sodium and potassium such as alkali metals other than sodium and potassium (such as lithium), alkaline earth metals (such as beryllium, magnesium, calcium, barium, etc.), and other metals (such as aluminum, zinc, cadmium, cobalt, chromium, copper, silver, iron, mercury, manganese, nickel, lead, tin, titanium), etc.

[0070] Specific metal soaps include, for example, metal octylate (such as zinc octylate), metal laurate (such as calcium laurate, barium laurate, zinc laurate), metal stearate (lithium stearate, magnesium stearate, calcium stearate, barium stearate, zinc stearate), metal ricinoleate (such as calcium ricinoleate, barium ricinoleate, zinc ricinoleate), etc.

[0071] The polyurethane (A) may contain one or more metal soaps.

[0072] When the polyurethane (A) contains a metal soap, the proportion of the metal soap 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 about 0.003% by mass or more, and may be 20% by mass or less [for example, 15% by mass or less (for example, 12% by mass or less), preferably 10% by mass or less (for example, 8% by mass or less), more preferably 5% by mass or less (for example, 3% by mass or less)].

[0073] Specific proportions of the metal soap include, for the entire polyurethane (A), 0.0001 to 10% by mass, preferably 0.001 to 5% by mass, more preferably 0.003 to 3% by mass, and the like.

[0074] Also, it is preferable that the polyurethane (A) contains at least one selected from a surfactant, an antioxidant, a tertiary amine compound, and a crosslinking structure regulator. Similar to the metal soap, such components also participate in hydrogen bonding to stabilize the association and efficiently perform the function of viscosity adjustment. Perhaps because of this, combined with the fulfillment of V2 / V1 described above, etc., it becomes easier to efficiently impart sufficient viscosity and control the viscosity increase, and it can be advantageous in terms of moldability (spinnability, etc.) and physical properties.

[0075] Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, and the like.

[0076] Examples of the nonionic surfactant include polyoxyethylene alkyl ether, alkyl monoglyceryl ether, polyoxyethylene alkylamine, fatty acid sorbitan ester, fatty acid diethanolamide, and the like. Among these, the hydrophilic part (Hydrophil) of a so-called surfactant is preferably of the ether type, and for example, it is preferably at least one of an ethylene oxide polymer, a propylene oxide polymer, and a copolymer of ethylene oxide and propylene oxide.

[0077] By containing at least one of a terminal-modified derivative of an ethylene oxide polymer, a terminal-modified derivative of a propylene oxide polymer, and a terminal-modified derivative of a copolymer of ethylene oxide and propylene oxide as a nonionic surfactant, the spinnability can be enhanced, and for example, the antibacterial property can be made excellent.

[0078] The so-called hydrophobic part (Hydrophob) of the surfactant is the aforementioned terminal-modified structure, and an alkyl group, a phenyl group, or a styrenated phenyl group is preferable. As the nonionic surfactant, specifically, polyoxyethylene stearyl ether, polyoxyethylene lauryl ether, polyoxyethylene ethyl phenyl ether, polyoxyethylene propyl phenyl ether, polyoxyethylene styrenated phenyl ether, polyoxyethylene sorbitol tetraoleate, etc. can be mentioned. More preferable is polyoxyethylene styrenated phenyl ether, and polyoxyethylene oxypropylene trisstyrenated 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. can be mentioned. Most preferable is the case where the added molar number of these styrene groups has a distribution and a mixture of these is used.

[0079] Examples of cationic surfactants include quaternary ammonium salts (quaternary ammonium ions) and the like. Among quaternary ammonium salts, there are differences in antibacterial activity 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 suppressing thermal decomposition and the like, it is preferable to select a chain type and chain length of an alkyl group or the like that are large, that is, an alkyl group having a large number of carbon atoms. And from the hygienic aspect, it is preferable to contain an antibacterial agent (having antibacterial properties).

[0080] Particularly preferable ammonium ions from this viewpoint are didecyldimethylammonium ions, oleyltrimethylammonium ions, and the like. These are usually supplied by inorganic salts such as chlorides, bromides, iodides, and organic acid salts such as sulfonates, carboxylates, and phosphates. Among them, sulfonates and carboxylates are preferable from the viewpoint of stability such as discoloration and heat resistance.

[0081] Specific examples of the salts having the above structure include didecyldimethylammonium methylsulfonate fluoride, di-n-decyldimethylammonium trifluoromethanesulfonate, di-n-decyldimethylammonium pentafluoroethanesulfonate, n-hexadecyltrimethylammonium trifluoromethanesulfonate, and benzyldimethylcoconut oil alkylammonium pentafluoroethanesulfonate, and the like.

[0082] The antioxidant is not particularly limited, and examples thereof include phenol compounds. The phenol compound may be a hindered phenol compound, and particularly, hindered phenols may be preferably used.

[0083] Examples of phenolic compounds (hindered phenolic compounds, etc.) include 3,5-di-t-butyl-4-hydroxy-toluene, 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-hydroxy-benzyl-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'-oxamidobis[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) 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 phenolic compounds.

[0084] Preferred specific examples of such high molecular weight hindered phenol compounds include, for example, addition polymers of divinylbenzene and cresol, addition polymers of dicyclopentadiene and cresol isobutylene adducts, polymers of chloromethylstyrene and compounds such as cresol, ethylphenol, t-butylphenol, etc. Here, divinylbenzene and chloromethylstyrene may be p- or m-. Also, cresol, ethylphenol, and t-butylphenol may be any of o-, m-, or p-.

[0085] Among them, from the viewpoints of stabilizing viscosity and easily obtaining good spinnability, etc., it is preferably a compound with a molecular weight of 300 or more. Furthermore, for efficiently exhibiting a high spinning speed, heat resistance during dyeing, resistance to unsaturated fatty acids, and resistance to heavy metals, etc., 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), an adduct of divinylbenzene and p-cresol having a repeating number of 6 to 12, or a combination thereof may be used. Among them, 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione may also be preferably used.

[0086] As the phenol compound, a mono-hindered phenol compound is also preferable. Examples of the mono-hindered phenol compound include ethylene-1,2-bis(3,3-bis[3-t-butyl-4-hydroxyphenyl]butyrate) having a structure in which a mono-hindered hydroxyphenyl group is covalently bonded to a bisester skeleton (the following compound), etc.

[0087]

Chemical formula

[0088] Specifically, a hindered phenol compound having a molecular weight of 1,000 or more is preferred. There are no particular limitations other than the relatively high molecular weight of 1,000 or more. Preferred specific examples of such high molecular weight hindered phenol compounds include addition polymers of divinylbenzene and cresol, addition polymers of dicyclopentadiene and cresol isobutylene adducts, polymers of chloromethylstyrene and compounds such as cresol, ethylphenol, and t-butylphenol. Here, divinylbenzene and chloromethylstyrene may be p- or m-. Also, cresol, ethylphenol, and t-butylphenol may be any of o-, m-, and p-.

[0089] Among them, from the viewpoints of stabilizing the viscosity and obtaining good spinnability, etc., it is preferably a hindered phenol compound of a polymer derived from cresol. Furthermore, in order to efficiently exhibit a high spinning speed, heat resistance during dyeing, resistance to unsaturated fatty acids, and resistance to heavy metals, etc., it is preferably to contain a certain amount of such high molecular weight hindered phenol compounds, but it is preferably not too much from the viewpoint of obtaining better basic physical properties as a polyurethane fiber.

[0090] The tertiary amine compound is not particularly limited as long as it is a compound having an amino group in its structure. However, from the viewpoints of chlorine deterioration resistance and yellowing property of the polyurethane elastic fiber, among primary to tertiary amino groups, those having only a tertiary amino group in the molecule are particularly preferred.

[0091] Relatively high molecular weight tertiary amine compounds may be preferably used. In such tertiary amine compounds, the range of the number average molecular weight is preferably, for example, in the range of 2,000 to 10,000, and more preferably may be in the range of 2,000 to 4,000.

[0092] Examples of the tertiary amine compound include, more specifically, a linear high molecular weight compound having a number average molecular weight of 2,000 or more obtained by the reaction of t-butyldiethanolamine and methylene-bis-(4-cyclohexylisocyanate), a high molecular weight compound having a branched structure containing a primary amino group, a secondary amino group, and a tertiary amino group in the molecular skeleton such as polyethyleneimine, and the like.

[0093] Examples of the crosslinking structure regulator include monoamines, diamines, and the like. More specifically, monoamines (e.g., dimethylamine, diethylamine, cyclohexylamine, etc.), diamines (e.g., ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, hexamethylenediamine, p-phenylenediamine, p-xylylenediamine, m-xylylenediamine, 1,3-cyclohexyldiamine, hexahydrometaphenylenediamine, 2-methylpentamethylenediamine) and the like can be mentioned. Particularly preferred is the mixed use of monoamine and diamine.

[0094] When the polyurethane (A) contains a surfactant, the proportion of the surfactant can be selected from, for example, a range of about 0.0001% by mass or more with respect to the whole polyurethane (A), and may be 0.0005% by mass or more, preferably 0.001% by mass or more, more preferably about 0.003% by mass or more, 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), more preferably 5% by mass or less (e.g., 3% by mass or less)].

[0095] Specific proportions of the surfactant include 0.0001 to 10% by mass, preferably 0.001 to 5% by mass, more preferably 0.003 to 3% by mass, etc., with respect to the whole polyurethane (A).

[0096] 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 0.0005% by mass or more, preferably 0.001% by mass or more, more preferably about 0.002% by mass or more, and may be 20% by mass or less [for example, 15% by mass or less (for example, 12% by mass or less), preferably 10% by mass or less (for example, 8% by mass or less), more preferably 7% by mass or less (for example, 5% by mass or less)].

[0097] Specific proportions of the antioxidant include, for the entire polyurethane (A), 0.0001 to 10% by mass, preferably 0.001 to 7% by mass, more preferably 0.002 to 5% by mass, and the like.

[0098] In addition, from the viewpoints of moldability (for example, spinnability) and physical properties (strength, yellowing resistance, durability, etc.) of the polyurethane (A), the proportion of the decomposition products of the antioxidant (phenol compound, etc.) may be 1% by mass or less, preferably 0.5% by mass or less, based on the entire polyurethane (A).

[0099] When the polyurethane (A) contains a tertiary amine compound, the proportion of the tertiary amine compound can be selected from the 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 about 0.2% by mass or more, and may be 30% by mass or less [for example, 20% by mass or less (for example, 15% by mass or less), preferably 12% by mass or less (for example, 10% by mass or less), more preferably 7% by mass or less (for example, 5% by mass or less)].

[0100] Specific proportions of the tertiary amine compound include, for the entire polyurethane (A), 0.01 to 20% by mass, preferably 0.1 to 10% by mass, more preferably 0.2 to 5% by mass, and the like.

[0101] In addition, from the viewpoints of moldability (e.g., spinnability) and physical properties (strength, yellowing resistance, durability, etc.), the proportion of the decomposition product 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 polyurethane (A).

[0102] When the polyurethane (A) contains a crosslinking structure regulator, the proportion of the crosslinking structure regulator can be selected from a range of, for example, about 0.0001% by mass or more, 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 polyurethane (A), 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., 2% by mass or less)].

[0103] Specific proportions of the crosslinking structure regulator include, for example, 0.0001 to 10% by mass, preferably 0.001 to 5% by mass, more preferably 0.002 to 2% by mass, etc., based on the total amount of the polyurethane (A).

[0104] The polyurethane (A) is not particularly limited, and commercially available products (circulation products) may be used, or those produced or molded by conventional methods may also be used.

[0105] In such a polyurethane (A), the production method or molding method from which it is derived is also not particularly limited and can be appropriately selected according to 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 method, wet spinning method, dry spinning method, etc.).

[0106] In addition, the polyurethane (A) may be an unused product or a used product.

[0107] In addition, the polyurethane (A) may be one that has been left unattended or stored (e.g., left unattended or stored for one month or more (e.g., six months or more, one year or more, etc.)) without being used (sold, used for various purposes, etc.) after production {e.g., the fiber itself, a wound yarn body [e.g., a warping beam which is an intermediate product for knitting], a processed yarn, etc.}, and may also be molding scraps [e.g., scraps (not forming a wound yarn body) cut during the process of obtaining a wound yarn body through various spinning methods, etc.]. Further, it may be a used product (post-consumer product).

[0108] By using such products left unattended or stored (e.g., those to be discarded due to excess inventory, etc.), molding scraps, used products, etc., polyurethane can be utilized [recycled] efficiently.

[0109] In addition, for polyurethane that satisfies the above-described properties, if it is a commercially available product, a product that satisfies the above-described properties may be selected from commercially available products, or if it is a manufactured product, a product manufactured to satisfy the above-described properties may be used. For example, since the viscosity (ease of thickening) of polyurethane is considered to be affected by association as described above, it can be adjusted efficiently by adjusting the ease of such association. To give a specific example, regarding the resin component (polyurethane) itself, the ease of association can be adjusted efficiently according to the progress of the reaction [e.g., using polyurethane in which the reaction of the polymerization components has proceeded sufficiently (and thus crystal nuclei that can become association nuclei are likely to be generated)], and in addition, the ease of such association can also be adjusted efficiently by the presence or absence of the above-described high molecular weight components and the blending (and further the amount) of other components.

[0110] In addition, the polyurethane (A) containing other components may be manufactured by adding and blending to the base resin component (polyurethane) by a conventional method, etc., or a product in which other components have already been blended (containing other components) in commercially available products, recycled products, etc. may be used as it is.

[0111] [Use of Additives] The additive of the present invention is composed of polyurethane (A).

[0112] The target (object to be added, compounding target) of such an additive is not limited, but in particular, it may be a dope. That is, the additive of the present invention may be an additive for dope (an agent for adding to dope).

[0113] Also, the additive (polyurethane (A)) can, as described above, increase or adjust the viscosity (realize viscosity maintenance, suppress viscosity reduction), and in addition, can improve the moldability (spinnability) and physical properties.

[0114] Therefore, the additive (polyurethane (A)) may be used for applications corresponding to such functions. For example, the additive (polyurethane (A)) may be a viscosity (viscosity) regulator [viscosity (viscosity) controller, viscosity (viscosity) increasing agent, thickening agent, viscosity (viscosity) maintaining agent], a moldability (spinnability, etc.) improver (enhancer), and / or a physical property (for example, at least one physical property selected from strength, elongation, heat resistance, and durability) improver (enhancer), etc. (and may be used for such applications).

[0115] In particular, since the additive (polyurethane (A)) is suitable for use in dope (and further for improving viscosity and physical properties as described above), the dope application will be described in detail below.

[0116] <Dope, etc.> Dope is a liquid containing a resin (resin component), and it may be a solvent-free one (bulk dope), but usually it may also contain a resin and a solvent {in particular, it may be a solution containing a resin [or a dispersion, a solution (or dispersion) in which at least the resin is dissolved (or dispersed)]}.

[0117] Since polyurethane (A) is also a resin, when it is blended into the dope, it becomes the resin constituting the dope.

[0118] The resin component (such as polyurethane) that constitutes such a dope (contained in the dope) may be composed of only polyurethane (A), or may contain polyurethane (A) and another resin (B) (a resin component different from polyurethane (A)).

[0119] That is, the dope may be a dope containing only polyurethane (A) as the resin, or may be a dope containing polyurethane (A) and resin (B) as the resin.

[0120] Note that the dope containing polyurethane (A) and resin (B) may be obtained by mixing polyurethane (A) and resin (B), or may be obtained by mixing polyurethane (A) into a system (dope) containing resin (B) in advance.

[0121] In particular, polyurethane (A) is preferably used in combination with resin (B) in view of functions such as viscosity control, improvement of moldability (spinnability) and physical properties.

[0122] Resin (B) may be either non-polyurethane or polyurethane, but in view of the fact that the additive (polyurethane (A)) is polyurethane, it is preferably at least polyurethane. In other words, the dope may be a polyurethane dope (a dope containing polyurethane as resin (B)).

[0123] Such polyurethane (sometimes referred to as polyurethane as resin (B), polyurethane (B), etc.) is not particularly limited, and examples thereof include polyurethanes similar to those described in the section of polyurethane (A). The preferred embodiments of polyurethane (B) are also the same as those described for the above-mentioned polyurethane (A).

[0124] In particular, polyurethane (B) and polyurethane (A) may be of the same type or the same strain as each other (for example, both polyurethane (A) and (B) are polyurethane ureas, etc.).

[0125] When the dope contains the resin (B), the ratio of the polyurethane (A) to the total amount of the polyurethane (A) and the resin (B) (for example, polyurethane (B)) can be appropriately selected according to the object to be improved or enhanced [for example, moldability (spinnability, etc.), physical properties (strength, elongation, heat resistance, etc.)] and the degree thereof. For example, it may be 0.1% by mass or more (for example, 0.5% by mass or more), preferably 1% by mass or more (for example, 2% by mass or more), more preferably 3% by mass or more (for example, 5% by mass or more), and may be 8% by mass or more (for example, 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.

[0126] The ratio (upper limit value of the ratio) of the polyurethane (A) to the total amount of the polyurethane (A) and the resin (B) (for example, polyurethane (B)) may be selected from the range of about 99.9% by mass or less (for example, 99.5% by mass or less), and may be about 99% by mass or less (for example, 98% by mass or less), preferably about 97% by mass or less (for example, 95% by mass or less), and may be 90% by mass or less (for example, 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.

[0127] Specific examples of the ratio of the polyurethane (A) to the total amount of the polyurethane (A) and the resin (B) (for example, polyurethane (B)) include, for example, 0.1 to 99.9% by mass (for example, 0.5 to 99% by mass), 1 to 99% by mass (for example, 3 to 97% by mass), 5 to 95% by mass (for example, 10 to 90% by mass), 1 to 50% by mass, 3 to 40% by mass, 50 to 99% by mass, 60 to 95% by mass, etc.

[0128] Note that the ratio of the polyurethane (A) to 100 of the total amount of the polyurethane (A) and the resin (B) (for example, polyurethane (B)) can also be appropriately selected so as to obtain the viscosity and viscosity ratio described later.

[0129] 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), etc. For example, the number average molecular weight of the resin [for example, polyurethane (A) alone, a mixed resin of polyurethane (A) and resin (B) (such as polyurethane (B))] may be selected from the range of 2000 or more (for example, 3000 or more, 4000 or more), and may be, for example, 5000 or more (for example, 6000 or more, 7000 or more), preferably 8000 or more (for example, 9000 or more), more preferably 10000 or more (for example, 11000 or more, 12000 or more, 13000 or more, 14000 or more), and may also be 15000 or more (for example, 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).

[0130] Note that the upper limit of the number average molecular weight of the resin constituting the dope is not limited, but may be selected from the range of about 2000000 or less (for example, 1500000 or less, 1200000 or less), and may be, for example, 1000000 or less (for example, 800000 or less, 700000 or less), preferably 500000 or less (for example, 300000 or less), more preferably 200000 or less (for example, 180000 or less, 150000 or less, 120000 or less), and may also be 100000 or less (for example, 90000 or less, 80000 or less, 70000 or less, 60000 or less, 55000 or less, 50000 or less, 45000 or less, 40000 or less, 35000 or less).

[0131] Specific examples of the number average molecular weight of the resin constituting the dope include, for example, 10000 to 300000, 20000 to 200000, 30000 to 150000, etc.

[0132] In particular, the resin constituting the dope may have a peak derived from a high molecular weight component [for example, generally a peak in the region of a number average molecular weight of 1,000,000 or more (for example, 1,000,000 to 50,000,000, 1,000,000 to 30,000,000, 2,000,000 to 15,000,000, 3,000,000 to 10,000,000)] in GPC (GPC chart).

[0133] Note that such a peak derived from a high molecular weight component may be generated in the system (polymerization in the dope) or may be derived from a 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 a high molecular weight component can also be found in the resin constituting the dope.

[0134] Having the molecular weight range and the peak derived from a high molecular weight component as described above is likely to be advantageous in terms of, for example, moldability (spinnability, etc.) and physical properties.

[0135] If the resin (B) can constitute a resin together with the polyurethane (A) in the dope (during use as a dope), it may be contained in the dope from the raw material (monomer) stage. For example, through a dope containing the polyurethane (A) and the raw material of the resin (B) (for example, a monomer serving as a raw material of the polyurethane), polymerization proceeds in the system (in the dope) to obtain a dope containing the polyurethane (A) and the resin (B).

[0136] The dope may contain other components (components other than the resin). Such other components depend on the resin constituting the dope and the use of the dope, etc. For example, metallic soaps, surfactants, antioxidants, tertiary amine compounds, cross-linking structure regulators, 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, oil agents (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.), catalysts (catalyst components, e.g., polyurethane amine-based catalysts, organometallic catalysts), and the like of the aforementioned components can be mentioned.

[0137] In addition, such other components may be contained in the polyurethane (A) in advance, may be separately added to the dope, or may be combined with those contained in the polyurethane (A) and those added separately.

[0138] The preferred embodiments (preferred components, proportions contained in the resin, etc.) of the other components are also the same as those described for the polyurethane (A).

[0139] When the dope contains other components, the proportion of the other components (proportion of the total amount) can be selected, for example, from a range of about 50% by mass or less, and may be 40% by mass or less (e.g., 30% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, etc.) with respect to the total amount of the resin and the other components (e.g., polyurethane (A) containing other components; total amount of polyurethane (A) containing other components and resin (B); total amount of polyurethane (A) which may contain other components, resin (B), and other components separately blended into the dope, etc.).

[0140] 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% by mass or more with respect to the total amount of the resin and the metal soap (e.g., polyurethane (A) containing the metal soap; the total amount of polyurethane (A) containing the metal soap and resin (B); the total amount of polyurethane (A) which may contain the metal soap, resin (B) and the metal soap separately blended in the dope, etc.), and may be, for example, 0.0005% by mass or more, preferably 0.001% by mass or more, more preferably about 0.003% by mass or more, 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)].

[0141] Specific examples of the proportion of the metal soap include, for example, 0.0001 to 10% by mass, preferably 0.001 to 5% by mass, more preferably 0.003 to 3% by mass, etc. with respect to the total amount of the resin and the metal soap.

[0142] 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 with respect to the total amount of the resin and the surfactant (e.g., polyurethane (A) containing the surfactant; the total amount of polyurethane (A) containing the surfactant and resin (B); the total amount of polyurethane (A) which may contain the surfactant, resin (B) and the surfactant separately blended in the dope, etc.), and may be, for example, 0.0005% by mass or more, preferably 0.001% by mass or more, more preferably about 0.003% by mass or more, 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)].

[0143] Specific examples of the proportion of the surfactant include 0.0001 to 10% by mass, preferably 0.001 to 5% by mass, more preferably 0.003 to 3% by mass, etc. with respect to the total amount of the resin and the surfactant.

[0144] 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, 0.0005% by mass or more, preferably 0.001% by mass or more, more preferably 0.002% by mass or more, and may be 20% by mass or less [for example, 15% by mass or less (for example, 12% by mass or less), preferably 10% by mass or less (for example, 8% by mass or less), more preferably 7% by mass or less (for example, 5% by mass or less)] with respect to the total amount of the resin and the antioxidant (for example, polyurethane (A) containing an antioxidant; the total amount of polyurethane (A) containing an antioxidant and resin (B); the total amount of polyurethane (A) which may contain an antioxidant, resin (B) and the antioxidant separately blended into the dope, etc.).

[0145] Specific proportions of the antioxidant include, for example, 0.0001 to 10% by mass, preferably 0.001 to 7% by mass, more preferably 0.002 to 5% by mass, etc. with respect to the total amount of the resin and the antioxidant.

[0146] In addition, from the viewpoints of moldability (for example, spinnability) and physical properties (strength, yellowing resistance, durability, etc.), the proportion of the decomposition product of the antioxidant (phenol compound, etc.) may be 1% by mass or less, preferably 0.5% by mass or less with respect to the total amount of the decomposition products of the resin and the antioxidant.

[0147] 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, 0.05% by mass or more, preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and may be 30% by mass or less [for example, 20% by mass or less (for example, 15% by mass or less), preferably 12% by mass or less (for example, 10% by mass or less), more preferably 7% by mass or less (for example, 5% by mass or less)] with respect to the total amount of the resin and the tertiary amine compound (for example, polyurethane (A) containing a tertiary amine compound; the total amount of polyurethane (A) containing a tertiary amine compound and resin (B); the total amount of polyurethane (A) which may contain a tertiary amine compound, resin (B) and the tertiary amine compound separately blended into the dope, etc.).

[0148] As the proportion of the specific tertiary amine compound, it is, for example, 0.01 to 20% by mass, preferably 0.1 to 10% by mass, more preferably 0.2 to 5% by mass, etc. with respect to the total amount of the resin and the tertiary amine compound.

[0149] From the viewpoints of moldability (e.g., spinnability) and physical properties (strength, yellowing resistance, durability, etc.), the proportion of the decomposition product of the tertiary amine compound may be 1% by mass or less, preferably 0.5% by mass or less, with respect to the total amount of the resin and the decomposition product of the tertiary amine compound.

[0150] When the dope contains a crosslinking structure regulator, the proportion of the crosslinking structure regulator can be selected, for example, from the range of about 0.0001% by mass or more with respect to the total amount of the resin and the crosslinking structure regulator (e.g., the total amount of polyurethane (A) containing the crosslinking structure regulator; the total amount of polyurethane (A) containing the crosslinking structure regulator and resin (B); the total amount of polyurethane (A) which may contain the crosslinking structure regulator, resin (B) and the crosslinking structure regulator separately blended in the dope, etc.), and may be 0.0005% by mass or more, preferably 0.001% by mass or more, more preferably 0.002% by mass or more, 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., 2% by mass or less)].

[0151] As the specific proportion of the crosslinking structure regulator, it is, for example, 0.0001 to 10% by mass, preferably 0.001 to 5% by mass, more preferably 0.002 to 2% by mass, etc. with respect to the total amount of the resin and the crosslinking structure regulator.

[0152] The dope may contain a solvent.

[0153] As the solvent, depending on the type of resin (B), the molding method, the form of the molded article, etc., for example, organic solvents {for example, amide solvents [for example, chain aliphatic amides such as N,N-dimethylformamide, N,N-dimethylacetamide (DMAc), etc.; cyclic aliphatic amides such as N-methyl-2-pyrrolidone, N-vinylpyrrolidone, etc.], halogen solvents (for example, 1,1-difluorotetrachloroethane, dichloromethane, etc.), ether solvents (for example, cyclic ethers such as 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, etc.), ester solvents (for example, fatty acid esters such as ethyl acetate, etc.), ketone solvents (for example, chain ketones such as acetone, methyl ethyl ketone, etc.; cyclic ketones such as cyclohexanone, etc.), nitrile solvents (for example, acetonitrile, etc.), sulfur solvents (for example, sulfone solvents such as diethyl sulfone, etc.; sulfoxide solvents such as dimethyl sulfoxide, etc.), alcohol solvents (for example, alkanols such as methanol, ethanol, isopropanol, etc.), amine oxide solvents (for example, N-methylmorpholine N-oxide), etc.}, water, etc. can be mentioned.

[0154] The solvent may be used alone or in combination of two or more.

[0155] Among them, polar solvents (for example, aprotic polar solvents or protic polar solvents, particularly aprotic polar solvents) such as amide solvents (for example, DMAc, dimethylformamide, dimethyl sulfoxide, vinylpyrrolidone, etc.), sulfur solvents (for example, dimethyl sulfoxide, etc.) can be preferably used. The SP value [(cal / cm) 1 / 2 of such a solvent (for example, polar solvent) may be, for example, about 5 to 16, preferably 6 to 15, more preferably 6.5 to 14 (for example, 7 to 13).

[0156] Note that the SP value may be, for example, the Hansen solubility parameter (method by Hansen). Such a Hansen solubility parameter can be measured or calculated by, for example, the Hansen sphere method or the like.

[0157] In a dope containing a solvent, the solid content (or components other than the solvent, resin, other components, etc.) concentration may be, for example, 1 to 90% by mass (for example, 3 to 95% by mass), preferably 5 to 80% by mass (for example, 10 to 70% by mass), and more preferably 15 to 60% by mass (for example, 20 to 50% by mass), etc., depending on the molding mode and the like.

[0158] In particular, when the dope is used as a spinning solution (solution for spinning), etc., the solid content concentration may be, for example, 5 to 80% by mass, preferably 8 to 70% by mass, and more preferably 10 to 60% by mass (for example, 15 to 55% by mass, 20 to 50% by mass, 25 to 45% by mass, 35 to 55% by mass, 30 to 60% by mass).

[0159] In the dope (for example, a dope containing a solvent), the proportion of polyurethane (A) may be, for example, 0.1% by mass or more (for example, 0.5% by mass or more), preferably 1% by mass or more (for example, 2% by mass or more), and more preferably about 3% by mass or more (for example, 5% by mass or more), and may also be 8% by mass or more (for example, 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.

[0160] In the dope, the upper limit value of the proportion of polyurethane (A) can be appropriately selected according to whether it contains a solvent or not, etc. In particular, in a dope containing a solvent, the proportion (upper limit value of the proportion) of polyurethane (A) can be selected from a range of about 99% by mass or less (for example, 97% by mass or less), 95% by mass or less (for example, 90% by mass or less), preferably 85% by mass or less (for example, 80% by mass or less), and more preferably 75% by mass or less (for example, 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), etc.

[0161] 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 set to a suitable concentration in the spinning solution as described above), etc. For example, at 40°C, it may be selected from a range of about 10 poise (= 1 Pa·s = 1000 mPa·s) or more, 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 about 1000 poise or more (for example, 1100 poise or more, 1200 poise or more), and it may also be 1300 poise or more (for example, 1400 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.

[0162] The viscosity (upper limit value) of the dope is not limited, but may be selected from a range of about 100,000 poises or less at 40 °C, 80,000 poises or less (for example, 60,000 poises or less, 50,000 poises or less, 40,000 poises or less), preferably 30,000 poises or less (for example, 20,000 poises or less, 15,000 poises or less, 12,000 poises or less), more preferably about 10,000 poises or less (for example, 9,000 poises or less, 8,000 poises or less), and may even be 7,000 poises or less (for example, 6,500 poises or less, 6,000 poises or less, 5,500 poises or less, 5,000 poises or less, 4,500 poises or less, 4,400 poises or less, 4,300 poises or less, 4,200 poises or less, 4,100 poises or less, 4,000 poises or less, 3,900 poises or less, 3,800 poises or less, 3,700 poises or less, 3,600 poises or less, 3,500 poises or less, 3,400 poises or less, 3,300 poises or less, 3,200 poises or less, 3,100 poises or less, 3,000 poises or less, 2,900 poises or less, 2,800 poises or less, 2,700 poises or less, 2,600 poises or less, 2,500 poises or less, 2,400 poises or less, 2,300 poises or less, 2,200 poises or less, 2,100 poises or less, 2,000 poises or less, 1,900 poises or less, 1,850 poises or less, 1,800 poises or less), etc.

[0163] The viscosity of the dope may change over time, but when used as the dope, it may maintain (hold) a viscosity within the above range.

[0164] Also, the viscosity of the dope may change over time, but the change is preferably small, and more preferably it thickens over time.

[0165] For example, at 40°C, in terms of the ratio (ratio, viscosity ratio, viscosity after 24 hours / initial viscosity, V2 / V1) between the viscosity (initial viscosity, V1) at the time of dope preparation (for example, when polyurethane (A) is dissolved (mixed)) and the viscosity (viscosity after 24 hours, V2) after 24 hours have elapsed (left standing) after preparation (for example, after dissolution (mixing)), it 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, 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), and 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) may be satisfied, and 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.) may be satisfied.

[0166] The upper limit of the viscosity after 24 hours / initial viscosity (V2 / V1) is not particularly limited, and for example, it may be selected from the range of about 20 or less (for example, 15 or less), for example, 10 or less (for example, 8 or less, 7 or less, 6 or less), preferably 5 or less (for example, 4.5 or less, 4 or less), more preferably 3.5 or less (for example, 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).

[0167] Specific examples of the viscosity after 24 hours / initial viscosity (V2 / V1) include, for example, 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, 1.05 to 1.2, etc.

[0168] Within such a range, it is easy to efficiently suppress a decrease in viscosity or moderately increase the viscosity, and it is advantageous in terms of moldability (such as spinnability) and physical properties.

[0169] In addition, the viscosities (V1, V2) of the dope are measured using a viscometer (for example, a falling ball viscometer) (for example, measured according to the method of ASTM D1343-69), with the state where the solid components (such as polyurethane (A), resin (B), etc.) are sufficiently dissolved (dispersed) at 40°C as the starting point (initial viscosity (V1)), and the state 24 hours after this starting point as the end point (viscosity after 24 hours (V2)), and can be measured, for example, by the method described below.

[0170] 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, the dope containing the solvent and the resin (B) may be obtained by mixing the polyurethane (A) into the system containing the resin (B) (or its raw material) and the solvent, or may be obtained by mixing the polyurethane (A), the resin (B), and the solvent at once.

[0171] Note that during the mixing, heating and stirring may be appropriately performed for the purpose of promoting the melting (dissolving) or dispersion of the polyurethane (A), and various components may also be mixed.

[0172] The dope can be used for applications according to the form of the molded product, etc., and for example, it may be suitably used for the production of fibers (yarns).

[0173] Specifically, fibers (yarns) can be produced by spinning the dope.

[0174] The fiber contains polyurethane (A) as a resin, and typically may be a polyurethane fiber (yarn) {for example, a polyurethane fiber containing polyurethane as the main resin [for example, mainly containing polyurethane (A), mainly containing polyurethane (A) and polyurethane (B)] (for example, a polyurethane elastic fiber)}.

[0175] The spinning method is not particularly limited as long as it is a method using the dope, and for example, a solution spinning method (for example, a dry spinning method) may be suitably used.

[0176] In such a spinning method (for example, dry spinning method), spinning conditions and the like can also be those known or customary and are not particularly limited. In addition, the obtained fiber (yarn) may be treated (or surface-treated) with a customary additive (fiber treatment agent or finishing agent, for example, silicones, sizing agents, the aforementioned components such as inorganic substances and inorganic porous materials, etc.) at an appropriate timing (for example, at the time of winding up, etc.). (A customary additive may be applied, adhered to, or contained.)

[0177] By using the dope (or polyurethane (A)), a molded article [fiber (yarn), etc.] can be obtained. Therefore, such a molded article is also included in the present invention.

[0178] Such a molded article may usually reflect the form of polyurethane (A) or the dope. For example, when 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.

Examples

[0179] Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited by the examples at all.

[0180] First, the measurement and evaluation methods of various physical properties, etc. are shown. Unless otherwise specified, the measurement was carried out under the conditions of 23°C and a relative humidity of 60%.

[0181] <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. A viscosity tube with an inner diameter of 31.4 (±0.2) mm was used.

[0182] <Viscosity ratio of the initial and after 24 hours in a 20 mass% DMAc solution>

[0183] The sample (polyurethane, polyurethane (A)) was sufficiently dried (at about 40 °C under a reduced pressure of 1 kPa or less for 8 hours in a vacuum dryer), and then mixed with N,N-dimethylacetamide (DMAc) to a concentration of 20% by mass, and stirred at 23 °C (atmospheric temperature) for 4 hours to prepare a 20% by mass DMAc solution.

[0184] For stirring, a cylindrical container was used, and a helical ribbon stirring blade that covered 85% of the outer shape of the projection surface with respect to the bottom surface of the container was used.

[0185] The obtained 20% by mass DMAc solution was allowed to stand at 40 °C (the temperature of the constant temperature bath of the falling ball viscometer) for 2 hours to stabilize it, and then the initial viscosity at 40 °C (the viscosity after standing for 2 hours to stabilize) and the viscosity after standing for 24 hours (after an additional 24 hours elapsed) were measured by the method described in the <Viscosity>.

[0186] Then, from the obtained initial viscosity and the viscosity after 24 hours, the viscosity ratio (initial viscosity / viscosity after 24 hours) was calculated.

[0187] <Viscosity ratio of the dope at the initial stage and after 24 hours> The dope (spinning solution) was allowed to stand at 40 °C (the temperature of the constant temperature bath of the falling ball viscometer) for 2 hours to stabilize it, and then the initial viscosity at 40 °C (the viscosity after standing for 2 hours to stabilize) and the viscosity after standing for 24 hours (after an additional 24 hours elapsed) were measured by the method described in the <Viscosity>.

[0188] Then, from the initial viscosity and the viscosity after 24 hours, the viscosity ratio (initial viscosity / viscosity after 24 hours) was calculated.

[0189] <Molecular weight> The measurement of the molecular weight by GPC was carried out under the following conditions. Column: 2 SHODEX KF-806M manufactured by Showa Denko K.K. Solvent: N,N-dimethylacetamide (DMAc) 1 ml / min Temperature: 40 °C Detector: Differential refractometer (RI detector) Standard substance: Polystyrene

[0190] <Fiber diameter and size> Embedded in an embedding agent (paraffin resin or epoxy resin), and an image was taken at a magnification at which the fiber cross-section perpendicular to the fiber axis could be observed by SEM to obtain the fiber diameter. The area of the fibers randomly extracted from each of the taken images within the same image was measured, and the diameter obtained by converting to a perfect circle was measured to the first decimal place in μm units. The simple arithmetic mean of the results for 10 filaments was calculated, and the value obtained by rounding the first decimal place was taken as the fiber diameter (μm). Here, when there are hollow parts or gap parts in the fiber cross-section perpendicular to the fiber axis, the area of the hollow parts was also added to the area of the fibers. Also, the length and size (dimensions) were measured in the same way by SEM.

[0191] <Spinnability> In dry spinning, the number of thread breaks when continuously spinning a 22 dtex, 3-filament yarn (fiber) for 96 hours was counted, and the following determination was made. Number of thread breaks 0 times = Very good ◎ Number of thread breaks 1 - 2 times = Good 〇 Number of thread breaks 3 - 4 times = Passable △ Number of thread breaks 5 times or more = Poor ×

[0192] <Elongation at break, Tensile strength> The elongation at break and tensile strength were measured by subjecting the sample to a tensile test using an Instron 5564 type tensile testing machine. A sample with a gauge length of 5 cm (L1) was repeatedly stretched 5 times by 300% at a tensile speed of 50 cm / min. At this time, the stress at 300% elongation was taken as (G1). Next, the length of the sample was held for 30 seconds at 300% elongation. The stress after holding for 30 seconds was taken as (G2). Next, the elongation of the sample was allowed to recover, and the length of the sample when the stress became 0 was taken as (L2). This operation of 300% elongation, holding, and recovery was repeated until the sample was cut during the 6th elongation. The stress at break was taken as (G3), and the sample length at break was taken as (L3). Hereinafter, the above characteristics were calculated by the following formula. Breaking strength (cN) = (G3) 20 or more: ◎, 17 or more and less than 20: 〇, 14 or more and less than 17: △, less than 14: × Elongation at break (%) = 100 × ((L3) - (L1)) / (L1) 480 or more: ◎, 460 or more and less than 480: 〇, 430 or more and less than 460: △, less than 430: ×

[0193] <Heat resistance> A two-way half tricot with 9 wales per inch and 18 courses per inch on the machine, consisting of 85% by weight of nylon filaments (24 dtex, 7 filaments) and 15% by weight of a sample (fiber, 44 dtex), was produced by a normal knitting method to obtain a knitted fabric in the raw state. The obtained knitted fabric in the raw state was preset under the conditions of 170 °C for 60 seconds with 3% elongation, 0.1 ml of Chemical 1 was applied, and then (almost simultaneously or within 1 minute), 0.1 ml of Chemical 2 was applied. After that, dry heat treatment (after dry heat treatment at 175 °C for 60 seconds, taken out once and cooled to room temperature, and then dry heat treatment at 180 °C for 60 seconds) was carried out. Next, it was subjected to a flexure tester with a maximum elongation of 20% alternately in the longitudinal and transverse directions at 2 times per second. For Chemical 1, a spinning oil agent for mineral oil-based nylon containing 1% oleic acid was used. For Chemical 2, an aqueous copper acetate solution (copper concentration 100 ppm) was used. The knitted fabric in the raw state with Chemical 1 and Chemical 2 attached in this way was a model that reproduced the fact that a small amount of machine oil (mixed with metal components) during knitting and a spinning oil agent for nylon were slightly attached to the nylon-based stretch knitted fabric in the pre-dyeing stage. The amount of Chemical 1 attached to 0.9 g of the knitted fabric in the raw state was 3.0 mg, and the amount of Chemical 2 attached was 3.0 mg. The obtained stretch fabric was dyed by a conventional method. The degree of damage to the sample (polyurethane) structure in the obtained dyed stretch fabric was visually observed or observed under magnification, and the determination was made according to the following criteria. The determination was carried out by 5 people, and the mode (the determination that appeared most frequently) was used. Also, when the determination was divided into 2 people, 2 people, and 1 person, the determination was "△". ◎: No damage and the knitted structure is also homogeneous. 〇: No damage. △: The raw material is sunken and shows depression. When observed under magnification, the sample (polyurethane elastic fiber) is embrittled. ×: There are holes in the fabric.

[0194] <Composite durability, yellowing resistance> For composite durability, the sample yarn was stretched by 100%, and the retention rate of the breaking strength after the exposure treatments of (a), (b), and (c) below was determined. For the measurement sample form and measurement method of yellowing resistance (yellow discoloration), the sample yarn was wound around a 5×5 cm sample plate with the minimum load closely so that the influence of the color of the sample plate did not appear, and used as a sample. The front surfaces of the sample and the standard white surface for daily use (4.3.4 of JIS Z 8722) were covered in close contact with a homogeneous, flat, and transparent glass plate of about 1 mm. The measurement of the b value was calculated based on the following formula using a Hunter color difference meter according to Method C (Hunter method) of JIS L 1013. The number of measurements was 5 times, and the average value was adopted. b = 7.0(Y - 0.847Z) / Y 1 / 2 (However, X, Y, and Z were calculated according to JIS Z 8701) The yellowing resistance (yellow discoloration) was evaluated by the degree of yellowing (hereinafter abbreviated as Δb) after the exposure treatments of (a) and (b) for the sample. During each exposure treatment, the degree of yellowing 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 type weather meter manufactured by Suga Test Instruments Co., Ltd., the sample was exposed for 25 hours at a temperature and humidity of 63°C and 60% RH. (b) Nitrogen oxide (NOx) exposure treatment Using a sealed container (Scott tester) in which the sample stand rotates, the sample was exposed for 20 hours at a temperature and humidity of 10 ppm of NO2 gas, 40°C, and 60% RH. (c) Chlorine bleach (Cl2) exposure treatment The sample was exposed to a 500 ppm aqueous solution of "Kao Hi-Ter" manufactured by Kao Corporation in a constant temperature bath at 40°C for 30 minutes, and then the cycle of 10-minute water washing was repeated 8 times. The judgment criteria are as follows.

[0195] ·Composite durability ◎ for 60% or more, 〇 for 40% or more and less than 60%, △ for 20% or more and less than 40%, × for less than 20%

[0196] ·Degree of yellowing ◎ for less than 3, 〇 for 3 or more and less than 6, △ for 6 or more and less than 10, × for 10 or more

[0197] [Reference Example 1] A solution (35% by mass) of 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) in N,N'-dimethylacetamide (hereinafter sometimes abbreviated as DMAc) was polymerized to obtain a polymer solution PUUV. The molar ratio of 4,4'-MDI to 2,4'-MDI was 97:3. Diethylamine was used as the polymerization terminator, and the molar ratio of ethylenediamine to diethylamine was 8:1. Next, as an antioxidant, a 1:1 (mass ratio) mixture of a polyurethane (DuPont's "Metacure" (registered trademark) 2462) produced by the reaction of t-butyldiethanolamine and methylene-bis-(4-cyclohexylisocyanate) and a condensation polymer of p-cresol and divinylbenzene (DuPont's "Metacure" (registered trademark) 2390) was used, and a DMAc solution (35% by mass) of this mixture was prepared as an antioxidant solution.

[0198] The above solution PUUV, antioxidant solution, and ethylenediamine were uniformly mixed at a ratio of 99.5 parts by mass, 0.5 parts by mass, and 0.1 parts by mass, respectively, to obtain a spinning dope (spinning solution, dopant) with a concentration of 35% by mass.

[0199] The initial viscosity of the spinning dope was 1900 P (poise) (=190,000 mPa·s), and the viscosity after 24 hours was 1850 P. The viscosity ratio was calculated to be 0.97.

[0200] The as-obtained spinning dope was directly used as a dope, and dry spinning was carried out at a dry nitrogen temperature of 300 °C or higher so that DMAc and floating ethylenediamine in the spinning solution were reduced to 1 / 100 or less of the spinning dope content.

[0201] At this time, the speed ratio of the godet roller to the winder was set to 1:1.20, and fibers of 22 dtex / 3 fil multifilament (polyurethane elastic fibers) were spun. The treating agent (oil agent) described below was fed to the roller by the oiling roller before winding. The winding speed was 600 m / min, and a surface drive winder was used to wind onto a cylindrical paper tube with a length of 58 mm through a traverse guide with a winding width of 38 mm, obtaining dry-spun fibers (polyurethane elastic fibers) as a 500 g wound yarn package.

[0202] The obtained fibers were ply yarns in which three filaments were plyed together. The rotation speed of the oiling roller was adjusted so that the amount of treating agent applied was a predetermined amount with respect to the yarn. Also, the amount of treating agent applied was measured using n-hexane as an extraction solvent in accordance with JIS-L1073 (Test Methods for Synthetic Fiber Filament Yarns).

[0203] The composition of the treating agent used here was 80 parts by mass of polydimethylsiloxane having a viscosity of 1×10 -5 m 2 / s at 25 °C, 15 parts by mass of mineral oil having a viscosity of 1.2×10 -5 m 2 / s at 25 °C, and 5 parts by mass of magnesium distearate with an average particle diameter of 0.5 μm.

[0204] The number average molecular weight of the polymer constituting the fiber (or yarn) was 20,000.

[0205] The results including various evaluations are shown in a table.

[0206] [Reference Example 2] In Reference Example 1, the prepared solution PUUV was directly used as a spinning dope (spinning dope with a concentration of 35% by mass).

[0207] The initial viscosity of the spinning dope was 2200 P, and the viscosity after 24 hours was 2000 P. The viscosity ratio was calculated to be 0.91.

[0208] Then, using this spinning dope as it was, dry-spun fibers were obtained in the same manner as in Reference Example 1.

[0209] The number average molecular weight of the polymer constituting the fiber (or yarn) was 27,000.

[0210] The results including various evaluations are shown in a table. As is clear from the table, when using the above dope (spinning dope), compared with the case of using the dope (spinning dope) obtained in Reference Example 1, the resulting fibers were inferior in terms of physical properties (breaking strength, elongation at break, heat resistance, yellowing resistance).

[0211] [Reference Example 3] In Reference Example 2, a spinning dope (a spinning dope 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.

[0212] The initial viscosity of the spinning dope was 3000 P, and the viscosity after 24 hours was 2450 P. The viscosity ratio was calculated to be 0.82.

[0213] Then, using this spinning dope as it was, dry-spun fibers were obtained in the same manner as in Reference Example 1.

[0214] The number average molecular weight of the polymer constituting the fiber (or yarn) was 30,000.

[0215] The results including various evaluations are shown in a table.

[0216] As is clear from the table, when using the above dope (spinning dope), the resulting fibers showed inferior physical properties (breaking strength, heat resistance, and yellowing resistance) compared to the case where the dope (spinning dope) obtained in Reference Example 1 was used.

[0217] [Reference Example 4] Fibrous polyurethane [polyurethane composition (PTMG, MDI, BDO (butanediol)), ground product of post-consumer yarn produced by melt spinning method (length about 2 mm, fiber diameter (average fiber diameter) 244 μm)] was prepared. For grinding, a three-blade helical cutting type grinder was used to grind until a size of 2 mm was achieved.

[0218] Regarding this polyurethane, the initial viscosity in a 20 mass% DMAc solution was measured to be 2200 P, and the viscosity after 24 hours was 1975 P. The viscosity ratio was calculated to be 0.90.

[0219] Also, the number average molecular weight of this polyurethane was 23000, and there was no peak (peak top) in the region with a number average molecular weight of 1 million or more (the region of the GPC chart corresponding to a number average molecular weight of 1 million or more).

[0220] Next, the above polyurethane, the spinning dope obtained in Reference Example 1, and DMAc were mixed and stirred at 23 °C (atmospheric temperature) for 4 hours to prepare a solution.

[0221] For stirring, a cylindrical container was used, and a helical ribbon stirring blade that covers 85% of the outer shape of the projection area with respect to the bottom surface of the container was used.

[0222] Then, the resulting solution was further concentrated to obtain a dope. The concentration of this dope was 35 mass%, and the ratio of the above polyurethane in the total solid content (polymer, polyurethane) contained in the dope was made 30 mass%.

[0223] Also, the initial viscosity of this dope was 2200 P, and the viscosity after 24 hours was 1700 P. The viscosity ratio was calculated to be 0.77.

[0224] Then, using this dope, dry-spun fibers were obtained in the same manner as in Reference Example 1.

[0225] The number average molecular weight of the polymer constituting the fiber (or yarn) was 20,000.

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

[0227] As is clear from the table, when using the dope (spinning solution) containing the above polyurethane, the resulting fibers had inferior physical properties (yellowing resistance) compared to the case of using the dope (spinning solution) obtained in Reference Example 1.

[0228] [Example 1] Fibrous polyurethane [polyurethane composition (PTMG, MDI, BDO), ground product of post-consumer yarn manufactured by dry spinning method (length about 2 mm, fiber diameter (average fiber diameter) 260 μm)] was prepared. For the grinding, a three-blade helical cutting type grinder was used to grind until a size of 2 mm was obtained.

[0229] For this polyurethane, the initial viscosity in a 20 mass% DMAc solution was measured to be 1800 P, and the viscosity after 24 hours was 2000 P. The viscosity ratio was calculated to be 1.11.

[0230] Also, the number average molecular weight of this polyurethane was 30,000, and there was a peak (existed) in the region where the number average molecular weight was 1,000,000 or more.

[0231] Then, using this polyurethane, a dope was obtained in the same manner as in Reference Example 4.

[0232] The concentration of this dope was 35% by mass, and the proportion of the above polyurethane in the total solid content (polymer, polyurethane) contained in the dope was made to be 30% by mass.

[0233] Also, the initial viscosity of this dope was 2600 P, and the viscosity after 24 hours was 2600 P, and the viscosity ratio of these was calculated to be 1.00.

[0234] Then, using this dope, dry-spun fibers were obtained in the same manner as in Reference Example 1.

[0235] The number average molecular weight of the polymer constituting the fiber (or yarn) was 29,000.

[0236] The results including various evaluations are shown in a table.

[0237] As is clear from the table, when using the dope (spinning dope) containing the above polyurethane, compared with the case of using the dope (spinning dope) obtained in Reference Example 1, the spinnability was remarkably improved, and the physical properties (elongation at break, heat resistance, composite durability) of the obtained fibers were also remarkably excellent.

[0238] As described above, the dope (spinning dope) obtained in Reference Example 1 is a dope that can achieve excellent physical properties compared to the dopes of Reference Examples 2 to 3 manufactured separately from Reference Example 1. However, compared with the dope obtained in this Reference Example 1, such remarkable improvement in spinnability and further remarkable improvement in physical properties were achieved.

[0239] [Example 2] In Example 1, 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 above polyurethane in the total solid content (polymer, polyurethane) contained in the dope was made to be 60% by mass.

[0240] The initial viscosity of this dope was 1950 P, and the viscosity after 24 hours was 2600 P, and the viscosity ratio of these was calculated to be 1.33.

[0241] 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 yarn) was 29,500.

[0242] The results including various evaluations are shown in a table.

[0243] As is clear from the table, when using the dope (spinning dope) containing the above polyurethane, the spinnability was significantly improved compared to the case of using the dope (spinning dope) obtained in Reference Example 1, and the physical properties (breaking strength, elongation at break, heat resistance, composite durability) of the resulting fibers were also significantly excellent.

[0244] The physical property (breaking strength) was significantly superior compared to Example 1 with a lower addition ratio.

[0245] [Example 3] In Example 1, except that a DMAc dispersion (35% by mass) of metal soap (magnesium stearate) and a DMAc dispersion (35% by mass) of surfactant (polyoxyethylene lauryl ether) were uniformly mixed (formulated) so that each was 1 part by mass with respect to 98 parts by mass of the dope, a dope was obtained in the same manner as in Example 1.

[0246] The initial viscosity of this dope was 1900 P, and the viscosity after 24 hours was 2700 P, and the viscosity ratio was calculated to be 1.42.

[0247] Then, using this dope, dry-spun fibers were obtained in the same manner as in Reference Example 1.

[0248] The number average molecular weight of the polymer constituting the fiber (or yarn) was 30,000.

[0249] The results including various evaluations are shown in a table.

[0250] As is clear from the table, when using the dope (spinning solution) containing the above polyurethane, the spinnability was significantly improved compared to the case of using the dope (spinning solution) obtained in Reference Example 1, and the physical properties (breaking strength, elongation at break, heat resistance, composite durability) of the resulting fibers were also significantly excellent.

[0251] In addition, the spinnability and physical properties (breaking strength, elongation at break) were significantly superior compared to Example 1 in which no metal soap and surfactant were blended.

[0252] Therefore, even when using a polyurethane containing a metal soap (and further a surfactant), the same results can be obtained.

[0253] To confirm this, a dry-spun fiber was obtained in the same manner as above by previously incorporating the same amount of metal soap (and surfactant) into the polyurethane, and similar tendencies were shown in terms of spinnability and physical properties. In addition, for the polyurethane previously containing a metal soap (and surfactant), the initial viscosity in a 20% by mass DMAc solution was measured to be 1760 P, the viscosity after 24 hours was 1970 P, and the viscosity ratio of these was calculated to be 1.12.

[0254] [Example 4] In Example 1, a dope was obtained in the same manner as in Example 1, except that a DMAc solution (35% by mass) of an antioxidant (ethylene-1,2-bis(3,3-bis[3-t-butyl-4-hydroxyphenyl]butyrate)) was uniformly mixed (formulated) so as to be 3 parts by mass with respect to 97 parts by mass of the dope.

[0255] The initial viscosity of this dope was 1800 P, the viscosity after 24 hours was 2600 P, and the viscosity ratio of these was calculated to be 1.44.

[0256] Then, using this dope, a dry-spun fiber was obtained in the same manner as in Reference Example 1.

[0257] Incidentally, the number average molecular weight of the polymer constituting the fiber (or yarn) was 31,000.

[0258] The results including various evaluations are shown in a table.

[0259] As is also clear from the table, when using the dope (spinning solution) containing the above polyurethane, compared with the case of using the dope (spinning solution) obtained in Reference Example 1, the spinnability was significantly improved, and the physical properties (breaking strength, elongation at break, heat resistance, composite durability) of the obtained fibers were also significantly excellent.

[0260] Incidentally, the spinnability and physical properties (breaking strength, heat resistance, composite durability) were significantly excellent compared with Example 1 in which no antioxidant was compounded.

[0261] Therefore, even when using a polyurethane containing an antioxidant, similar results can be obtained.

[0262] To confirm this, a dry-spun fiber was obtained in the same manner as above by previously incorporating the antioxidant into the polyurethane in the same amount, and similar tendencies were shown in terms of spinnability and physical properties. Incidentally, for the polyurethane previously containing the antioxidant, the initial viscosity in a 20 mass% DMAc solution was measured to be 1710 P, the viscosity after 24 hours was 1900 P, and the viscosity ratio was calculated to be 1.11.

[0263] [Example 5] Fibrous polyurethane [a polyurethane composition (PTMG, MDI, EDA), a ground product of post-consumer yarn produced by the dry spinning method (length about 2 mm, fiber diameter (average fiber diameter) 220 μm)] was prepared.

[0264] Incidentally, for the grinding, a three-blade helical cutting type grinder was used to grind until a size of 2 mm was obtained.

[0265] Regarding this polyurethane, the initial viscosity in a 20 mass% DMAc solution was measured to be 2900 P, and the viscosity after 24 hours was 3050 P. The viscosity ratio of these was calculated to be 1.05.

[0266] Also, the number average molecular weight of this polyurethane was 30,000, and there was a peak in the region of a number average molecular weight of 1,000,000 or more.

[0267] Then, using this polyurethane, a dope was obtained in the same manner as in Reference Example 4.

[0268] The concentration of this dope was 35 mass%, and the ratio of the above polyurethane to the total solid content (polymer, polyurethane) contained in the dope was made 30 mass%.

[0269] Also, the initial viscosity of this dope was 2600 P, and the viscosity after 24 hours was 2800 P. The viscosity ratio of these was calculated to be 1.08.

[0270] Then, using this dope, dry-spun fibers were obtained in the same manner as in Reference Example 1.

[0271] Incidentally, the number average molecular weight of the polymer constituting the fiber (or yarn) was 30,000.

[0272] The results including various evaluations are shown in a table.

[0273] As is clear from the table, when using the dope (spinning solution) containing the above polyurethane, compared with the case of using the dope (spinning solution) obtained in Reference Example 1, the spinnability was significantly improved, and the physical properties (breaking strength, elongation at break, heat resistance, composite durability) of the obtained fibers were also significantly excellent.

[0274] Although it is a polyurethane different from that used in Example 1, it was found that it shows a similar tendency.

[0275] [Example 6] Fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground product of a wound body produced by the dry spinning method (length approximately 2 mm, fiber diameter (average fiber diameter) 225 μm)] was prepared.

[0276] Note that for the grinding, a three-blade helical cutting type grinder was used to grind until a size of 2 mm was achieved.

[0277] Regarding this polyurethane, the initial viscosity in a 20 mass% DMAc solution was measured to be 3000 P, and the viscosity after 24 hours was 3900 P. These viscosity ratios were calculated to be 1.30.

[0278] Also, the number average molecular weight of this polyurethane was 30500, and there was a peak in the region where the number average molecular weight was 1 million or more.

[0279] Then, using this polyurethane, a dope was obtained in the same manner as in Reference Example 4. The concentration of this dope was 35 mass%, and the ratio of the above polyurethane in the total solid content (polymer, polyurethane) contained in the dope was made 30 mass%.

[0280] Also, the initial viscosity of this dope was 2900 P, and the viscosity after 24 hours was 3200 P. These viscosity ratios were calculated to be 1.10.

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

[0282] Note that the number average molecular weight of the polymer constituting the fiber (or yarn) was 33000.

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

[0284] As is clear from the table, when using the dope (spinning solution) containing the above polyurethane, compared with the case of using the dope (spinning solution) obtained in Reference Example 1, the spinnability was remarkably improved, and the physical properties (breaking strength, elongation at break, heat resistance, composite durability) of the resulting fibers were also remarkably excellent.

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

[0286] In particular, perhaps because the viscosity ratio after 24 hours in a 20 mass% DMAc solution was also larger than that of the polyurethane used in Example 1, the improvement in spinnability was particularly remarkable.

[0287] [Example 7] Fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), a ground product of a wound body produced by the dry spinning method (length about 2 mm, fiber diameter (average fiber diameter) 560 μm)] was prepared.

[0288] Note that for the grinding, a three-blade helical cutting type grinder was used to grind until it reached a size of 2 mm.

[0289] Regarding this polyurethane, the initial viscosity in a 20 mass% DMAc solution was measured to be 4200 P, and the viscosity after 24 hours was 6500 P, and these viscosity ratios were calculated to be 1.55.

[0290] Also, the number average molecular weight of this polyurethane was 30000, and there was a peak in the region where the number average molecular weight was 1 million or more.

[0291] Next, a 20 mass% DMAc solution of the above polyurethane was concentrated under reduced pressure at 60 °C until it became a 35 mass% DMAc solution, mixed with the spinning solution obtained in Reference Example 1, and stirred for 2 hours to prepare a solution (dope).

[0292] Note that for the stirring, a cylindrical container was used, and a helical ribbon stirring blade that covers 85% of the outer shape of the projection surface with respect to the bottom surface of the container was used.

[0293] 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 made to be 30% by mass.

[0294] Also, the initial viscosity of this dope was 2900 P, and the viscosity after 24 hours was 4200 P, and the viscosity ratio of these was calculated to be 1.45.

[0295] Then, using this dope, dry-spun fibers were obtained in the same manner as in Reference Example 1.

[0296] The number average molecular weight of the polymer constituting the fiber (or yarn) was 30,000.

[0297] The results including various evaluations are shown in a table.

[0298] As is also clear from the table, when using the dope (spinning dope) blended with the above polyurethane, compared with the case of using the dope (spinning dope) obtained in Reference Example 1, the spinnability was remarkably improved, and the physical properties (breaking strength, elongation at break, heat resistance, composite durability, yellowing resistance) of the obtained fibers were also remarkably excellent.

[0299] It was a polyurethane different from that used in Example 1, and although the method for preparing the dope was also changed, it was found that the same tendency was shown.

[0300] [Example 8] Fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground product of a wound body produced by the dry spinning method (length about 2 mm, fiber diameter (average fiber diameter) 1265 μm)] was prepared. For the grinding, a three-blade helical cutting type grinder was used, and the grinding was carried out until it reached a size of 2 mm.

[0301] Regarding this polyurethane, the initial viscosity in a 20% by mass DMAc solution was measured to be 2900 P, and the viscosity after 24 hours was 8600 P, and the viscosity ratio of these was calculated to be 2.97.

[0302] Also, the number average molecular weight of this polyurethane was 29,000, and there was a peak in the region where the number average molecular weight was 1,000,000 or more.

[0303] Next, a 20 mass% DMAc solution of the above polyurethane was concentrated under reduced pressure at 80 °C until it became a 35 mass% DMAc solution, and mixed with the spinning dope obtained in Reference Example 1 to prepare a solution (dope). Note that a cylindrical container was used for stirring, and a helical ribbon stirring blade that covered 85% of the outer shape of the projection surface with respect to the bottom surface of the container was used.

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

[0305] Also, the initial viscosity of this dope was 2680 P, and the viscosity after 24 hours was 3800 P, and the viscosity ratio was calculated to be 1.42.

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

[0307] Note that the number average molecular weight of the polymer constituting the fiber (or yarn) was 29,000.

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

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

[0310] It was found that although it was a polyurethane different from that used in Example 1 and the method for preparing the dope was also changed, it showed a similar tendency.

[0311] [Example 9] Fibrous polyurethane [a polyurethane composition (PTMG, MDI, EDA), a ground product of a wound body produced by the dry spinning method (length about 2 mm, fiber diameter (average fiber diameter) 1205 μm)] was prepared. For the grinding, a three-blade helical cutting type grinder was used to grind until a size of 2 mm was obtained.

[0312] Regarding this polyurethane, the initial viscosity in a 20 mass% DMAc solution was measured to be 4200 P, and the viscosity after 24 hours was 10500 P, and the viscosity ratio of these was calculated to be 2.50.

[0313] Also, the number average molecular weight of this polyurethane was 28000, and there was a peak in the region of a number average molecular weight of 1 million or more.

[0314] Next, the above polyurethane, the spinning dope obtained in Reference Example 1, and diethylamine were mixed and stirred for 2 hours to prepare a solution (dope).

[0315] For the stirring, a cylindrical container was used, and a helical ribbon stirring blade that covers 85% of the outer shape of the projection surface with respect to the bottom surface of the container was used.

[0316] The concentration of this dope was 35 mass%, and the ratio of the above polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30 mass%, and the ratio of diethylamine was 0.2 mass%.

[0317] Also, the initial viscosity of this dope was 3300 P, and the viscosity after 24 hours was 4300 P, and the viscosity ratio of these was calculated to be 1.30.

[0318] Then, using this dope, dry-spun fibers were obtained in the same manner as in Reference Example 1.

[0319] Note that the number average molecular weight of the polymer constituting the fiber (or yarn) was 44000.

[0320] The results including various evaluations are shown in a table.

[0321] As is clear from the table, when using the dope (spinning solution) containing the above polyurethane, compared with the case of using the dope (spinning solution) obtained in Reference Example 1, the spinnability was significantly improved, and the physical properties (breaking strength, elongation at break, heat resistance, composite durability) of the resulting fibers were also significantly excellent.

[0322] Although it was a polyurethane different from that used in Example 1 and the method for preparing the dope was also changed, it was found that the same tendency was shown.

[0323] [Example 10] Fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground product of a wound body produced by the dry spinning method (length about 2 mm, fiber diameter (average fiber diameter) 1245 μm)] was prepared. Note that for grinding, a three-blade helical cutting type grinder was used to grind until a size of 2 mm was obtained.

[0324] Regarding this polyurethane, the initial viscosity in a 20 mass% DMAc solution was measured to be 4200 P, and the viscosity after 24 hours was 6600 P, and the viscosity ratio of these was calculated to be 1.57.

[0325] Also, the number average molecular weight of this polyurethane was 30000, and there was a peak in the region where the number average molecular weight was 1 million or more.

[0326] Next, 2 parts by mass of a 20 mass% DMAc solution of a surfactant (polyoxyethylene styrenated phenyl ether) was blended with 98 parts by mass of a 20 mass% DMAc solution of the above polyurethane to prepare a solution. And it was mixed with the spinning solution obtained in Reference Example 1.

[0327] Note that for stirring, a cylindrical container was used, and a helical ribbon stirring blade that covers 85% of the outer shape of the projection surface with respect to the bottom surface of the container was used.

[0328] Then, the obtained solution was further concentrated to obtain a dope.

[0329] The concentration of this dope was 35% by mass, and the proportion of the above 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.

[0330] Also, the initial viscosity of this dope was 3300 P, and the viscosity after 24 hours was 4300 P, and the viscosity ratio was calculated to be 1.30.

[0331] Then, using this dope, dry-spun fibers were obtained in the same manner as in Reference Example 1.

[0332] The number average molecular weight of the polymer constituting the fiber (or yarn) was 40,000.

[0333] The results including various evaluations are shown in a table.

[0334] As is clear from the table, when using the dope (spinning dope) containing the above polyurethane, compared with the case of using the dope (spinning dope) obtained in Reference Example 1, the spinnability was significantly improved, and the physical properties (breaking strength, elongation at break, heat resistance, composite durability) of the obtained fibers were also significantly excellent.

[0335] It was found that although it was a polyurethane different from that used in Example 1 and the method for preparing the dope was also changed, the same tendency was shown.

[0336] [Example 11] Fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), pulverized product of a wound body produced by the dry spinning method (length about 2 mm, fiber diameter (average fiber diameter) 1222 μm)] was prepared.

[0337] For pulverization, a three-blade helical cutting type pulverizer was used to pulverize until it reached a size of 2 mm.

[0338] Regarding this polyurethane, the initial viscosity in a 20% by mass DMAc solution was measured to be 2800 P, and the viscosity after 24 hours was 9000 P. The viscosity ratio was calculated to be 3.21.

[0339] Also, the number average molecular weight of this polyurethane was 33000, and there was a peak in the region where the number average molecular weight was 1 million or more.

[0340] Next, the above polyurethane, the spinning dope obtained in Reference Example 1, and a 20% by mass DMAc solution of a hindered phenol antioxidant {ethylene-1,2-bis(3,3-bis[3-t-butyl-4-hydroxyphenyl]butyrate)} were mixed to prepare a solution.

[0341] For stirring, a cylindrical container was used, and a helical ribbon stirring blade that covered 85% of the outer shape of the projection area with respect to the bottom surface of the container was used.

[0342] Then, the obtained solution was further concentrated to obtain a dope.

[0343] The concentration of this dope was 35% by mass, and the ratio of the above polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass, and the ratio of the hindered phenol antioxidant was 1.0% by mass.

[0344] Also, the initial viscosity of this dope was 4200 P, and the viscosity after 24 hours was 8080 P. The viscosity ratio was calculated to be 1.92.

[0345] Then, using this dope, dry-spun fibers were obtained in the same manner as in Reference Example 1.

[0346] Note that the number average molecular weight of the polymer constituting the fiber (or thread) was 34000.

[0347] The results including various evaluations are shown in a table.

[0348] As is clear from the table, when using the dope (spinning solution) containing the above polyurethane, the spinnability was significantly improved compared to the case of using the dope (spinning solution) obtained in Reference Example 1, and the physical properties (breaking strength, elongation at break, heat resistance, composite durability) of the resulting fibers were also significantly excellent.

[0349] It was found that a polyurethane different from that used in Example 1 and with a changed method for preparing the dope showed a similar tendency.

[0350] [Example 12] Fibrous polyurethane [polyurethane composition (PTMG, MDI, EDA), ground product of a wound body produced by the dry spinning method (length about 2 mm, fiber diameter (average fiber diameter) 660 μm)] was prepared.

[0351] For the grinding, a three-blade helical cutting type grinder was used to grind until a size of 2 mm was obtained.

[0352] For this polyurethane, the initial viscosity in a 20% by mass DMAc solution was measured to be 2800 P, and the viscosity after 24 hours was 9000 P. The viscosity ratio was calculated to be 3.21.

[0353] Also, the number average molecular weight of this polyurethane was 33000, and there was a peak in the region of a number average molecular weight of 1 million or more.

[0354] Next, a hindered phenolic antioxidant {ethylene-1,2-bis(3,3-bis[3-t-butyl-4-hydroxyphenyl]butyrate)} and a 20% by mass DMAc solution of ethylenediamine were mixed with the above polyurethane to prepare a solution (dope). For the stirring, a cylindrical container was used, and a helical ribbon stirring blade covering 85% of the outer shape of the projection area with respect to the bottom surface of the container was used.

[0355] The concentration of this dope was 35% by mass (among which, the concentration of the hindered phenolic antioxidant was 0.7% by mass and the concentration of ethylenediamine was 0.07% by mass).

[0356] Also, the initial viscosity of this dope was 7200 P, and the viscosity after 24 hours was 12100 P. The viscosity ratio was calculated to be 1.68.

[0357] Then, using this dope, dry-spun fibers were obtained in the same manner as in Reference Example 1.

[0358] The number average molecular weight of the polymer constituting the fiber (or yarn) was 53000.

[0359] The results including various evaluations are shown in a table.

[0360] As is clear from the table, when using the dope (spinning solution) blended with the above polyurethane, compared with the case of using the dope (spinning solution) obtained in Reference Example 1, the spinnability was significantly improved, and the physical properties (breaking strength, composite durability) of the obtained fibers were also significantly excellent.

[0361] It was a polyurethane different from that used in Example 1, and the ratio of polyurethane in the dope was also changed from Example 12 (using only the above polyurethane in the dope), but it was found that the same tendency was shown.

[0362] From the comparison with other examples, it was suggested that when combining the above polyurethane with the polymerization components of polyurethane separately to form a dope, it is more advantageous in terms of physical properties.

[0363] [Example 13] A polyurethane-urea resin molded product (RIM molded product) [ground product (granular, particle size about 0.1 - 2 mm) of a polyurethane-urea composition (PTMG, MDI, EDA)] was prepared. For grinding, a three-blade helical cutting type grinder was used for grinding.

[0364] Regarding this polyurethane, the initial viscosity in a 20% by mass DMAc solution was measured to be 2900 P, and the viscosity after 24 hours was 3200 P. The viscosity ratio was calculated to be 1.10.

[0365] Next, the above polyurethane, the spinning dope obtained in Reference Example 1, diethylamine, and DMAc were mixed and stirred at 40 °C (atmospheric temperature) for 2 hours to prepare a solution.

[0366] For stirring, a cylindrical container was used, and a helical ribbon stirring blade that covered 85% of the outer shape of the projection surface with respect to the bottom surface of the container was used.

[0367] Then, the obtained solution was further concentrated to obtain a dope. The concentration of this dope was 35% by mass, and the ratio of the above polyurethane in the total solid content (polymer, polyurethane) contained in the dope was 30% by mass, and the ratio of diethylamine was 0.06% by mass.

[0368] Also, the initial viscosity of this dope was 3000 P, and the viscosity after 24 hours was 2800 P. The viscosity ratio was calculated to be 0.93.

[0369] 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 yarn) was 12000.

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

[0371] As is clear from the table, when using the dope (spinning dope) containing the above polyurethane, compared with the case of using the dope (spinning dope) obtained in Reference Example 1, the spinnability was significantly improved, and the physical properties (heat resistance) of the obtained fibers were also significantly excellent.

[0372] Although it was a polyurethane different from that used in Example 1, it was found to show a similar tendency. From a comparison with other examples, it was suggested that a fibrous polyurethane shape was more advantageous in terms of spinnability and physical properties.

[0373] [Example 14] A fibrous polyurethane [a polyurethane composition (PTMG, MDI, EDA), a wound body of post-consumer yarn produced by the wet spinning method (length about 2 mm, fiber diameter (average fiber diameter) 660 μm)] was prepared.

[0374] For pulverization, a three-blade helical cutting method pulverizer was used, and pulverization was carried out until a size of 2 mm was obtained.

[0375] Regarding this polyurethane, the initial viscosity in a 20 mass% DMAc solution was measured to be 2800 P, and the viscosity after 24 hours was 12000 P, and the viscosity ratio of these was calculated to be 4.29.

[0376] Also, the number average molecular weight of this polyurethane was 33000, and there was no peak in the region of a number average molecular weight of 1 million or more.

[0377] Next, the above polyurethane and DMAc were mixed and stirred at 23 °C (atmospheric temperature) for 2 hours to prepare a solution. For stirring, a cylindrical container was used, and a helical ribbon stirring blade that covered 85% of the outer shape of the projection surface with respect to the bottom surface of the container was used.

[0378] And the obtained solution was further concentrated to obtain a dope.

[0379] The concentration of this dope was 35 mass%. Also, the initial viscosity of this dope was 6600 P, and the viscosity after 24 hours was 13400 P, and the viscosity ratio of these was calculated to be 2.03.

[0380] And using this dope, dry-spun fibers were obtained in the same manner as in Reference Example 1.

[0381] The number average molecular weight of the polymer constituting the fiber (or yarn) was 34,000.

[0382] The results including various evaluations are shown in a table.

[0383] As is clear from the table, when using the dope (spinning solution) containing the above polyurethane, compared with the case of using the dope (spinning solution) obtained in Reference Example 1, there is no inferiority in the physical properties of the obtained fiber or the result is significantly excellent in some physical properties (composite durability).

[0384] In addition, from the comparison with other examples, it was suggested 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.

[0385] [Example 15] A fibrous polyurethane [a polyurethane composition (PTMG, MDI, EDA), a wound body of post-consumer yarn produced by the wet spinning method (length about 2 mm, fiber diameter (average fiber diameter) 1290 μm)] was prepared. For pulverization, a three-blade helical cutting type pulverizer was used and pulverization was carried out until it reached a size of 2 mm.

[0386] For this polyurethane, the initial viscosity in a 20% by mass DMAc solution was measured to be 2200 P, the viscosity after 24 hours was 8850 P, and the viscosity ratio was calculated to be 4.02.

[0387] Also, the number average molecular weight of this polyurethane was 33,000, and there was a peak in the region where the number average molecular weight was 1,000,000 or more.

[0388] Next, the above polyurethane and DMAc were mixed and stirred at 23 °C (ambient temperature) for 2 hours to prepare a solution. For stirring, a cylindrical container was used, and a helical ribbon stirring blade that covers 85% of the outer shape of the projection surface with respect to the bottom surface of the container was used.

[0389] Then, the obtained solution was further concentrated to obtain a dope.

[0390] The concentration of this dope was 35% by mass. Also, the initial viscosity of this dope was 3020 P, and the viscosity after 24 hours was 6450 P. The viscosity ratio was calculated to be 2.14.

[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 yarn) was 42,000.

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

[0394] As is clear from the table, when using the dope (spinning solution) containing the above polyurethane, compared with the case of using the dope (spinning solution) obtained in Reference Example 1, the spinnability can be significantly improved, and the resulting fibers are also comparable in physical properties or significantly superior in some physical properties (composite durability).

[0395] In addition, from the comparison with other examples, it was suggested that when 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.

[0396] [Table 1]

Industrial Applicability

[0397] According to the present invention, additives and the like can be provided. Such additives can be suitably used as additives for dopes.

Claims

Claim 1: An additive for a dope containing a solvent, wherein the solvent contains N,N-dimethylacetamide, when the viscosity at 40 °C when dissolved in N,N-dimethylacetamide at 20% by mass is V1, and the viscosity after dissolution and after 24 hours at 40 °C is V2, V1 is 1800 to 4200 poise, V2 is 2000 to 12000 poise, and the value of V2 / V1 is 1.02 to 3.5, and it has a structure with a polymer diol and a diisocyanate as starting materials, the polymer diol contains polytetramethylene ether glycol, and the diisocyanate contains diphenylmethane diisocyanate, and is composed of a polyurethane (A) (however, excluding the case where the polyurethane (A) is any of the following (a), (b), (c)). (a) A polyurethane urea composed of a polymer diol having a number average molecular weight of 1000 to 10000, a diisocyanate, and a mixed diamine composed of ethylenediamine as a chain extender and a diamine represented by the following formula (1), wherein the content of the diamine represented by the following formula (1) in the mixed diamine is 10 to 30 mol% 【Chemical 1】 (wherein X and Y each represent -(CH ２ ), and n represents an integer of 1 to 3.) (b) A polyurethane urea composed of a polymer diol having a number average molecular weight of 1000 to 10000, a diisocyanate, and a mixed diamine composed of ethylenediamine as a chain extender and 1,3-diaminocyclohexane, wherein the molar ratio of ethylenediamine to 1,3-diaminocyclohexane in the mixed diamine is ethylenediamine / 1,3-diaminocyclohexane = 90 / 10 (c) A polyurethane urea composed of a polymer diol having a number average molecular weight of 1000 to 10000, a diisocyanate, and a mixed diamine composed of ethylenediamine as a chain extender and 1,3-propylenediamine, wherein the molar ratio of ethylenediamine to 1,3-propylenediamine in the mixed diamine is ethylenediamine / 1,3-diaminocyclohexane = 80 / 20). Claim 2: An additive for a dope containing a solvent, wherein the solvent contains N,N-dimethylacetamide, When dissolved in N,N-dimethylacetamide at 20% by mass at 40°C, the viscosity is V1, and after dissolution, when the viscosity after 24 hours at 40°C is V2, V1 is 1800 to 4200 poises, V2 is 2000 to 12000 poises, the value of V2 / V1 is 1.3 or more and 5 or less, and it has a structure with polymer diol and diisocyanate as starting materials, the polymer diol contains polytetramethylene ether glycol, and the diisocyanate contains diphenylmethane diisocyanate, an additive composed of polyurethane (A).

3. The additive according to claim 2, wherein the value of V2 / V1 of the polyurethane (A) is 1.3 to 3.

5.

4. The additive according to claim 1, wherein the value of V2 / V1 of the polyurethane (A) is 1.05 to 3.

21.

5. The additive according to claim 1, wherein V2 of the polyurethane (A) is 2100 poises or more.

6. The additive according to claim 1, wherein the polyurethane (A) satisfies the following (i) or (ii). (i) V2 is 2000 to 5000 poises, and the value of V2 / V1 is 1.05 or more (ii) V2 is more than 5000 poises

7. The additive according to claim 1, wherein the number average molecular weight of the polyurethane (A) is 10000 or more.

8. The additive according to claim 1, wherein the polyurethane (A) contains at least one selected from metal soaps, surfactants, and antioxidants.

9. The additive according to claim 1, wherein the polyurethane (A) contains a metal soap in a proportion of 0.003 to 3% by mass.

10. 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 contains an antioxidant in a proportion of 0.002 to 5% by mass.

11. The additive according to claim 1, wherein the polyurethane (A) is fibrous.

12. The additive according to claim 1, wherein the polyurethane (A) is at least one selected from molded articles, molded scraps, and post-consumer products stored for one month or more after production.

13. The additive according to claim 1, which is a viscosity modifier.

14. The additive according to claim 1, wherein the dope is a polyurethane dope.

15. A dope containing the polyurethane (A) according to any one of claims 1 to 14 and N,N-dimethylacetamide.

16. The dope according to claim 15, wherein the proportion of the polyurethane (A) is 1% by mass or more.

17. The dope according to claim 15, wherein the number average molecular weight of the resin constituting the dope is 10,000 or more.

18. The dope according to claim 15, comprising at least one selected from metal soaps, surfactants, and antioxidants.

19. The dope according to claim 15, having a solid content concentration of 5 to 80% by mass.

20. [[ID=...]] The dope according to claim 15, wherein when the viscosity of the dope at the time of preparation is V1 at 40°C and the viscosity of the dope after 24 hours at 40°C after preparation is V2, the value of the viscosity of the dope V2 / the viscosity of the dope V1 is 0.8 or more.

21. The dope according to claim 15, wherein when the viscosity of the dope at the time of preparation is V1 at 40°C and the viscosity of the dope after 24 hours at 40°C after preparation is V2, the value of the viscosity of the dope V2 / the viscosity of the dope V1 is 1 to 5.

22. The dope according to claim 15, wherein when the viscosity of the dope at the time of preparation is V1 at 40°C and the viscosity of the dope after 24 hours at 40°C after preparation is V2, the value of the viscosity of the dope V2 / the viscosity of the dope V1 is 1.01 to 3.5, and the viscosity of the dope V1 and the viscosity of the dope V2 are 1,000 to 10,000 poises.

23. A method for producing fibers by spinning the dope according to claim 15.

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