WO2019139217A1 - Polyurethaneurea elastic yarn having good toughness and preparation method therefor - Google Patents

Abstract

The present invention relates to a polyurethaneurea elastic yarn in which an isomer of diisocyanate is applied to secure excellent toughness without degrading polymerization stability and heat resistance, and a preparation method therefor.

Description

Polyurethane-urea elastic yarn having good toughness and method for manufacturing the same

The present invention relates to a polyurethane-urea elastic yarn having good toughness and a method for producing the same, and more particularly, to a polyurethane-urea elastic yarn having good toughness, Urethane elastic yarn.

When polyurethane urea elastic yarn is used as a fabric by knitting with a relative yarn (nylon, polyester, cotton, etc.), a polyurethane urea having excellent toughness is used to secure excellent knitting workability under high rpm and high DR conditions. Need elasticity.

The polyurethane urea elastic yarn has been conventionally most commonly used for improving the properties of yarn and problems caused thereby are as follows.

1) In modifying polyol and diisocyanate, the modulus has been increased by increasing the hard segment content by increasing the capping ratio. However, since the excess hydrogen bonding strength is decreased, the elongation of elastic yarn is decreased to inhibit knitting workability .

2) Increasing the content of soft segment by decreasing the capping ratio or weakening the hydrogen bonding force by using the auxiliary chain extender has increased the elongation of the elastic yarn. However, since the heat resistance is insufficient, it is difficult to obtain proper properties after fabric processing Problems arise.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made to solve the above problems, and it is an object of the present invention to provide a polyurethane-urea elastic yarn excellent in toughness and a method for producing the same.

As means for solving the above-mentioned problems,

The polyurethane elastic yarn having good toughness according to an embodiment of the present invention,

Characterized in that the polyurethane prepolymer comprises a diisocyanate mixture comprising from 1 to 5 mol% of 2,4'-MDI, the capping ratio is from 1.6 to 2.0, and the secondary polymer has a solids content of from 32 to 38 wt% .

Further, the rate of increase of turbidity per hour of the secondary polymer is 0.05 to 0.20 NTU / hr.

Further, the toughness of the elastic yarn is 200 g * cm or more.

Further, the elastic yarn has a heat resistance of 45% or more.

A method for producing a polyurethane-urea elastic yarn having good toughness according to an embodiment of the present invention includes:

Contacting the diisocyanate mixture comprising 1 to 5 mol% of polyol and 2,4'-MDI with a capping ratio of 1.6 to 2.0 to produce a polyurethane prepolymer; Adding a solvent to the prepolymer, contacting the polymer with a diamine chain extender and an amine chain terminator to prepare a second polymer having a solid content of 32 to 38% by weight; And then spinning the second polymerizate to prepare a polyurethane-urea elastic yarn.

Further, the rate of increase of turbidity per hour of the secondary polymer is 0.05 to 0.20 NTU / hr.

Further, the toughness of the elastic yarn is 200 g * cm or more.

Further, the elastic yarn has a heat resistance of 45% or more.

According to an embodiment of the present invention,

Characterized in that it comprises the polyurethane-urea elastic yarn and is excellent in knitting workability under high rpm and high DR conditions.

INDUSTRIAL APPLICABILITY The polyurethane-urea elastic yarn of good toughness according to the present invention and its production method have the effect of securing excellent toughness without lowering polymerization stability and heat resistance. Further, the polyurethane-urea elastic yarn of the present invention has an excellent knitting workability at high rpm and high DR conditions when it is used as a fabric by knitting with nylon, polyester, cotton or the like as a mating yarn.

Hereinafter, the polyurethane-urea elastic yarn of good toughness according to the present invention and its production method will be described in more detail.

The present invention is characterized in that the polyurethane prepolymer comprises a diisocyanate mixture containing 1 to 5 mol% of 2,4'-MDI, the capping ratio is 1.6 to 2.0, and the second polymer has a solid content of 32 to 38 wt% To a polyurethane urea elastic yarn having good toughness.

The present invention also relates to a process for preparing a polyurethane prepolymer by reacting a diisocyanate mixture comprising a polyol and 1 to 5 mol% of 2,4'-MDI, with a capping ratio of 1.6 to 2.0. Adding a solvent to the prepolymer, contacting the polymer with a diamine chain extender and an amine chain terminator to prepare a second polymer having a solid content of 32 to 38% by weight; And then spinning the second polymerizate to prepare a polyurethane-urea elastic yarn. The present invention also relates to a method for producing a polyurethane-urea elastic yarn having good toughness.

Suitable polyols for use in the present invention include polytetramethylene ether glycol, polytrimethylene ether glycol, polypropylene glycol polycarbonate diol, mixtures of alkylene oxide and lactone monomers, copolymers of poly (tetramethylene ether) glycol, 3- A copolymer of methyl-tetrahydrofuran and tetrahydrofuran, or a mixture of two or more thereof, but is not limited thereto.

The present invention uses a diisocyanate mixture. The diisocyanate mixture preferably contains 1 to 5 mol% of 2,4'-MDI which is a diisocyanate isomer. When the 2,4'-MDI is less than 1 mol% in the diisocyanate mixture, the strength of the polyurethane urea elastic yarn is lowered. When the 2,4'-MDI is more than 5 mol%, the heat resistance of the polyurethane urea elastic yarn is lowered.

Examples of the diisocyanates other than 2,4'-MDI constituting the diisocyanate mixture include aromatic diisocyanates, aromatic diisocyanates, and alicyclic diisocyanates. Specific examples thereof include 4,4-diphenylmethane Diisocyanate, 1,5'-naphthalene diisocyanate, 1,4'-phenylene diisocyanate, hexamethylene diisocyanate, 1,4'-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, isophorone Diisocyanate, toluene diisocyanate, butylene diisocyanate, hydrogenated P, P-methylene diisocyanate, and the like, or a mixture of two or more thereof, but is not limited thereto, Diphenylmethane diisocyanate is preferable.

Also, it is preferable that the diisocyanate mixture contains 95 to 99 mol% of a diisocyanate other than 2,4'-MDI, for example, 4,4-diphenylmethane diisocyanate.

The polyol and the diisocyanate mixture are contacted to prepare a polyurethane prepolymer, wherein the diisocyanate mixture may be added all at once or in two or more stages and in any order.

When the polyol is contacted with the diisocyanate mixture in the present invention, the capping ratio, which means the diisocyanate molar ratio / polyol molar ratio, is preferably within the range of 1.6 to 2.0. When the capping ratio is less than 1.6, the hard segment content is excessively low, resulting in insufficient power and heat resistance of the elastic yarn. When the hard segment content is over 2.0, the hard segment content is excessively high.

The secondary polymer can be prepared by adding a suitable solvent to the polyurethane prepolymer and using a mixture of a single chain extender or a mixture of chain extenders with a single chain terminator or a mixture of chain terminators.

The solvent may be, for example, DMAc, DMF, DMSO, N-methylpyrrolidinone (NMP) or the like (including a mixture), preferably DMAc.

In the present invention, the chain extender is at least one kind of diamine, and examples of usable diamines include hydrazine, ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 1,2- Butane), 1,3-butanediamine (1,3-diaminobutane), 1,4-butanediamine (1,4-diaminobutane), 1,3-diamino-2,2- , 4'-methylenebis-cyclohexylamine, 1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane, 1,6-hexanediamine, 2,2- 1-methylcyclohexane, N-methylaminobis (3-propylamine), 2-methyl-1,5-pentanediamine, 1,5-diaminopentane, 1,4-cyclo 1,3-diamino-4-methylcyclohexane, 1,3-cyclohexane-diamine, 1,1-methylene-bis (4,4'-diaminohexane) 5,5-trimethylcyclohexane, 1,3-pentanediamine (1,3-diaminopentane), m-xylylenediamine, and mixtures thereof. It is not limited. Ethylene diamine is preferred as the chain extender.

In the present invention, the chain terminator is at least one amine, and examples of usable amines include, but are not limited to, diethylamine, cyclohexylamine, n-hexylamine, and mixtures thereof. As the chain terminator, diethylamine is preferable.

In the present invention, an effective amount of various additives may be used in the polyurethane-urea elastic yarn of the present invention, so long as the advantageous aspects of the present invention are not impaired. Examples include quenching agents such as titanium dioxide and stabilizers such as hydrotalcite, mixtures of huntite and hydro-magneite, barium sulphate, hindered phenol and zinc oxide, dye and dye enhancers, antimicrobial agents, Oil, hindered amine light stabilizer, UV blocker and the like.

The secondary polymer of the present invention is characterized by having a solid content of 32 to 38% by weight. When the solid content is less than 32% by weight, the viscosity retention rate is excessively low, and the aging time is excessively increased, so that the polymerization stability can not be secured and the amount of radiant heat required for drying during dry spinning increases, If the weight% is exceeded, the turbidity increase rate is excessively high and the tendency of fine phase separation increases, which makes it impossible to secure the polymerization stability and the strength and elongation of the elastic yarn are deteriorated.

The secondary polymer of the present invention is characterized in that the turbidity rising rate per hour is 0.05 to 0.20 NTU / hr. Since the turbidity increase rate and the viscosity aging rate are in a proportional relationship, when the turbidity increase rate is less than 0.05 NTU / hr, the viscosity aging rate is excessively low and when the turbidity increase rate exceeds 0.20 NTU / hr, the viscosity aging rate becomes excessively high .

The polyurethane urea elastic yarn is produced by spinning the secondary polymer of the present invention, and in this case, it is preferable to dry-spin it.

The polyurethane-urea elastic yarn of the present invention has a toughness of 200 g * cm or more. If it is less than 200g * cm, the strength, modulus or elongation of the elastic yarn is very low, which may cause problems in workability when knitted with the counter yarn.

The polyurethane-urea elastic yarn of the present invention is characterized by having a heat resistance of 45% or more. If the ratio is less than 45%, thermal embrittlement occurs due to a high heat treatment process for setting the post-process of the knitted fabric mixed with the counterpart yarn, resulting in yellowing of the fabric.

The polyurethane-urea elastic yarn of the present invention or the polyurethane-urea elastic yarn produced by the production method of the present invention can be used as a mixed knit fabric by knitting with a counter yarn. In this case, the counterpart yarn is nylon, polyester, cotton, and the like, and is not limited as long as it is suitable for knitting with polyurethane-urea elastic yarn. The mixed knit fabric of the present invention has a characteristic of exhibiting excellent knitting workability under high rpm and high DR (elongation degree) conditions because it contains polyurethane urea having excellent toughness.

Hereinafter, the present invention will be described in detail with reference to specific examples and comparative examples, which should not be construed as limiting the scope of the present invention only for illustrating the present invention.

Methods for measuring the properties of the elastic yarn shown in the following Examples and Comparative Examples are as follows.

(1) Capping ratio measurement method

Capping ratio = diisocyanate mole ratio / polyol mole ratio

(2) Viscosity increase rate (elapsed time rate)

 800 g of secondary polymer was weighed into a 1 L reactor, and the viscosity of the polymer was measured at 40 rpm while continuously maintaining the temperature of the polymer at 40 ° C (40 ° C hot water was passed through the reactor jacket) at 8 rpm.

* Viscosity per hour Loss rate [Poise / hr] = (viscosity after 48 hours - initial viscosity) / 48

(3) Turbidity measurement method

 Turbidity Meters (Model: HI 98703) were used to measure the turbidity of the secondary polymer (polyurethane urea sampled immediately after completion of the polymerization of the polyurethane prepolymer and chain extender) five times, using the minimum value.

(4) Turbidity Measuring rate of change with time

 The turbidity is measured at intervals of 24 hours while storing the second polymer in an oven at 40 ° C.

   Change in turbidity over time [NTU / hr] = (turbidity after 48 hr - initial turbidity) / 48

(5) Measurement of toughness

 toughness [g * cm] = 200% modulus * breaking length

The tensile strength, elongation, 200% modulus (load applied to the yarn at 200% elongation) was measured using an automatic power meter (MEL, Textechno) with a load cell of 32 cN, a sample length of 10 cm and a tensile speed of 100 cm / Measure.

(6) Heat resistance measurement

 Heat resistance (power retention before and after heat treatment) (%) = yarn power after heat treatment / untreated yarn power X 100

   1) Yarn power (5th unload @ 200%) Measuring method: Using automatic mechanical strength measuring device (MEL, Textechno), sample 10cm x 20 strands, 300% After reading the power value of the 200% section, divide it by the number of strands and de.

   2) Heat treatment method of yarn: The yarn is stretched 100% in the atmospheric state, treated at 190 ℃ for 1 minute, and 100 ℃ for 30 minutes.

Example  One

A mixture of 2 mol% of 2,4'-diphenylmethane diisocyanate (2,4'-MDI) and 98 mol% of 4,4'-diphenylmethane diisocyanate was reacted with polytetramethylene glycol to obtain a capping ratio (CR ) Of 1.75 and an NCO% of 2.81%. As a chain extender, 100 mol% of ethylenediamine was used, diethylamine was used as a chain terminator, and diethylenetriamine was used as a viscosity stabilizer. The ratio of the chain extender and the chain terminator was 7: 1, and the amine used was prepared to a total concentration of 7 mol%. Dimethyl acetamide was used as the solvent, and the solid content of the final polymer (secondary polymer) was 35.2 % By weight of polyurethane-urea spinning solution. The spinning solution obtained as described above is dry-spun at a speed of 1,000 m / min to prepare a polyurethane-urea elastic yarn of 20 denier and 1 filament.

Example 2

A polyurethane-urea elastic yarn was prepared in the same manner as in Example 1, except that a mixture of 3 mol% 2,4'-MDI and 97 mol% 4,4'-MDI was reacted.

Example 3

A polyurethane-urea elastic yarn was prepared in the same manner as in Example 1, except that a mixture of 4 mol% 2,4'-MDI and 96 mol% 4.4'-MDI was reacted.

Example 4

A polyurethane-urea elastic yarn was prepared in the same manner as in Example 1, except that a mixture of 5 mol% of 2,4'-MDI and 95 mol% of 4,4'-MDI was reacted.

Example 5

A polyurethane-urea elastic yarn was prepared in the same manner as in Example 2, except that the solid content of the second polymer was 36.5% by weight.

Example 6

A polyurethane-urea elastic yarn was prepared in the same manner as in Example 2, except that the solid content of the second polymer was 37.8 wt%.

Comparative Example 1

A polyurethane-urea elastic yarn was prepared in the same manner as in Example 1, except that a mixture of 0.5 mol% of 2,4'-MDI and 99.5 mol% of 4,4'-MDI was reacted.

Comparative Example 2

A polyurethane-urea elastic yarn was prepared in the same manner as in Example 1 except that a mixture of 7 mol% 2,4'-MDI and 93 mol% 4,4'-MDI was reacted.

Comparative Example 3

The polyurethane-urea elastic yarn was prepared in the same manner as in Example 2, except that the capping ratio was 2.05.

Comparative Example 4

The polyurethane-urea elastic yarn was prepared in the same manner as in Example 2, except that the solid content of the secondary polymer was 40.2% by weight.

Comparative Example 5

The polyurethaneurea elastic yarn was produced in the same manner as in Example 2, except that the capping ratio was 1.45.

Comparative Example 6

A polyurethane-urea elastic yarn was prepared in the same manner as in Example 2, except that the solid content of the secondary polymer was 30.2% by weight.

Properties of the polyurethane-urea elastic yarn obtained by the above Examples and Comparative Examples are shown in Table 1 below.

	2,4'-MDI [mol%]	Capping ratio	Secondary solids [%]	Secondary Polymer Viscosity [Poise]	Viscosity over time [poise / hr]	Turbidity increase rate [NTU / hr]	Toughness [g * cm]	Strength [g / de]	Shindo [%]	Heat resistance [%]
Example 1	2%	1.75	35.2%	1300	80	0.15	216.3	1.32	503	58.1
Example 2	3%	1.75	35.2%	1300	71	0.13	209.4	1.40	506	56.0
Example 3	4%	1.75	35.2%	1300	61	0.11	213.8	1.50	509	53.7
Example 4	5%	1.75	35.2%	1300	52	0.10	225.0	1.64	500	52.2
Example 5	3%	1.75	36.5%	1450	78	0.15	209.1	1.41	510	55.7
Example 6	3%	1.75	37.8%	1600	89	0.16	205.4	1.38	501	55.9
Comparative Example 1	0.5%	1.75	35.2%	1300	116	0.33	198.2	1.00	486	61.0
Comparative Example 2	7%	1.75	35.2%	1300	21	0.02	178.6	1.60	470	44.8
Comparative Example 3	3%	2.05	35.2%	1050	131	0.43	196.2	1.05	436	64.5
Comparative Example 4	3%	1.75	40.2%	1900	120	0.37	186.0	1.20	465	54.3
Comparative Example 5	3%	1.45	35.2%	1550	7	0.01	99.2	0.98	451	39.1
Comparative Example 6	3%	1.75	30.2%	700	10	0.01	169.2	1.16	470	44.2

Examples 1 to 6 show that the toughness of the polyurethane-urea elastic yarn is more preferably 200 g * cm or more at a turbidity rise rate of 0.05 to 0.20 NTU / hr, an intensity of 1.10 g / de or more, an elongation of 500% Level. ≪ / RTI >

In Comparative Example 1, the turbidity rising rate was as high as 0.33 NTU / hr, and the viscosity aging rate was increased to 100 P / hr or more, indicating that the polymerization stability could not be secured and the strength was lowered.

In Comparative Example 2, the turbidity rising rate was excessively low at 0.02 NTU / hr, and the viscosity aging rate was reduced to 50 P / hr or less, so that the aging time for formation of a viscosity suitable for spinning became abnormally long, '-DI decreased due to the weakening of the hydrogen bonding force as the content of MDI increases.

Comparative Examples 3 and 4 show that the polymerization stability can not be secured because the turbidity rising rate is excessively high, and Comparative Examples 5 and 6 show that the turbidity rising rate is excessively low so that the polymerization stability can not be secured.

Claims (10)

1. Characterized in that the polyurethane prepolymer comprises a diisocyanate mixture comprising from 1 to 5 mol% of 2,4'-MDI, the capping ratio is from 1.6 to 2.0, and the secondary polymer has a solids content of from 32 to 38 wt% Polyurethane urea elastic yarn with good toughness.
2. The polyurethane-urea elastic yarn according to claim 1, wherein the rate of turbidity increase per hour of the secondary polymer is 0.05 to 0.20 NTU / hr.
3. The polyurethane-urea elastic yarn according to claim 1, wherein the toughness of the elastic yarn is 200 g * cm or more.
4. The polyurethane-urea elastic yarn according to claim 1, wherein the elastic yarn has a heat resistance of 45% or more.
5. Contacting the diisocyanate mixture comprising 1 to 5 mol% of polyol and 2,4'-MDI with a capping ratio of 1.6 to 2.0 to produce a polyurethane prepolymer; Adding a solvent to the prepolymer, contacting the polymer with a diamine chain extender and an amine chain terminator to prepare a second polymer having a solid content of 32 to 38% by weight; And preparing a polyurethane-urea elastic yarn by spinning the second polymerizate. The method for producing a polyurethane-urea elastic yarn having good toughness.
6. 6. The process for producing a polyurethane-urea elastic yarn according to claim 5, wherein the rate of turbidity increase per hour of the second polymer is 0.05 to 0.20 NTU / hr.
7. 6. The method for producing a polyurethane-urea elastic yarn according to claim 5, wherein the toughness of the elastic yarn is 200 g * cm or more.
8. The method for producing a polyurethane-urea elastic yarn according to claim 5, wherein the heat resistance of the elastic yarn is 45% or more.
9. A mixed knit fabric excellent in knitting workability under high rpm and high DR conditions including the polyurethaneurea elastic yarn of any one of claims 1 to 4.
10. A mixed knit fabric excellent in knitting workability under high rpm and high DR conditions including the polyurethane-urea elastic yarn by the production method of any one of claims 5 to 8.