Anti-pilling merino wool fabric, including clothing and manufacturing method thereof

Abstract

The present invention provides a wool fabric with anti-pilling coating and resistance to fiber loss on the fabric surface. The coating is formed by a coating formulation of at least two diisocyanates, at least two catalysts, a water dispersant, a buffer and water. The coating formulation provides a polycarbodiimide crosslinker that is reactive to relatively small reactive groups on the polypeptides of the wool fabric and promotes crosslinking between polypeptides of the wool fabric under relatively mild processing conditions, thereby enhancing the mechanical strength of the wool fabric compared to conventional treatment methods for wool fabrics, while no significant impact on the original facing Merino wool fabric and / or clothing and fiber loss on the fabric surface are observed. A corresponding coating formulation and a method for manufacturing anti-pilling wool fabric are also provided. The present invention is used for finished wool fabrics, the fibers of which have been dyed with one or more colorants, and / or one or more dyes, and / or one or more reactive dyes.

Description

Technical Field

[0001] The present invention provides a merino wool fabric resistant to pilling. Specifically, the present invention provides a merino wool fabric resistant to pilling, the wool fabric having a pilling resistance of at least level 4 as determined by the JIS L1076 ICI method and a fiber loss of less than 0.2% w / w after 15 cycles of home laundering without using a laundry net. Also provided are related manufacturing methods and garments comprising the fabric. Background Art

[0002] Compared with synthetic fibers such as polyester, fibers of animal fibers such as merino wool are relatively weak in tensile strength and are prone to fiber breakage. Fabrics comprising wool fibers are prone to fiber loss on the fabric surface during wearing or laundering, forming fuzz. In addition, the presence of cuticle scales on the surface of merino wool fibers also causes a difference in the coefficient of friction between fibers. The presence of mechanical actions including washing, rubbing, and abrasion on the surface of the wool fabric will cause the directional movement of fibers, thereby allowing the fuzz to entangle into pill pellets, and the aggregated pellets will eventually fall off from the surface of the merino wool fabric.

[0003] To reduce fiber loss and pilling on the surface of merino wool fabrics, conventional solutions mainly involve reducing fiber loss and fuzz entanglement and pill pellet aggregation, reducing the frictional force between fibers, and increasing the mechanical strength of the fibers. Specifically, these methods include enzyme treatment for removing smaller and shorter loose fibers on the fabric surface; plasma treatment for reducing the frictional force between fibers; and using polyacrylate coatings on wool fibers to increase the mechanical strength of the wool fibers, thereby reducing fiber loss on the surface. However, these methods generally have drawbacks. For example, the use of polyacrylate coatings is not applicable to finished merino wool fabrics and / or garments and can cause significant discoloration of the original finish. Enzyme treatment can potentially cause more fiber loss because this method is not selective only for loose fibers on the fabric surface. Plasma treatment has obstacles in industrialization.

[0004] Therefore, there is a need for a new merino wool fabric that includes improved mechanical properties while avoiding surface pilling and fiber loss due to coating. Summary of the Invention

[0005] Accordingly, one aspect of the present invention provides a pilling-resistant Merino wool fabric having a pilling resistance of at least grade 4 and a fiber loss of less than 0.2% w / w after 15 cycles of home laundering without using a laundry net. The pilling-resistant Merino wool fabric is coated with a formulation. The formulation comprises about 8 to 30% w / w of an aqueous polymer binder and about 70 to 92% w / w of an aqueous buffer, wherein the polymer binder comprises at least two diisocyanates, at least two catalysts, and a water dispersant.

[0006] In a preferred embodiment, the pilling resistance of the wool fabric of the present invention is determined according to the JIS L1076 ICI method.

[0007] In an embodiment of the first aspect of the present invention, the at least two diisocyanates include isophorone diisocyanate and 1,6-hexamethylene diisocyanate.

[0008] In a specific embodiment, the molar ratio of isophorone diisocyanate to 1,6-hexamethylene diisocyanate is 4:1.

[0009] In an embodiment of the first aspect of the present invention, the at least two catalysts include 3-methyl-1-phenyl-2-phospholene-1-oxide and dibutyltin(IV) dilaurate.

[0010] In a specific embodiment, the molar concentration of 3-methyl-1-phenyl-2-phospholene-1-oxide relative to the at least two diisocyanates is about 0.2 to 1.0%.

[0011] In another specific embodiment, the concentration of dibutyltin(IV) dilaurate relative to the water dispersant is about 0.01% w / w.

[0012] In an embodiment, the water dispersant is one or both of polyethylene glycol monomethyl ether 350 and polyethylene glycol monomethyl ether 550.

[0013] In an embodiment, the buffer is selected from phosphates or borates; the buffer is adjusted to about pH 8.0.

[0014] The formulation of the present invention introduces a polycarbodiimide crosslinking agent into the less reactive carboxylic acid groups present on the Merino wool fabric fibers. The polycarbodiimide polymer chains of the crosslinking agent can also be adjusted by varying the ratio of different monomers, the added catalysts, and / or the reaction conditions, thereby increasing the flexibility of the formulation. The formulation of the present invention can be fully cured at room temperature within 48 hours and easily forms a coating on existing Merino wool fabrics.

[0015] The second aspect of the present invention provides a method for manufacturing the merino wool fabric in the first aspect. The method comprises:

[0016] providing a merino wool fabric;

[0017] preparing a coating formulation, which comprises:

[0018] mixing a first diisocyanate and a second diisocyanate in a first molar ratio with a first catalyst in a second molar ratio relative to the first diisocyanate and the second diisocyanate to form a first solution,

[0019] adding a water dispersant in a first weight percentage and a second catalyst in a second weight percentage relative to the total weight of the first diisocyanate and the second diisocyanate to the first solution to form a second solution,

[0020] adding water to the second solution and then mixing until a homogeneous solution of a polymer binder in water is formed as a third solution,

[0021] preparing a fourth solution comprising an aqueous buffer with a pH of 8.0,

[0022] adding the fourth solution to the third solution and then mixing until a homogeneous solution is formed, thereby obtaining the coating formulation;

[0023] applying the coating formulation to the merino wool fabric; and

[0024] removing the excess coating formulation from the merino wool fabric and then drying.

[0025] In one embodiment, the first diisocyanate is selected from isophorone diisocyanate and the second diisocyanate is selected from 1,6 - hexamethylene diisocyanate.

[0026] In a specific embodiment, the first molar ratio between the first diisocyanate and the second diisocyanate is 4:1.

[0027] In another specific embodiment, the first catalyst is selected from 3 - methyl - 1 - phenyl - 2 - phospholene - 1 - oxide.

[0028] More specifically, the second molar ratio of the first catalyst to the first diisocyanate and the second diisocyanate is about 0.2% to 1%.

[0029] In one embodiment, the water dispersant is one or both of polyethylene glycol monomethyl ether 350 and polyethylene glycol monomethyl ether 550.

[0030] In a specific embodiment, the first weight percentage of the water dispersant is about 126% relative to the total weight of the first diisocyanate and the second diisocyanate.

[0031] In one embodiment, the second catalyst is selected from dibutyltin(IV) dilaurate.

[0032] In a specific embodiment, the second weight percentage of the second catalyst is about 0.01% relative to the weight of the water dispersant.

[0033] In one embodiment, the buffer is selected from phosphates or borates.

[0034] In one embodiment, the first diisocyanate and the second diisocyanate are mixed by stirring until a clear solution is obtained, and then the mixture is heated to 160 °C and maintained for about 35 to 50 minutes, and then the mixture is cooled to about 120 °C to obtain the first solution.

[0035] In one embodiment, the second solution is obtained by first mixing the second catalyst and the water dispersant until a homogeneous solution is formed, and then adding the homogeneous solution to the first solution and stirring at about 120 °C for about 2 hours.

[0036] In one embodiment, after cooling the second solution to 80 °C, water is added dropwise to the second solution with stirring until a clear homogeneous solution is obtained and a water content of about 63% w / w in the polymer binder is reached.

[0037] In one embodiment, the fourth solution is added to the third solution and then mixed until a homogeneous solution is formed as the coating formulation, and the fourth solution contains at least about 70% w / w of an aqueous buffer relative to the third solution.

[0038] In any one or more aspects of the present invention, the wool fabric described herein coated with the coating formulation of the present invention and / or manufactured according to the methods described herein may be a finished wool fabric that has been dyed with one or more colorants, and / or dyes and / or one or more reactive dyes.

[0039] There is also provided an article of clothing comprising the described merino wool fabric and / or prepared by the method in any aspect of the present invention, the article of clothing including but not limited to ribbed knitwear, shirts, dresses, sweaters, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The present disclosure will be more fully understood from the following detailed description which is provided solely for purposes of illustration of the disclosure and is thus not limiting, wherein:

[0041] Figure 1A Schematically depict the technical problem of crosslinking wool fibers in the presence of reactive dyes on finished merino wool fabrics and / or garments;

[0042] Figure 1B Schematically depict how the present invention solves Figure 1A the technical problems of the prior art depicted in

[0043] Figure 1C Schematically depict how, according to an embodiment of the present invention, the present invention provides crosslinking with reactive groups on wool fabrics in the presence of reactive dyes;

[0044] Figure 2 Schematically depict the preparation of the coating formulation;

[0045] Figure 3A Show the pilling resistance performance of the present invention on a single jersey knit determined by surface morphology according to the JIS L1076 ICI method; the inset in the upper right shows a series of reference photos of the surface morphology of the corresponding fabrics of different grades (1.0 to 5.0) determined according to the JIS L1076 ICI method;

[0046] Figure 3B Show the pilling resistance performance of the present invention on a 2×2 rib stitch determined by surface morphology according to the JIS L1076 ICI method; the inset in the upper right shows a series of reference photos of the surface morphology of the corresponding fabrics of different grades (1.0 to 5.0) determined according to the JIS L1076 ICI method.

[0047] Define

[0048] Unless otherwise indicated, the term "a / an" is used to include one or more than one, and the term "or" is used to mean non-exclusive "or". Further, it should be understood that the terms or phrases used herein and not otherwise defined are for descriptive purposes only and are not restrictive. Additionally, all publications, patents, and patent documents mentioned in this document are incorporated herein by reference in their entirety as if individually incorporated by reference. If there is an inconsistency in the usage between this document and those incorporated by reference, the usage in the incorporated references should be regarded as supplementary to the usage in this document; if there is an irreconcilable inconsistency, the usage in this document shall prevail.

[0049] In the preparation methods described herein, unless a chronological or operational order is explicitly recited, the steps may be performed in any order without departing from the principles of the present invention. The recitation in a claim of the gist of performing one step first and then subsequently performing several other steps shall mean that the first step is performed before any other step, but the other steps may be performed in any suitable order, unless an order is further recited within the other steps. For example, a claim element reciting "step A, step B, step C, step D, and step E" shall be construed to mean that step A is performed first, step E is performed last, and steps B, C, and D may be performed in any order between step A and step E, and the order still falls within the literal scope of the claimed method. A given step or subset of steps may also be repeated. Additionally, unless the explicit claim language recites that the specified steps are performed separately, the steps may be performed in parallel. For example, the claimed step of performing X and the claimed step of performing Y may be performed simultaneously in a single operation, and the resulting method will fall within the literal scope of the claimed method.

[0050] As used herein, "Association" or variations thereof, as described with respect to the interactions between different compounds, molecules, and / or substances, may refer to any physical, chemical, and / or other possible bonding between the compounds, molecules, and / or substances to which such expressions or terms are applied.

[0051] As used herein, a "water dispersant" refers to a reagent that aids in the dispersion of a polycarbodiimide polymer in water. Specifically, this reagent reacts with the polycarbodiimide polymer to form "caps" on both ends of the polymer, so as to present a homogeneous solution of the polycarbodiimide polymer in water.

[0052] In the present disclosure, "polycarbodiimide polymer" and "polycarbodiimide crosslinker" are used interchangeably to refer to a polymer that reacts with less reactive groups on animal fibers, such as finished wool fabrics or garments, such as merino wool fabrics or garments.

[0053] The pilling resistance of the wool fabrics or garments described herein is tested and graded according to the JIS L1076 ICI method. A grade of 5 indicates excellent pilling resistance, and a grade of 1 indicates poor pilling resistance.

[0054] The "color change" of the finished wool fabrics or garments described herein is graded for the original finished wool fabrics or garments according to the gray scale of ISO105 - A02. A grade of 5 indicates the least effect on the color change of the original finish of the fabric, and a grade of 1 indicates a significant effect on the color change of the original finish of the fabric. Detailed Description

[0055] The present invention will be described in detail by the following examples / instances in conjunction with the accompanying drawings. It should be understood that the specific examples are provided for illustrative purposes only and should not be construed in a restrictive manner.

[0056] Turning Figure 1A , polypeptides of wool fibers on typical fabrics, such as polypeptides of merino wool fibers, have reactive functional groups, and among these reactive functional groups, amino groups (NH 2 ) usually react with one or more reactive dyes to provide surface finishing and / or coloring of wool fabrics. Therefore, it has become extremely challenging to crosslink wool fibers to increase the mechanical strength of wool fibers to reduce surface fiber loss; this surface lacks reactive functional groups to react and / or crosslink with the polymer of the protective polymer coating, thereby improving the mechanical strength of the fibers and reducing fiber loss and pilling on the fabric surface. To solve this technical problem, the present invention provides a polymer that crosslinks with the polypeptides of wool fabrics at less reactive functional groups, and the processing / reaction conditions are relatively mild and can be carried out in water. The covalent bond between the reactive dye and the amino group on the polypeptide of the wool fiber remains intact, thereby reducing the probability of color change of the original finish of the wool fabric and / or clothing ( Figure 1B ). In a preferred embodiment, a polycarbodiimide crosslinking agent is provided as the crosslinking agent, which interacts with the carboxylic acid groups on the polypeptides of wool fibers, thereby first forming O-acylisourea groups and then forming N-acylurea groups when one polypeptide crosslinks with another polypeptide through the polycarbodiimide polymer ( Figure 1C ).

[0057] Turning Figure 2 , the polycarbodiimide crosslinking agent in the present invention is formed by reacting at least two monomers, such as two diisocyanates, namely isophorone diisocyanate (IPDI) and 1,6-hexamethylene diisocyanate (HDI), with a first catalyst, such as 3-methyl-1-phenyl-2-phospholene-1-oxide (MPPO), for a first period of time (t 1 ) to form a first reaction product (200), namely a polycarbodiimide polymer. After cooling, the polycarbodiimide polymer further reacts with a water dispersant such as methoxypolyethylene glycol 550 (MPEG 550) and a second catalyst such as dibutyltin(IV) dilaurate for a second period of time (t 2 ) to form a polymer binder, and then it is cooled. Water is added dropwise to the polymer binder and, under stirring, heated to a temperature (T1) until a homogeneous solution (210) of the polymer binder in water is obtained. The homogeneous solution (210) is further mixed with a buffer solution of pH 8.0 before being coated on the wool fabric.

[0058] In a preferred embodiment, t 1 is about 50 minutes, and the first reaction between the two diisocyanates and the first catalyst is carried out at about 155 - 160 °C, more preferably at 160 °C.

[0059] In another preferred embodiment, t 2 is about 2 hours, and the second reaction between the polycarbodiimide polymer, MPEG 550 and dibutyltin(IV) dilaurate is carried out at about 120 °C.

[0060] In yet another preferred embodiment, T1 is about 80 °C, and the homogeneous solution obtained after dropwise addition of water to the polymer binder has a final water content of about 63% w / w.

[0061] In another preferred embodiment, the homogeneous solution of the above polymer binder in water is mixed with an aqueous phosphate or borate buffer at pH 8.0, wherein the above solution is at least 8% of the total solution weight.

[0062] Examples

[0063] Example 1 - Preparation of a coating formulation for merino wool fabric:

[0064] Table 1 below outlines the composition (I) of the polymer binder in water according to an embodiment of the present invention.

[0065] Table 1 - Composition of Polymer Adhesive in Water (I) :

[0066]

[0067]

[0068] Preparation Procedure:

[0069] 1) Under stirring, 3 - methyl - 1 - phenyl - 2 - phospholene - 1 - oxide (MPPO) (0.5 mol% relative to the total amount of the two diisocyanates), isophorone diisocyanate (IPDI) and 1,6 - hexamethylene diisocyanate (HDI) (25 mol% relative to the amount of isophorone diisocyanate, or molar ratio of IPDI to HDI = 4:1) were charged into a 500 mL flask until a clear solution was obtained. Then, the solution was heated to 160 °C and maintained for 50 minutes (t 1 );

[0070] 2) After 50 minutes, cool the solution to 120 °C. While stirring, add dibutyltin(IV) dilaurate (0.01 wt% relative to MPEG550) to MPEG 550 (126 wt% relative to the total weight of the two diisocyanates) until a homogeneous solution is obtained. While stirring, add the homogeneous solution to the above-cooled solution. At 120 °C, keep the reaction mixture stirred for 2 hours (t 2 )

[0071] 3) After stirring for 2 hours, cool the reaction mixture from (2) to 80 °C (T1). While stirring, add water dropwise (170 wt% relative to the total weight of the reagents added) until a clear homogeneous solution is obtained. Final water content: 63% w / w.

[0072] Example 2 - Variations in the composition and / or preparation conditions of the polymer binder formulation:

[0073] Table 2 below outlines three other examples (i.e., compositions (II), (III), and (IV) of the polymer binder in water) in addition to composition (I) of the polymer binder in water described in Example 1:

[0074] Table 2 :

[0075] Composition of Polymer Adhesive in Water MPEG <![CDATA[t 1 / minute]]> <![CDATA[t 2 / hour]]> T1 / ℃ (I) 550 50 2 80 (II) 350 35 17 60 (III) 550 50 2 60 (IV) 550 50 17 80

[0076] Example 3 - Further variations in the manufacture of the polymer binder

[0077] Table 3 below outlines further variations in the manufacture of the polymer binder including polyethylene glycol monomethyl ether 350 (MPEG 350).

[0078] Table 3:

[0079]

[0080] Example 4 - Pilling resistance of Merino wool fabrics with different coating formulations

[0081] In this example, compositions (I) to (IV) of the polymer binder in water from Examples 1 and 2 at approximately 8% w / w were added to approximately 92% w / w of a phosphate buffer solution or borate buffer at pH 8.0, and then Merino wool fabrics with 2×2 rib weave were immersed in each coating formulation.

[0082] Under laboratory conditions, the Merino wool fabrics were immersed in 350 mL of the coating formulation at room temperature or 25 °C

[0083] Agitate in a wash fastness tester for 30 minutes. Next, press out the excess solution from each fabric using a laboratory wringer (at approximately 10 lbs), then tumble dry at 80 °C for 30 minutes. Next, under ambient conditions, hang-dry the various fabrics for 48 hours and iron them, then conduct the tests.

[0084] Table 4 below outlines the pilling resistance results obtained according to the JIS L1076 ICI method.

[0085] Table 4 :

[0086]

[0087] As can be seen from Table 4, the pilling resistance results of the 2×2 ribbed merino wool fabric coated with any one of the coating formulations of compositions (I), (II), (III), or (IV) including a polymer binder in water and a phosphate or borate buffer at pH 8 are superior to those of the uncoated merino wool fabric.

[0088] Example 5 – Variation in the ratio between the aqueous polymer binder and the aqueous buffer:

[0089] Table 5 below provides two different ratios of the aqueous polymer binder (Table 1) to the buffer solution (phosphate or borate) and the pilling resistance of the coated merino wool fabric on 2×2 ribbing determined according to the JIS L1076 ICI method. The conditions and procedures for forming the coating on the black 2×2 ribbing follow those described in Example 4.

[0090] Table 5 :

[0091]

[0092] As can be seen from Table 5, the black merino wool fabric in 2×2 ribbing coated with the coating formulation with a higher proportion of polymer binder has lower pilling resistance than the fabric coated with the coating formulation with a lower proportion of polymer binder (or a higher buffer portion).

[0093] Example 6 - Influence of different fabric structures and / or colors on pilling resistance, color change of the original finish, and fiber loss during 15 cycles of home laundering without using a laundry net

[0094] Table 6 below outlines the pilling resistance of single - face plain - knitted fabrics and 2×2 rib - knitted fabrics in different colors (white, black, green, blue, and red) coated with the coating formulation of Entry 1 in Example 5 compared to 2×2 rib - knitted fabrics, as determined by the JIS L 1076 ICI method. The results of the color - change gray - scale grading for the original finish of merino - wool fabrics were evaluated according to ISO105 - A02.

[0095] For the evaluation of fiber loss for the home - laundering cycle according to JIS L0217 Method 103, according to the test standard, in a designated washing machine, using an ECE standard detergent, a merino - wool garment was washed for 5 minutes without using a laundry net, rinsed for 2 minutes, and then rinsed for another 2 minutes. The above cycle was repeated 15 times. Then, the washed garment was laid flat to dry. All the fibers discharged from the washing - machine hose and the fibers remaining in the washing machine were collected. They were dried and the humidity was adjusted to standard conditions before measuring the weight. The percentage of fiber loss was defined as the amount of fiber loss (g) divided by the weight of the garment before the test (g).

[0096] Table 6:

[0097]

[0098] Figure 3A and 3B shows the pilling - resistance grading results of single - face plain - knitted fabrics and 2×2 rib - knitted fabrics in different colors coated with the coating formulation of Entry 1 in Example 5 compared to uncoated knitted fabrics.

[0099] As can be seen from Table 6, as described above, single - face plain - knitted fabrics and 2×2 rib - knitted fabrics coated with the coating formulation of Entry 1 in Example 5, regardless of color, produced excellent pilling resistance (at least Grade 4.0) and had minimal color change relative to the original finish (according to the gray - scale grading for the original finish of merino - wool fabrics according to ISO105 - A02). Forming a coating on single - face plain - knitted fabrics and 2×2 rib - knitted fabrics did not significantly affect the fiber loss of coated and surface - finished merino - wool garments after 15 home - laundering cycles without using a laundry net. Regardless of the construction method or color, merino - wool fabrics coated with the coating formulation of the present invention have excellent pilling resistance, minimal color change relative to the original finish, and no significant fiber loss after 15 home - laundering cycles without using a laundry net.

[0100] Example 7 - Comparative Composition (V) of Polymer Binder in Water

[0101] Table 7 below outlines comparative composition (V) of the polymeric binder in water relative to (I) described in Example 1.

[0102] Table 7 :

[0103] Material Amount (volume / weight) Molar amount Isophorone diisocyanate 5.8 mL / 6.1 g 27.7 mmol 1,6 - Hexamethylene diisocyanate 1.1 mL / 1.2 g 6.87 mmol 3 - Methyl - 1 - phenyl - 2 - phospholene - 1 - oxide 33.1 mg 0.172 mmol Triethylene glycol monomethyl ether 2.8 mL / 2.9 g Dibutyltin(IV) dilaurate 0.28 mg Water 17 mL

[0104] The main difference between composition (V) and (I) is the choice of the water dispersant. Triethylene glycol monomethyl ether is used in composition (V) instead of the polyethylene glycol monomethyl ether (MPEG) used in composition (I). The remaining ingredients and reaction conditions of composition (V) are substantially the same as those used in (I). This composition does not form a homogeneous polymeric binder solution in water and is thus not suitable as an ingredient for a coating formulation for providing a pilling-resistant Merino wool fabric.

[0105] Example 8 - Comparative composition (VI) of the polymeric binder in water: Table 8 below outlines comparative composition (VI) of the polymeric binder in water relative to (I) described in Example 1.

[0106] Table 8 :

[0107] Material Amount (volume / weight) Molar amount Isophorone diisocyanate 5.4 mL / 5.7 g 25.7 mmol 1,6 - Hexamethylene diisocyanate 1.0 mL / 1.1 g 6.24 mmol 3 - Methyl - 1 - phenyl - 2 - phospholene - 1 - oxide 30.7 mg 0.160 mmol Polyethylene glycol monomethyl ether 1000 16g Dibutyltin(IV) dilaurate 1.6 mg Water 17 mL

[0108] Polyethylene glycol monomethyl ether 1000 (MPEG 1000) is used in composition (VI) instead of polyethylene glycol monomethyl ether 550 (MPEG 550) used in (I). The remaining ingredients and reaction conditions of composition (VI) are substantially the same as those used in (I). This composition does not form a homogeneous polymeric binder solution in water and is thus not suitable as an ingredient for a coating formulation for providing a pilling-resistant Merino wool fabric.

[0109] Industrial Applicability

[0110] The present invention is applicable to wool fabrics, including Merino wool fabrics, particularly finished wool fabrics or finished garments, in order to impart a pilling resistance of at least level 4 determined according to certain criteria, while preventing color change and fiber loss during laundering.

Claims

1. A method for producing anti-pilling Merino wool fabric, characterized in that: The method comprises: Merino wool fabrics are available; A coating formulation is prepared comprising: A first diisocyanate and a second diisocyanate are mixed with 3-methyl-1-phenyl-2-phosphole-1 oxide in a first molar ratio to form a first solution, wherein the molar concentration of the 3-methyl-1-phenyl-2-phosphole-1 oxide is 0.2 to 1.0% relative to the first diisocyanate and the second diisocyanate, A water dispersant and dibutyltin dilaurate in an amount of 126% by weight relative to the total weight of the first diisocyanate and the second diisocyanate are added to the first solution to form a second solution, wherein the water dispersant is one or both of polyethylene glycol monomethyl ether 350 and polyethylene glycol monomethyl ether 550, wherein the weight percentage of the dibutyltin dilaurate is 0.01% relative to the weight of the water dispersant, adding water to the second solution followed by mixing until a homogeneous solution of the polymer binder in water is formed as a third solution, preparing a fourth solution comprising a pH 8.0 aqueous buffer, adding the fourth solution to the third solution followed by mixing until a homogeneous solution is formed, thereby obtaining the coating formulation; applying the coating formulation to the merino wool fabric; and Excessive amounts of the coating formulation are removed from the merino wool fabric, followed by drying, to obtain the pilling resistant merino wool fabric having a pilling resistance of at least grade 4 as determined by the JIS L1076 ICI method and a fiber loss of less than 0.2% w / w in 15 cycles of home laundry without a laundry net.

2. The method according to claim 1, wherein the first diisocyanate is selected from isophorone diisocyanate and the second diisocyanate is selected from 1,6-hexamethylene diisocyanate.

3. The method of claim 2, wherein a first molar ratio between the first diisocyanate and the second diisocyanate is 4:

1.

4. The method according to claim 1, wherein the first diisocyanate and the second diisocyanate are mixed by stirring until a clear solution is obtained, and then the mixture is heated to 160°C for 35 to 50 minutes, and then the mixture is cooled to 120°C to obtain the first solution.

5. The method according to claim 1, wherein the second solution is obtained by first mixing the dibutyltin dilaurate and the water dispersant until a homogeneous solution is formed, then adding the homogeneous solution to the first solution and stirring at 120°C for 2 hours.

6. The method of claim 1, wherein after cooling the second solution to 80°C, water is added dropwise to the second solution under stirring until a clear homogeneous solution is obtained and a water content of 63% w / w in the polymer binder is reached.

7. The method of claim 1, wherein the fourth solution is added to the third solution followed by mixing until a homogenous solution is formed as the coating formulation, the fourth solution comprising at least 70% w / w of an aqueous buffer relative to the third solution.

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