A glue for briefs production and its preparation method and application

Abstract

The application relates to the technical field of glue processing, in particular to glue for briefs production and a preparation method and application thereof, which comprises components A and B, wherein the component A is prepared from the following raw materials in parts by weight: polyether polyol 30-45 parts, polyester polyol 15-25 parts, diphenylmethane diisocyanate 15-20 parts, hydroxyl-modified nano silicon dioxide 3-5 parts, hydroxyl-terminated silicone oil 2-4 parts, TPU micro powder 5-8 parts, a catalyst 0.1-0.3 parts and other additives 0-1 part; and the component B is prepared from the following raw materials in parts by weight: polyaspartic acid ester 50-60 parts, castor oil modified polyol 20-30 parts, silane coupling agent 3-5 parts and polyether modified polysiloxane 2-4 parts. The glue is coated on the waistband and other parts of the briefs through the above formula, and a network structure glue layer with elasticity is formed after solidification, so that the waistband and other parts are more skin-friendly, do not slide off, do not deform and fall off during use, have good air permeability and softness, and the comfort of the briefs is improved.

Description

Technical Field

[0001] This application relates to the field of adhesive processing technology, and more specifically, to an adhesive for underwear production, its preparation method, and its application. Background Technology

[0002] Modal fabric has a delicate and soft feel, and its moisture absorption and breathability are even better than pure cotton, making it suitable for underwear. However, modal fabric has poor drape and is prone to deformation, which can lead to unstable fit and poor body shape when used to make underwear.

[0003] To address the issues of underwear made from modal fabric being unstable and not conforming to the body shape, the following methods are now being used: Employing a seamless, one-piece cutting method, the main body of the underwear is constructed into a seamless tubular structure through cylindrical knitting or three-dimensional weaving, thus eliminating side seams and traditional stitching seams. This effectively avoids friction and irritation at seams, as well as issues like buttock pinching and hem rolling, resulting in a more ergonomic overall structure. However, its drawbacks include high requirements for production equipment, necessitating the use of specialized seamless knitting machines or heat-pressing equipment. The complex process leads to higher production costs compared to traditional piece-sewing methods. Furthermore, the seamless structure demands strict sizing accuracy, has a low tolerance for error, and is not conducive to large-scale flexible production. The widened, high-elastic waistband design utilizes a 3-5cm wide high-elastic webbing or double-layer folded structure in the waist area to increase the stress-bearing area and distribute pressure. Seamless folding or heat-pressing processes replace traditional elastic band stitching, achieving anti-slip, anti-binding, and anti-rolling effects. However, this method highly relies on the fabric's own resilience. Modal fibers have poor elastic recovery; under repeated stretching and washing, the waistband area is prone to stress relaxation and permanent deformation, causing the anti-slip effect to decrease with increased use and limiting the product's lifespan. Seamless bonding technology uses polyurethane hot melt adhesive film or dotted silicone coating to bond the edges of fabric through heat pressing, replacing traditional sewing stitches. This achieves a smooth, bump-free surface and improves the fit against the skin. However, under repeated washing and high-temperature drying conditions, the adhesive interface is prone to aging, detachment, or delamination, leading to structural failure. Simultaneously, the adhesive area can obstruct the capillary pores between fibers, causing localized reduced breathability and affecting wearing comfort. Summary of the Invention

[0004] In order to effectively improve the shape stability and anti-loosening ability of modal fabric while maintaining its original soft and skin-friendly properties, and to achieve long-lasting fit and durable anti-slip effect, this application provides an adhesive for underwear production, its preparation method and application.

[0005] In a first aspect, this application provides an adhesive for underwear production, employing the following technical solution: An adhesive for use in the production of underwear comprises component A and component B, wherein component A is prepared from the following raw materials in parts by weight: 30-45 parts of polyether polyol 15-25 parts of polyester polyol 15-20 parts of diphenylmethane diisocyanate 3-5 parts of hydroxyl-modified nano-silica 2-4 parts of hydroxyl-terminated silicone oil 5-8 parts of TPU micro powder Catalyst 0.1-0.3 parts Other adjuvants: 0-1 part; Component B is prepared from the following raw materials in parts by weight: 50-60 parts of polyaspartic acid ester 20-30 parts of castor oil modified polyol 3-5 parts of silane coupling agent 2-4 parts of polyether-modified polysiloxane.

[0006] By adopting the above technical solution, the adhesive is applied to the waistband and other parts of the underwear. After curing, it forms an elastic network structure adhesive layer, which makes the waistband and other parts fit the skin better, does not slip, does not deform or fall off during use, and has good breathability and softness, thus improving the comfort of the underwear.

[0007] The synergistic crosslinking of polyether polyol and polyester polyol in component A with polyaspartic acid ester and castor oil-modified polyol in component B forms an adhesive layer that combines flexibility and deformation resistance. This ensures the adhesive layer won't compromise the soft feel of the modal fabric due to excessive stiffness. The elastic crosslinked network formed after curing can adapt to repeated stretching and deformation during underwear wear, ensuring that the anti-slip and anti-rolling effects do not diminish with increased use. It also compensates for the low elastic recovery rate of modal fibers, effectively inhibiting stress relaxation and permanent deformation in key areas such as the waistband and edges. This solves the problem of diminishing anti-slip effects and limited product lifespan associated with traditional widened, high-elasticity waistband solutions.

[0008] Meanwhile, the hydroxyl-modified nano-silica introduced into component A of the adhesive can enhance the mechanical strength and weather resistance of the adhesive layer. The silane coupling agent and hydroxyl-terminated silicone oil can improve the interfacial bonding force between the adhesive layer and the modal fiber. Combined with the toughening effect of TPU micro powder, the adhesive layer can avoid the structural failure problems of adhesive layer aging, delamination and separation in traditional polyurethane hot melt adhesive film or silicone coating solutions under multiple water washing and high temperature drying conditions, thus achieving long-term stability of the seamless bonding structure.

[0009] The combination of component A (hydroxyl-terminated silicone oil) and component B (polyether-modified polysiloxane) optimizes the micropore structure of the adhesive layer. Unlike traditional adhesives, it does not clog the capillary pores between modal fibers, thus avoiding the drawback of reduced breathability in certain areas. This ensures that the area of ​​the underwear that touches the skin can still maintain the excellent moisture absorption and breathability of the modal fabric, balancing structural stability and wearing comfort.

[0010] Finally, the adhesive of this application is compatible with conventional hot-pressing bonding equipment and does not rely on the special seamless knitting machine and high-precision shaping equipment required for seamless cutting solutions. It can achieve the structural advantages of seamless bonding, simplify the process flow, reduce the investment in production equipment and the difficulty of process error tolerance, and solve the defects of traditional seamless molding solutions such as high production cost, low size accuracy error tolerance, and unfavorable to large-scale flexible production.

[0011] Preferably, the polyether polyol is polytetrahydrofuran ether diol with a number average molecular weight of 2000-4000 g / mol.

[0012] By adopting the above technical solution and optimizing the number-average molecular weight of polyether polyol, it can synergistically improve the elasticity and film-forming properties of component A of the adhesive with polyester polyol. Combined with the reinforcing effect of hydroxyl-modified nano silica and TPU micro powder, and the cross-linking characteristics of component B polyaspartic acid ester, a highly elastic and tough adhesive layer is formed after curing, which enhances the anti-loosening and water-washing ability of parts such as the waistband of underwear, and effectively reduces problems such as aging delamination and waistband deformation.

[0013] Preferably, the polyether polyol is composed of polytetrahydrofuran ether diol with a number average molecular weight of 2000-4000 g / mol and polyoxyethylene ether diol with a number average molecular weight of 1000-2000 g / mol.

[0014] By employing the above technical solution, polytetrahydrofuran ether glycol ensures the elasticity and film-forming properties of the adhesive, while low molecular weight polyethylene oxide ether glycol enhances its hydrophilicity and component compatibility. Combined with reinforcing and crosslinking components in the system, the cured adhesive layer is more uniform, highly elastic, strong, washable, and has better skin-friendliness.

[0015] Preferably, the number-average molecular weight of the polyester polyol is 2000-3000 g / mol.

[0016] By adopting the above technical solution and optimizing the number-average molecular weight of polyester polyol, a suitable soft and hard segment structure can be formed with polyether polyol, balancing the flexibility and cohesion of the adhesive. Its excellent reactivity with diisocyanate can enhance the crosslinking density of components A and B, resulting in better elasticity and stronger deformation resistance of the adhesive layer, without affecting the softness and breathability of the fabric.

[0017] Preferably, the hydroxyl-modified nano-silica has an average particle size of 10-500 nm and a specific surface area of ​​150-300 m² / g.

[0018] By adopting the above technical solution, the average particle size and specific surface area of ​​hydroxyl-modified nano-silica are optimized, making it easy to disperse uniformly in adhesives. The large specific surface area significantly increases the contact sites with the resin matrix. Through the strong interaction between hydroxyl groups and polyethers and polyester polyols, the internal bonding force of the adhesive layer is strengthened, the mechanical properties of the adhesive are improved, and the tensile and relaxation resistance of areas such as the waistband is enhanced, solving the problem of modal's easy deformation. At the same time, it is conducive to forming a dense adhesive layer structure with a certain degree of porosity, which not only improves the water resistance to avoid the aging and delamination of traditional adhesive layers, but also does not clog the capillaries of modal fibers, ensuring breathability and skin-friendliness. It is compatible with conventional processes, making the underwear fit and durable for a long time.

[0019] Preferably, the castor oil-modified polyol has a hydroxyl value of 160-180 mg KOH / g and an iodine value of ≤10 g I2 / 100 g.

[0020] By adopting the above technical solution, the parameters of castor oil-modified polyol are optimized to form a strong and highly elastic adhesive network with component A (isocyanate) and component B (polyaspartic acid ester). This strengthens the tensile and anti-loosening capabilities of the adhesive areas in the underwear, solving the problem of deformation in the modal waistband. The low iodine value (≤10gI2 / 100g) reduces the content of unsaturated bonds, improving the washability and aging resistance of the adhesive layer and reducing delamination. Simultaneously, its modified structure optimizes the pores of the adhesive layer, preventing clogging of the modal fiber capillaries and ensuring breathability and skin-friendliness.

[0021] Preferably, the polyaspartic acid ester has an amine value of 200-300 mg KOH / g and a viscosity of 200-500 mPa·s at 25°C.

[0022] By adopting the above technical solution and optimizing the parameters of polyaspartic acid ester, a precise ratio can be formed with the isocyanate groups of diphenylmethane diisocyanate in component A. This ensures a sufficient and controllable crosslinking reaction, avoiding both insufficient adhesive layer strength and easy relaxation due to excessively low crosslinking density, and embrittlement and loss of elasticity caused by excessively dense crosslinking. This imparts excellent tensile and deformation resistance to the adhesive layer, effectively improving stress relaxation issues in areas such as the waistband of modal underwear. Simultaneously, the workability and component compatibility of component B are considered, allowing for uniform miscibility with castor oil-modified polyols and silane coupling agents, avoiding local agglomeration and ensuring a uniform structure after curing. Preferably, the number-average molecular weight of the hydroxyl-terminated silicone oil is 1000-3000, and the viscosity at 25°C is 20-100 mPa·s.

[0023] By adopting the above technical solution, the parameters of the hydroxyl-terminated silicone oil are optimized to ensure its uniform dispersion in component A, and it can form a stable bond with polyols and nano-silica through hydroxyl groups. Its siloxane structure can optimize the flexibility and surface smoothness of the adhesive layer, reduce the friction between the adhesive layer and the skin, and form breathable channels to prevent the adhesive layer from blocking the capillary pores of modal fibers. In addition, it can improve the wash resistance and anti-aging properties of the adhesive layer, reduce the phenomenon of adhesive layer delamination, strengthen the anti-loosening ability of the waistband area, and take into account both skin-friendly breathability and long-lasting fit, making it compatible with conventional production processes.

[0024] Preferably, the TPU micro powder has a particle size of 2-10 μm and a Shore hardness of 75A-95A.

[0025] By adopting the above technical solution and optimizing the parameters of TPU micropowder, it is uniformly dispersed in component A without agglomeration, forming a dense elastic matrix with polyether / polyester polyol. Appropriate Shore hardness balances the flexibility and deformation resistance of the adhesive layer, avoiding both excessive hardness leading to brittleness and insufficient support due to insufficient hardness. It can synergistically enhance the elastic recovery rate of the adhesive layer with hydroxyl-modified nano-silica, improving the resistance to repeated stretching and relaxation in areas such as the waistband, while not clogging fiber pores, ensuring skin-friendly breathability, and adapting to conventional processes to achieve long-lasting fit and durability in underwear.

[0026] Secondly, this application provides a method for preparing adhesive for underwear production, employing the following technical solution: A method for preparing an adhesive for underwear production includes the following preparation steps: Component A: Polyether polyol, polyester polyol, diphenylmethane diisocyanate, hydroxyl-modified nano silica, hydroxyl-terminated silicone oil, TPU micro powder, catalyst and other additives are mixed evenly to obtain Component A. Component B: Component B is obtained by mixing polyaspartic acid ester, castor oil modified polyol, silane coupling agent and polyether modified polysiloxane. Preparation of adhesive: Mix component A and component B at a weight ratio of 100:(12-14) to obtain adhesive for use in underwear production.

[0027] By adopting the above technical solution, after mixing components A and B in a specific ratio, each component exerts a synergistic effect, resulting in an adhesive with excellent bonding strength to commonly used underwear fabrics. After curing, the adhesive layer is soft and not stiff, with good elasticity and anti-slip properties, ensuring that the underwear does not fall off during wear. It also has good breathability and washability, meeting the stringent requirements of underwear production for environmental protection, skin affinity, and durability.

[0028] Thirdly, this application provides an application of an adhesive for underwear production, employing the following technical solution: An application of an adhesive for underwear production involves applying the adhesive for underwear production described in the first aspect or the adhesive for underwear production prepared in the second aspect to a modal fabric in a dotted or mesh coating manner at a coating amount of 8-15 g / m². After coating, the fabric is cured for 4-6 hours at a temperature of 20-40°C and a relative humidity of 50-70%, and then sewn into underwear.

[0029] By adopting the above technical solution, it is ensured that the adhesive can be evenly applied to areas such as the waistband of the underwear to form an elastic and non-slip adhesive layer, while preserving the original breathability, moisture absorption and softness of the modal fabric to the greatest extent, and avoiding the discomfort caused by a stiff adhesive layer.

[0030] In summary, this application has the following beneficial effects: 1. It compensates for the resilience defects of modal fibers, and the cured adhesive layer provides long-lasting anti-slip and anti-curling properties, effectively inhibiting stress relaxation and permanent deformation of the waistband.

[0031] 2. Hydroxyl-modified nano-silica and polyether-modified polysiloxane are combined to form microporous channels, which avoids clogging the fiber capillary pores, maintains the excellent moisture absorption, breathability and soft skin-friendly properties of modal fabric, and solves the problem of stuffiness and discomfort.

[0032] 3. TPU micro powder toughening and silane coupling agent strengthen interfacial bonding, further improving water washability and reducing the problem of adhesive layer aging, debonding and cracking; Detailed Implementation Example

[0033] The polyether-modified polysiloxane is BASF's Tegomer 5840.

[0034] The hydroxyl-modified nano silica used in this application is obtained by immersing silica in hydrogen peroxide at 45°C for 2 hours, then removing it and air-drying it.

[0035] The castor oil-modified polyols were produced by Shanghai Shuyu Chemical Co., Ltd.

[0036] Example 1

[0037] An adhesive for use in underwear production is prepared by the following method: Component A: Mix 30g of polyether polyol, 15g of polyester polyol (polycaprolactone diol), 15g of diphenylmethane diisocyanate, 3g of hydroxyl-modified nano silica, 2g of hydroxyl-terminated silicone oil, 5g of TPU micro powder, 0.1g of catalyst (bismuth neodecanoate), and 0g of other additives evenly to obtain Component A. The polyether polyol is composed of polytetrahydrofuran ether diol with a number average molecular weight of 2000 g / mol and polyoxyethylene ether diol with a number average molecular weight of 1000 g / mol in a weight ratio of 1:2. The number-average molecular weight of the polyester polyol is 2000 g / mol; The average particle size of the hydroxyl-modified nano-silica is 10 nm, and the specific surface area is 150 m² / g. The number-average molecular weight of the hydroxyl-terminated silicone oil is 1000, and its viscosity at 25°C is 20 mPa·s. The TPU micro powder has a particle size of 2μm and a Shore hardness of 75A. Component B: Mix 50g of polyaspartic acid ester, 20g of castor oil modified polyol, 3g of silane coupling agent (γ-glycidyl etheroxypropyltrimethoxysilane) and 2g of polyether modified polysiloxane to obtain Component B; Preparation of adhesive: Mix component A and component B in a weight ratio of 100:12 to obtain adhesive for underwear production; The amine value of polyaspartic acid ester is 200 mg KOH / g, and its viscosity at 25℃ is 200 mPa·s. The hydroxyl value of the castor oil-modified polyol is 160 mg KOH / g, and the iodine value is ≤10 g I2 / 100g.

[0038] The difference between Examples 2-3 and Example 1 lies in the types, amounts, and parameters of raw materials used to prepare the adhesive for underwear production. Specific differences are shown in Table 1. Table 1. Types, dosages, and parameters of raw materials used in the preparation of adhesives for underwear production.

[0039] In Example 2, the polyether polyol was composed of polytetrahydrofuran ether diol with a number average molecular weight of 3000 g / mol and polyoxyethylene ether diol with a number average molecular weight of 1500 g / mol in a weight ratio of 1:3.

[0040] In Example 3, the polyether polyol was composed of polytetrahydrofuran ether diol with a number average molecular weight of 4000 g / mol and polyoxyethylene ether diol with a number average molecular weight of 2000 g / mol in a weight ratio of 1:4.

[0041] Example 4 An adhesive for underwear production, the difference between this embodiment and Example 1 is that the polyether polyol is made of polytetrahydrofuran ether diol with a number average molecular weight of 2000 g / mol.

[0042] Example 5 An adhesive for underwear production, the difference between this embodiment and Example 1 is that the polyester polyol has a number-average molecular weight of 500 g / mol.

[0043] Example 6 An adhesive for underwear production, the difference between this embodiment and Example 1 is that the hydroxyl value of the castor oil-modified polyol is 150 mg KOH / g.

[0044] Example 7 An adhesive for underwear production, the difference between this embodiment and Example 1 is that the amine value of polyaspartic acid ester is 150 mg KOH / g.

[0045] Comparative Example Comparative Example 1 An adhesive for underwear production. The difference between this comparative example and Example 1 is that all polyether polyols are replaced with polyester polyols.

[0046] Comparative Example 2 An adhesive for underwear production. The difference between this comparative example and Example 1 is that TPU micro powder is omitted.

[0047] Comparative Example 3 An adhesive for underwear production. The difference between this comparative example and Example 1 is that hydroxyl-modified nano-silica is replaced with ordinary silica.

[0048] Comparative Example 4 An adhesive for underwear production, the difference between this comparative example and Example 1 is that dimethyl silicone oil is used instead of terminal hydroxyl silicone oil.

[0049] The dimethyl silicone oil is Wacker Chemie AK10.

[0050] Comparative Example 5 An adhesive for underwear production, the difference between this comparative example and Example 1 is that polyetheramine is used instead of polyaspartic acid ester.

[0051] The polyetheramine is BASF Baxxodur® EC301.

[0052] Comparative Example 6 An adhesive for underwear production, the difference between this comparative example and Example 1 is that no polyether-modified polysiloxane is added.

[0053] Application examples Application Example 1 An application of an adhesive for underwear production involves applying the adhesive for underwear production from Example 1 to modal fabric in a dotted or mesh pattern at a coating amount of 8 g / m². After coating, the fabric is cured for 4 hours at a temperature of 20°C and a relative humidity of 50%, and then sewn into underwear.

[0054] The difference between Application Example 2-13 and Application Example 1 lies in the source of the adhesive used in the production of underwear. The specific differences are shown in Table 2: Table 2 Sources of glue used in underwear production

[0055] Elasticity test: Cut a sample 3cm wide and 15cm long (L0) from the glued part of the waistband in Application Examples 1-13, fix one end, and apply a 15N tension to the other end for 30 minutes (simulating daily stretching of the waistband). After releasing the tension, let it stand for 30 minutes, measure the length L1, and calculate: Rebound retention rate = [(L1-L0) / L0]×100%.

[0056] Air permeability test of the glued area at the waistband: Refer to GB / T 5453 "Determination of air permeability of textile fabrics".

[0057] Wearing simulation dynamic testing method: Using the Instron dynamic fatigue testing machine, apply a sinusoidal cyclic stretch of 0-50% elongation to the waistband of the sample garment at a frequency of 0.5Hz for 1000 cycles. After every 100 cycles of dynamic stretching, perform an AATCC 1353A wash and dry. After the test, observe whether there are cracks or delamination in the adhesive layer. If not, test the elasticity.

[0058] Anti-slip performance test: Cut 5cm × 5cm sample pieces from the glued section of the waistband of Application Examples 1-13. Fix the sample pieces on an inclined platform (refer to GB / T 22895-2009 "Determination of Static and Dynamic Coefficients of Friction of Paper and Paperboard"). Place a standard silicone leather simulated skin counterweight (200g) on ​​top. Slowly raise the platform at a speed of 0.5° / s. When the counterweight begins to slide, record the platform tilt angle θ and calculate the static friction coefficient μs = tanθ. The test data are shown in Table 3: Table 3 Experimental data from Application Examples 1-13

[0059] Based on the above data, it can be seen that this application, through the A / B component synergistic crosslinking system, forms a highly elastic network structure adhesive layer in the waistband area of ​​modal underwear, achieving excellent performance with a rebound retention rate of ≥85%, a breathability loss rate of ≤18.5%, and a static friction coefficient of ≥0.35. This effectively solves the problem of loosening and slippage caused by poor elasticity of modal fabric, and also overcomes the problem that traditional adhesives cannot simultaneously achieve bonding strength and breathability. Furthermore, after 1000 dynamic stretches and 10 washes, there are no cracks or delamination, extending the product's service life.

[0060] Comparing Example 1 with Comparative Examples 1-6, it is evident that this application, through the synergistic use of polyether polyol with polyester polyol, TPU micro powder, hydroxyl-modified nano-silica pores, hydroxyl-terminated silicone oil, polyaspartic acid ester, and polyether-modified polysiloxane, significantly improves the resilience retention rate, substantially reduces the breathability loss rate, achieves a static friction coefficient that reaches an anti-slip level and does not diminish over time, and exhibits no cracking or delamination after dynamic stretching and multiple washes. This solves the problems of poor fiber resilience leading to slippage and loosening in modal underwear, the incompatibility between traditional adhesive bonding and breathability, and poor water resistance causing easy delamination and cracking.

[0061] Comparing Examples 1 and 4-7, it is evident that this application, by designing the composite use of polyether polyols, the molecular weight of polyester polyols, the hydroxyl value of castor oil-modified polyols, and the amine value of polyaspartic acid esters within the optimized parameter range, enables each component to form an optimal synergistic effect during the curing reaction, resulting in an adhesive network with high resilience, strong adhesion, excellent breathability, and water resistance. This solves the problems of loosening and slippage, impaired breathability, and poor elasticity in modal underwear. Deviating from the above-mentioned optimal parameters leads to a decrease in resilience retention, breathability, and anti-slip performance.

[0062] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. An adhesive for use in the production of underwear, characterized in that, It includes component A and component B, wherein component A is prepared from the following raw materials in parts by weight: 30-45 parts of polyether polyol 15-25 parts of polyester polyol 15-20 parts of diphenylmethane diisocyanate 3-5 parts of hydroxyl-modified nano-silica 2-4 parts of hydroxyl-terminated silicone oil 5-8 parts of TPU micro powder Catalyst 0.1-0.3 parts Other adjuvants: 0-1 part; Component B is prepared from the following raw materials in parts by weight: 50-60 parts of polyaspartic acid ester 20-30 parts of castor oil modified polyol 3-5 parts of silane coupling agent 2-4 parts of polyether-modified polysiloxane.

2. The adhesive for underwear production according to claim 1, characterized in that: The polyether polyol is composed of polytetrahydrofuran ether diol with a number average molecular weight of 2000-4000 g / mol and polyoxyethylene ether diol with a number average molecular weight of 1000-2000 g / mol.

3. The adhesive for underwear production according to claim 1, characterized in that: The number-average molecular weight of the polyester polyol is 2000-3000 g / mol.

4. The adhesive for underwear production according to claim 1, characterized in that: The hydroxyl-modified nano-silica has an average particle size of 10-500 nm and a specific surface area of ​​150-300 m² / g.

5. The adhesive for underwear production according to claim 1, characterized in that: The castor oil-modified polyol has a hydroxyl value of 160-180 mg KOH / g and an iodine value of ≤10 g I2 / 100 g.

6. The adhesive for underwear production according to claim 1, characterized in that: The polyaspartic acid ester has an amine value of 200-300 mg KOH / g and a viscosity of 200-500 mPa.s at 25°C.

7. The adhesive for underwear production according to claim 1, characterized in that: The number-average molecular weight of the hydroxyl-terminated silicone oil is 1000-3000, and its viscosity at 25°C is 20-100 mPa·s.

8. The adhesive for underwear production according to claim 1, characterized in that: The TPU micro powder has a particle size of 2-10 μm and a Shore hardness of 75A-95A.

9. A method for preparing an adhesive for underwear production as described in any one of claims 1-8, characterized in that, The preparation steps include the following: Component A: Polyether polyol, polyester polyol, diphenylmethane diisocyanate, hydroxyl-modified nano silica, hydroxyl-terminated silicone oil, TPU micro powder, catalyst and other additives are mixed evenly to obtain Component A. Component B: Component B is obtained by mixing polyaspartic acid ester, castor oil modified polyol, silane coupling agent and polyether modified polysiloxane. Preparation of adhesive: Mix component A and component B at a weight ratio of 100:(12-14) to obtain adhesive for use in underwear production.

10. An application of an adhesive for underwear production, characterized in that: The adhesive for underwear production as described in any one of claims 1-8 or the adhesive for underwear production prepared in claim 9 is applied to modal fabric in a dot or mesh pattern at a coating amount of 8-15 g / m². After coating, it is cured for 4-6 hours at a temperature of 20-40°C and a relative humidity of 50-70%, and then sewn into underwear.

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