Preparation method and application of high-elasticity and low-hardness TPEE / TPE composite elastomer material

Abstract

The invention discloses a preparation method and application of a high-elasticity and low-hardness TPEE / TPE composite elastomer material, and belongs to the technical field of high polymer material modification. According to the material, TPEE and TPE are taken as main bodies, ethylene-methyl acrylate-glycidyl methacrylate terpolymer is added as a compatilizer, and nano organic montmorillonite is matched as a nucleation / rheology modifier, so that the two-phase compatibility and melt spinning stability are remarkably improved. After the composite material is subjected to drying, melt spinning, high-speed airflow drafting, lapping and low-temperature hot rolling reinforcement, the prepared spun-bonded non-woven fabric has high elasticity, low hardness, soft hand feeling and good air permeability, and is suitable for the fields of high-end medical dressings, sports protection, sanitary products and the like. According to the invention, the technical problems of difficult processing, thick fibers and hard cloth cover of the elastomer in a spunbond process are effectively solved, and the application prospect of the high-performance elastic non-woven fabric is expanded.

Description

Technical Field

[0001] This invention belongs to the field of polymer material modification technology, specifically relating to a method for preparing and applying a high-elasticity, low-hardness TPEE / TPE composite elastomer material. Background Technology

[0002] Spunbond nonwoven fabrics have been widely used in medical and health, personal care, home furnishing and clothing fields due to their advantages such as continuous and efficient production process, uniform product structure and good mechanical properties. Traditional spunbond nonwoven fabrics mainly use general polymer materials such as polypropylene (PP) and polyester (PET) as raw materials. Their products are competitive in terms of strength and cost, but they have obvious shortcomings in softness, elastic recovery and skin-touch comfort, making it difficult to meet the needs of high-end and high-comfort applications.

[0003] To improve the elasticity and softness of nonwoven fabrics, the industry has explored the introduction of elastomer materials. Among these, thermoplastic polyester elastomers (TPEE) possess excellent mechanical strength, high and low temperature resistance (-40℃ to 120℃), and outstanding resilience. However, their high hardness (typically Shore D above 40D) and high melt viscosity lead to difficulties in spinning, poor fiber forming stability, and stiff finished fabric surfaces when used directly in high-speed spunbond processes. On the other hand, styrene-based thermoplastic elastomers (such as SEBS-based TPEs) offer excellent softness and a gentle touch, but their strength, heat resistance, and creep resistance are relatively poor, making it difficult to meet the basic requirements of nonwoven fabrics for mechanical strength and dimensional stability when used alone.

[0004] Simply blending TPEE and TPE to combine their advantages still faces significant technical bottlenecks in practical applications: First, there is an inherent thermodynamic incompatibility between TPEE (polar polyester phase) and SEBS-type TPE (non-polar styrene-olefin phase), which easily leads to phase separation during blending, resulting in weak interfacial adhesion and severely affecting the mechanical properties of the fiber and the continuity of the spinning process; Second, the melt rheological behavior of the composite system is complex, making it difficult to simultaneously meet the stringent requirements of high-speed spunbonding processes for melt strength, elongation, and stability, and problems such as melt fracture, filament breakage, or uneven fineness are prone to occur during high-speed drawing; Third, the final product often fails to achieve an ideal balance between high elasticity, low hardness, and sufficient strength, either resulting in insufficient elasticity and a stiff hand feel, or excessively low strength that renders it impractical.

[0005] Therefore, developing a special composite elastomer material and supporting process that can effectively solve the compatibility problem between TPEE and TPE, has suitable processing rheological properties, and can stably produce nonwoven fabrics with high elasticity, low hardness and good mechanical properties on conventional spunbonding equipment has become a technical problem that urgently needs to be solved in this field, and has important industrial application value. Summary of the Invention

[0006] This invention provides a method for preparing and applying a high-elasticity, low-hardness TPEE / TPE composite elastomer material. The material uses TPEE and TPE (such as SEBS) as the matrix, and by adding EMA-GMA compatibilizer and nano-OMMT rheology modifier, the compatibility of the two phases and the stability of melt spinning are significantly improved. Its preparation includes drying, premixing, and melt blending granulation. When applied to nonwoven fabrics, through melt spinning, high-speed airflow stretching, web laying, and low-temperature hot rolling, a high-elasticity, low-hardness, soft, and breathable spunbond nonwoven fabric can be obtained, suitable for high-end medical, hygiene, and protective applications.

[0007] On the one hand, the present invention provides a highly elastic, low-hardness TPEE / TPE composite elastomer material, employing the following technical solution: A highly elastic, low-hardness TPEE / TPE composite elastomer material, comprising the following components by weight: 50-70 parts of TPEE base resin; 20-30 parts of TPE elastomer; 3-8 parts of compatibilizer, which is a terpolymer of ethylene-methyl acrylate-glycidyl methacrylate; Nucleating agent / rheology modifier 1-3 parts, which is nano-organic montmorillonite.

[0008] Preferably, the TPE elastomer is at least one of SEBS, SEPS, or SEEPS.

[0009] Preferably, the composite elastomer material further includes 0.3-0.8 parts of antioxidant and 0.5-2 parts of lubricant.

[0010] Preferably, the antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].

[0011] On the other hand, the present invention also provides a method for preparing a highly elastic, low-hardness TPEE / TPE composite elastomer material, using the following technical solution: A method for preparing a highly elastic, low-hardness TPEE / TPE composite elastomer material includes the following steps: S1. Pretreatment: Dry the TPEE base resin, TPE elastomer and compatibilizer at 80-90℃ until the water content is less than 300 ppm; S2, Premix: The TPEE base resin, TPE elastomer, compatibilizer dried in step S1 are mixed with nucleating agent / rheology modifier, antioxidant, and lubricant to obtain a premix. S3. Melt blending and granulation: The premixed material prepared in step S2 is fed into a twin-screw extruder and melt-blended, extruded, cooled and granulated in a temperature range of 170-215℃ to obtain a composite elastomer material.

[0012] Preferably, in step S3, the screw speed of the twin-screw extruder is 300-500 rpm, and it is equipped with vacuum exhaust.

[0013] The present invention also provides a method for preparing spunbond nonwoven fabric using the above-mentioned high-elasticity, low-hardness TPEE / TPE composite elastomer material.

[0014] A method for preparing spunbond nonwoven fabric using the above-mentioned high-elasticity, low-hardness TPEE / TPE composite elastomer material includes the following steps: P1. After drying the composite elastomer material, melt spinning is performed, and the temperature of the spinning assembly is 220-240℃. P2. Using an airflow with a pressure of 0.3-0.6 MPa, the ejected molten stream is stretched to form continuous filaments and laid into a web. P3. The fiber web is hot-rolled and reinforced at 80-110℃ and 30-60 N / mm to obtain spunbond nonwoven fabric.

[0015] Preferably, the spinning speed of melt spinning in step P1 is ≥3000 m / min.

[0016] Preferably, the temperature of the airflow in step P2 is 10-20°C higher than the melting point of the composite elastomer material.

[0017] The present invention also provides a spunbond nonwoven fabric prepared by the above method.

[0018] In summary, the beneficial effects of the present invention are as follows: This invention represents a key breakthrough in materials systems. By employing the synergistic effect of a specific structured EMA-GMA compatibilizer and a nano-OMMT rheology modifier, the compatibility problem between TPEE and TPE is fundamentally solved. Furthermore, the viscoelastic properties of the composite melt are precisely controlled, enabling the material to maintain high resilience (resilience > 85%) while significantly reducing overall hardness (reaching Shore A 70-85), and possessing excellent melt strength and spinning stability. This overcomes the long-standing technical bottlenecks of poor spinnability and coarse fiber denier in high-speed spunbond processes for elastomers.

[0019] Based on the aforementioned material innovations, this invention brings significant benefits at both the process and product levels. This specialized material can be stably and rapidly produced directly on conventional spunbond equipment (spinning speed ≥3000 m / min). Furthermore, through an optimized low-temperature hot rolling process, it can produce spunbond nonwoven fabrics with finer fibers (1.0-2.0 denier), high elasticity (longitudinal elongation >150%), low hardness, a soft touch, and good breathability. This greatly enhances the comfort and added value of the products, enabling their widespread application in high-end medical dressings, sports protective gear, and high-requirement hygiene products. Attached Figure Description

[0020] Figure 1 This is a photograph of the spunbond nonwoven fabric prepared in Example 4. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to the embodiments.

[0022] Example Example 1 A highly elastic, low-hardness TPEE / TPE composite elastomer material is prepared using the following specific steps: S1. Dry 60 parts TPEE (Hytrel 4068), 25 parts TPE elastomer (SEBS) and 6 parts EMA-GMA in a forced-air dryer at 80-90℃ for 4-6 hours to reduce the moisture content to below 300 ppm.

[0023] S2. Add the dried TPEE, TPE, EMA-GMA from step S1, along with 2.5 parts of nano OMMT, 0.5 parts of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], lubricant, and 1 part of calcium stearate to a high-speed mixer in proportion, and mix at room temperature for 5-10 minutes to obtain a premix.

[0024] S3. The premixed material from S2 is fed into a twin-screw extruder, and under a protective atmosphere, it is melt-blended, extruded, cooled, pelletized, and dried to obtain the composite elastomer material. The process parameters of the twin-screw extruder are as follows: zone 1 to die head temperatures are set at 170℃, 190℃, 210℃, 215℃, 210℃, and 205℃; screw speed is 300-500 rpm; and vacuum exhaust port pressure is maintained below -0.05 MPa.

[0025] Example 2 A highly elastic, low-hardness TPEE / TPE composite elastomer material is prepared using the following specific steps: S1. Dry 55 parts TPEE (Hytrel 4068), 30 parts TPE elastomer (SEBS) and 8 parts EMA-GMA in a forced-air dryer at 80-90℃ for 4-6 hours to reduce the moisture content to below 300 ppm.

[0026] S2. Add the dried TPEE, TPE, EMA-GMA from step S1, along with 1.5 parts of nano OMMT, 0.5 parts of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], lubricant, and 1 part of calcium stearate to a high-speed mixer in proportion, and mix at room temperature for 5-10 minutes to obtain a premix.

[0027] S3. The premixed material from S2 is fed into a twin-screw extruder, and under a protective atmosphere, it is melt-blended, extruded, cooled, pelletized, and dried to obtain the composite elastomer material. The process parameters of the twin-screw extruder are as follows: zone 1 to die head temperatures are set at 170℃, 190℃, 210℃, 215℃, 210℃, and 205℃; screw speed is 300-500 rpm; and vacuum exhaust port pressure is maintained below -0.05 MPa.

[0028] Example 3 A highly elastic, low-hardness TPEE / TPE composite elastomer material is prepared using the following specific steps: S1. Dry 65 parts TPEE (Hytrel 4068), 20 parts TPE elastomer (SEBS) and 8 parts EMA-GMA in a forced-air dryer at 80-90℃ for 4-6 hours to reduce the moisture content to below 300 ppm.

[0029] S2. Add the dried TPEE, TPE, EMA-GMA from step S1, along with 2 parts of nano OMMT, 0.5 parts of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid], lubricant, and 1 part of calcium stearate to a high-speed mixer in proportion, and mix at room temperature for 5-10 minutes to obtain a premix.

[0030] S3. The premixed material from S2 is fed into a twin-screw extruder, and under a protective atmosphere, it is melt-blended, extruded, cooled, pelletized, and dried to obtain the composite elastomer material. The process parameters of the twin-screw extruder are as follows: zone 1 to die head temperatures are set at 170℃, 190℃, 210℃, 215℃, 210℃, and 205℃; screw speed is 300-500 rpm; and vacuum exhaust port pressure is maintained below -0.05 MPa.

[0031] Example 4 A method for preparing spunbond nonwoven fabric includes the following steps: S1. The composite elastomer materials prepared in Examples 1-3 and Comparative Examples 1-2 are dried at 75-85°C for more than 4 hours.

[0032] S2. The dried material is fed into the spunbond extruder, melted, and precisely metered before being ejected from the spinning assembly. The spinning assembly temperature is 220-240℃, and the spinning speed is ≥3000 m / min.

[0033] S3. High-pressure, low-temperature airflow is used to rapidly draw the ejected molten fine stream (airflow pressure 0.3-0.6 MPa, temperature 10-20℃ higher than the material melting point) to form ultra-fine continuous filaments, which are then evenly laid on a mesh curtain to form a fiber web.

[0034] S4. The fiber web is guided between a pair of heated rolls for hot rolling and bonding. The roll temperature is 80-110℃, the pressure is 30-60 N / mm, and the linear speed is 100-300 m / min. This low-temperature hot rolling condition benefits from the material's low melting and bonding temperature, which avoids excessive fiber agglomeration and loss of elasticity caused by high temperatures.

[0035] S5. Cool, trim, and roll up the reinforced nonwoven fabric to obtain the finished product. Figure 1 The image shown is a photograph of the spunbond nonwoven fabric prepared in Example 4.

[0036] Comparative Example Comparative Example 1 The specific preparation steps of a TPEE / TPE composite elastomer material are as follows: S1. Dry 80 parts of TPEE (Hytrel 4068) and 20 parts of TPE elastomer (SEBS) in a forced-air dryer at 80-90℃ for 4-6 hours to reduce the moisture content to below 300 ppm.

[0037] S2. Add the dried TPEE, TPE, EMA-GMA from step S1, along with 0.5 parts of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] and 1 part of calcium stearate to a high-speed mixer in proportion, and mix at room temperature for 5-10 minutes to obtain a premix.

[0038] S3. The premixed material from S2 is fed into a twin-screw extruder, and under a protective atmosphere, it is melt-blended, extruded, cooled, pelletized, and dried to obtain the composite elastomer material. The process parameters of the twin-screw extruder are as follows: zone 1 to die head temperatures are set at 170℃, 190℃, 210℃, 215℃, 210℃, and 205℃; screw speed is 300-500 rpm; and vacuum exhaust port pressure is maintained below -0.05 MPa.

[0039] Comparative Example 2 The specific preparation steps of a TPEE / TPE composite elastomer material are as follows: S1. Dry 60 parts TPEE (Hytrel 4068), 25 parts TPE elastomer (SEBS), 3 parts POE-g-MAH and 6 parts EMA-GMA in a forced-air dryer at 80-90℃ for 4-6 hours to reduce the moisture content to below 300 ppm.

[0040] S2. Add the dried TPEE, TPE, EMA-GMA, POE-g-MAH from step S1, along with 0.5 parts of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid], lubricant, and 1 part of calcium stearate to a high-speed mixer in proportion, and mix at room temperature for 5-10 minutes to obtain a premix.

[0041] S3. The premixed material from S2 is fed into a twin-screw extruder, and under a protective atmosphere, it is melt-blended, extruded, cooled, pelletized, and dried to obtain the composite elastomer material. The process parameters of the twin-screw extruder are as follows: zone 1 to die head temperatures are set at 170℃, 190℃, 210℃, 215℃, 210℃, and 205℃; screw speed is 300-500 rpm; and vacuum exhaust port pressure is maintained below -0.05 MPa.

[0042] Test case Test Example 1 The performance of the composite elastomer materials prepared in Examples 1-3 and Comparative Examples 1-2 was tested using the following methods: Tensile and elastic recovery rate tests were performed using a Kinseo universal testing machine. Longitudinal and transverse specimens (typically 150 mm long and 25 mm wide) were cut according to standard specifications. The tensile speed was set on the universal testing machine (e.g., 300 mm / min), and the specimens were stretched to the set elongation (e.g., 100%) or until fracture. The breaking strength and elongation at break were recorded. For the elastic recovery rate test, cyclic stretching was performed: after stretching to the target elongation, the specimen was held for a certain time, then retracted at the same speed. Calculations were then performed. Elastic recovery rate = [(stretch length - residual length after shrinkage) / stretch length] × 100%.

[0043] Using an air permeability tester, employing the Graeme or Schubert method, the amount of air passing through per unit time under a specified pressure difference is determined.

[0044] Water vapor transmission rate test: Cut an elastic nonwoven fabric sample, seal it on a moisture permeation cup containing desiccant, weigh it, and then put it into a constant temperature and humidity chamber. Take it out and weigh it at regular intervals, calculate the weight gain of the moisture permeation cup per unit time, and then calculate the water vapor transmission rate.

[0045] As shown in Table 1, Examples 1-3 of the present invention exhibit significant advantages in key mechanical properties and elasticity: their longitudinal elongation at break (370%-410%) and transverse elongation at break (340%-370%) far exceed those of the comparative examples, while maintaining a higher elastic recovery rate. Although the data on skin contact pressure, elastic recovery rate after cycling, and breathability and moisture permeability are similar among the groups, the significant improvement in the aforementioned core mechanical data proves that the present invention effectively solves the compatibility problem between TPEE and TPE through the synergistic effect of specific compatibilizers and rheology modifiers, thereby achieving an excellent balance between high elasticity and low hardness in the material.

[0046] Table 1 Performance tests of Examples 1-3 and Comparative Examples 1-2

[0047] Test Example 2 The spunbond nonwoven fabrics prepared from the composite elastomer materials of Examples 1-3 and Comparative Examples 1-2 in Example 4 were subjected to performance tests, and the specific methods are as follows: The core method for determining the melt flow index (MFR) of composite materials is as follows: Dry the composite material sample to remove moisture and prevent it from affecting the molten state. Use a melt flow rate meter with a corresponding die (commonly 2.095mm), set the standard test temperature (190℃ for TPE, 230℃ for TPEE), and maintain temperature stability. Load the sample into the barrel, apply a specified load (commonly 2.16kg), hold at the temperature, and then press the material. Record the mass of the extruded melt within 10 minutes. The final result is the melt flow index (MFR) (g / 10min) = extruded melt mass × conversion factor.

[0048] The tensile and elastic recovery rate tests were conducted using the method described in Test Example 1.

[0049] As shown in Table 2, the nonwoven fabrics prepared in Examples 1-3 of this invention (with added EMA-GMA compatibilizer and nano-OMMT) are significantly superior to the comparative examples in terms of longitudinal breaking elongation (165%-210%), elastic recovery rate (85%-90%), hand feel (soft to very soft), and fiber fineness (1.3-1.8 denier). In particular, Comparative Example 1 (without compatibilizer and rheology modifier) ​​has poor spinning stability, coarse fibers (2.5 denier), and a stiff product with low elasticity; Comparative Example 2 (using conventional compatibilizer POE-g-MAH) shows improvements in various properties, but is still significantly inferior to this invention. This strongly demonstrates that the specific compatibilizer and rheology modifier system used in this invention plays a decisive synergistic role in achieving nonwoven fabrics with high elasticity, low stiffness, and stable spinning.

[0050] Table 2 Properties of spunbond nonwoven fabrics made from the materials of Examples 1-3 and Comparative Examples 1-2

[0051] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A highly elastic, low-hardness TPEE / TPE composite elastomer material, characterized in that, By weight, it includes the following components: 50-70 parts of TPEE base resin; 20-30 parts of TPE elastomer; 3-8 parts of compatibilizer, wherein the compatibilizer is an ethylene-methyl acrylate-glycidyl methacrylate terpolymer; 1-3 parts of nucleating agent / rheology modifier, wherein the nucleating agent / rheology modifier is nano-organo-montmorillonite.

2. The high-elasticity, low-hardness TPEE / TPE composite elastomer material according to claim 1, characterized in that, The TPE elastomer is at least one of SEBS, SEPS, or SEEPS.

3. A high-elasticity, low-hardness TPEE / TPE composite elastomer material according to claim 1 or 2, characterized in that, The composite elastomer material also includes 0.3-0.8 parts of antioxidant and 0.5-2 parts of lubricant.

4. The high-elasticity, low-hardness TPEE / TPE composite elastomer material according to claim 3, characterized in that, The antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid].

5. A method for preparing a high-elasticity, low-hardness TPEE / TPE composite elastomer material as described in any one of claims 1-4, characterized in that, Includes the following steps: S1. Pretreatment: Dry the TPEE base resin, TPE elastomer and compatibilizer at 80-90℃ until the water content is less than 300ppm; S2, Premix: The TPEE base resin, TPE elastomer, compatibilizer dried in step S1 are mixed with nucleating agent / rheology modifier, antioxidant, and lubricant to obtain a premix. S3. Melt blending and granulation: The premixed material prepared in step S2 is fed into a twin-screw extruder and melt-blended, extruded, cooled and granulated in a temperature range of 170-215℃ to obtain the composite elastomer material.

6. The method for preparing a high-elasticity, low-hardness TPEE / TPE composite elastomer material according to claim 5, characterized in that, In step S3, the screw speed of the twin-screw extruder is 300-500 rpm, and it is equipped with vacuum exhaust.

7. A method for preparing spunbond nonwoven fabric using the high-elasticity, low-hardness TPEE / TPE composite elastomer material as described in any one of claims 1-4, characterized in that, Includes the following steps: P1. After drying the composite elastomer material, melt spinning is performed, and the temperature of the spinning assembly is 220-240℃. P2. Using an airflow with a pressure of 0.3-0.6 MPa, the ejected molten stream is stretched to form continuous filaments and laid into a web. P3. The fiber web prepared in step P2 is hot-rolled and reinforced at 80-110℃ and 30-60 N / mm to obtain the spunbond nonwoven fabric.

8. The method according to claim 7, characterized in that, In step P1, the spinning speed of melt spinning is ≥3000m / min.

9. The method according to claim 7, characterized in that, In step P2, the temperature of the airflow is 10-20°C higher than the melting point of the composite elastomer material.

10. A spunbond nonwoven fabric, characterized in that, It is prepared by the method described in any one of claims 7-9.

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