A composition for artificial leather and a method for producing artificial leather

Abstract

The application discloses a kind of artificial leather compositions and the preparation method of artificial leather.The artificial leather compositions include hydrogenated styrene-butadiene copolymer;The hydrogenated styrene-butadiene copolymer is composed of high flow SEBS and high-strength SEBS.The composition has excellent processability, can effectively reduce the calendering temperature, and the artificial leather obtained by calendering, foaming and other processes has excellent folding resistance, wear resistance and low temperature performance, and can be used in many occasions such as car sofa leather, shoe upper leather and luggage leather.The artificial leather also has the advantage of recycling, and can be effectively recycled in the fields of shoemaking, asphalt modification and sports ground mat.

Description

Technical Field

[0001] This invention relates to a composition for artificial leather and a method for preparing artificial leather, belonging to the field of artificial leather materials and their processing technology. Background Technology

[0002] Currently, car, train, and furniture seats are made of soft PVC, polyurethane artificial leather, or natural leather. The production processes of existing soft PVC and polyurethane leather require the use of plasticizers, dimethylformamide, isocyanate monomers, etc., resulting in significant VOC emissions and necessitating large-scale VOC treatment and air purification systems. Artificial leather also releases VOCs over a long period during use. Soft PVC leather can also leach plasticizers, or the leachate of plasticizers can cause the artificial leather to crack easily. Polyurethane leather has poor water resistance and will crumble after 3-5 years. When artificial leather is burned, it produces large amounts of harmful substances such as dioxins and NOx. X wait.

[0003] As people's living standards improve, they place higher demands on the production and furniture environment, hoping that polymer materials will be environmentally friendly throughout their entire life cycle—from production and use to disposal—releasing less VOCs, and being easy to dispose of or not producing harmful substances after disposal, and easily decomposed by bacteria. Therefore, the artificial leather industry is seeking new materials to address these issues.

[0004] Chinese patent CN114426754A discloses a method of using vulcanization crosslinking to improve the overall performance of SEBS artificial leather products. However, this composition has poor processing fluidity, a high calendering temperature, and is prone to over-crosslinking during crosslinking, which can cause the leather products to become brittle, have a poor hand feel, and have reduced abrasion resistance. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the first objective of the present invention is to provide a composition for artificial leather that is environmentally friendly, recyclable, and has good processing performance, and the artificial leather prepared therefrom has excellent comprehensive properties, such as good adhesion, wear resistance, and folding resistance.

[0006] The second objective of this invention is to provide a method for preparing artificial leather that is simple, has mild and controllable conditions, and is easy to industrialize.

[0007] To achieve the above-mentioned technical objective, a composition for artificial leather is characterized by comprising a hydrogenated styrene-butadiene copolymer;

[0008] The hydrogenated styrene-butadiene copolymer is composed of high-flow SEBS and high-strength SEBS;

[0009] The high-liquidity SEBS has the following structure:

[0010]

[0011] Where, n1 = 42–52; n2 = 42–52; m1 = 166–285; m2 = 433–611;

[0012] The high-strength SEBS has the following structure:

[0013]

[0014] Among them, x=1~10; y+z=1~13; z / y≦0.3; n=500~2000.

[0015] The hydrogenated styrene-butadiene copolymer of this invention contains high-flowability SEBS with a relatively low molecular weight and a side alkyl chain structural unit ratio of over 65%. This allows for good compatibility with other low-molecular-weight saturated resins, resulting in excellent processing performance. Furthermore, the polymer has low hardness, and by adjusting its dosage, the final leather products exhibit excellent softness. The high-strength SEBS is essentially a completely random SEBS with a microblock structure. On one hand, this structure endows it with good compatibility with polar topcoat agents; on the other hand, the z / y ratio in this polymer is below 0.3, with y components predominating, thus exhibiting high mechanical strength characteristics similar to polyethylene.

[0016] The artificial leather composition of this invention mainly uses a combination of high-flow SEBS and high-strength SEBS. High-flow SEBS can improve the processability of the composition, and the calendering temperature is reduced by about 20°C compared with existing PVC artificial leather during the calendering process. High-strength SEBS can improve the melt strength of the composition, and still have good mechanical properties under high expansion ratio (0.25~0.35) foaming conditions. In particular, the combination of the two gives the artificial leather good comprehensive mechanical properties, with a Martindale abrasion resistance of more than 100,000 cycles, a low temperature (-20°C) folding resistance of more than 50,000 cycles, and a room temperature folding resistance of more than 100,000 cycles.

[0017] As a preferred embodiment, the mass ratio of the high-flowability SEBS to the high-strength SEBS is 5:(1-3); the most preferred mass ratio of the high-flowability SEBS to the high-strength SEBS is 5:(1.5-2.5). When the ratio is much lower than 5:2, the composition has high hardness and the leather product has a poor hand feel, while when it is much higher than 5:2, the mechanical strength of the composition is insufficient and it cannot provide good physical properties.

[0018] As a preferred embodiment, the composition for artificial leather comprises hydrogenated styrene-butadiene copolymer, a polar resin, a tackifier, a flame retardant, and an abrasion retardant. The polar resin, tackifier, and abrasion retardant are introduced as auxiliary materials. The tackifier improves the adhesion between the artificial leather and the base fabric, while the polar resin resolves the compatibility issues between non-polar SEBS and the polar surface coating agent, thereby achieving a good surface coating effect. The abrasion retardant improves its abrasion resistance.

[0019] As a preferred embodiment, the composition for artificial leather comprises the following components by weight percentage: 70-80% hydrogenated styrene-butadiene copolymer; 5%-15% polar resin; 5%-10% tackifier; and 1%-5% abrasion resistant agent. When the proportion of hydrogenated styrene-butadiene copolymer is too low, the leather product has a poor tactile feel; when the proportion of hydrogenated styrene-butadiene copolymer is too high, the content of other functional components is low, failing to achieve good surface coating and adhesion to the base fabric.

[0020] As a preferred embodiment, the composition for artificial leather is preferably composed of the following components by weight percentage: 78% hydrogenated styrene-butadiene copolymer; 10% polar resin; 10% tackifier; and 2% abrasion resistant agent.

[0021] As a preferred embodiment, the polar resin includes at least one of polyacrylate and polyurethane.

[0022] As a preferred embodiment, the tackifier comprises hydrogenated C5 resin.

[0023] As a preferred embodiment, the wear-resistant agent comprises a silicone resin.

[0024] The preferred polar resins, tackifiers, and wear-resistant agents are well compatible with the hydrogenated styrene-butadiene copolymer and can be fully blended and dispersed with the hydrogenated styrene-butadiene copolymer to exert its effect.

[0025] As a preferred embodiment, the composition for artificial leather may also include conventional artificial leather additives such as flame retardants, which are added as needed.

[0026] The present invention also provides a method for preparing artificial leather, wherein the artificial leather is prepared by blending and extruding the composition to obtain granules; the granules are then subjected to calendering and foaming to obtain the final product.

[0027] As a preferred embodiment, the extrusion molding employs a co-rotating twin-screw extruder with a screw speed of 120–240 rpm. The extrusion chamber of the co-rotating twin-screw extruder is divided into six temperature zones from the feeding section to the die head. The temperatures of the feeding section, each temperature zone of the extrusion chamber, and the die head are as follows: feeding section 95–105°C, zone 1 135–145°C, zone 2 170–180°C, zone 3 175–185°C, zone 4 175–185°C, zone 5 175–185°C, and die head 155–165°C. Extrusion under these preferred temperature conditions results in granules with a smooth surface and reduces the likelihood of polymer aging and chain breakage due to excessively high temperatures.

[0028] As a preferred embodiment, the temperature during the rolling process is 120–150°C.

[0029] As a preferred embodiment, azodicarbonamide is used as a foaming agent in the foaming process, and the foaming temperature is 170-180℃.

[0030] Compared with existing technologies, the beneficial technical effects of the present invention are as follows:

[0031] The artificial leather composition of this invention uses high-flowability SEBS to improve the processability of the composition. The artificial leather is prepared by calendering, and the calendering temperature is about 20°C lower than that of existing PVC artificial leather, which is beneficial for energy saving and reducing production costs. At the same time, the use of high-strength SEBS can improve the melt strength of the composition, and it still has good mechanical properties under high-ratio (0.25~0.35) foaming conditions. In addition, functional auxiliary materials can be further introduced, such as the introduction of tackifying resin to improve the adhesion between artificial leather and base fabric, the introduction of polar resin to solve the compatibility between non-polar polymers such as SEBS and polar surface coating agents, thereby obtaining a good surface coating effect, and abrasion-resistant agents to improve its abrasion resistance.

[0032] The artificial leather prepared by the composition of this invention has excellent comprehensive properties. Compared with existing PVC artificial leather, it has better low-temperature performance, with a minimum service temperature of about -50°C. Since SEBS is a non-polar polymer, its hydrolysis resistance is significantly improved compared with PU leather. Moreover, the composition can be used as the intermediate foaming layer of artificial leather, with a foaming ratio of about 0.3, and has excellent adhesion to the base fabric layer. It can also be used as the surface layer of artificial leather, and has good compatibility with the topcoat. The prepared artificial leather has a Martindale abrasion resistance of more than 100,000 cycles, a low-temperature (-20°C) folding resistance of more than 50,000 cycles, and a room-temperature folding resistance of more than 100,000 cycles.

[0033] The artificial leather composition of the present invention is safe and environmentally friendly, with VOCs below 10ppm, and also has the advantage of being recyclable. It can be effectively recycled in fields such as shoemaking, asphalt modification, and sports mats.

[0034] The artificial leather preparation method of the present invention is simple, the conditions are mild and controllable, and it is easy to realize industrial production. Detailed Implementation

[0035] The following specific embodiments are intended to further illustrate the content of the present invention, rather than to limit the scope of protection of the claims.

[0036] The raw materials used in the following specific embodiments are all conventional commercially available products.

[0037] High-flowability SEBS (Sinopec Baling Petrochemical Co., Ltd., model YH-505, number average molecular weight 47820, styrene content 20%, 1,2-structure content in unhydrogenated butadiene units 67.3%).

[0038] High-strength SEBS (Sinopec Baling Petrochemical Co., Ltd., model YH-520, number average molecular weight of 72365, styrene content of 20%, and 1,2-structure content of 16.9% in butadiene units before hydrogenation);

[0039] Acrylic resin (Kuraray, Japan, model LA2250);

[0040] Hydrogenated C5 resin (Zhejiang Henghe Petrochemical Co., Ltd., H5-1000);

[0041] Silicone resin (Guangzhou Haochangyue, SA-400).

[0042] Example 1

[0043] 50 parts by weight of high-flow SEBS, 25 parts by weight of high-strength SEBS, 10 parts by weight of acrylic resin, 10 parts by weight of hydrogenated C5 resin and 5 parts by weight of silicone resin were mixed evenly in a high-speed mixer, and then extruded and granulated in a twin-screw extruder to obtain the composition. The composition was then processed into leather through calendering and foaming processes, and its performance was tested.

[0044] The parameters for the twin-screw extrusion process are set as follows:

[0045] Feeding section Zone 1 Zone 2 Three Districts District 4 Fifth District District 6 machine head 80℃ 130℃ 170℃ 170℃ 170℃ 170℃ 170℃ 160℃

[0046] The rolling temperature is 130℃;

[0047] The foaming temperature is 170℃, and the foaming time is 15 minutes.

[0048] Martindale abrasion resistance test standard: ASTM D 4966;

[0049] Flexural endurance test standard: QB / T2714-2005.

[0050] Example 2

[0051] 50 parts by weight of high-flowability SEBS, 25 parts by weight of high-strength SEBS, 13 parts by weight of acrylate resin, 10 parts by weight of hydrogenated C5 resin, and 2 parts by weight of silicone resin were mixed evenly in a high-speed mixer, and then extruded and granulated in a twin-screw extruder to obtain the composition. The mixture was then calendered and foamed to form leather, and its performance was tested. The process parameters are as described in Example 1.

[0052] Example 3

[0053] 45 parts by weight of high-flow SEBS, 30 parts by weight of high-strength SEBS, 13 parts by weight of acrylic resin, 10 parts by weight of hydrogenated C5 resin and 2 parts by weight of silicone resin were mixed evenly in a high-speed mixer, and then extruded and granulated in a twin-screw extruder to obtain the composition. The composition was then processed into leather through calendering and foaming processes, and its performance was tested.

[0054] For process parameters and conditions, please refer to Example 1.

[0055] Example 4

[0056] 40 parts by weight of high-flow SEBS, 35 parts by weight of high-strength SEBS, 13 parts by weight of acrylic resin, 10 parts by weight of hydrogenated C5 resin and 2 parts by weight of silicone resin were mixed evenly in a high-speed mixer, and then extruded and granulated in a twin-screw extruder to obtain the composition. The composition was then processed into leather through calendering and foaming processes, and its performance was tested.

[0057] For process parameters and conditions, please refer to Example 1.

[0058] Example 5

[0059] 55 parts by weight of high-flow SEBS, 20 parts by weight of high-strength SEBS, 13 parts by weight of acrylic resin, 10 parts by weight of hydrogenated C5 resin and 2 parts by weight of silicone resin were mixed evenly in a high-speed mixer, and then extruded and granulated in a twin-screw extruder to obtain the composition. The composition was then processed into leather through calendering and foaming processes, and its performance was tested.

[0060] For process parameters and conditions, please refer to Example 1.

[0061] Example 6

[0062] 60 parts by weight of high-flow SEBS, 15 parts by weight of high-strength SEBS, 13 parts by weight of acrylic resin, 10 parts by weight of hydrogenated C5 resin and 2 parts by weight of silicone resin were mixed evenly in a high-speed mixer, and then extruded and granulated in a twin-screw extruder to obtain the composition. The composition was then processed into leather through calendering and foaming processes, and its performance was tested.

[0063] For process parameters and conditions, please refer to Example 1.

[0064] Example 7

[0065] 50 parts by weight of high-flow SEBS, 25 parts by weight of high-strength SEBS, 15 parts by weight of acrylic resin, 5 parts by weight of hydrogenated C5 resin and 5 parts by weight of silicone resin were mixed evenly in a high-speed mixer, and then extruded and granulated in a twin-screw extruder to obtain the composition. The composition was then processed into leather through calendering and foaming processes, and its performance was tested.

[0066] For process parameters and conditions, please refer to Example 1.

[0067] Example 8

[0068] 50 parts by weight of high-flow SEBS, 30 parts by weight of high-strength SEBS, 10 parts by weight of acrylic resin, 5 parts by weight of hydrogenated C5 resin and 5 parts by weight of silicone resin were mixed evenly in a high-speed mixer, and then extruded and granulated in a twin-screw extruder to obtain the composition. The composition was then processed into leather through calendering and foaming processes, and its performance was tested.

[0069] For process parameters and conditions, please refer to Example 1.

[0070] Example 9

[0071] 50 parts by weight of high-flow SEBS, 25 parts by weight of high-strength SEBS, 13 parts by weight of polyurethane, 10 parts by weight of hydrogenated C5 resin and 2 parts by weight of silicone resin were mixed evenly in a high-speed mixer, and then extruded and granulated in a twin-screw extruder to obtain the composition. The composition was then processed into leather through calendering and foaming processes, and its performance was tested.

[0072] For process parameters and conditions, please refer to Example 1.

[0073] Example 10

[0074] 50 parts by weight of high-flow SEBS, 25 parts by weight of high-strength SEBS, 15 parts by weight of polyurethane, 5 parts by weight of hydrogenated C5 resin and 5 parts by weight of silicone resin were mixed evenly in a high-speed mixer, and then extruded and granulated in a twin-screw extruder to obtain the composition. The composition was then processed into leather through calendering and foaming processes, and its performance was tested.

[0075] For process parameters and conditions, please refer to Example 1.

[0076] Comparative Example 1

[0077] 30 parts by weight of commercially available PVC (Inner Mongolia Junzheng, model SG-5), 35 parts of calcium powder and 35 parts of dioctyl phthalate were mixed evenly in a high-speed mixer, and then extruded and granulated in a twin-screw extruder to obtain the composition. The composition was then processed into leather through calendering and foaming processes, and its performance was tested.

[0078] For process parameters and conditions, please refer to Example 1.

[0079] Comparative Example 2

[0080] 50 parts by weight of commercially available SEBS (Sinopec Baling Petrochemical Co., Ltd., model YH-502), 25 parts of No. 26 white oil, 10 parts of acrylate resin, 10 parts of hydrogenated C5 resin and 5 parts of silicone resin were mixed evenly in a high-speed mixer, and then extruded and granulated in a twin-screw extruder to obtain the composition. The mixture was then processed into leather through calendering and foaming processes, and its performance was tested.

[0081] For process parameters and conditions, please refer to Example 1.

[0082] Comparative Example 3

[0083] 50 parts by weight of commercially available SEBS (Sinopec Baling Petrochemical Co., Ltd., model YH-502), 25 parts of No. 26 white oil, 10 parts of polypropylene resin, 10 parts of hydrogenated C5 resin and 5 parts of silicone resin were mixed evenly in a high-speed mixer, and then extruded and granulated in a twin-screw extruder to obtain the composition. The mixture was then processed into leather through calendering and foaming processes, and its performance was tested.

[0084] For process parameters and conditions, please refer to Example 1.

[0085] Comparative Example 4

[0086] 70 parts by weight of high-flow SEBS, 5 parts by weight of high-strength SEBS, 13 parts by weight of acrylic resin, 10 parts by weight of hydrogenated C5 resin and 2 parts by weight of silicone resin were mixed evenly in a high-speed mixer, and then extruded and granulated in a twin-screw extruder to obtain the composition. The composition was then processed into leather through calendering and foaming processes, and its performance was tested.

[0087] For process parameters and conditions, please refer to Example 1.

[0088] Comparative Example 5

[0089] 35 parts by weight of high-flow SEBS, 40 parts by weight of high-strength SEBS, 13 parts by weight of acrylic resin, 10 parts by weight of hydrogenated C5 resin and 2 parts by weight of silicone resin were mixed evenly in a high-speed mixer, and then extruded and granulated in a twin-screw extruder to obtain the composition. The composition was then processed into leather through calendering and foaming processes, and its performance was tested.

[0090] For process parameters and conditions, please refer to Example 1.

[0091] The main performance test results of the above embodiments and comparative examples are shown in the table below:

[0092]

[0093]

Claims

1. A composition for use in artificial leather, characterized in that: Contains hydrogenated styrene-butadiene copolymer; The hydrogenated styrene-butadiene copolymer is composed of high-flow SEBS and high-strength SEBS; The high-liquidity SEBS has the following structure: ； in, n1 =42～52； n2=42～52； m1=166～285； m2=433～611； The high-strength SEBS has the following structure: ； in, x=1~10； y+z=1~13; z / y≦0.3; n=500~2000； The mass ratio of the high-flowability SEBS to the high-strength SEBS is 5:(1~3).

2. The composition for artificial leather according to claim 1, characterized in that: The composition for artificial leather comprises hydrogenated styrene-butadiene copolymer, polar resin, tackifier, and abrasion resistant agent.

3. The composition for artificial leather according to claim 2, characterized in that: The composition for artificial leather comprises the following components by weight percentage: Hydrogenated styrene-butadiene copolymer 70-80%; Polar resin 5%~15%; Tackifier 5%~10%; Abrasion-resistant agent 1%~5%.

4. The composition for artificial leather according to claim 3, characterized in that: The polar resin includes at least one of polyacrylate and polyurethane.

5. The composition for artificial leather according to claim 3, characterized in that: The tackifier includes hydrogenated C5 resin.

6. The composition for artificial leather according to claim 3, characterized in that: The wear-resistant agent includes silicone resin.

7. A method for preparing artificial leather, characterized in that: The composition for artificial leather according to any one of claims 1 to 6 is blended and extruded to obtain granules; the granules are then calendered and foamed to obtain the final product.

8. The method for preparing artificial leather according to claim 7, characterized in that: The extrusion molding process uses a co-rotating twin-screw extruder with a screw speed of 120~240 rpm. The extrusion chamber of the co-rotating twin-screw extruder is divided into 6 temperature zones from the feeding section to the die head. The temperatures of the feeding section, the extrusion chamber, and the die head are as follows: feeding section 95~105℃, zone 1 135~145℃, zone 2 170~180℃, zone 3 175~185℃, zone 4 175~185℃, zone 5 175~185℃, and die head 155~165℃.

9. The method for preparing artificial leather according to claim 7, characterized in that: During the rolling process, the temperature is 120~150℃.

10. The method for preparing artificial leather according to claim 7, characterized in that: Azodicarbonamide is used as a foaming agent in the foaming process, and the foaming temperature is 170~180℃.

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