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CN-122013549-A - Preparation method of high-toughness bio-based synthetic leather

CN122013549ACN 122013549 ACN122013549 ACN 122013549ACN-122013549-A

Abstract

The invention discloses a preparation method of high-toughness bio-based synthetic leather, which comprises the following steps of preprocessing base cloth, padding bio-based emulsion, drying to obtain a polycaprolactone processed base cloth layer, coating aqueous bio-based polyurethane surface layer slurry on release paper, drying to form an aqueous bio-based polyurethane surface layer, coating solvent-free polycaprolactone-based polyurethane slurry on the aqueous bio-based polyurethane surface layer, immediately attaching the polycaprolactone processed base cloth layer to the solvent-free polycaprolactone-based polyurethane surface layer after the solvent-free polycaprolactone-based polyurethane surface layer is pre-baked to a set dryness, compacting to obtain composite crust leather, curing the composite crust leather, stripping the release paper, spraying surface treatment liquid on the surface, and drying to obtain a synthetic leather finished product, wherein the synthetic leather has the advantages of ultrahigh toughness, high strength, low VOC and high bio-based content.

Inventors

  • XU HUIMIN
  • LIN XIAOFANG
  • SU DEYE

Assignees

  • 安安(中国)有限公司

Dates

Publication Date
20260512
Application Date
20260313

Claims (10)

  1. 1. A preparation method of high-toughness bio-based synthetic leather is characterized by comprising the following steps: S1, preprocessing a base fabric, padding biological base emulsion, and drying to obtain a polycaprolactone processed base fabric layer; S2, coating aqueous bio-based polyurethane surface layer slurry on release paper, and drying to form an aqueous bio-based polyurethane surface layer; S3, coating solvent-free polycaprolactone-based polyurethane slurry on a water-based bio-based polyurethane surface layer, pre-baking to a set dryness, immediately attaching a polycaprolactone-treated base cloth layer on the water-based bio-based polyurethane surface layer, and compacting to obtain composite crust leather, wherein the solvent-free polycaprolactone-based polyurethane slurry is prepared by mixing 80-95 parts of polycaprolactone polyol, 5-20 parts of polycarbonate diol, 59-63 parts of isocyanate and 0.5-0.55 part of compound catalyst; And S4, curing the composite crust leather, stripping the release paper, spraying a surface treatment liquid on the surface, and drying to obtain a synthetic leather finished product.
  2. 2. The method for preparing high-toughness bio-based synthetic leather according to claim 1, wherein the polycaprolactone polyol is prepared by ring-opening polymerization of epsilon-caprolactone and 1, 4-butanediol, has a number average molecular weight of 2000+/-200 and a hydroxyl value of 56-60mgKOH/g.
  3. 3. The method for preparing high-toughness bio-based synthetic leather according to claim 2, wherein the isocyanate is HDI trimer with NCO content of 21+ -1%.
  4. 4. The method for preparing high-toughness bio-based synthetic leather according to claim 3, wherein the compound catalyst is a mixture of an organozinc catalyst and an organozirconium catalyst, and the mass ratio of the organozinc catalyst to the organozirconium catalyst is 1 (1-1.5).
  5. 5. The preparation method of the high-toughness bio-based synthetic leather according to claim 4, wherein in the step S1, the pretreatment is plasma treatment, the treatment power is 450-550W, the treatment time is 2-4S, the bio-based emulsion is a mixed emulsion of polycaprolactone emulsion and nanocellulose, wherein the solid content of the polycaprolactone emulsion is 12+/-1%, and the addition amount of the nanocellulose accounts for 1-2% of the total mass of the emulsion.
  6. 6. The preparation method of the high-toughness bio-based synthetic leather according to claim 5, wherein in S2, the raw materials of the aqueous bio-based polyurethane surface layer slurry comprise, by mass, 78-83 parts of bio-based polyurethane, 3-6 parts of tackifier, 1.5-2 parts of defoamer, 2-4 parts of bridging agent and 11-14 parts of color paste; The soft segment of the bio-based polyurethane is formed by compounding polycaprolactone polyol and linseed oil polyol according to the mass ratio of (2.5-3.0) to 1.
  7. 7. The preparation method of the high-toughness bio-based synthetic leather according to claim 1, wherein in the step S3, the solvent-free polycaprolactone-based polyurethane slurry is dried to form a solvent-free polycaprolactone-based polyurethane connecting layer, the pre-drying temperature is 120-130 ℃, the pre-drying time is 2-3min, and the dryness of the connecting layer after the pre-drying is controlled to be 63-67%.
  8. 8. The preparation method of the high-toughness bio-based synthetic leather is characterized in that in S4, a surface treatment layer is formed after surface treatment liquid is sprayed, raw materials of the surface treatment liquid comprise, by mass, 86-87 parts of castor oil modified waterborne polyurethane, 7-8 parts of sulfonate modified isocyanate bridging agent and 4-6 parts of wear-resistant agent, wherein the wear-resistant agent is a compound of graphene and boron nitride according to a mass ratio of 1:2, and the wear-resistant agent is subjected to ultrasonic dispersion treatment before use.
  9. 9. The method for preparing high-toughness bio-based synthetic leather according to claim 8, wherein in the step S4, the curing treatment is performed by heating in a sectional manner, the first-stage curing temperature is 130-135 ℃ for 0.5-1.5min, and the second-stage curing temperature is 135-140 ℃ for 1-2min.
  10. 10. The method for preparing the high-toughness bio-based synthetic leather according to claim 1, wherein the base fabric is 800-900 μm polyester knitted fabric, the warp breaking strength is more than or equal to 300N/5cm, and the weft breaking strength is more than or equal to 280N/5cm.

Description

Preparation method of high-toughness bio-based synthetic leather Technical Field The invention belongs to the technical field of synthetic leather manufacturing, and particularly relates to a preparation method of high-toughness bio-based synthetic leather for the fields of automotive interiors, high-end home furnishings and consumer goods. Background With the increasing strictness of environmental regulations and the enhancement of environmental awareness of consumers, the synthetic leather industry is accelerating the transformation from traditional petroleum-based, solvent-based processes to aqueous, solvent-free and other green processes. However, current environment-friendly synthetic leather often faces a performance compromise while pursuing green production. However, three major problems are encountered when using biobased materials for synthetic leather: First, compatibility issues. The common biological base material (such as polylactic acid PLA) has large chemical structure difference with the polyurethane matrix, so that the interface bonding force of the biological base material and the polyurethane matrix is weak, just like water and oil are difficult to fuse, and the synthetic leather is easy to delaminate and peel in use. Second, performance balancing issues. Although many bio-based resins are environment-friendly in source, the synthetic leather is hard and brittle, and is broken after folding, so that the synthetic leather is soft and firm, and is difficult to meet the double requirements of the fields of automobile interiors, high-end bags and the like on soft touch and high durability. Third, the base fabric reinforcement problem. When the base cloth is used as a skeleton of the synthetic leather and is treated by a biological base material, the strength of the base cloth is often insufficient, or the base cloth is too hard and not soft, and the base cloth is difficult to be compatible. Therefore, development of synthetic leather which can not only keep high bio-based content, but also surpass the traditional petroleum-based products in aspects of flexibility, strength, durability and the like is still a technical problem to be solved in the synthetic leather products. Disclosure of Invention Aiming at the defects of the existing synthetic leather, the invention provides a preparation method of the high-toughness bio-based synthetic leather which takes polycaprolactone polyol as a core and has the advantages of ultrahigh toughness, high strength, low VOC emission and high bio-based content. In order to achieve the aim, the preparation method of the high-toughness bio-based synthetic leather is realized by the following technical scheme that the preparation method comprises the following steps: S1, preprocessing a base fabric, padding biological base emulsion, and drying to obtain a polycaprolactone processed base fabric layer; S2, coating aqueous bio-based polyurethane surface layer slurry on release paper, and drying to form an aqueous bio-based polyurethane surface layer; S3, coating solvent-free polycaprolactone-based polyurethane slurry on a water-based bio-based polyurethane surface layer, pre-baking to a set dryness, immediately attaching a polycaprolactone-treated base cloth layer on the water-based bio-based polyurethane surface layer, and compacting to obtain composite crust leather, wherein the solvent-free polycaprolactone-based polyurethane slurry is prepared by mixing 80-95 parts of polycaprolactone polyol, 5-20 parts of polycarbonate diol, 59-63 parts of isocyanate and 0.5-0.55 part of compound catalyst; And S4, curing the composite crust leather, stripping the release paper, spraying a surface treatment liquid on the surface, and drying to obtain a synthetic leather finished product. Further, the polycaprolactone polyol is prepared by ring-opening polymerization of epsilon-caprolactone and 1, 4-butanediol, the number average molecular weight of the polycaprolactone polyol is 2000+/-200, and the hydroxyl value of the polycaprolactone polyol is 56-60mgKOH/g. Further, the isocyanate is an HDI trimer having an NCO content of 21±1%. Further, the compound catalyst is a mixture of an organozinc catalyst and an organozirconium catalyst, and the mass ratio of the organozinc catalyst to the organozirconium catalyst is 1 (1-1.5). Further, in S1, the pretreatment is plasma treatment, the treatment power is 450-550W, the treatment time is 2-4S, the bio-based emulsion is a mixed emulsion of polycaprolactone emulsion and nanocellulose, wherein the solid content of the polycaprolactone emulsion is 12+/-1%, and the addition amount of the nanocellulose accounts for 1-2% of the total mass of the emulsion. Further, in S2, the raw materials of the aqueous bio-based polyurethane surface layer slurry comprise, by mass, 78-83 parts of bio-based polyurethane, 3-6 parts of tackifier, 1.5-2 parts of defoamer, 2-4 parts of bridging agent and 11-14 parts of color paste, wherein the soft segment of the