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EP-3770211-B1 - POLYPROPYLENE FILM AND POLYPROPYLENE COMPOSITE FILM

EP3770211B1EP 3770211 B1EP3770211 B1EP 3770211B1EP-3770211-B1

Inventors

  • WU, Qichao
  • CHEN, Huixue
  • ZHOU, Chunfa
  • HUANG, Jianghao
  • SONG, Daiying
  • MENG, Lijie
  • PANG, Yongtao

Dates

Publication Date
20260513
Application Date
20181205

Claims (11)

  1. A polypropylene membrane, which is formed by a method comprising the steps of mixing of raw materials, film formation, and radiation modification, wherein the raw materials comprise: polypropylene 20-50 parts by weight; polyolefin elastomer 20-45 parts by weight; polyethylene 30-60 parts by weight; ethylene-vinyl acetate copolymer 1-8 parts by weight; cross-linking agent 0.5-10 parts by weight; and silicon dioxide 0-1 parts by weight; wherein the polyolefin elastomer, also called polyolefin thermoplastic elastomer (TPO), is a two-phase separated polymer mixture composed of rubber and polyolefin resin, wherein the rubber is any one selected from a group consisting of ethylene propylene diene monomer rubber (EPDM), nitrile-butadiene rubber (NBR) and butyl rubber (IIR), or a mixture thereof.
  2. The polypropylene membrane according to claim 1, wherein the raw materials further comprise 1-10 parts by weight of calcium carbonate.
  3. The polypropylene membrane according to claim 1, wherein the raw materials further comprise 0.1-1 parts by weight of a stabilizer; and the stabilizer is selected from hindered amine light stabilizer and/or anti-ultraviolet agent.
  4. The polypropylene membrane according to claim 1, wherein the raw materials further comprise 0.2-1.8 parts by weight of an external lubricant; and the external lubricant is selected from a group consisting of metal soap lubricants and/or fatty acid salt lubricants.
  5. The polypropylene membrane according to claim 1, wherein the raw materials further comprise 0.3-1.5 parts by weight of high-molecular-weight organosilicon.
  6. A polypropylene composite membrane, which is made by subjecting a composite membrane to radiation administration, and the composite membrane comprises following layers in order, a first polypropylene membrane; a first coating layer; a printing layer; a second coating layer; a second polypropylene membrane; and a polyurethane coating; wherein the first polypropylene membrane is the polypropylene membrane of claim 1, and the first coating layer and the second coating layer are independently selected from a chlorinated polypropylene coating or a reactive polyurethane coating.
  7. The polypropylene composite membrane according to claim 6, wherein a glue coating is disposed on one side, to which is not contact with the first coating layer, of the first polypropylene membrane.
  8. The polypropylene composite membrane according to claim 6, wherein a third coating layer is disposed between the second polypropylene membrane and the polyurethane coating; and the third coating layer is a chlorinated polypropylene coating or a reactive polyurethane coating.
  9. The polypropylene composite membrane according to claim 6, wherein the second polypropylene membrane is the polypropylene membrane of claim 1
  10. The polypropylene membrane according to any one of claims 1-5, wherein the radiation modification is carried out at a radiation dose between 40-100 kGy.
  11. The polypropylene composite membrane according to any one of claims 6-9, wherein the radiation administration has a radiation dose between 40-100 kGy.

Description

FIELD The present disclosure relates to the field of decorative accessories, specifically to a polypropylene membrane and a polypropylene composite membrane. BACKGROUND In the existing decorative materials market, as consumers' awareness of environmental protection increases, the requirements for materials are becoming stricter. Since polyvinyl chloride (PVC) resin contains elemental chlorine, a harmful substance (Dioxin) released during its incineration process is a highly carcinogenic substance, which directly harms the environment and people's health. Therefore, PVC is regarded as a non-environmental protection factor. In the future, PVC will be eliminated as a material. Therefore, within the scope of thermoplastics, the industry hopes to replace PVC with another environmentally friendly thermoplastic resin. The first consideration is to replace with polypropylene (PP). Patent CN 100540296 C discloses a membrane composition comprising 20 wt% polypropylene, 20 wt% linear low-density polyethylene (LLDPE), 20% very low density polyethylene (VLDPE), 30% ethylene-propylene-diene (EPDM) rubber, 10 wt% of an ethylene copolymer, and 0,5 wt% crosslinking agent. The decorative material is mainly formed by compounding the decorative film and the skeleton through secondary molding methods such as thermal bonding, coating, and vacuum forming. The skeleton can be various shapes of wood, plastic, metal, etc. However, due to the low melt strength of polypropylene, it is easy to rupture during high-temperature vacuum forming, which limits the use of PP decorative films. SUMMARY In view of this, a technical problem to be solved in the present disclosure is providing a polypropylene membrane and a polypropylene composite membrane, and the polypropylene membrane has a low vacuum forming temperature and a high melt strength. The present disclosure provides a polypropylene membrane as defined by claim 1 in the set of claims. Preferably, the polypropylene membrane further comprises 1-10 parts by weight of calcium carbonate. Preferably, the polypropylene membrane further comprises 0.1-1 parts by weight of a stabilizer; and the stabilizer is selected from hindered amine light stabilizer and/or anti-ultraviolet agent. Preferably, the polypropylene membrane further comprises 0.2-1.8 parts by weight of an external lubricant; and the external lubricant is selected from a group consisting of metal soap lubricants and/or fatty acid salt lubricants. Preferably, the polypropylene membrane further comprises 0.3-1.5 parts by weight of high-molecular-weight organosilicon. The present disclosure further provides a polypropylene composite membrane, which is made by subjecting a composite membrane to radiation administration, and the composite membrane comprises following raw materials in order, a first polypropylene membrane;a first coating layer;a printing layer;a second coating layer;a second polypropylene membrane; anda polyurethane coating;the first polypropylene membrane is the polypropylene membrane as defined by claim 1 in the set of claims;the first coating layer and the second coating layer are independently selected from a chlorinated polypropylene coating or a reactive polyurethane coating. Preferably, a glue coating is disposed on one side, to which is not contact with the first coating layer, of the first polypropylene membrane. Preferably, a third coating layer is disposed between the second polypropylene membrane and the polyurethane coating; and the third coating layer is a chlorinated polypropylene coating or a reactive polyurethane coating. Preferably, the second polypropylene membrane is the polypropylene membrane as defined by claim 1 in the set of claims. The present disclosure provides a polypropylene membrane, which is formed by a method comprising the steps of mixing of the following raw materials, film formation, and radiation modification, the raw materials comprising: 20-50 parts by weight of polypropylene; 20-45 parts by weight of polyolefin elastomer; 30-60 parts by weight of polyethylene; 1-8 parts by weight of ethylene-vinyl acetate copolymer; 0.5-10 parts by weight of cross-linking agent; and 0-1 parts by weight of silicon dioxide. Comparing with the conventional art, the vacuum forming temperature of the polypropylene membrane is decreased by adjusting the amounts of main ingredients (polypropylene, polyolefin elastomer and polyethylene) in the present disclosure. At the same time, after the radiation modification, the molecular chains of the polymers crosslink and twist with each other, and the melt strength of the polypropylene membrane is increased, making the molecular chains hard to move during the high-temperature vacuum forming, thereby making the product obtained by vacuum forming not easy to rupture and the surface details of the products not easy to become shallow or even disappear. DETAILED DESCRIPTION The technical solutions in the embodiments of the present disclosure will be described clearly an