According to the classification of the base material of clear car coat paint protection film:

1. Poor weather resistance of PVC: it hardens and becomes brittle at low temperatures, ages and becomes loose at high temperatures, is prone to yellowing, degumming, poor toughness, and elasticity – it has a weak protective function for automotive paint surfaces.
2. The concept coined by TPH domestically does not actually have this material. The main component is PVC, with more plasticizers and stabilizers added. The brightness and aging time are improved compared to PVC, and there is no repair function.
3. TPU has excellent characteristics of high tension, high tensile strength, toughness, and aging resistance, as well as many excellent functions such as high waterproofing, moisture permeability, wind resistance, cold resistance, antibacterial, mold resistance, warmth preservation, and UV resistance.

Composition of thermoplastic elastomer TPU:

1、 Hard section

Provide engineering performance: 1. Heat resistance 2. Oil and solution resistance 3. Tear strength 4. Tensile strength 5. Modulus

2、 Soft section

Provide elastic properties: compression permanent deformation, tensile deformation, impact resistance, low-temperature performance, hardness/flexibility

The ratio of hard to soft segments affects hardness, modulus, and flexibility.

TPU soft segment structure and performance:

1: Polyester type polyester type TPU contains ester groups with high cohesion, and compared to polyether type TPU, the product has higher mechanical strength, oil resistance, chemical resistance, and thermal oxidation stability. Polyester based TPU is prone to chain breakage due to the presence of easily hydrolyzed ester groups, which can be attacked by water molecules. The acid generated by hydrolysis can also catalyze further hydrolysis of polyester, resulting in poorer water resistance of polyester based TPU compared to polyether based TPU and moderate cost.

2: Polyether type polyether type TPU has good flexibility and excellent low-temperature performance due to the easy rotation of the ether group in the soft segment, and there is no ester group in the polyether that is relatively easy to hydrolyze. Its hydrolysis resistance is better than that of the polyether type. However, the mechanical strength, oil resistance, and heat resistance of TPU are worse than those of polyester TPU, resulting in higher production costs.

3: Polycaprolactone type Polycaprolactone type TPU is between polyester and polyether, with good comprehensive performance, excellent mechanical strength, oil resistance, chemical resistance, wear resistance, and tear resistance. It has good flexibility, superior low-temperature performance, and there is no ester group that is relatively easy to hydrolyze. Its hydrolysis resistance is good. However, the price is relatively high and is commonly used in medical artificial organs and blood vessels.

TPU hard segment structure and performance:

1: Polyurethane prepared from aromatic aromatic isocyanates has a rigid aromatic ring in its hard segment, which increases its cohesive strength. The material strength is generally higher than that of aliphatic isocyanate polyurethane, but its UV degradation resistance is poor, and it is prone to yellowing and degumming.

2: Aliphatic polyurethane does not turn yellow. Different isocyanate structures also have different effects on the durability of polyurethane. Aromatic polyurethane has better thermal oxidation resistance than aliphatic polyurethane because the hydrogen on the aromatic ring is more difficult to oxidize.

So if the TPU sold on the market is considered aliphatic or aromatic, it is not comprehensive. It should be made of polyester type aromatic TPU material, etc.