1、Discussion on the application of PPF Coatings

1-1 Type

1-2Characteristics of different types of coatings

2.Selection of Coatings for Paint Protective Film
2-1. 2K-PU? Physicochemical index of self-healing coating

item	index
content	38±3%
viscosity	6-50s（Tu-4viscometer）
activation time	≥2h
baking time	100-130℃, 2-3min,rewinding without returning to stick
ripening temperature&time	60-80℃, ＞48h

Note: the advantages and disadvantages of foul resistance and aging resistance depend on whether the coating is fully cross-linked; It is an effective method to put the surface treated film into the ripening box. The ripening time is at least 24 hours, and the effect is better if it can reach more than 48 hours.

2-2 In view of the existing situation that there is no national or industry standard for PPF, we have the tests of the following items as the basic standard.
coating film test standard 1

item	test		standard
Light transmittance	＞92%
Carburetor-resistance cleaner	30-60s (no lose of light)		reference GB/T 23989-2009
Water contact angle	≥95°
Elongation rate	≥75%
Pencil hardness	2H
Water boiling resistance	80℃ 30min	adhesion 0-1grade
Bending resistance	2mm
Pressure concave resistance	＞10mm
Impact resistance	100cm qualified
UV aging resistance	QUV 1000h △E＜1

?coating film test standard 2

item	method		result
anti-fouling（washable level）24h	black ink，level	JG/T304-2011	1
	oil mark pen，level		1
	spraying paint，level		2
Solvent-wipe resistance (Butanone, load 1000g, repeat 10 times)	GB/T23989-2009		no exposed substrate of paint film
Water resistance168h	GB/T 1733-1993		No bubbles, no cracking, no spalling, no discoloration, no loss of light
Alkali resistance（5%NaOH，24h）	GB/T 30648.4-2015		No bubbles, no cracking, no spalling, no discoloration, no loss of light
Acid resistance（5%H2SO4，24h）	GB/T 30648.4-2015		No bubbles, no cracking, no spalling, no discoloration, no loss of light
Low temperature resistance（-20℃，24h）	GB/T 2423.1-2008		No bubbles, no cracking, no spalling, no discoloration, no loss of light
Moisture and heat resistance（85℃，85%，24h）	GB/T 1740-2007		No bubbles, no spalling, no wrinkles
Salt spray aging 72h	GB/T 1771-2007		No bubbles, no cracking, no spalling, no discoloration, no loss of light
Artificial accelerated aging500-1000h	GB/T 1865-2009		No bubbles, no spalling, no wrinkles

3. JIAZHI?Application of easy-cleaning functional resin in PPF coatings
Brief introduction of products
JIAZHI?easy-cleaning functional resin series products are independently developed with advanced polymerization technology by XOANONS. The products are divided into two categories: hydrophilic type and hydrophobic type, both of which can be crosslinked and cured with isocyanate curing agent. Hydrophilic coating needs to cooperate with alcohol and other cleaning agents to remove stains, which has the advantage of good flexibility; hydrophobic coating is not as flexible as hydrophilic coating, but has excellent anti-fouling performance, less residual stains under the same conditions, and easier to clean.

Product use
After the coating prepared by this kind of resin is coated on the surface of TPU, TPH and other substrates, the coatings can be used for PPF, mobile phone protection film, electronic products, Arts and crafts products, metal products, furniture and so on.

Product model and technical parameters
Silicon modified

	JIAZHI?JZ-9540	JIAZHI?JZ-9540-10	JIAZHI?JZ-9540-20	JIAZHI?JZ-9562-10
Composition	Silicone modified hydroxyl acrylic resin solution	Silicon modified hydroxyl acrylic resin solution	Silicon modified hydroxyl acrylic resin solution	Silicon modified hydroxyl acrylic resin solution
Appearance	Slight yellowish to yellowish clear liquid	Slight yellowish to yellowish clear liquid	Slight yellowish to yellowish clear liquid	Transparent to slight yellowish clear liquid
Solvent	BAC/PMA	BAC/PMA	BAC/PMA	PMA
Viscosity (Rotating viscometer) (25±0.2)℃	100-1000mPa·s	100-1000mPa·s	100-1000mPa·s	100-1000mPa·s
Content (140℃ 2h)	50±3%	50±3%	50±3%	54±3%
Hydroxyl value (Theoretical value of solid resin)	120±5 mg KOH/g	127±5 mg KOH/g	170±5 mg KOH/g	179±5 mg KOH/g

Functional monomer modified

	JIAZHI?JZ-9582	JIAZHI?JZ-9516
Composition	Hydroxy acrylic resin solution modified by functional monomer	Hydroxy acrylic resin solution modified by functional monomer
Appearance	Slight yellowish to yellowish translucent liquid	Slight yellowish to yellowish translucent liquid
Solvent	BAC/Xylene	BAC
Viscosity (25±0.2)℃	100-1000mPa·s (Rotating viscometer)	X~Z1(Bubble viscometer)
Content (140℃ 2h)	50±3%	60±3%
Hydroxyl value (Theoretical value of solid resin)	72±5 mg KOH/g	40±5 mg KOH/g

Products recommendation 1- for TPH film

item	requirement	resin model
Main resin		JZ-9540	JZ-9540-10	JZ-9540-20	JZ-9582	JZ-9516	JZ-9562-10
Oil-pen resistance	A little residue after alcohol wipe	√	√	√
	No residue after alcohol wipe				√	√	√
	A slight residue after dry cleaning	√	√	√	√
	No residue after dry cleaning						√
Elongation rate (flexibility)	＞60%	√	√	√	√	√	√
	＞80%		√	√	√	√	√
	＞100%				√	√
	＞150%					√
Recovery	Thermal repair	√	√	√	√	√	√
	Room temperature self-repair			√
Time for carburetor cleaner to lose luster	No requirement	√	√	√	√	√	√
	No change in 30s	√	√	√	√		√
	No change in 60s						√
	No change after volatilization drying						√
Weather resistance （Aging test of QUVB）	1000h	√	√	√	√	√	√
	2000h				√	√
	3000h				√	√

Products recommendation 2- for TPU film

Main resin	requirement	resin model
Oil-pen resistance		JZ-9540	JZ-9540-10	JZ-9540-20	JZ-9582	JZ-9516	JZ-9562-10
Elongation rate (flexibility)	A little residue after alcohol wipe	√	√	√
	No residue after alcohol wipe				√	√	√
	A slight residue after dry cleaning	√	√	√	√
	No residue after dry cleaning						√
Recovery	＞50%	√	√	√	√	√	√
	＞60%		√	√	√	√	√
	＞70%			√	√	√	√
	＞110%				√	√	?
	＞150%				?	√
Time for carburetor cleaner to lose luster	Thermal repair	√	√	√	√	√	√
	Room temperature self-repair			√
Weather resistance （Aging test of QUVB）	No requirement	√	√	√	√	√	√
	No change in 30s	√	√	√	√		√
	No change in 60s						√
	No change after volatilization drying						√
Main resin	1000h	√	√	√	√	√	√
	2000h				√	√
	3000h				√	√

Note：1.Under the baking condition (100m / 130C 2-3min), the higher the temperature is, the longer the time is, the better the effect is.

Ripening conditions: it is suggested that 60ml at 80 ℃. The ripening time is at least 24 hours, and if it can reach more than 48 hours, the effect is better, and the performance of oil-resistant pen and carburetor cleaning agent is improved.

In view of the variability of substrate, film thickness, baking and aging conditions, the data provided in this table are for reference only.

Weather resistance: the weather resistance of JZ-9582A/9516A coating itself is up to 3000h, and the weather resistance of TPH film needs to be tested.

Recommended formula for PPF

composition	material	proportion（%）
Part A	Easy-cleaning resin	76-80
	Solvent	make up to100
	Dryer agent（1%）	1
	XOANONS?WE-D8920BR（leveling agent)	0.25
	Total	100
Part B	isocyanate curing agent	suggestion NCO:OH=1.05-1.1

Remarks:

Different types of curing agents have a slight impact on product performance, the conventional recommendation is N3390 or Japanese CORONATE 2793, specific formula reference product TDS;

It is recommended to use the same solvent as the resin dilution. Such as the use of other solvents, need to evaluate the compatibility in the resin system;

A, B components mixed, under the condition of a lid, the storage life is 5-7 hours. Therefore, the mixed material should be used as soon as possible, otherwise the material will be gelatinized and cannot be used.

Bake at 100ml / 130 ℃ for 3 minutes, then cool and rewind, then continue to mature at 60-80 ℃. The higher the temperature, the longer the time, the better the effect.

5. According to the surface drying performance of the coating and the requirements of the activation period after the mixing of A and B components, the amount of drier can be adjusted, and the drier can choose organotin or other types of auxiliaries.

Application test
Below, after we prepare the varnish with JIAZHI ?JZ-9540-10/9582 as the main resin, we test the characteristics of the coating through experiments. Some projects are tested compared with an international brand of hydrophilic paint at the same time to compare the different performances on different types of products.

1.After preparing the paint according to the suggested formula, the paint is coated on TPU film, and the theoretical film thickness is about 12 μ m.
Curing condition: bake at 120 ℃ for 3 min and continue to ripening at 80 ℃ for 48 h.

Water contact angle and elongation

material	Water contact angle	elongation
A hydrophilic coating from a brand	74.5°	120%
XOANONS?JZ-9540-10（silicon modified）	101.6°	75%
XOANONS?JZ-9582（functional monomer modified）	100.7°	110%

3.Measurement of anti-fouling performance（Take JZ-9540-10 as an example）

The coating with JIAZHI?JZ-9540-10 as the main resin has a better cleaning effect after being contaminated by the oil pen and self-spray paint. The dry wipe of ordinary paint is ineffective, and the residual traces are still obvious after alcohol wiping.

4.Rain spot test

After rain water drips, place it at room temperature for 2 weeks and wipe it with a wet cloth. The paint with JIAZHI ?JZ-9540-10 as the main resin has no residual traces after wiping, and ordinary coatings have residual spots.

Solvent resistance test

Solvent resistance (butanone)：
Manual test: observe the surface after 50 times of flushing with water, the paint film is normal, there is no exposed bottom and loss of light.
1kg force test: observe the surface after 10 times of flushing with water, the paint film is normal, there is no exposed bottom and loss of light.

Hot-healing performance test

The surface of the paint film is brushed with copper brush for 10-20 times (about 100-200g force), and there are obvious brush marks in visual inspection. Hot water at 60-70 ℃ is poured on the paint film, and no brush marks are observed on the surface, which can be restored to the original state.

The brush mark is obvious by the copper brush.??? Recovered by hot water.

Effect of different films on product properties

film supplier	Elongation	Anti-fouling property(oil mark-pen)
Customer 1	80-85%	The anti-fouling properties of the same coating on different films are obviously different, and the overall trend is that the anti-fouling properties of the films with high stretch strength are slightly worse, and the anti-fouling properties of the films with low stretch strength are better.
Customer 2	60-65%
Customer 3	When it is stretched to 90%, the film is broken. And the paint film is not damaged before fracture.
Customer 4	65-70%
Customer 5	90-100%
Customer 6	70-75%
Customer 7	60-65%

Due to the diversity of film substrates, the performance of the same coating varies greatly on different substrates, so customized services can be provided according to the substrates and requirements of different customers.

4.Some suggestions

A good paint protective film not only depends on choosing the right coating, but also the advantages and disadvantages of the film itself are also very important to the embodiment of the final performance.

The initial product flexibility of hydrophobic paint protective film coating is slightly weak, and the flexibility of the product modified by special monomer can achieve the better effect of hydrophilic type, and its anti-fouling performance is better than that of hydrophilic type, with excellent weather resistance. It can be selected according to the actual requirements.