Sericite powder

Sericite is a layered silicate composed of two layers of silicon oxygen tetrahedra sandwiching a layer of aluminum oxygen octahedron, forming a complex silicon oxygen layer.

Product Overview KDJ Product features Cases

Product Overview

1.Description

Sericite is a layered silicate composed of two layers of silicon oxygen tetrahedra sandwiching a layer of aluminum oxygen octahedron, forming a complex silicon oxygen layer. It has the characteristics of small natural particle size and easy processing of ultrafine particles. Hardness of 2-3, in addition, the chemical composition and structure of sericite are similar to kaolin, and it also has certain characteristics of clay minerals. It has good dispersibility and suspension in aqueous media and organic solvents, with white color, fine particles, and viscosity.

KDJ

Test item	unit	H1	H3	H4	H5	H6	H8	H9	D4	D5	D8
Grain size D50	μm	20±2.0	18±1.8	16±1.6	15±1.5	12±1.2	7±1.0	6±1.0	16±1.6	15±1.5	7±1.0
Whiteness，≥	%	72	72	74	74	76	76	76	77	77	78
SiO₂	%	60-70	60-70	55-65	55-65	55-65	55-65	42-52	55-65	55-65	55-65
Al₂O₃，≥	%	13	13	15	15	16	16	10	16	16	16
‌K₂O‌，≥	%	4.5	4.5	4.5	4.5	4.5	4.5	2.0	6.0	6.0	6.0
Fe₂O₃，≤	%	2.5	2.5	2.5	2.5	2.5	2.5	2.5	1.5	1.5	1.5
Volatile components，≤	%	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.8	0.8	0.8
Production method		winnowing	winnowing	winnowing	winnowing	winnowing	winnowing	winnowing	wet process	wet process	wet process

Product features

3.Product features

(1) Applied in coatings, it can improve the anti permeability and scratch resistance of the coating, and has good weather resistance and corrosion resistance.

(2) Applied to rubber and plastic products, it can reduce the shrinkage and warping rate of the products, improve their mechanical properties, heat resistance, insulation, chemical stability, and increase their surface glossiness and weather resistance.

Cases

Application case of sericite in coatings

Unique UV shielding function improves the weather resistance of the coating and delays powdering and discoloration. In the exterior wall coating system of buildings, different proportions and specifications of sericite powder are added for artificial aging resistance experiments.

Reference formula for building exterior wall coatings

Raw material name	Specification/Model	additive amount	Raw material name	Specification/Model	additive amount
Deionized water	self-made	230	talc	1250目	30
Hydroxyethyl cellulose	30000	2.2	tsp	800目	250
Dispersant	sodium salt	6.5	Rutile titanium dioxide	996	125
Wetting agent	X-405	1	emulsion	pure acrylic	240
PROPYLENE GLYCOL	import	15	bactericide	188S	2
Defoamer	mineral oil	3	coalescent	Alcohol ester twelve	15
Kaolinite	1250目	25	multi-functional agent	AMP-95	1.5
Sericite	indefinite	50	thickener	associative	12.5

Adding different specifications of sericite and testing without adding it

时间	Sericite	No addition of sericite	800目	1250目	Illite sericite
400H	Appearance	No bubbles, no peeling, no cracks
	Color change	2	1	1	2
	Pulverization	1	0	0	1
600H	Appearance	Bubbling and peeling	No bubbles, no peeling, no cracks		Bubbling and peeling
	Color change	2	2	1	2
	Pulverization	3	1	0	2

Reference formula for waterproof coating

Raw material name	Specification/Model	additive amount	Raw material name	Specification/Model	additive amount
Deionized water	Self-made	30	Sericite	Indefinite	50
Glyco	BASF-YPC	20	Talc	400目	70
Waterproof lotion	Domestic	500	wollastonite	800目	100
Wetting agent	X-405	2	Di-2-ethylhexyl phthalate		10
Coalescent	Alcohol ester twelve	6	Preservative	188S	1
Defoamer	Mineral oil	3	Thickener	Associative	1-3
ground calcium carbonate	800目	200

Adding different specifications of sericite and testing without adding it

Testing items		No sericite added	Add muscovite
Tensile strength	No processing，MPa	1.1	1.5
	Retention rate after heating treatment，%	90	110
	Retention rate after alkali treatment，%	65	78
	Retention rate after UV treatment，%	85	92
	Acid treatment，%	50	62
Fracture elongation rate	No processing，%	315	362
	Heating treatment，%	215	255
	UV treatment，%	210	260
	Alkali treatment，%	205	255
Heating expansion rate, shrinkage，%		0.9	0.6
Impermeability（0.3Mpa，30min）		waterproof	waterproof
Low temperature flexibility（Φ10mm stick）		-10℃No cracks	-10℃No cracks

Excellent acid and alkali resistance, high temperature resistance, and good electrical insulation greatly improve the anti-corrosion and electrical insulation properties of anti-corrosion coatings. The following is a partial inspection of adding sericite powder to epoxy primer. The inspection results are shown in the table below.

Performance testing table for epoxy primer with different specifications of sericite powder added

performance	Add variety
performance	No sericite added	Sericite 400 mesh	Sericite 800 mesh	Illite sericite
Storage capacity (7 days)	good	good	good	Slightly swollen
Adhesion (grade)	1	1	1	1
Water resistance (h)	340	340	340	340
Salt spray resistance (h	148	550	600	280
Salt water resistance (h)	305	520	580	350

Note: Other indicators tested are similar, no detailed explanation was provided. From the above test data, it can be seen that the addition of sericite powder significantly improves the various properties of the coating film.

By utilizing the extinction properties of muscovite, formula costs can be reduced. muscovite has a strong extinction shielding function and can absorb more than 80% of ultraviolet radiation. By making good use of this, it can replace extinction agents, reduce coating formula costs, and improve market competitiveness.

Through multiple experiments, the following curve relationship between gloss and addition amount can be obtained:

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Application case of sericite in engineering plastics

The use of sericite with two-dimensional sheet-like structure in engineering plastics can improve the dimensional stability of products and enhance their wear resistance. By adding a certain proportion of sericite powder to the original formula, the adhesive material can be kept unchanged, the strength of the product can be improved, and the reinforcement effect can reach or approach the level of using white carbon black. Sericite has good insulation and solubility in plastics. Adding 50% sericite to polypropylene increases the breakdown voltage from 20 kV/mm to 47.5 kV/mm. As a reinforcing filler for plastic composite materials, improving the performance of plastic products is no less than that of glass fiber and white carbon black, thereby effectively reducing costs. Sericite powder also has excellent acid and alkali resistance, flame retardancy, and corrosion resistance, which can improve the heat resistance of products and reduce shrinkage and warping rates.

Sericite powder can be added to engineering plastics such as PP, PA, PPS, TPE, ABS,etc.; Can produce automotive accessories such as steering wheel, instrument panel, door panel, bumper, seats, etc.; It is also used in the production of plastic parts such as computer casings, washing machine frames, fan blades, ventilation ducts, and machine covers.

Add sericite powder

Product name	Mica and fiberglass reinforcement PP	Add Scale	5%
Base material	PP	/
Test room environmental conditions	23±2°C，50±10RH
Test projec	unit	test method	Test condition	Test values
Tensile strength	Mpa	ASTM D638	50mm/min	55
Elongation at brea	%	ASTM D638	50mm/min	2
Bending strength	Mpa	ASTM D790	5mm/min	90
Flexural modulu	Mpa	ASTM D790	5mm/min	5200
Impact strength of cantilever beam gap	KJ/m²	ASTM D256	KJ、23°C	55
Heat distortion temperature	°C	ASTM D648	0.45MPa	140
Melt flow velocity	g/10min	ASTM D1238	230℃,2.16kg	5
Density	g/cm²	ASTM D792	23°C	1.27
Flame retardant performance	Class	UL94	1/8IN(3.2mm)	HB
ASH	%	ASTM D2584	700℃/30min	40±3
Shrinkage rate	%	ASTM D955	23°C	0.4-0.8
Glow wire	°C	GB/T 5169.10/12-2013	750℃/800℃	pass through
Remarks: (1) The performance of the dye may differ from the above values. (2) The test values are averages and are for reference only. (3) When there is a difference between the UL yellow card physical property data and the above values, the physical property table data shall prevail.

The application of sericite in the rubber industry

The main function of muscovite in rubber products is to improve the strength of the products, and the reinforcement effect can reach or approach the level of using white carbon black. Improve the dimensional stability, stress cracking resistance, toughness, anti-aging, cracking resistance, and wear resistance of the product. Has excellent heat resistance, reduces shrinkage and warping rates; Sericite can also improve the gas resistance and expansion resistance of products.

In addition, utilizing the insulation properties of sericite can improve the electrical performance of rubber products.

Product Features:

1) Has good processing performance and can replace 30-50% of semi reinforced or other particulate carbon black;

2) Adding a certain proportion of sericite powder can maintain the performance of the adhesive while reducing product costs.

The application of sericite in cosmetics

The natural ingredients and unique sheet-like thin layer structure of cosmetic grade sericite powder endow it with a smooth texture and good chemical stability. The comfortable texture provides excellent skin affinity and glossiness, while also having the characteristics of soft, smooth, delicate, and strong coverage in cosmetics. It is pure natural, non-toxic, and harmless, making it the preferred high-end powder material in the cosmetics industry. It can be widely used in honey powder, eye shadow, liquid foundation, powder, powder blusher and many other fields.

Product Features:

1) Fine particles, strong dispersibility, able to mix evenly with water and glycerol;

2) Delicate and smooth texture, silky softness, and soft luster;

3) Good adsorption and excellent affinity with the skin, elastic, giving a velvety feeling;

4) Anti UV is a natural inorganic sunscreen agent with better performance than TiO2 and ZnO, which can improve the SPF value of sunscreen products.

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