This section introduces silicone oligomer products that can be used as raw materials for coating agents and that react with moisture in the air to cure at room temperature.
Coating agents made from silicone oligomers form highly hard, transparent, and weather-resistant films, and their excellent water repellency and water sliding properties contribute to maintaining the beauty of the substrate.

Features and Image of the Coating Layer

Forms a highly transparent, hard, water-repellent and stain-resistant film

What are Silicone Oligomers?

Shin-Etsu Chemical uses the term “silicone oligomers” to refer to relatively low-molecular-weight silicones with a three-dimensional cross-linked siloxane backbone. Among them, Type A products, which contain only alkoxysilyl groups as reactive functional groups, are mainly used as raw materials for room temperature curing coatings.

Curing Mechanism of Type A Silicone Oligomers

Room Temperature Curing is Possible

Alkoxysilyl groups, when used in combination with a curing catalyst, are de-alcoholized and condensed by moisture in the air to form a cured film at room temperature.

Solvent-free

Since most products are 100% silicone active ingredient and contain no solvents, there is a wide range of applicable applications.

Good Compatibility

Owing to the low molecular weight, silicone resins and silicone oligomers can be blended with each other according to the required properties.

Performance of Silicone Oligomers (Type A)

High Hardness

Silicone oligomers are mainly composed of the three functionalities (T units) shown below, and when cured, they form a three-dimensional network structure.
This three-dimensional network structure has the second highest cross-link density after the tetrafunctional (Q) units that make up inorganic glass, resulting in high hardness.

Mono-functional (M unit)	Di-functional (D unit)	Tri-functional (T unit)	Tetra-functional (Q unit)
Triorgano Silhemioxane ［R3SiO1/2]	Siloxane ［R2SiO2/2]	Silsesquioxane [RSiO3/2]	Silicate ［SiO4/2]

Heat Resistance (Flame Retardance)

Compared to the carbon-carbon (C-C) bond energy of ordinary organic resins, the Si-O bond energy of silicones is about 25-60% higher, so they are known to be resistant to decomposition even at high temperatures.
However, because it has a small number of organic groups such as methyl and phenyl, the cured film reacts with oxygen and thermally decomposes and volatilizes when exposed to high temperatures. But silica (SiO₂) remains afterwards, making it more flame-resistant than organic resins.

Heating Loss Curve of Methyl/Phenyl Silicone Resin (in Air)

Water Repellency

The cured film of silicone oligomers has a lower surface tension than organic resins, which results in a higher water contact angle and excellent water repellency.
This low surface tension is due to the low intermolecular forces of silicones.

Weather Resistance

Type A methyl silicone oligomers do not absorb light in the wavelength range of sunlight, so they are hardly affected by sunlight.
Organic resins, on the other hand, absorb light in the sunlight wavelength range and are therefore susceptible to decomposition and degradation.

Silicone Resin Absorption Band of Sunlight Wavelengths

Product Line Up

There are two types of silicone oligomers (Type A): a one-component type that contains a curing catalyst in advance, and a two-component type in which a curing catalyst is added separately. Both types are used according to their merits.

One-component Type (Containing a Curing Catalyst)

*Click on the product name in the table to go to the individual product web page.

Two-component Type (Need to Add Curing Catalyst)

1. A method of adjusting the curing speed, physical properties of the coating, and improving the surface performance of the coating by “adding” another product to KR-500.

*Click on the product name in the table to go to the individual product web page.

* Although this is a one-component product, it can be added to other oligomer products to give them various functions.

2. “Replacing” KR-500 with another silicone oligomer product enables to improve curing speed, coating physical properties, coating surface properties, etc.

*Click on the product name in the table to go to the individual product web page.