Reflective paints, which have the property of reflection light, are used in a variety of places, including houses, lighting fixtures, and PCB for digital equipment.

It is important to pick up a paint that suits the application because the reflection mechanism and properties such as UV resistance and heat resistance differ depending on the reflective paint.

In this article, we will explain the type of reflection paint and how to pick up one for individual application, and the recommended reflective paint with excellent UV resistance and heat resistance

“Reflective paints” reflect light in a variety of spectra, such as IR, visible, and UV.

The reflectance of light and the type of light that can be reflected differ because of mechanism of the paints.　Three types of reflective paint are explained: “one with high reflectance in the visible light area”, “one with high reflectance in the near IR area”, and “one with retroreflective properties”.

Reflection by white color

Reflective paints with white or pale colors are characterized by high reflectance of light in the visible light area. It also reflects sunlight, so it has an excellent heat shielding effect.

For example, using a white reflective paint on the roof or exterior walls of a house can effectively reflect sunlight and control the rise in temperature inside the house due to radiant heat.

High reflection

Among the reflective paints with excellent heat shielding effect, the high reflectance of light in the near IR area is the “high solar reflectance paint”.

Since the near IR area accounts for about 50% of the solar energy, it inhibits heat absorption on the painted surface and prevents the temperature from rising.

It is sometimes referred to as “heat-shielding paint” because of its high heat-shielding effect.

Retroreflection

White reflective paint and high solar reflectance paint reflect light by special components contained in the paint film. The retroreflective paint has a different reflection mechanism from the heat shielding paint.

Retroreflective paint is a paint that uses a mechanism of light called retroreflection.

Retroreflection refers to a mechanism that reflects light in the direction opposite to the direction of incidence. In the case of retroreflective paint, we have realized retroreflection by arranging small glass beads in the coating film and devising the angle between refractive index and reflection of light.

For example, retroreflective paint is used on road signs, bicycle reflectors, and other items that require strong reflection of light.

The properties such as UV resistance and heat resistance differ depending on the components used in the reflective paint. It is important to pick up a reflective paint with weather resistance that suits the usage environment and application.

Temperature

Also, be careful with the material of the place where reflection paint is applied, as some reflective paints contain solvents or require heating to cure the paint film. In the following, we will explain how to pick up reflective paint for each application.

UV resistance

Pigments contained in reflective paints may deteriorate after being exposed to ultraviolet rays or heat for a long period of time, causing a choking in which white powder blows out.

Therefore, when using reflective paint outdoors, or when using reflective paint in areas where strict quality control is required, such as semiconductors and medical devices, it is important to select products that are highly weather-resistant.

In case of choosing reflective paints that are highly weather resistant, pay attention to resins and plastics that have a role in protecting your pigments.

For example, acrylic resin paints have excellent weather resistance, and are resistant to moisture as well as solar.

Also, silicone can be added to the reflective coating of acrylic resin to further enhance weather resistance.

Heat resistance

When reflective paint is used outdoors or in hot environments, heat resistance is also required in addition to UV resistance. Check the resin and plastic used in reflective paints, as with UV resistance.

The most heat resistant material is silicone resin.

Protecting the reflective paint pigments with silicon increases their durable life.

Applicable materials

Genral paints have the property of curing at room temperature.

However, some reflective inks need to be heated after painting to cure, while others cure by exposure to light. Some reflective paints contain solvents in their uncured state.

Therefore, it is also important to pick up reflective paint from the viewpoints of “whether the object to be coated can withstand light and heat” and “whether there is no problem even if a solvent adheres to the object to be coated”.

Asahi Rubber’s white silicone ink is characterized by a reflectivity of over 95% and high weather resistance. Our reflective paints are used for printed circuit boards in digital equipment as well as lighting fixtures and optical measuring equipment.

Ceramic Ink Hybrid Paste and White Silicone Ink for UV are introduced which are superior in weather resistance.

Product characteristics

Asahi Rubber’s white silicone ink is characterized by a high reflectance of over 95%.

If white silicone ink is applied to LED printed circuit board, it is possible to increase the light-extraction efficiency inside the semiconductors.

It also has higher heat resistance and UV resistance than ordinary epoxy-based ink, and no noticeable decrease in reflectance was observed even after 1000 hours of heat resistance testing or 1 hour of

UV irradiation.　

White silicone ink can be selected from three product lineups depending on the items to be coated.

For example, when coating soft-bendable FPC (flexible printed circuit boards) or films, SWR Series-white silicone ink is suitable.　Conversely, PR Series is recommended when coating to hard rigid substrates or metallic substrates.　FR Series coating film hardness is in the middle of the two, and is used for ceramics boards and so on.　Asahi Rubber also prepares an even more weather-resistant product lineup.

Ceramic Ink Hybrid Paste (RG Series) has heat resistance and can be applied to ceramic boards.

White silicone ink for UV is recommended for use on medical devices and other devices that require UV resistance.

Application

Asahi Rubber’s white silicone ink is used in various scenes.

Applications are as follows.

● Reflectors (street lights, high ceiling lights, etc.)

● General rigid circuit boards (LED luminaires)

● Pressed products (lighting fixtures, integrating spheres, etc.)

● FPC (bendable-type luminaire)

It is also possible to paint films on metal plates, film substrates, ceramic substrates, etc. using white silicone ink. Please contact us when you need reflective coating with high reflection, heat resistance and UV resistance.

“Reflective paint” is a paint that reflects infrared light, visible light, solar, and other light.

The reflective paint is not the same, and each has its own characteristics.

There are three types of reflective paints: “those with high reflectance in the visible light region,” “those with high reflectance in the near infrared region,” and “those with retroreflective properties.”

Since the characteristics, such as UV resistance and heat resistance, differs depending on the components of the reflective ink, it is important to select a type of paint that suits the environment of use. Asahi Rubber’s reflective ink combines three characteristics: high reflection, heat resistance, and high UV resistance.

It is recommended for those looking for highly functional reflective ink for lighting fixtures, optical measuring instruments, and PCB for digital equipment.　It is recommended for those looking for highly functional reflective ink for lighting fixtures, optical measuring instruments, and PCB for digital equipment.

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