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How to Choose Raw Materials for UV Wood Coatings (Part 2)

Release time:

2026-03-09 23:26

How to Choose Raw Materials for UV Wood Coatings (Part 2)

In a complete UV wood coating formulation system, in addition to resins and photoinitiators, the selection of reactive diluents and various additives is equally critical. Reactive diluents serve a dual purpose: they help adjust the application viscosity while also participating in the crosslinking reaction. The design of their functionality and the precise adjustment of their dosage directly influence the coating’s applicability, curing rate, and crosslink density of the resulting film. Although additives constitute only a small proportion of the formulation, they play a crucial role in finely tuning the coating’s storage stability, rheological behavior during application, and the final surface finish of the film. Properly selecting these two types of raw materials is the key to ensuring that UV wood coatings remain stable and reliable throughout the entire process—from application to film formation.

1. Reactive Diluent

Active diluents play a dual role in UV wood coatings: on the one hand, they adjust the viscosity of the coating to suit various application methods such as roller coating, spray coating, or dip coating; on the other hand, their molecules contain polymerizable double bonds that undergo cross‑linking reactions with the resin during the curing process, becoming an integral part of the coating film network. Unlike volatile organic solvents found in conventional coatings, active diluents participate almost entirely in the reaction and exhibit extremely low volatility—this is a key source of the environmentally friendly characteristics of UV coatings.

Based on the number of polymerizable groups in a molecule, reactive diluents can be divided into three categories: monofunctional, difunctional, and polyfunctional.

1. Monofunctional Diluents: Monofunctional diluents each contain a single double bond per molecule, such as isooctyl acrylate and hydroxyethyl acrylate. They are characterized by low viscosity, high conversion rates, and minimal volume shrinkage; however, their crosslinking density is relatively low, making it difficult to form high‑performance coatings when used alone. Monofunctional diluents are primarily employed as viscosity‑reducing components while also enhancing the flexibility of the coating.

2. Difunctional Diluents: Each molecule of a difunctional diluent contains two double bonds, such as dipropylene glycol diacrylate and tripropylene glycol diacrylate. While reducing viscosity, these diluents also participate in cross‑linking reactions, making them the most commonly used type of diluent in UV formulations. Difunctional diluents strike an excellent balance between viscosity and curing speed.

3. Polyfunctional Diluents: Polyfunctional diluents each contain three or more double bonds per molecule, such as trimethylolpropane triacrylate and pentaerythritol tetraacrylate. They offer high crosslink density, fast curing speed, and significant hardness contribution; however, they have relatively high viscosity and exhibit noticeable volume shrinkage. Using excessive amounts can lead to increased coating brittleness and reduced adhesion.

The selection of reactive diluents must take into account factors such as viscosity, dilution efficiency, curing speed, shrinkage rate, and irritancy. With increasingly stringent environmental regulations, low-irritancy, low-odor monomers are receiving growing attention. Ethoxylation or propoxylation modification can significantly reduce the skin irritancy of monomers while also mitigating oxygen inhibition during polymerization.

II. Additives

Although additives are used in small quantities in formulations—typically no more than 5%—they play a crucial role in regulating the storage stability of coatings, their application performance, and the final film properties. The commonly used additives for UV wood coatings mainly include the following categories:

1. Defoamers: Defoamers are used to eliminate bubbles generated during paint production and coating processes, thereby preventing defects such as pinholes, craters, and fish eyes in the coating. Silicone-based defoamers and non-silicone defoamers each have their own characteristics; it is necessary to select a product that strikes a balance between compatibility and defoaming efficiency based on the specific paint system.

2. Wetting and Dispersing Agents: Wetting and dispersing agents promote the uniform dispersion of pigments and fillers in coatings, preventing flocculation and sedimentation while enhancing the color uniformity and gloss of the coating film. For tinted paint systems, the selection of wetting and dispersing agents is particularly crucial.

3. Leveling Agents: Leveling agents reduce the surface tension of coatings, promoting uniform spreading of the coating film before drying and eliminating surface defects such as brush marks and orange peel, thereby achieving a smooth and even coating appearance. Silicone-based leveling agents and acrylate leveling agents are common choices.

4. Thixotropic Agents: Thixotropic agents regulate the rheological behavior of coatings, reducing viscosity under high shear to facilitate application while restoring viscosity under low shear to prevent sagging. Fumed silica is the most commonly used thixotropic agent in UV wood coatings; its surface hydroxyl groups form hydrogen-bonding networks with the resin, imparting thixotropy to the coating.

5. Matte Powder: Matte powder, also known as matting agent, is used to formulate matte coatings. It forms a micro‑rough texture on the coating surface, scattering light and reducing gloss. The type, particle size, and addition amount of matte powder directly affect gloss uniformity and hand feel. Research indicates that matte powder must be properly matched with the resin system and curing process in order to achieve a stable, low-gloss finish.

Functional additives impart special properties to coatings. UV absorbers can enhance yellowing resistance; nano‑alumina or nano‑silica can significantly improve abrasion resistance; antibacterial agents enable coatings to inhibit microbial growth; and anti‑graffiti additives give coatings easy‑clean characteristics when it comes to oily ink marks and the like.

III. Summary

The selection of reactive diluents and additives is a crucial step in optimizing UV wood coatings formulations. Reactive diluents must be chosen based on the viscosity requirements dictated by the application method, while also taking into account the characteristics of different functional groups—such as their impact on curing speed and volumetric shrinkage—in a comprehensive manner. At the same time, attention should be paid to the product’s irritancy and environmental performance. When selecting additives, it is essential to target specific functions like defoaming, wetting and dispersion, leveling, thixotropy, and matting, ensuring both compatibility with the main resin system and consistent performance. The incorporation of functional additives can add value to the coating, endowing it with properties such as antibacterial efficacy, abrasion resistance, and ease of cleaning. By carefully selecting these raw materials, UV wood coatings can better adapt to diverse application processes and meet a wide range of performance demands.

Disclaimer: The above content is sourced from the internet and is for reference only; if any content infringes upon your rights, please contact us and we will remove it promptly.

Bossin Recommended Products – UV Wood Coatings
Putty primer
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, containing 20% TPGDA.
B-520	Polyester acrylate	Low viscosity, high gloss, excellent wettability, and cost-effective.
B-522	Polyester acrylate	Low shrinkage, excellent flexibility, strong adhesion, and high cost performance.
Sanding Primer
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, containing 20% TPGDA.
B-160D	Modified epoxy acrylate	Good flexibility, yellowing resistance, and excellent adhesion.
B-163	Modified epoxy acrylate	Good flexibility, excellent pigment wetting, and strong adhesion.
B-520	Polyester acrylate	Low viscosity, high gloss, excellent wettability, and cost-effective.
B-522	Polyester acrylate	Low shrinkage, excellent flexibility, strong adhesion, and high cost performance.
Primer
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-02	Phosphate ester acrylate	Enhance adhesion to substrates such as metal, glass, and plastic.
B-05	Phosphate ester acrylate	Enhance adhesion to substrates such as metal, glass, and plastic.
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, containing 20% TPGDA.
B-165	Modified epoxy acrylate	Good flexibility and strong adhesion.
B-522	Polyester acrylate	Low shrinkage, excellent flexibility, strong adhesion, and high cost performance.
B-535	Polyester acrylate	Good adhesion, fast curing, excellent flexibility, and yellowing resistance.
B-546	Polyester acrylate	Good adhesion, fast curing, and excellent flexibility.
White primer
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, containing 20% TPGDA.
B-160D	Modified epoxy acrylate	Good flexibility, yellowing resistance, and excellent adhesion.
B-520	Polyester acrylate	Low viscosity, high gloss, excellent wettability, and cost-effective.
B-522	Polyester acrylate	Low shrinkage, excellent flexibility, strong adhesion, and high cost performance.
B-529	Polyester acrylate	Good adhesion, low shrinkage, and excellent resin compatibility.
B-560	Polyester acrylate	Fast curing and excellent pigment wetting.
Glossy topcoat
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, containing 20% TPGDA.
B-163	Modified epoxy acrylate	Good flexibility, excellent pigment wetting, and strong adhesion.
B-165	Modified epoxy acrylate	Good flexibility and strong adhesion.
B-21C	Active amine photoinitiator	Low color, antioxidant and polymerization inhibitor, enhanced curing rate
B-301	Aromatic Polyurethane Acrylate	Fast curing, good toughness, and excellent sandability.
B-302	Aromatic Polyurethane Acrylate	Fast curing, high strength, good toughness, and excellent grindability.
B-574C	Polyester acrylate	Low viscosity, low odor, good wettability, suitable for LED UV applications.
B-601	Aromatic Polyurethane Acrylate	High hardness, scratch resistance, chemical resistance, and excellent value for money.
B-609	Aliphatic polyurethane acrylate	Fast curing, high hardness, scratch resistance, and chemical resistance.
B-868	Organosilicon Photocurable Resin	Good leveling, smooth finish, fast curing, and stain resistance.
B-868H	Organosilicon Photocurable Resin	Good leveling, smooth finish, fast curing, and stain resistance.
B-910A2	Aliphatic polyurethane acrylate	Low viscosity, yellowing resistance, chemical resistance, and steel wool resistance.
B-912	Aliphatic polyurethane acrylate	Fast curing, high hardness, good toughness, and excellent chemical and abrasion resistance.
Matte finish paint
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-160D	Modified epoxy acrylate	Good flexibility, yellowing resistance, and excellent adhesion.
B-163	Modified epoxy acrylate	Good flexibility, excellent pigment wetting, and strong adhesion.
B-21C	Active amine photoinitiator	Low color, antioxidant and polymerization inhibitor, enhanced curing rate
B-328M	Aliphatic polyurethane acrylate	Low gloss, low viscosity, good wettability, pleasant to the touch.
B-328R	Aliphatic polyurethane acrylate	Low gloss, excellent matting effect, good wetting properties, and a fine, smooth hand feel.
B-333	Aliphatic polyurethane acrylate	Low viscosity, good matting effect, excellent wettability, and good flexibility.
B-572	Polyester acrylate	Low viscosity, low odor, good wettability, suitable for LED UV applications.
B-650A	Aliphatic polyurethane acrylate	Low viscosity, good matting effect, fast curing, and excellent wettability.
B-868	Organosilicon Photocurable Resin	Good leveling, smooth finish, fast curing, and stain resistance.
B-868H	Organosilicon Photocurable Resin	Good leveling, smooth finish, fast curing, and stain resistance.
B-910A2	Aliphatic polyurethane acrylate	Low viscosity, yellowing resistance, chemical resistance, and steel wool resistance.
B-912	Aliphatic polyurethane acrylate	Fast curing, high hardness, good toughness, and excellent chemical and abrasion resistance.
Bright white paint
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, containing 20% TPGDA.
B-160D	Modified epoxy acrylate	Good flexibility, yellowing resistance, and excellent adhesion.
B-301	Aromatic Polyurethane Acrylate	Fast curing, good toughness, and excellent sandability.
B-302	Aromatic Polyurethane Acrylate	Fast curing, high strength, good toughness, and excellent grindability.
B-560	Polyester acrylate	Fast curing and excellent pigment wetting.
B-574C	Polyester acrylate	Low viscosity, low odor, good wettability, suitable for LED UV applications.
B-601	Aromatic Polyurethane Acrylate	High hardness, scratch resistance, chemical resistance, and excellent value for money.
B-868	Organosilicon Photocurable Resin	Good leveling, smooth finish, fast curing, and stain resistance.
B-868H	Organosilicon Photocurable Resin	Good leveling, smooth finish, fast curing, and stain resistance.
B-912	Aliphatic polyurethane acrylate	Fast curing, high hardness, good toughness, and excellent chemical and abrasion resistance.
Adherent
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-05	Phosphate ester acrylate	Enhance adhesion to substrates such as metal, glass, and plastic.
B-509B	Polyester acrylate	Good adhesion, excellent flexibility, and excellent pigment wetting.
B-531	Polyester acrylate	Good adhesion, impact resistance, excellent flexibility, and yellowing resistance.
B-535	Polyester acrylate	Good adhesion, fast curing, excellent flexibility, and yellowing resistance.
B-546	Polyester acrylate	Good adhesion, fast curing, and excellent flexibility.
B-590	Polyester acrylate	Good adhesion, fast curing, and excellent pigment wetting.
Filler type
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, containing 20% TPGDA.
B-520	Polyester acrylate	Low viscosity, high gloss, excellent wettability, and cost-effective.
B-522	Polyester acrylate	Low shrinkage, excellent flexibility, strong adhesion, and high cost performance.
B-529	Polyester acrylate	Good adhesion, low shrinkage, and excellent resin compatibility.
Retouch color
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-560	Polyester acrylate	Fast curing and excellent pigment wetting.
Hardened
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, containing 20% TPGDA.
B-301	Aromatic Polyurethane Acrylate	Fast curing, good toughness, and excellent sandability.
B-302	Aromatic Polyurethane Acrylate	Fast curing, high strength, good toughness, and excellent grindability.
B-560	Polyester acrylate	Fast curing and excellent pigment wetting.
B-574C	Polyester acrylate	Low viscosity, low odor, good wettability, suitable for LED UV applications.
B-601	Aromatic Polyurethane Acrylate	High hardness, scratch resistance, chemical resistance, and excellent value for money.
B-912	Aliphatic polyurethane acrylate	Fast curing, high hardness, good toughness, and excellent chemical and abrasion resistance.
Matte
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-328M	Aliphatic polyurethane acrylate	Low gloss, low viscosity, good wettability, pleasant to the touch.
B-328R	Aliphatic polyurethane acrylate	Low gloss, excellent matting effect, good wetting properties, and a fine, smooth hand feel.
B-329D	Aliphatic polyurethane acrylate	Low irritation, low viscosity, excellent wettability, and pleasant to the touch.
B-333	Aliphatic polyurethane acrylate	Low viscosity, good matting effect, excellent wettability, and good flexibility.
B-650A	Aliphatic polyurethane acrylate	Low viscosity, good matting effect, fast curing, and excellent wettability.
Solid-color paint
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-519	Self‑Curing Polyester Acrylate	Self‑initiated Photocuring Performance
B-530	Polyester acrylate	Low viscosity, excellent hydrophobicity, thixotropic properties, and improved ink mist.
B-560	Polyester acrylate	Fast curing and excellent pigment wetting.
Yellowing resistance
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-160D	Modified epoxy acrylate	Good flexibility, yellowing resistance, and excellent adhesion.
B-431	Alicyclic Specialty Acrylates	Yellowing resistance, excellent wettability, low viscosity, fast curing.
Coating by spraying
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-160D	Modified epoxy acrylate	Good flexibility, yellowing resistance, and excellent adhesion.
Roller Coating
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-100	Bisphenol A epoxy acrylate	High hardness, high gloss, excellent chemical resistance, and rich body.
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, containing 20% TPGDA.
B-160D	Modified epoxy acrylate	Good flexibility, yellowing resistance, and excellent adhesion.
B-163	Modified epoxy acrylate	Good flexibility, excellent pigment wetting, and strong adhesion.
B-165	Modified epoxy acrylate	Good flexibility and strong adhesion.
B-520	Polyester acrylate	Low viscosity, high gloss, excellent wettability, and cost-effective.
B-522	Polyester acrylate	Low shrinkage, excellent flexibility, strong adhesion, and high cost performance.
Solvent-free spraying
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-251	Aromatic Polyurethane Acrylate	Fast curing, excellent flexibility, and good wetting performance with black ink pigments.
B-520	Polyester acrylate	Low viscosity, high gloss, excellent wettability, and cost-effective.
B-574C	Polyester acrylate	Low viscosity, low odor, good wettability, suitable for LED UV applications.
LED-UV
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, containing 20% TPGDA.
B-21C	Active amine photoinitiator	Low color, antioxidant and polymerization inhibitor, enhanced curing rate
B-27	Active amine photoinitiator	Low color, benzene-free, low odor, antioxidant and anti‑polymerization.
B-570	Polyester acrylate	Low viscosity, benzene-free, low odor, suitable for LED UV.
B-574	Polyester acrylate	Benzene-free, low odor, and VOC levels meet cigarette packaging standards.
B-574C	Polyester acrylate	Low viscosity, low odor, good wettability, suitable for LED UV applications.
Excimer lamp
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-241	Aliphatic polyurethane acrylate	Fast matting speed, excellent skin feel, and yellowing resistance.
Skin feel
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, containing 20% TPGDA.
B-165	Modified epoxy acrylate	Good flexibility and strong adhesion.
B-241	Aliphatic polyurethane acrylate	Fast matting speed, excellent skin feel, and yellowing resistance.
B-328M	Aliphatic polyurethane acrylate	Low gloss, low viscosity, good wettability, pleasant to the touch.
B-328R	Aliphatic polyurethane acrylate	Low gloss, excellent matting effect, good wetting properties, and a fine, smooth hand feel.
B-574C	Polyester acrylate	Low viscosity, low odor, good wettability, suitable for LED UV applications.
B-868	Organosilicon Photocurable Resin	Good leveling, smooth finish, fast curing, and stain resistance.
B-868H	Organosilicon Photocurable Resin	Good leveling, smooth finish, fast curing, and stain resistance.
Monomer Recommendations
Product Model/English Abbreviation	Product Name/Product Type	Product Features
BM2223 (TPGDA)	Di(propylene glycol) diacrylate	Good flexibility and low volatility.
BM2224 (EO-HDDA)	Ethoxylated 1,6-hexanediol diacrylate	Good adhesion to plastics, excellent dilutability, and low volatility.
BM3231 (TMPTA)	Trimethylolpropane triacrylate	High crosslink density, high hardness, high gloss, and excellent wear resistance.
BM3235 (PET3A)	Pentaerythritol triacrylate	Fast curing, high crosslink density, high hardness, and excellent chemical resistance.
BM3380 (3EO-TMPTA)	Ethoxylated trimethylolpropane triacrylate	More flexible and less irritating than TMPTA.
BM6261 (DPHA-80)	Dipentaerythritol hexaacrylate	High crosslink density, high hardness, chemical and abrasion resistance, and water resistance.
BM6263 (DPHA-90)	Dipentaerythritol hexaacrylate	High crosslink density, high hardness, chemical and abrasion resistance, and water resistance.

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Analysis of Key Techniques in Coating UV Wood Coatings (Part 1)

How to Choose Raw Materials for UV Wood Coatings (Part 1)