Language
- Chinese

language

Tel

Tel

+8618142863185
Follow us

Official Accounts

Official Accounts
Top

News

Detailed Explanation of the Classification of UV 3C Coatings (Part 1)

Release time:

2026-06-22 17:04

Detailed Explanation of the Classification of UV 3C Coatings (Part 1)

UV 3C coatings come in a wide variety, and can be classified into numerous types depending on the criteria used. Whether based on curing mechanisms, product forms, coating layers, or functional properties, each classification highlights differences in formulation design, application methods, or end-use scenarios. Understanding these classification schemes and their respective characteristics helps make more informed product selections in practical applications.

I. Classification by Curing Mechanism

1. UV/EB-curable type

Based on their curing mechanisms, radiation-curable coatings can be classified into two major categories: ultraviolet-curable coatings and electron-beam-curable coatings.

UV-curable coatings are the mainstream choice in the 3C industry. They cure via a polymerization reaction initiated by ultraviolet irradiation, offering advantages such as rapid curing, relatively low equipment costs, and suitability for assembly-line production, thereby commanding the largest share of the radiation-curing market.

EB curing employs high-energy electron beams to initiate the curing reaction, eliminating the need for photoinitiators and achieving greater cure depth. It is well suited for applications demanding exceptional resistance to yellowing, such as transparent coatings, as well as for thick‑layer curing. However, EB curing equipment entails a significant capital investment, and because electron beams possess strong penetrating power, stringent protective measures are required for operators, thereby limiting its adoption in the 3C sector.

2. Free-radical and cationic curing types

Within UV-curable coatings, depending on the differences in the photoinitiator system, they can be further classified into radical-curing, cationic-curing, and hybrid-curing types.

Free-radical curing systems use acrylate resins as the matrix and achieve rapid curing via free-radical polymerization. This is currently one of the most widely used coating technologies in the 3C industry, offering advantages such as fast curing, mature processing, and controllable costs. However, it suffers from surface tackiness caused by oxygen inhibition, which must be addressed through careful control of the curing environment or formulation design. Free-radical curing systems dominate the coating of products such as smartphone housings and laptop panels.

Cationic curing systems achieve crosslinking through the reaction of epoxy resins with cationic photoinitiators. Cationic polymerization is unaffected by oxygen inhibition, enabling the formation of a dense three-dimensional crosslinked network with low shrinkage and excellent adhesion. However, this process is relatively slow and sensitive to moisture, limiting its application in 3C coatings; it is primarily used in specific applications where high adhesion is critical.

Hybrid curing systems integrate the advantages of both radical and cationic curing, achieving performance optimization through the synergistic interaction of these two mechanisms. Such systems offer unique value in specific application scenarios, making them well suited for situations that demand both rapid curing and superior performance, thereby balancing the requirements of both aspects to a certain extent.

II. Classification by Product Form

Based on the physical composition of the coating, UV 3C coatings can be classified into solvent-based UV coatings, waterborne UV coatings, and all‑solid‑content UV coatings, among others.

1. Solvent-based UV coatings

Solvent-based UV coatings represent a traditional product format, containing a certain proportion of organic solvents to adjust application viscosity. These coatings boast well-established formulation systems and broad application versatility, delivering excellent coating performance and ensuring strong adhesion and superior surface finishes on a wide range of substrates. However, solvent-based systems release volatile organic compounds during curing, resulting in relatively poor environmental performance; consequently, they are being gradually replaced as environmental regulations tighten. At present, they are primarily used in specialized applications where performance requirements are particularly demanding and no waterborne alternatives yet exist.

2. Waterborne UV Coatings

Waterborne UV coatings use water as the primary diluent, resulting in significantly lower volatile organic compound (VOC) emissions compared to solvent-based systems, and they combine the dual advantages of rapid UV curing with the environmental friendliness and low toxicity of waterborne formulations. These coatings can deliver high-gloss or deep-matte clear finishes, as well as single-layer metallic effects, on plastic substrates, making them a key focus in the ongoing shift toward more sustainable practices. However, waterborne systems still face challenges, such as shadowing under complex geometries and potential degradation of certain substrates—issues that remain critical areas for continued technological advancement.

3. All-solid UV-curable coating

All‑solid UV‑curable coatings contain no volatile components; all their constituents either participate in the curing reaction or become part of the cured film, making them a highly environmentally friendly class. These coatings place stringent demands on application equipment and process control, yet they offer irreplaceable advantages in certain high‑end applications, primarily targeting markets with both rigorous environmental and performance requirements.

III. Classification by Coating Layers

Based on their functional roles within the coating system, UV 3C coatings can be categorized into types such as primers, midcoats, and topcoats.

1. Primer

The primer is the coating that directly contacts the substrate, primarily providing adhesion and sealing substrate defects. When selecting a primer, compatibility with the substrate must be considered; for substrates with low surface energy, a primer formulation offering superior adhesion-promoting performance should be chosen. The performance of the primer directly affects the reliability of the entire coating system and serves as the foundational layer of the coating architecture.

2. Intermediate Coating

The midcoat is positioned between the primer and the topcoat, serving to further enhance the coating’s fillability and overall performance. It is employed in certain high-end coating systems, where its incorporation helps address the limitations of the primer and provides a smoother substrate for the topcoat, thereby improving the coating’s surface quality and aesthetic appearance.

3. Topcoat

The topcoat is the outermost layer of the coating system, performing key functions such as wear resistance, scratch resistance, and decorative appeal. It must exhibit excellent leveling, high hardness, and superior scratch resistance, while also offering a range of surface finishes—gloss, matte, or special tactile effects—as required. The curing conditions of the topcoat directly influence its appearance and quality, making it the layer that interfaces most directly with the end user in the entire coating system.

IV. Conclusion

UV 3C coatings can be classified along three dimensions: curing mechanism, product formulation, and coating layer. Based on the curing mechanism, they are divided into UV‑curing and EB‑curing systems, with radical‑initiated curing being the dominant approach in the 3C sector. By formulation, they include solvent‑borne, waterborne, and all‑solid‑content types, with waterborne technology representing a key direction for environmentally friendly transformation. From a coating‑layer perspective, they are categorized into primers, midcoats, and topcoats, each serving distinct functional roles. These classification schemes emphasize different aspects yet collectively form a product portfolio that meets the diverse surface‑finishing needs of 3C electronic devices. Understanding these categories enables more informed decision‑making in practical applications, taking into account specific performance requirements, application conditions, and environmental standards.

Disclaimer: The above content has been compiled from publicly available sources and is provided for reference only. If any infringement occurs, please contact us, and we will address it promptly.

Bosheng Related Product Recommendations – 3C Coatings
General-purpose
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-102	Bisphenol A epoxy acrylate	High hardness, high gloss, chemical resistance, contains 15% TMPTA.
B-151	Modified epoxy acrylate	Low halogen, yellowing-resistant, excellent plating performance, and strong adhesion.
B-165	Modified epoxy acrylate	Good flexibility and strong adhesion
B-216	Aliphatic polyurethane acrylate	Fast curing, high fullness, and excellent toughness.
B-368	Aliphatic polyurethane acrylate	Good toughness, excellent leveling, excellent bend resistance, and excellent heat resistance.
B-574C	Polyester acrylate	Low viscosity, low odor, excellent wettability, suitable for LED UV.
B-601	Aromatic polyurethane acrylate	High hardness, scratch resistance, chemical resistance, and excellent cost-effectiveness.
B-6019	Special functional group acrylate	Good leveling, excellent wettability, resistant to boiling water, and superior color dispersion.
B-609	Aliphatic polyurethane acrylate	Fast curing, high hardness, scratch resistance, and chemical resistance.
B-615A	Aliphatic polyurethane acrylate	Fast curing, excellent toughness, wear resistance, and chemical resistance.
B-619W	Aliphatic polyurethane acrylate	Fast curing, high hardness, excellent toughness, wear resistance, and chemical resistance.
B-6380N	Special functional group acrylate	Excellent adhesion to plastics, strong hiding power, and improved paint film appearance.
B-919B	Aliphatic polyurethane acrylate	Fast curing, high hardness, excellent toughness, and outstanding chemical and wear resistance.
Matte
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-572	Polyester acrylate	Low viscosity, low odor, excellent wettability, suitable for LED UV.
B-650A	Aliphatic polyurethane acrylate	Low viscosity, excellent matting effect, fast curing, and good wettability.
Wearable device
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-6211	Aliphatic polyurethane acrylate	Fast curing, high hardness, scratch-resistant, and free of organotin.
Hand feel
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-328M	Aliphatic polyurethane acrylate	Low gloss, low viscosity, excellent wettability, and a pleasant hand feel.
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.
Large-area spraying
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-374	Aliphatic polyurethane acrylate	Good flexibility, excellent leveling, resistant to abrasion and chemicals, and resistant to yellowing.
Car interior
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-6063	Special functional group acrylate	High molecular weight, low curing shrinkage
B-6210	Aliphatic polyurethane acrylate	Low viscosity, chemical resistance, environmental resistance, and dual photothermal curing.
B-6263	Special functional group acrylate	Fast curing, high build, boil‑water resistant, and excellent toughness.
B-916	Aliphatic polyurethane acrylate	Low viscosity, solvent resistance, chemical resistance, and steel-wool resistance.
B-919B	Aliphatic polyurethane acrylate	Fast curing, high hardness, excellent toughness, and outstanding chemical and wear resistance.
Resistant to steel wool
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-910A2	Aliphatic polyurethane acrylate	Low viscosity, yellowing resistance, chemical resistance, and steel-wool resistance.
B-916	Aliphatic polyurethane acrylate	Low viscosity, solvent resistance, chemical resistance, and steel-wool resistance.
B-919B	Aliphatic polyurethane acrylate	Fast curing, high hardness, excellent toughness, and outstanding chemical and wear resistance.
Oil-resistant pen
Product Model/English Abbreviation	Product Name/Product Type	Product Features
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.
Battery casing
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-431	Cycloaliphatic Specialty Acrylate	Yellowing-resistant, excellent wettability, low viscosity, fast curing
B-548	Polyester acrylate	Withstands high temperatures of 250–280°C.
Solid color paint
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-519	Self-curing polyester acrylate	Self-initiated photopolymerization performance
B-560	Polyester acrylate	Fast curing and excellent pigment wetting.
Yellowing resistance
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-151	Modified epoxy acrylate	Low halogen, yellowing-resistant, excellent plating performance, and strong adhesion.
B-160D	Modified epoxy acrylate	Good flexibility, yellowing resistance, and excellent adhesion.
B-216	Aliphatic polyurethane acrylate	Fast curing, high fullness, and excellent toughness.
B-296	Aliphatic polyurethane acrylate	Fast curing, chemical resistance, yellowing resistance, impact resistance
B-431	Cycloaliphatic Specialty Acrylate	Yellowing-resistant, excellent wettability, low viscosity, fast curing
Monomer Recommendation
Product Model/English Abbreviation	Product Name/Product Type	Product Features
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)	Pentaerythritol triacrylate	More flexible and less irritating than TMPTA.
BM4241 (DiTMPTA-80)	Bis(2,3-dihydroxypropyl) tetraacrylate	High crosslink density, high hardness, chemical and wear resistance, and water resistance.
BM4242 (Di-TMPTA)	Bis-trimethylolpropane tetraacrylate	High crosslink density, high hardness, chemical and wear resistance, and water resistance.
BM6261 (DPHA-80)	Dipentaerythritol hexaacrylate	High crosslink density, high hardness, chemical and wear resistance, and water resistance.
BM6263 (DPHA-90)	Dipentaerythritol hexaacrylate	High crosslink density, high hardness, chemical and wear resistance, and water resistance.

Share to:

Detailed Explanation of the Classification of UV 3C Coatings (Part II)

Coating methods for UV 3C coatings