A Complete Guide to Rosin, Hydrogenated Rosin, Water White Hydrogenated Rosin and Maleated Rosin
2026-04-01
What is Rosin?
Based on its source, rosin is classified into three types: gum rosin, wood rosin, and tall oil rosin. Rosin is a transparent, brittle, solid natural resin; it is a relatively complex mixture composed of resin acids (such as abietic acid and pimaric acid), small amounts of fatty acids, resin acid anhydrides, and neutral substances.
The primary constituents of rosin are resin acids, which account for approximately 90% of its composition; their molecular formula is C19H29COOH, and their molecular weight is 302.46. Resin acids are the most representative of the rosin acids; classified as unsaturated acids, they contain conjugated double bonds, strongly absorb ultraviolet light, and are capable of undergoing auto-oxidation or induced oxidation when exposed to air.
Rosin itself is not very toxic to the human body, but it often contains heavy metals such as lead and toxic compounds. In addition, the industry pursues low-cost repeated use, and the peroxides produced by the oxidation of rosin seriously affect human health, making it a regulated product.
Quality Indicators of Rosin
The quality of rosin is determined by factors such as color, acid value, softening point, and transparency. Generally, the lighter the color, the higher the quality; furthermore, the greater the content of rosin acids, the higher the acid value and the higher the softening point.
Item | Special Grade | Grade 1 | Grade 2 | Grade 3 | Grade 4 | Grade 5 |
Appearance | Transparent, hard and brittle solid (common to all grades) |
| ||||
Color | Pale yellowish | Light yellow | Yellow | Deep yellow | Yellowish brown | Yellowish red |
Softening Point (Ring & Ball) / °C ≥ | 76 | 76 | 75 | 75 | 74 | 74 |
Acid Value /(mg KOH/g) ≥ | 166 | 166 | 165 | 165 | 164 | 164 |
Unsaponifiable Matter /% ≤ | 5 | 5 | 5 | 6 | 7 | 7 |
Ethanol Insoluble Matter /% ≤ | 0.03 | 0.03 | 0.03 | 0.03 | 0.04 | 0.04 |
Ash Content /% ≤ | 0.02 | 0.02 | 0.03 | 0.03 | 0.04 | 0.04 |
Rosin Physicochemical Properties
Item | Specific Parameters/Description | Item | Specific Parameters/Description |
Appearance | Pale yellow to light brown, with glassy luster and turpentine odor | Glass Transition Temperature (Tg) | 30～38℃ |
Density | 1.060~1.085g/cm³ | Refractive Index | 1.5453 |
Crystal Type | Amorphous, no melting point | Flash Point (Open Cup) | 216℃ |
Softening Point (Ring and Ball Method) | 72～76℃ | Ignition Point | Approx. 480~500℃ |
Boiling Point | Approx. 300℃ (0.67kPa) | Oxidation Characteristics | Easily oxidized in air, with darkening color |
Solubility | Soluble in ethanol, ether, acetone, toluene, carbon disulfide, dichloroethane, turpentine, petroleum ether, gasoline, oils and alkaline solutions | ||
What is Hydrogenated Rosin?
Hydrogenated rosin is an important rosin-modified product with good antioxidant properties, low brittleness, high thermal stability, and light color. It is widely used in various fields such as adhesives, synthetic rubber, coatings, inks, papermaking, electronics, and food.
Hydrogenated rosin has a lighter color, higher antioxidant properties, does not oxidize in air, is less prone to discoloration under light, reduces brittleness, exhibits a tendency towards crystallization, increases solubility, and improves initial viscosity, compatibility, adhesion, and aging resistance.
Hydrogenated Rosin Properties Table
Item | Specification / Description | Item | Specification / Description |
Appearance | Amorphous transparent solid resin | Acid Value | 162 mgKOH/g |
Main Component | Contains approximately 75% dihydroabietic acid | Saponification Value | 167 mgKOH/g |
Relative Density | 1.045 | Flash Point (Open Cup) | 203℃ |
Softening Point | 70～72°C | Solubility | Soluble in ethanol, acetone, dichloroethane, carbon disulfide, toluene, turpentine, petroleum ether, solvent gasoline and vegetable oils |
Refractive Index | 1.5270 | Properties | Good oxidation resistance, low brittleness, high thermal stability |
Viscosity (60% Toluene Solution) | 3.6 mPa·s | Toxicity | Non-toxic; LD₅₀ = 7600 mg/kg |
Quality Indicators of Hydrogenated Rosin
Item | Specification |
|
| ||
Special Grade | Grade 1 | Grade 2 | |||
Appearance | Transparent | ||||
Color | Glass Block Colorimetry | Meet the requirements of rosin color standard glass blocks | |||
Not darker than Lovibond color | Yellow | 12 | 20 | 30 | |
Red | 1.4 | 2.1 | 2.5 | ||
Acid Value, mgKOH/g ≥ | 162.0 | 160.0 | 158.0 | ||
Softening Point (Ring & Ball), ℃ ≥ | 72.0 | 71.0 | 70.0 | ||
Ethanol Insoluble Matter, % ≤ | 0.020 | 0.030 | 0.040 | ||
Unsaponifiable Matter, % ≤ | 7.0 | 8.0 | 9.0 | ||
Abietic Acid, % ≤ | 2.00 | 2.50 | 3.00 | ||
Dehydroabietic Acid, % ≤ | 10.0 | 10.0 | 15.0 | ||
Oxygen Absorption, % ≤ | 0.20 | 0.20 | 0.30 | ||
Industrial Applications of Hydrogenated Rosin
- Hydrogenated rosin can be formulated into modified rosin for electronics applications. The resulting soldering fluxes feature excellent soldering performance, high reliability, no corrosion to electronic components, and strong resistance to humidity, heat, and mold.
- In the adhesive industry, hydrogenated rosin is widely used as a tackifier in hot-melt, pressure-sensitive, and rubber-based adhesives.
- In the food industry, it is used as a gum base in chewing gum, preventing discoloration during long-term storage. Hydrogenated rosin is also employed in the production of fruit protective coatings.
- In papermaking, hydrogenated rosin enables the production of high-grade paper with excellent water resistance and lightfastness.
- In the cosmetics industry, hydrogenated rosin is used in liquid lipsticks and shampoos, helping to enhance the gloss of hair.
What is Water White Hydrogenated Rosin?
Water white hydrogenated rosin is a type of hydrogenated rosin obtained by partially or completely saturating the conjugated double bonds of abietic resin acids in rosin with hydrogen under a catalyst and certain temperature and pressure. Its aliases include hydrogenated rosin, water white hydrogenated rosin, fully hydrogenated rosin, and refined hydrogenated rosin.
Water white hydrogenated rosin is divided into regular hydrogenated grade and highly hydrogenated grade.Regular hydrogenated rosin is mainly composed of dihydroabietic acid, with the molecular formula C₂₀H₃₂O₂. Highly hydrogenated rosin consists mainly of tetrahydroabietic acid and dihydroabietic acid, with the molecular formulas C₂₀H₃₄O₂ and C₂₀H₃₂O₂, respectively.
Water White Hydrogenated Rosin Properties & Specifications
Item | Specification / Description | Item | Specification / Description |
Appearance | Amorphous transparent solid resin | Acid Value | ≥ 166.0 mgKOH/g |
Density | Approx. 1.404 g/cm³ | Softening Point | ≥ 76 ℃ |
Boiling Point | 228.8°C | Ethanol Insoluble Matter | ≤ 0.02 % |
Melting Point | 100–102 ℃ | Unsaponifiable Matter | ≤ 7.0 % |
Flash Point | 92.2°C | Abietic Acid Content | ≤ 2.0 % |
Applicable Standard | GB/T 14020-2006 | Dehydroabietic Acid Content | ≤ 8.0 % |
Tetrahydroabietic Acid Content (Highly Hydrogenated Grade) | ≥ 30 % | ||
Industrial Applications of Water White Hydrogenated Rosin
- In the rubber industry, hydrogenated rosin potassium soap and sodium soap are emulsifiers for synthetic rubber. Rosin soap left in rubber can be used as an active filler, both a plasticizer and a tackifier, as well as a softener for natural rubber and synthetic rubber.
- In the coating industry, deeply hydrogenated rosin is a raw material for preparing automotive coatings, which have weather resistance, UV resistance, and chemical resistance properties.
- In the adhesive industry, hydrogenated rosin is often used as a plasticizer in hot melt, pressure-sensitive, and rubber adhesives.
Chemically Modified Rosin
Contact Kerton Chemicals for Customized Rosin Product Solutions
Kerton Chemicals (https://www.kerton-industry.com/) is a trusted supplier of rosin, hydrogenated rosin, water white hydrogenated rosin, and special‑grade rosin. We combine professional R&D, standardized production, and global supply capabilities to deliver high‑performance solutions for the adhesive, coating, ink, electronics, and fine chemical industries.
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