Benzophenone, Diphenyl Ketone, Benzophenone‑1, Benzophenone‑3, Oxybenzone, Benzophenone‑4, Sulisobenzone, 119‑61‑9, 131‑56‑6, 131‑57‑7, 4065‑45‑6

Benzophenone, Diphenyl Ketone, Benzophenone‑1, Benzophenone‑3, Oxybenzone, Benzophenone‑4, Sulisobenzone, 119‑61‑9, 131‑56‑6, 131‑57‑7, 4065‑45‑6

1. BENZOPHENONE (CAS No: 119‑61‑9)

General Information
Benzophenone is the simplest member of the benzophenone family. It appears as white crystalline flakes or powder with a characteristic sweet, rose‑like odor.

Physical & Chemical Properties

• Appearance: white crystalline solid

• Odor: sweet, reminiscent of roses

• Melting point: ~48 °C

• Boiling point: 305 °C

• Solubility: insoluble in water; soluble in organic solvents (acetone, ethanol, benzene)

Applications

1. Fragrance Fixative: Widely used in soaps, perfumes, and cosmetics to impart a sweet note and prolong the scent. It is found in rose, geranium, vanilla, cream, peach, and oriental fragrances.

2. Industrial Intermediate: Used in the synthesis of pharmaceuticals (e.g., diphenhydramine hydrochloride, bicyclohexyridine), organic pigments, and pesticides.

3. Polymerization Inhibitor: Prevents unwanted polymerization of styrene and other monomers during storage.

4. UV Absorber & Photoinitiator: Employed in UV‑curable coatings, inks, adhesives, and varnishes to initiate polymerization upon exposure to UV light.

5. Rubber Industry: Acts as a low‑temperature fast vulcanizing agent for fluoro rubber.

2. BENZOPHENONE‑1 (CAS No: 131‑56‑6)

General Information
Benzophenone‑1 (2,4‑dihydroxybenzophenone) is primarily used as a UV stabilizer and light stabilizer for industrial materials.

Applications

• UV Absorber: Protects plastics, adhesives, resins, and coatings from discoloration and degradation caused by UV radiation.

• Photoinitiator: Used in UV‑curable inks, coatings, and adhesives.

• Cosmetics: Occasionally used in sunscreens to enhance UV protection, though less common than Benzophenone‑3 or ‑4.

3. BENZOPHENONE‑3 (CAS No: 131‑57‑7) – Oxybenzone

General Information
Benzophenone‑3 (oxybenzone) is one of the most widely used benzophenone derivatives. It acts as a broad‑spectrum UV filter in personal care products. It is also naturally found in some plants and fruits like grapes.

Chemical Properties

• Molecular Formula: C₁₄H₁₂O₃

• Molecular Weight: 228.24 g/mol

• Appearance: pale yellow crystalline powder

• Melting Point: 62–64 °C

• Solubility: insoluble in water; soluble in oils, alcohols, and organic solvents

Applications

1. Sunscreens & Cosmetics: Absorbs UV‑A and UV‑B rays, protecting skin and hair from sun damage. Used in lotions, creams, lip balms, and hair care products.

2. Color & Fragrance Stabilizer: Prevents fading of colors and oxidative degradation of fragrances in soaps, shampoos, and shower gels when exposed to sunlight.

3. Polymerization Inhibitor: Inhibits styrene polymerization during production and storage.

4. Food Flavoring: Under certain regulations (e.g., GB 2760‑1996), it may be used in trace amounts as a flavor fixative for vanilla, cream, fresh fruit, nut, and peach flavors.

5. Industrial: Used in varnishes, paints, plastic coatings, and printing inks as a UV stabilizer and photoinitiator.

4. BENZOPHENONE‑4 (CAS No: 4065‑45‑6) – Sulisobenzone

General Information
Benzophenone‑4 (sulisobenzone, sodium benzophenone‑4 sulfonate) is a water‑soluble benzophenone derivative. Its water solubility makes it ideal for clear formulations and water‑based products.

Physical & Chemical Properties

• INCI Name: Benzophenone‑4 / Sulisobenzone

• Appearance: yellowish powder

• Solubility: soluble in water; insoluble in oils

• Stability: stable in the pH range 5–8

Applications & Benefits

1. Water‑Soluble UV Filter: Used in sunscreens, often combined with oil‑soluble UV filters to boost SPF and provide broad‑spectrum protection.

2. Color Protector: Prevents fading of dyes and pigments in shampoos, conditioners, mascaras, and other colored cosmetics, especially when packaged in clear containers.

3. Fragrance Protector: Prevents oxidation and spoilage of perfumes and fragrances in cosmetic products.

4. Preservative‑like Action: Helps protect formulations from degradation caused by bacteria, fungi, and yeast, thereby extending shelf life.

5. Enhances Penetration: Aids in the delivery of other active ingredients into the skin.

6. Approved Usage: Approved by the FDA (USA) and in European countries at typical usage levels of 5‑8%.

Summary Table

Comparison Table of Benzophenone Derivatives

Key Differences at a Glance

• Solubility: Benzophenone‑4 is distinctly water‑soluble, making it suitable for clear, water‑based products such as shampoos, body washes, and mascaras. The others are oil‑soluble or only slightly water‑soluble.

• Primary Use: Benzophenone and Benzophenone‑1 are mainly used in industrial applications (resins, coatings, polymers). Benzophenone‑3 and Benzophenone‑4 are heavily used in cosmetics and personal care.

• UV Protection: All possess UV‑absorbing properties. Benzophenone‑3 is the most common broad‑spectrum UV filter (UV‑A/UV‑B) in sunscreens, while Benzophenone‑4 is the water‑soluble alternative, often used to boost SPF in aqueous formulations.

• Fragrance Fixation: Benzophenone and Benzophenone‑3 are widely used as fragrance fixatives in soaps and perfumes; Benzophenone‑4 also protects fragrances from oxidation, serving a similar stabilizing role.

Benzophenone Derivatives – Other Names, Alternatives, and Sectoral Suitability