[L1] 1 Overview [L2] 1) Definition of Paint [L4] - A substance having fluidity as a solid or liquid at room temperature, which forms a dried film when applied to the surface of an object. [L5] * It is a chemical product that protects, beautifies, and exerts functional purposes by forming a film. [L4] - Paint is a semi-finished product that becomes a finished product only after undergoing the means of painting. [L5] * Paint is a chemical product aimed at obtaining a coating film, and its purpose is to form a coating film. [L4] - Factors determining paint properties include the type of raw materials, mixing ratio, and curing conditions. [L2] 2) Difference between Paint, Coating Film, and Painting [L4] - Paint: The initial form for obtaining a coating film as a chemical product, considered for functionality to form a film and transportability. [L4] - Coating Film: Refers to a protective layer applied to an object that protects it, provides beautification functions, and has specific functionalities. [L4] - Painting: Refers to coating an object, including a series of processes to obtain a coating film (application, drying). [L2] 3) Purpose of Paint [L4] - Protection of objects: Waterproofing, moisture proofing, rust prevention, corrosion protection, oil resistance, chemical resistance, etc. [L4] - Beautification: Change of color, gloss, marking, texture, leveling, stereoscoping, etc. [L4] - Functionality: Electromagnetic shielding, antistatic, antibacterial, insulation, heat resistance, flame retardancy, elasticity, condensation prevention, anti-slip, etc. [L4] - Economic Feasibility: Plating, wallpaper, and tiles exist to protect and beautify objects, but paint is the easiest to coat compared to other products, allows free renewal, and is economical. [L2] 4) Conditions of Paint [L4] - Must have high concentration and low viscosity to form a thick film with a single coat. [L4] - Must have quick-drying properties to prevent sagging. [L4] - Must form a smooth coating film. [L4] - The coating film must be hard, flexible, and have good adhesion. [L4] - The coating film must have weather resistance and chemical resistance. [L1] 2 Composition of Paint [L2] 1) Resin [L4] - Acts as an adhesive between the substrate and coating layers. [L4] - Dispersion medium for pigments. [L4] - Determines the characteristics of the paint and coating film. [L2] 2) Hardener (Curing Agent) [L4] - Used in thermosetting resin paints by curing reaction. [L5] * The coating film is created by the reaction between the resin and the hardener. [L4] - Not used in thermoplastic resin paints (film formed by physical drying such as solvent evaporation without using a curing reaction). [L2] 3) Solvent [L4] - Used as a catalyst to dissolve resin or hardener. [L4] - Aims to facilitate painting by adjusting the viscosity of the resin solution and to grant an excellent appearance to the coating film. [L5] * Workability Control: Viscosity adjustment, drying property adjustment by evaporation rate, spray workability adjustment. [L4] - Must meet required properties such as solubility. [L5] * Must have solubility for the resin. [L5] * Must be colorless and not turbid. [L5] * Must evaporate at room temperature. [L4] - Classification of Solvents [L5] a. Non-polar solvents: Aliphatic hydrocarbons (Gasoline), Aromatic hydrocarbons (Xylene, Toluene) [L5] b. Polar solvents: Alcohol-based (IPA, Methyl, Ethyl), Ester-based (Acetate), Ketone-based (Acetone), Others (Glycol) [L2] 4) Additives [L4] - Auxiliary substances that grant necessary functions to the paint from manufacture until the paint dries and maintains durability. [L4] - Substances added for the purpose of improving the performance of the coating film. [L4] - Classification by Function [L5] a. Plasticizers to improve physical properties of the coating film. [L5] b. Dryers to accelerate drying. [L5] c. Dispersants to improve pigment dispersion. [L5] d. Anti-skinning agents, preservatives, UV absorbers, etc. [L4] - Classification by Use [L5] a. During paint manufacture: Wetting agents, dispersants. [L5] b. During paint storage: Anti-skinning agents, anti-settling agents. [L5] c. During painting work: Defoamers. [L5] d. During film formation: Leveling agents, defoamers, curing accelerators. [L5] e. After film formation: Plasticizers, anti-blocking agents, UV absorbers, preservatives, flame retardants. [L2] 5) Pigment [L4] - Granting optical functions: Coloring, hiding, gloss. [L4] - Granting inherent properties of pigment: Rust prevention, luminescence, heat resistance. [L4] - Improving paint and film performance: Workability, hardness, elongation, adhesion. [L4] - Features of Organic Pigments [L5] a. Vivid and high tinting strength. [L5] b. Good chemical resistance but weak light resistance (UV influence). [L5] c. Low specific gravity and low toxicity. [L4] - Features of Inorganic Pigments [L5] a. Weak color and tinting strength. [L5] b. High specific gravity, poor mixability, and toxicity in the case of heavy metals. [L5] c. Excellent light resistance. [L1] 3 Types of Paint [L2] 1) Urethane Resin Paint [L4] - Polyurethane paint having urethane bonds or generating urethane bonds during the drying process. [L4] - Cures at low temperatures and has an excellent appearance. [L4] - Excellent adhesion, chemical resistance, and abrasion resistance. [L4] - Prone to yellowing and is toxic. [L5] * Yellowing occurs when aromatic isocyanate is used as a hardener; aliphatic isocyanate types that improve yellowing exist but are expensive. [L4] - Types of Urethane Resin [L5] a. Two-component Polyurethane Resin Paint [L5] b. Heat-curing Urethane Resin Paint [L2] 2) Epoxy Resin Paint [L4] - Polymer resin with ether bonds; rich in chemical resistance and reactivity due to the absence of ester bonds. [L4] - Excellent adhesion to substrates, abrasion resistance, and corrosion resistance. [L4] - Long curing time and significant influence by temperature during curing. [L4] - Types of Epoxy Resin [L5] a. Organic Polyamine Curing Type Paint [L5] b. Isocyanate Epoxy Resin Paint [L5] c. Heat-curing Epoxy Ester Paint [L2] 3) Alkyd Resin Paint [L4] - Resin-like substance produced by the combination of alcohol and acid. [L4] - Usually refers to resin modified with fatty acids from polybasic acids like phthalic anhydride and polyhydric alcohols like glycerin. [L4] - Physical properties depend on the type of modifying oil and oil length. [L4] - Types of Alkyd Resin [L5] a. Oil-modified Alkyd Resin [L5] b. Oil-free Alkyd Resin [L5] c. Modified Alkyd Resin [L4] - Features of Alkyd Resin [L5] a. Excellent durability and good weather resistance. [L5] b. Low price. [L5] c. Flexible yet tough with good gloss retention. [L5] d. Poor alkali resistance, making it difficult to use on cement. [L2] 4) Fluorine Resin Paint [L4] - Paint with a molecular structure where hydrogen in the aliphatic hydrocarbon molecular structure is replaced with fluorine. [L4] - Excellent heat resistance, cold resistance, abrasion resistance, weather resistance, and chemical resistance. [L4] - Used as long-term ultra-durable paint but is expensive. [L2] 5) Water-soluble Resin Paint [L4] - Main solvent is composed of water. [L4] - Safe and economical, but drying is slow and depends on humidity.