See Architectural coatings

General name for architectural and constructional coatings that have primary function of decorating interior and exterior parts of buildings, and secondary function of protection. They are also known as decorative coatings.
 

Test performed by pushing a knob with a constant speed against the back side of a coated panel causing deformation. During the test, also called Erichsen deformation test, knob is stopped when the first sign of crack formation is observed, deformation depth is measured in mm and this value is defined as deep cupping resistance.

Grinding of pigment agglomerates and aggregates close to their primary particle sizes after dispersion process. See Also Controlled flocculation

Pigment particles undergo controlled flocculation with the help of dispersion additives that hold on to the pigment particles over their pigment-loving groups. Bigger particle sizes are obtained compared to deflocculation; however, “hard precipitation” tendency of the coating decreases. Controlled flocculation is a widely used technique during dispersion of primer pigments and fillers.
 

Additives that accumulate on the surfaces of microbubbles in the wet coating and enables combination of microbubbles to grow into bigger bubbles that migrate to the paint surface and leave the system.(e.g., polyethers with limited compatibility, polyacrylates, polymethylalkylsiloxanes)

Grease on surfaces to be coated, causes poor adhesion for all types of coatings. Therefore, before application, it is important that grease of all kinds should be removed from the surface. First method to degrease before paint application is, wiping/washing the surface with a rag wet with solvent or with a brush. The second method is to remove grease by saponification from the surface by applying hot alkali solution.

Castor oil derivative, obtained by dehydrating castor oil, containing two conjugate double bonds and demonstrating drying oil properties. See Also Castor oil

Dehydrated castor oil

Castor oil derivative, obtained by dehydrating castor oil, containing two conjugate double bonds and demonstrating drying oil properties. See Also Castor oil

Castor oil

Vegetable oil obtained from seeds of Ricinus communis. It is used in production of oven dried or two component coatings as OH functional and monounsaturated ricinoleic acid constitutes almost 90% of the fatty acids it contains. During dehydration, castor oil loses one OH group and one H atom, thus losing one H2O from its molecule. This results in the formation of a new carbon-carbon double bond and since number of double bonds increases to two, the molecule turns into a drying oil which is called and separately used as “dehydrated castor oil”.

Castor oil derivatives

Castor oil derivatives, having tendencies to establish hydrogen bonds with the binders over their OH groups, provide the coating with a thixotropic structure. Sensitivity to high temperatures applied during paint production can be noted as their weakness.

Total quality arisen from the predicted qualifications of a product or a service during the design stage. For instance, a pizza shop could be founded to take orders of 10 different pizzas of which ingredients are predefined, via internet and deliver these orders to all locations in the city within 20 minutes in a hot and hygienic condition. (See Peelable coatings). On the other hand, another pizza shop, could be founded to serve pizzas in the shop in which its temperature is held constant in summer and winter at 25ºC and there are fresh flowers in a vase at each table. Customers choose the ingredients of pizza and they will be served at most 15 minutes. The difference between two services is stem from the difference between their design qualities.
See Also Production quality

Strip coats / Strippable coatings / Peelable coatings

Paints that can provide protection for a certain time to the surface on which they applied and after this period, they can be easily removed from the surface.

Production quality

Assessment of how close the characteristics of a product and service are after production process, relative to those projected during design stage. See Also Design quality

Coating defect described by coating’s inability to form a film during or after application to the surface. Dewetting occurs when surface tension of wet coating is higher than that of the application surface.

Solvent, of both ketone and alcohol character, obtained from condensation reaction of two acetone molecules and utilized in cellulose derived resins and epoxy based coatings.
Chemical name: 4-hydroxy-4-methyl pentane-2-one.
Chemical formula:

Boiling point: 167,9°C; evaporation number relative to ether: 135; specific gravity: 0,938; refractive index: 1,4241; flash point: 58°C
 

Solvent that is obtained from blending of dimethyl glutarate, dimethyl succinate and dimethyl adipate and that is a strong solvent for polyester resins. Blending ratio of three esters differs according to the producer. Typical composition and some properties of a widely used product of Invista, named DBE, are given below:

Typical chemical composition:
59% Dimethyl glutarate
20% Dimethyl succinate
21%Dimethyl adipate

Boiling range: 196-225°C; evaporation number relative to ether: >100; specific gravity: 1,092; refractive index: 1,423; flash point: 103°C
 

Ethyl diglycol

Tail solvent of ether alcohol structure, used to retard drying of cellulose derived resins, epoxy resins, polyester resin based coating systems and water-borne coatings at low quantities such as 1-2 %.
Chemical name: Diethylene glycol mono ethyl ether; 2-(2-ethoxyethoxy)ethanol (also known by the commercial name Carbitol)
Chemical formula: 

Boiling point: 202°C; evaporation number relative to ether: ~1200, specific gravity: 0,990; refractive index: 1,4270; flash point: 90°C

Ethyl diglycol acetate

Tail solvent used to retard drying of cellulose derived resins, polyester resins and short oil alkyd based coating systems at low quantities such as 1-2 %.
Chemical name: Diethylene glycol mono ethyl ether acetate; 2-(2-ethoxyethoxy) ethyl acetate.
Chemical formula: 

Boiling point: 217°C; evaporation number relative to ether: >1200, specific gravity: 1,009; refractive index: 1,4213; flash point: 98°C

Fluids that undergo a viscosity increase upon exposure to shear force (e.g., mixing or applying pressure) See Shear thickening fluids

Shear thickening fluidsFluids that undergo a viscosity increase upon exposure to shear force (e.g., mixing or shaking). They regain their original viscosity after removal of the shear force. Some pigment pastes with high pigment loading demonstrate shear thickening behaviour.

Reactive diluents

Chemicals that dissolve organic coating binder and participate in the cross-linking reaction because of the functional groups they bear. Therefore, they are not volatile or hazardous to environment.

Diluent

Although their particular solvency is moderate, when mixed with strong solvents they do not affect the solvency. Diluents are used in conjunction with thinners to reduce cost.

Percentage ratio of thinner amount that has to be added to a wet coating to bring it to the required viscosity, to the amount of undiluted wet coating.

Dimensional change of especially wood and metal in the form of shrinkage and expansion. Dimensional changes on metal surfaces are expansions and shrinkages occuring at varying ambient temperatures related to the expansion coefficient. For wood surfaces, dimensional change is due to the swelling of the material by capturing water at humid conditions or shrinkage due to loss of humidity at dry conditions.

Dimensional change in wood See Dimensional change

See Dimensional change

Dimensional change of especially wood and metal in the form of shrinkage and expansion. Dimensional changes on metal surfaces are expansions and shrinkages occuring at varying ambient temperatures related to the expansion coefficient. For wood surfaces, dimensional change is due to the swelling of the material by capturing water at humid conditions or shrinkage due to loss of humidity at dry conditions.

See Bisphenol F

Bisphenol F

Type of polyol obtained from the reaction of phenol and formaldehyde under strongly acidic conditions and used for production of epoxy resins with smaller molecular weight and higher functionality.
Chemical name: Dihydroxydiphenylmetane
Chemical formula: 
Melting point: 163°C

Coating application performed by dipping the object into a vessel or tank filled with wet paint at application viscosity. Possible coating defects such as sagging; settling, foaming and non-homogeneous film thickness can be avoided by complete control over application variables.

Type of roller applications, which are based on coating flat panels with rollers on a moving conveyer. In direct roller applications, rotation direction of “application roll” is the same as the conveyer’s moving direction. Having a lower shear than reverse roller application, direct roller application provides good results in primer and non-glossy top coat applications. See Also Reverse roller application, Roller coating applications

Reverse roller application

Paint application method where the applicator rolls run in the opposite direction to the conveyor movement. In this application, better levelling is achieved on the surface because sheer stress exerted on the paint film is higher than in direct rolling application. Reverse roller application method is preferred especially in glossy topcoats. See Also Roller coating applications, Direct roller application

Roller coating applications

Paint application performed by using three parallel rollers named as pick-up, feeding and applicator. Pick-up roller immersed in paint pan, moves around its axis and transfers the paint to the feeding roller which it is in touch with. Feeding roller transfers the paint to the applicator roller in contact with it. Application roller, transfers the coating onto the material to be coated which is moving on a conveyor belt. See Also Direct roller application, Reverse roller application

1) Scattering of a substance in another substance in small particles.
2) Homogeneous and stable mixture obtained by dispersion process.

Stabilization of dispersions

Process of preserving the homogeneous and dispersed state of the pigments in the paint. Stabilization is achieved by two basic mechanisms: (a) Pigment interfaces are electrically charged using convenient additives, therefore repulsion force between particles of similar charge keeps the pigments from agglomeration; (b) Polymeric dispersion additives carrying pigment-loving groups prevents the pigments from agglomeration by forming a polymer layer around the pigment particle (: steric hindrance)

Wetting and dispersing additives

General name for additives that are used to (a) perform dispersion of pigments and fillers using less energy in shorter time, (b) increase dispersion stability in the fluid composed of resin and solvent.

Dispersion of pigments and extenders

Breaking down of pigment flocculates which are combined as agglomerates or aggregates, in a binder and solvent medium. Dispersion of pigments and extenders is performed using high-speed dispersers and wet mills.

Polymeric dispersing additives

Dispersion additives having a branched/chained backbone which is compatible with paint resins and solvents in addition to having pigment affinic groups. Owing to their large molecules, polymeric dispersing additives form a layer around the pigment molecule they attach to so that other pigments are prevented from coming close. Therefore, they provide dispersion stabilization by steric hindrance.

Breaking down of pigment flocculates which are combined as agglomerates or aggregates, in a binder and solvent medium. Dispersion of pigments and extenders is performed using high-speed dispersers and wet mills.

DOI is one of the three concepts designating the reflected image quality, therefore, low DOI is an important defect for automotive OEM and car repair coatings. Low DOI is revealed by observation of scattering on the vicinity of the main light beam reflected with an angle of 20° from the varnish surface. However, scaterring in low DOI occurs in a much narrower angle interval than that of haze defect. Low DOI is perceived as reduction in sharpness and distinctness on the edges of the reflected image. Measurement of DOI is performed by DOI-meters produced by equipment producers. Low DOI can arise from light scattering caused by crystalline additives or binders in the coating film, or by tiny wrinkles on the surface of the coating.

Rocks formed by precipitation of calcium and magnesium carbonate together are called dolomites (CaCO3.MgCO3). Refractive index: 1,60; Specific gravity: 2,90. Filler material obtained by grinding of dolomite is used in exterior architectural coatings.

Thickness of a coating after application and formation of a dry and rigid film. Dry film thickness can be measured either by destructive or nondestructive methods.

The state in paint curing at which the paint film on the item will resist deformation due to the effects from firmly grasping, handling, raising and pushing etc. Since, different parameters are taken into account in the assembly of painted items; specific test methods are often preferred instead of standard methods.

Dryness level needed to stack coated pieces is called dry to stack, and time needed to reach this dryness level is called dry to stack time. In order to measure dry to stack time, coated pieces are stacked so that coated surface touch each other and is subjected to a constant pressure (e.g, 50 kg/m²) applied by a mass for 24 hours. Later on, easiness of separation from each other is observed and coated surfaces are investigated for defects such as delamination etc.

Grieves’ “drying index” is widely accepted to define drying oils:

Drying index=(Percentage of fatty acids with 2 double bonds)+2*(Percentage of fatty acids with 3 double bonds)

Oils having a drying index greater than 70 are classified as drying oils. Grieves’ formula cannot be applied to oils containing conjugate unsaturated fatty acids. “Iodine value” is also utilized to identify drying tendency.

Iodine value

Amount of iodine in grams required to saturate the double bonds in 100 grams of oil is called the iodine value. Iodine value is generally directly proportional to the oxidation drying capacity.

Time period required to reach the desired drying level after application, is defined as the drying time. Depending on the drying level, various drying times can be mentioned such as dust-free drying time, dry-to-touch time, dry-to-assembly time, dry-to-stack time and chemical drying time etc.

Dust free drying is defined as the shortest time which a dust dropped on a wet film will no longer stick to the surface. Tipping gently with the point finger on the film and the time at which paint does not adhere to the finger is the most frequently used test method to define dust free drying time. If this method is employed, before starting, the point finger should be wiped with a rag wet with acetone and the dampness and skin oil on the finger should be removed. A more practical method is starting a stopwatch after paint is applied. Cotton fibers are dropped on the wet test film from a height of 15 cm. After 10 seconds, cotton fibers are tried to removed by blowing over the test film. If no marks are left on the film, then stopwatch is stopped. Time passed is determined as dust free drying time and it is recorded with the ambient temperature. (e.g., Dust-free drying=5 minutes at 25°C)

Coloring chemical substance in the form of small particles so as not to cause the scattering of light, and is soluble in water and some organic solvents.