Acrylic resin

Copolymer which contains acrylic acid, acrylic acid ester, ethacrylic acid, methacrylic acid ester as the main chain. There are kinds such as thermoplastic acrylic resin, thermosetting acrylic resin, modified acrylic resin etc. Thermoplastic resins are used alone or with cellulose derivatives and rosin resins as acrylic lacquers for building exterior and for plastics. Main applications of acrylic resin beside paint are adhesives, printing ink, textile processing, leather tanning, etc. For its excellent durability and transparency, acrylic resin is used in aquarium as tank.



Alcohol is a substance in which a hydrogen atom of a hydrocarbon is replaced with a hydroxy group (-OH).

<Example of industrial alcohol>
● Methanol (CH 3 OH)
● Ethanol (C 2 H 5 OH)
● Isopropyl alcohol (CH 3 CH (OH) CH 3)
● N-propyl alcohol (CH 3 (CH 2) 2 OH)

Alcohol might be referred to as “Ethanol”

<Type of alcohol>
● Synthetic alcohol
● Fermentative alcohol

<Alcohol Business Act>
Alcohol which contains 90 degrees or more alcohol (when 15 degrees Celsius) is covered by the Alcohol Business Act and is classified to the following two.

① General alcohol
Inexpensive alcohol which does not include addition. Prior permissions are required for use.
Regular records such as usage records and usage quantities must be kept.
② Specific alcohol
Alcohol with addition to prevent illegal use of alcoholic beverages. No procedures such as usage records are necessary


Aniline point

The aniline point (mixed aniline point) is one of the indicators used to see the solubility of oils and fats.
Temperature at which sample and aniline are separated when the sample (substance to be tested) is mixed with an equal volume of aniline and cooled. Generally, lower the aniline point is, higher the solubility become. However, it cannot be measured unless the solvent separates from aniline at a certain temperature.





It means that the substance is decomposable by microorganisms. The substance decomposes to molecular level and becomes carbon dioxide and water due to the action of microorganisms.



Boiling point

Boiling point of a substance is the temperature at which the liquid starts boiling. Since the boiling temperature changes with atmospheric pressure, it usually indicates the temperature at which boiling starts at 1 atm. Quite often it is misunderstood as “the temperature at which the liquid becomes a gas” such as the “melting point” indicating the temperature of a solid becomes a liquid, but the liquid will also gasify even before the boiling point. Abbreviated as bp.



Burning point

Burning point is the minimum temperature of a liquid necessary for a certain substance to continue to burn. Basically, this temperature is higher than the flash point.




CAS№ is an abbreviation for “CAS registration number”, which is a worldwide common number issued by academic experts in the United States to identify chemical substances. By assigning a unique identification number to each chemical substance, even if there is an alias in the substance name, it can be judged whether it is the same substance or not by checking the CAS No. In Japan, there are also organizations conducting agency business of CAS and acquiring CAS registration number. The number of registered substances is more than 130 million at the stage of 2017.



Compatibility is a measure of how stable a substance is when mixed with another substance and if substances mix and do not change they are considered compatible. Conversely, separation without mixing at all is called “incompatibility”.
When judging affinities for two or more substances, polarity and SP value are used as indices.
(For example, since processed oils are often not polarized, they are soluble in non-polar hydrocarbons and the compatibility is good with each other because the SP value of the processing oil and the hydrocarbon type are close)





A solution which contains two liquids which cannot be mixed such as water and oil by refining and dispersing one of them into another. Making an emulsion of two separated liquids is called “emulsification”, and a substance used to do so is called “emulsifier”. Acrylic paint, mayonnaise, adhesive is familiar as emulsion.


Epoxy resin

Epoxy resin is a generic term for compounds having two or more epoxy groups in one molecule which becomes three-dimensional by adding curing agent. Epoxy resin produces a cured product having a network-like crosslinked structure as a reaction by mixing an epoxy polymer (main agent) and a curing agent.
There are both single-part type and two-part type in epoxy resins. For single-part type, main agent and a curing agent is mixed beforehand, and the curing agent reacts and cures by heating. Two-part type reacts by mixing an epoxy polymer (main agent) and a curing agent.


Has excellent adhesion (metal, glass, wood, concrete, etc.)
Corrosion resistance · Heat resistance · Chemical resistance · Water resistance · Weather resistance
There is no volatile matter released during curing, volume shrinkage during curing is small
Excellent strength and toughness
Excellent in electrical insulation which does not conduct electricity
Low toughness (susceptibility to fracture and resistance)
Weak against ultraviolet rays and deteriorates white
Curing is slow at low temperature


· Epoxy paint … Electrodeposition paint for automobiles, heavy anticorrosive paint for ships and bridges, paint for painting the inside of beverage cans
· Epoxy adhesive … Vehicle · Aircraft adhesive
· Electronic fields such as household appliances, personal computers, mobile phones (laminated boards, semiconductor sealing materials, insulated powder coatings, coil impregnating etc.)
· Composite materials for sporting goods such as golf clubs and tennis rackets
Since the epoxy resin forms a crosslinked structure upon curing, peeling / cleaning after curing is difficult.



Fermentative alcohol

Alcohol obtained by saccharification, fermentation, and distillation using starch or molasses as raw material. Generally fermentative alcohol refers to fermented ethanol. The use includes alcoholic beverages, other foods, cosmetics, detergents and industrial applications.


Flash point

Flash point is the lowest temperature which ignites and burns a material when approaching the source of the fire. Liquid evaporates without reaching the flash point, but it does not ignite because the concentration is not sufficient. As the temperature of the liquid rises, the amount of evaporation increases, and the concentration of combustible vapor rises which lead the liquid to ignite.
The Fire Services Act determines levels according to the flash point.



Flux is a mixture of natural plant resin (such as pine tar) and chemical agent. If it is applied on the base material in advance of soldering, spreading of molten solder improves which makes it is easy to finish beautifully and reduction of soldering failure can be expected.
【Main function of flux】
・By removing oxides which impede the conduction of heat on the metal surface of electronic parts or on the surface of solder, soldering becomes smooth
・By reducing the surface tension of the solder and weakening the stickiness, the flow (wetting) of the solder improves
・By covering the surface of solidified solder, base metal, and parts to prevent re-oxidation and prevent defects

Flux is contained in the center of general “thread solder”, but if it is insufficient, add flux. However, too much flux may cause troubles such as corrosion of the base metal and absorption of moisture and insulation deterioration, so it will eventually be treated with a flux cleaning agent such as IPA to wash away.




Hydrocarbon is a compound made from carbon atoms and hydrogen atoms only, as the name implies. It can be in gas, liquid and solid state according to molecular weight.


◆ Paraffin (= Alkane)
Generic term for chain type saturated hydrocarbons in which the general formula is CnH2n+2.
Paraffin can be classified into two types from the shape of the molecule which is normal paraffin and isoparaffin. Paraffin is a highly safe substance with extremely low odor and toxicity. Cleaning performance (dissolving power, degreasing power) is not as storong as naphthenic (= cycloparaffinic) and aromatic type, but it exerts sufficient effect for processing oil after metal working.
● Normal paraffin (Norpara)
Hydrocarbons with molecules not branched.
Also called saturated straight chain hydrocarbon. Normal hexane (n-hexane), normal heptane (n-heptane) etc. corresponds to this kind.
● Isoparaffin (Isoparas)
Hydrocarbons with molecules branched.
Also called branched hydrocarbons. 2,3-dimethylbutane, isooctane etc. correspond to this type.
◆ Cycloparaffin (Naphthene)
Hydrocarbons with cyclic molecules(CnH2n).
Also calledcycloalkane. Cyclohexane, cyclopentane etc. correspond to this type.
◆ Aromatics
Hydrocarbons having a structure like a benzene ring. It is a kind of unsaturated cyclic compound (Containing double bond). Benzene, toluene, xylene, etc. correspond to this kind.

Classification Name Solubility Toxicity Odor
Saturated aliphatic
Normal paraffin Low Low Low
Aromatic hydrocarbon Aromatics High High High



Ignition point

The ignition point is also referred to as the ignition temperature, which is the spontaneous ignition temperature. When it reaches this temperature or higher, it ignites itself even without fire base. Generally, the ignition point is higher than the burning point.



Molecule with the same molecular formula as another molecule, but with a different chemical structure are called “isomers”.
There are two types of isomer. In structural isomers, molecular formula matches but structural formula does not match (sequence and structure are different). In stereoisomers the bond structure is the same, but the geometrical positioning of atoms and functional groups in space differs.
Structural isomers generally differ largely in chemical properties, and stereoisomers does not differ as strong as structural isomers, but some differences arise.



Kb value

The Kauri-butanol value (“Kb value”) is a standardized measure of solvent power for a hydrocarbon solvent. A higher Kb value means the solvent is more aggressive or active in the ability to dissolve certain materials.
To measure, first, add a fixed amount of butanol solution of Kauri resin in a flask, place it on a type paper, drop the sample. Represent the amount of solvent (ml) when turbidity occurs and the print cannot be read. However, since Kauri resin butanol solution dissolves endlessly in alcohol and glycol, you must recognize that it is only an index.
※ The figure on the right is the KB value with hydrocarbons
(25 to 40 for paraffin, around 50 for cycloparaffin, around 100 for aromatic)
※ Since Kauri resin is dissolved in butanol for measurement of KB value, in polar solvents such as alcohols, ketones, esters, etc., the values gets very large, which cannot be an indicator to judge solubility.


Solvent Kb value
N‐hexane 30.5
Cyclohexane 60
Benzine 107
Toluene 105
Dimethylbenzene 103
Methylene chloride 136
Trichloroethylene 130
Tetrachlorethylene 90
1-Bromopropane 125



Melting point

Melting point refers to the temperature at which a solid becomes a liquid. Mostly it is the same as the freezing point. The melting point varies depending on the substance, and when other substances are contained, the melting point is fluctuated, so it can be confirmed whether or not impurities are contained, and it can be used for identification of substances.




Often used in the detergent field which represents the electrical bias present in the molecule. Compatibility between processing oil and detergent depends on the presence or absence of polarity. If both processing oil and hydrocarbon solvent have no polarity, it will be well compatible, but polar water-soluble processing oil (water has polarity) can be incompatible with hydrocarbons with no polarity and does not dissolve.


Polyurethane foam

“Foam produced by carbon dioxide which is generated when reacting a polyisocyanate compound with water.
Not only being used for condensation prevention and freeze prevention, it is also used for heat insulation, special modeling / foaming modeling, car aero parts, and for repair and reinforcement of FRP and DIY.”




Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) is a European Union regulation entered into force on 1 June 2007 which is a regulation governing chemical substances and their use in the EU. It is aimed on the protection of human health and environment, improvement of the competitiveness of the EU chemical industry. Chemical substances whose annual manufacturing / import amount exceeds 1 ton per business are targeted.



Resist comes from the meaning “withstand”. Resist can mean either a protective film or a substance used for forming a protective film for physical treatment such as sandblasting or chemical treatment such as etching.
This mechanism makes you process only the unprotected part by protecting a part of the surface with resin etc. beforehand (protective films may be peeled off after processing, or may be left). Depending on the application and coloring method, following can be named as sample
・Screen printing resist
・Etching resist
・Plating resist
・Solder resist


Restriction of Hazardous Substances

The RoHS Directive is enforced in the EU since July 2006 which limits the use of certain hazardous substances (such as lead and mercury) in electronic equipment. By restricting it, it aims to facilitate recycling, and to make harmless or reduce waste. Transportation from outside the EU has also been regulated which requires attention.
Laws and ordinances similar to this can be seen in countries other than the EU.
Ex. The marking for presence of the specific chemical substances for electrical and electronic equipment / JP

Risk assessment

“Risk assessment” is a process of covering risk assessment by identifying risks and analyzing them.
Risk assessment here refers to the implementation of guidelines on occupational health and safety management system “”Matters relating to the investigation of danger or harm, etc.””, and since April 1, 2006, efforts obligation has been made. The procedure is specified in Article 28, Paragraph 2 of the Industrial Safety and Health Act.”



Solidifying point

The solidifying point is the temperature which the liquid becomes solid. In many cases it is the same temperature as the melting point.


Solubility Parameter

Value used as a measure for intermolecular force which assumes that the force acting between solvent and solute is intermolecular force only. There are inherent SP values for substances, and there are principles that substances with close SP values are well compatible. The SP value of the oil-based lubricant is approx. 7 to 8.


Solvent Solubility Parameter
N‐hexane 7.3
Cyclohexane 8.2
Isobutyl acetate 8.3
Butyl acetate 8.4
Ethylbenzene 8.8
Dimethylbenzene 8.8
Toluene 8.9
Ethyl acetate 9.1
Benzine 9.2
Trichloroethylene 9.2
MEK 9.3
MIBK 9.6
Methylene chloride 9.7
Acetone 9.9
Isobutanol 11.2
N-butanol 11.3
IPA 11.4
N-propanol 12.4
Ethanol 12.7
Ethylene glycol 14.5
Methanol 14.5
Water 23.4


Specific gravity

Specific gravity is the ratio of the density of a substance to the density of a reference substance. As for liquid or solid substance, it is based on water and in case of a gas, it is based on air. Since it is ratio, there is no unit. Substances with specific gravity greater than 1 will sink and smaller than 1 will float in water, as it is a numerical value of the weight a substance has. It is also different from density.


Synthetic alcohol

Alcohol produced by chemical reaction. Generally synthetic alcohols refer to synthetic ethanol which is produced from ethylene directly reacting with water vapor. The use is limited for chemical industry only, such as detergents, cosmetics, pharmaceuticals, etc.



Urethane coating

Urethane paint is a two-part type paint using curing agent. Chemical reaction starts immediately after mixing the curing agent which foams a three-dimensional network structure to make a dense coating film. The coating film is soft, excellent in adhesion and well balanced compared to other paints in price, durability, functionality, etc. It is widely used as a coating material for outer wall and flooring material. On the other hand, the antifouling property and the durability against ultraviolet rays are inferior to silicon based paints. The service life is 8 to 10 years, which is longer than the acrylic paints (which the service life is 5 to 8 years).


Urethane resin

Urethane resin is a generic term for polymers which have urethane bonds. These are also called polyurethane or urethane rubber. It is produced by condensation of a compound including an isocyanate group and a hydroxyl group.
Since polyisocyanate which is a curing agent for urethane resin has very high reactivity with water, attention must be paid to high humidity and mixture of moisture.


A wide variety of physical properties obtained from low to high elasticity modulus
Excellent tensile strength, abrasion resistance, oil resistance
Excellent weather resistance, water resistance, chemical resistance
Heat resistance is lower than other synthetic rubbers
Gradually decomposed due to hydrolysis by moisture and influence of nitrogen compound, salt, ultraviolet light, heat, microorganisms etc. in the air


· Urethane paint (water-soluble urethane paint)
· Urethane adhesive (hot melt adhesive)
· Urethane foam
· Urethane Sponge
· Sealing material
· Filler, insulation
· Sound insulation material
· Textile products (stretch material)
· Leather goods
· Automobile parts (insulator, cushion)
Urethane is difficult to peel because it gets tough as the coating hardens.


Urethane waterproof

Urethane waterproofing is a method to form a rubbery and elastic waterproof layer by painting and curing a liquid urethane resin. Two-liquid type is common but moisture-curing single-liquid type and fast-curing spray type exists.




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