Yoneyama Kagaku Kogyo Kaisha, Ltd.

p-Nitrobenzoic acid

Product Features

  • We guarantee 99.0% min purity.
  • We control and standardize the content of chlorides, sulfates, lead and iron at the level required for electronic material applications.
p-Nitrobenzoic acid



Fiber drum of 20 kgs. net

Basic Information

Chemical formula
Specific gravity
Melting point
239 degree C.
About 0.274 grams/100 grams H2O at 20 degree C.
Lemon yellow color crystalline powder
Harmonized system (HS code)
Country of origin
UN number


Chloride (Cl)
5ppm max.
Sulfate (SO4)
10ppm max.
Lead (Pb)
5ppm max.
Iron (Fe)
2ppm max.
99.0% min.


What grade do you have?
We only produce a high purity grade for capacitor electrolyte.

End User Comments

Aluminum electrolytic capacitor manufacturer

“Since the other major manufacturer discontinued the manufacture of high-purity products, we expect Yoneyama to start producing p-Nitrobenzoic acid as overseas products are not of sufficient quality for use in capacitors.”

Who manufactures p-Nitrobenzoic acid?

Yoneyama Kagaku Kogyo Kaisha, Ltd.

Aerial Shoot


  • We have been producing high-performance chemicals using crystallization technology since 1918.
  • We have achieved stable quality because we control the manufacturing process by a quantitative method.
  • We produce phosphates, acetates, chlorides and sulfates which are conformable to the Japanese standards of quasi-drug ingredients typically used for cosmetics, shampoos, body soaps, and hair care products.


1918 Established in Osaka prefecture, Japan.
1962 Ashikaga Plant was created.
1966 Ashikaga Plant starts producing Ammonium acetate.
2001 Company acquires ISO 9001 certification (all business units).

Company Overview (as of March 31, 2020)

Company name Yoneyama Kagaku Kogyo Kaisha, Ltd.
Head office 5-2-18 Nishitenma, Kita-ku, Osaka, 530-0047, Japan
Date of establishment July 10, 1918
Capital JPY 24 million
Number of employees 90
Location Head office: Osaka
Branch offices: Tokyo, Nagoya
Plants: Osaka, Ashikaga
Technical department : Osaka
Affiliates: Suita (Osaka)


Plant location map

Osaka Plant

  • Phosphates
  • Sulfates

Ashikaga Plant

  • Acetates
  • Boric acid
  • Ammonium salts

Other Plants

  • p-Nitrobenzoic acid
  • Zinc sulfate
  • Potassium tetraborate

" End-User’s Laboratory "

Equipment for end-user’s pilot and small-scale production using our excellent crystallization technology


  • Production volume 100 - 1000 kgs.
  • We have facilities that can develop chemicals that meet the standards for reagent special grade, food additives, and capacitors.
  • Using the manufacturing data accumulated in the development process, you can move to mass production accurately and quickly.

Main Equipment

Device Name Capacity Quantity Material made of Comment
Feed tank 3,000 L 1 GL Room temperature to 120 degree C., full vacuum to atmospheric pressure
3,000 L 1 SUS Room temperature to 120 degree C., full vacuum to atmospheric pressure
Crystallization tank 3,000 L 1 SUS Room temperature to 120 degree C., full vacuum to atmospheric pressure
Filter 250mm x 5 1 SUS Cartridge type
80 L, 0.2 m2 1 SUS Nutsche type
Centrifuge 42 inches, 165 L 1 SUS Fully open, bottom ejection type
Conical dryer 300 L 1 SUS 40 to 120 degree C., full vacuum to atmospheric pressure
Loading chamber 18 m2 1 SUS Positive pressure control, HEPA filter
Kneader 50 L 1 SUS Room temperature to 120 degree C., full vacuum to atmospheric pressure

Case Study

1. Purification of water-soluble compounds

This labo's purification process removes impurities and provides them to users in pharmaceutical applications who require high purity products. "Purification of water-soluble compounds" is our specialty, and we often undertake requests for such purification in small lots (100 - 500 kgs.).

2. Purification and reduction of Fe of ammonium organic acid for plating

We have reduced impurities in ammonium organic acid, which is used as a complexing agent and buffer, by an impurity removal process + neutralization reaction + crystallization method. As a result, we are able to crystallize "high purity" and "low Fe value" crystals.