Chemical Manufacturer

History of The Company:

  • 1982, PT Justus Sakti Raya (Justus) was estabilished.
  • 1983, Became the first Unsaturated Polyester Resinproducer in Indonesia, under license from Showa Highpolymer Co. Ltd. (Japan).
  • 1990 Increased UPR production capacity from 6,000 to 12,000 tonnes/year under license from Showa Highpolymer Co. Ltd. (Japan).
  • 1991 Started manufacturing Metallic Soap/Drier under license from Lonza SpA (Italy).
  • 1992 Started manufacturing Polymer Emulsion (Latex) under license from Showa Highpolymer Co. Ltd. (Japan).
  • 1995 Increased UPR production capacity from 12,000 to 24,000 tonnes/year, under license from Lonza SpA (Italy).
  • 1997 Obtained ISO 9002 Certificate for UPR, Polymer Emulsion and Drier production.
  • 1998 Started manufacturing Maleic Anhydride and Fumaric Acid (food and technical grade) under license from Lonza SpA. About 70% of the produced quantity is exported worldwide.

Most of our qualified employees are chemists and engineers.  Our teams in Research and Development, Manufacturing and Marketing work together to create value for our customers. With well-equipped laboratories and strict quality control, customers are assured of good and consistent products from Justus. Furthermore, there are four laboratories and a small pilot plant in our four manufacturing plants for the quality control, new product development, application research, testing and process improvement.

Justus’s unique integrated  manufacturing capabilities facilitate a strong program of made-to-order items.  Since we manufacture many of our own starting materials, we maintain total control over every production process.  This enables us to make adjustments to materials and processing techniques at whatever point necessary to match the exact requirements of our customers’ specifications.

Our main manufacturing product are :

  • Unsaturated Polyester Resin YUKALAC®
  • Polymer Emulsion YUKASHU®
  • Metalic Soaps/Driers YUKALIC®
  • Maleic Anhydride
  • Fumaric Acid


Justus supplies high quality products, prompt service and necessary technical supports/advise to both local and overseas customers worldwide.  In order to achieve this goal, we incorporate appropriate technology to provide solutions for our customers’ needs.  Product and process improvements are routinely conducted at our Research and Development Department so that our product suit the changing needs of our customers.

We strongly believe that our customers’ full satisfaction is also ours.

1. Unsaturated Polyester Resin YUKALAC®
Types : Orthophthalic, Isophthalic, Halogen, Iso-Neo, Bisphenol, Maleic
Applications: General purpose, Boat, Flat and corrugated sheet, Paper impregnation, Pipes, Tanks, Profiles, Sanitary wares, Reinforced plastics, FRP reduced fire hazard, Gelcoat, Topcoat, FRP chemical resistance, SMC/BMC, Flexibilizer resin, Varnishes/wood coating, Buttons, Synthetic marbles, Clear casting, Putty, Polyester pigment paste, Polywood/decorative board, Vehicle body, Building Industry, Consumer goods, Etc.

2. Drier/Metallic Soap YUKALIC®
Types :

  • Naphthenate/Octoate of Lead, Cobalt, Manganese, Calcium, Zinc, Zirconium, Copper, Potassium, Natrium
  • Mixed Drier

Applications :
Paint and ink drier, paint additives (wetting and dispersing agent), extreme pressure agent (lubricant oil additives), combustion catalyst (for fuel oil), Adhesion agent for rubber, resin hardening accelerator, anti corrossion additives, wood treatment (fungicide), waterproof agent, resin stabilizer, anti root agent, antiseptic.


Some metals, in form of metallic soaps can catalyze and accelerate the oxidation and/or polymerization of drying oils.  These metallic soaps / driers, with a trade name ‘Yukalic’, can be used to control the speed and uniformity of drying and properties of the dried film.

Yukalic metallic soaps/driers have certain basic requisities, such as:

  • Perfect solubility in all solvents or solvent mixtures used in the varnish industry.
  • Good compatibility with all oleo resinous vehicles.
  • Long storage stability without sedimentation, colour changes or oxidation occuring.

Types of Metal and Functions:

  • Lead . Lead soaps driers promote thorough polymerization of the film, improving its flexibility and its resistance to water and salt at the same time.  However, since Lead Driers posses only modest drying properties, they are always combined with Cobalt and / or Manganese, and may be added at any stage in manufacture. Since Lead soap tends to flocculate with some oils and alkyd resins, it is advisable to add small amounts of Calcium drier which stabilizes the Lead, in order to eliminate or minimize this drawback.
  • Cobalt. Cobalt based driers catalyze the surface oxidation of varnish films.  In view of the speed at which they act, Cobalt driers should be added at the dilution stage.  This drier may be used alone, or combined with Lead, Manganese or Zirconium driers. In the Unsaturated Polyester Resin field, Cobalt driers promote the polymerization reaction, in addition with organic peroxides, at room temperature.  In general, Cobalt driers and peroxides are added to the resin separately, just at the moment of the resin use.
  • Manganese. Manganese based driers act both as oxidizers and as polymerizers.  As polymerizers they seem to be more active than Cobalt. In view of its double effect, Manganese drier may be used to considerable advantage in combination with Lead-Cobalt or Zirconium based products.
  • Calcium. Calcium soaps act as ‘Auxiliary driers’, stabilizing any possible tendency to flocculation by the Lead driers, and thus preventing loss of drying power. Calcium driers speed up incorporation in the stoving for linseed-synthetic resin varnishes. They may be used as a viscosity stabilizer.  Calcium drier also prevents loss of drying power during storage.
  • Zinc. Zinc soaps are ‘auxiliary driers’.  Used together with Cobalt, they give harder films, maintaining the film ‘open’ so as to maximise the effect of oxygen, ensuring more uniform drying throughout.  Zinc may also be used as a ‘stabilizer’ for Lead driers.  Yukalic Zinc drier posseses good wetting properties, cutting down the loss of drying power caused by certain pigments or fillers.
  • Zirconium. Zirconium driers are only slightly active as driers, but show exceptional ability in enhancing the activity of primary driers such as Cobalt and Manganese.  Zirconium can be used to replace the Lead without sacrificing drying times or significantly increasing costs.  Lead soaps should never be used in driers containing Zirconium, since they have a negative effect on the interesting properties of Zirconium.  Zirconium driers also decrease loss of drying power during storage.  The use of Zirconium soaps as co-driers gives improvements in all the properties of the film, colour retention, adhesion, flexibility, resistance to abrasion, knocks, washing, etc..
  • Copper. Copper soap acts as anti fouling drier in ship bottom paints.  The metalic soap of Copper are fungicidal and when properly applied to wood and cellulosic fibers extend the useful life of these materials in outdoor exposures. It is a root proofing agent for textiles, cordage, canvas, rope and fishing nets.  It insecticidal property imparts a long lasting protection against termites, beetle, ambrosia attacking timber/lumber .  The usual procedure in treatment of fibers, rope, and cloth is to apply the soaps in petroleum solvents.  Solvent solutions of Copper Naphthenate (metal content 1-3%) are used in brushing and dipping treatments of lumber which is used in contact with the soil.


  • The driers may be stored for several months if care is taken that the drums are well closed, and storage conditions are appropriate.
  • Owing to the presence of inflammable solvent, for safety reasons, it is advisable to avoid excessive storage temperature (if possible not exceed 25oC).
  • Strictly avoid that driers come into contact with, or are kept near to oxidizers/peroxides.
  • The normal practices for handling and using chemical products (wearing of gloves, goggles, protective clothing, etc.) should be followed.

3. Polymer Emulsion YUKASHU®
Types :
Vinyl Acetate-Acrylic Copolymer, Styrene-Acrylic Copolymer, Acrylic, Polyvinyl Acetate, Vinyl Acetate-Vinyl Versatate Copolymer, Ethylene Vinyl Acetate Copolymer.

Applications: Paint and Coating, Adhesive, Textile, Paper coating.


Polymer Emulsions, which have the trade name of YUKASHU®, are made by polymerization of monomers such as Vinyl Acetate, Acrylic Ester, Styrene and Ethylene in solution of surfactant or water soluble polymeric subtances.

YUKASHU® has several series in the field of:

  • ADHESIVES. PVAC homopolymers and copolymer adhesive are used in many applications such as packaging, wood bonding, book binding, paper overlay, paper tube, PVC sheet to wood, PVC sheet to MDF, lamination and envelope.
  • PAINT AND COATING VEHICLES. Vehicle for emulsion paint or coating of contruction material and metal (e.g. : interior/exterior flat/sand paint; wall coating for thick/thin texture finishes; multi layer wall coating glossy finishes; gloss top coating; roof paint; etc.)
  • TEXTILE BINDERS. It is applied to fabrics to increase their strength and resistance to wrinkling and shrinking, for flock finishing of cloth and plastic.  It is also used to bind non woven cloth, back coatings, pigment and printing binders and sizes.
  • PAPER COATINGS. Vehicle for coating and finishing for paper, reprocessing to improve quality such as printability, gloss, etc..
  • YUKA® Water Proofing [advertising]. YUKA® Water proofing is a synthetic product especially made for water proofing to overcome building leakage, and resistant to mildew and cracking. It is easily applied by brush.


  • YUKASHU® is packed 200 kgs netto in open head drum with 2 liners of LLDPE plastic bag.
  • YUKA® is packed, 1 kg netto in plastic can, 4 kg netto in plastic can, 20 kg netto in in steel can with 1 liner of plastic bag, 200 kg in open head drum with 2 liners of plastic bag.
  • To ensure safe storage of the emulsion, the containers should be well sealed to prevent evaporation of water and the formation of skin on the surface of the emulsion.
  • In common with normal pratice, the emulsion should not be exposed to frost and high temperature (ca. above 40oC) during storing.

4. Maleic Anhydride
Applications: Unsaturated Polyester Resin, Alkyd Resin, Ester, Copolymer, Tetrahydrofuran, Etc .

Handling and Storage Precautions:

  • Health hazards. Maleic Anhydride is an irritant to the skin and mucous membranes (eyes, nose, throat, and upper respiratory tract).  All persons working with Maleic Anhydride should wear chemical safety goggles, safety hat, rubber/leather safety shoes, rubber gloves, rubber approns, etc.
  • Fire and explosion hazards. Maleic Anhydride is combustible solid.  Care must be exercised in handling and storage to keep the Maleic Anhydride away from flame or sparks since its dust and the vapors from the molten product are flammable.
  • Building and equipment design. All rooms in which Maleic Anhydride is stored or handled should be provided with adequate ventilation.  All tanks intended for the storage of molten Maleic Anhydride/materials handling equipment should be electrically grounded to safely dissipate electric charges, and should be made of stainless steel as iron and standard steel are subject to corrosion.
  • Storage. The storage tank should be equipped with a temperature indicator.  Since the flash point of Maleic Anhydride is about 110oC (230oF) open cup, the storage tank temperatures should be regulated not to exceed approximately 100oC.

5. Fumaric Acid
Types: Industrial Grade, Food Grade

Unsaturated Polyester Resin, Alkyd Resin, Ester, Maleinated Oil, Food use, Etc.

Net 25 kg in multiwalled paper bags.
Net 500 kg in jumbo bags.

Handling and Storage Precautions

Health hazards
As Fumaric Acid is non toxic, no special precautions are required.  Nevertheless, prolonged contact may cause irritation and inhalation of dust may cause repiratory irritation.

Fire hazards
Although Fumaric Acid is only slightly inflammable, it should not be handled in close proximity to open flames.

Building and equipment design
Room in which Fumaric Acid is stored or handled should be provided with adequate ventilation.  All Fumaric Acid processing equipment should be made of stainless steel as iron and standard steel are subject to corrosion.

6. Waterproofing

  • Prevent water/ moisture permaebility into roof / asbestos walls
  • Seal fine crack on walls, roof, deck / concrete floor
  • Provide water proofing for external walls
  • Water proofing for toilet and building floors

Contact: PT Justus Sakti Raya – Chemical Manufacturer

Office : Wisma Justus
Jl. Danau Sunter Utara No. 27-28, Blok 03 Jakarta – Indonesia
Phone : 62-21-6515188, 65306066, 65304880
Fax     : 62-21-65305066 (Hunting)
E-mail : general_jsr[at]justus[dot]co[dot]id

Factory : Jl. Cakung Cilincing Raya, Jakarta 14130, Indonesia
Phone : 62-21-4400360, 4401616
Fax   : 62-21-4404108


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