Product Introduction

For zinc plating and zinc alloy plating
Trivalent Chromium Passivation Agent Tryner Series
Nippon Hyomen Kagaku Kabushiki Kaisha R & D center

Introduction

zinc itself is easily corroded, so appearance is impaired in a

Since steel members are inexpensive and easy to process,short period in the case of only by zinc plating the steel

they are used in various fields including automobiles,

member. In addition, if the corrosion of zinc proceeds andelectric products, building materials, etc. However,disappears from the surface of the steel member, the "untreated steel members are susceptible to rust and cannot

sacrificial protection" effect is also lost at the same time.1

maintain aesthetics and mechanical strength for a long

Therefore, it is necessary to protect the zinc plating film

period of time. Therefore, it is common for steel members toitself, a representative means is "chemical conversion film

be subjected to rust prevention treatment.

treatment". In the past, "chromate treatment" using

Zinc plating is widely used as a typical rust prevention

hexavalent chromium was used, but the use of hexavalenttreatment for steel because it has a "sacrificial protection"

chromium was regulated by the ELV Directive*1, which waseffect to suppress corrosion of steel members by preferential

implemented in 2000, and RoHS Directive*2, which wascorrosion of zinc, which has a larger ionization tendency

implemented in 2006. In recent years, "chromate treatment"

than steel in a corrosive environment.

has shifted to "trivalent chromium passivation", which does

Zinc exhibits excellent anticorrosive effect on steel, while

not use hexavalent chromium. "Trivalent chromium

Table 1: Lineup of TrynerProduct name

Plating type

Treatment
appearance

Features

Tryner TR-160 SeriesBlue iridescent

Organic acid-free, uniform blue appearance

Tryner TR-162 Series

color

Organic acid type, good impure metal resistanceTryner TR-173 Series

White to yellow

Tryner TR-175 Series
Tryner TR-177

Zinc plating

iridescent color

Tryner TR-184 SeriesBlack

Tryner TR-186 Series
Tryner TR-187 Series

JASCO 5W115 Series
Tryner TRF-930
Tryner TRF-966 Series

Inorganic silica type, outstanding red rust resistance
Easy wastewater treatment
For rack plating

Tryner TR-185 Series

Triner TRN-988 Series

Organic acid type, easy to manageFor barrel plating
For barrel plating, high rust prevention specification
For rack plating, cobalt-free

Zinc-nickel
alloy plating

Zinc-iron alloyplatingBlue iridescentHighest corrosion resistance among zinc-based

colorplating

Black

Adapted for high-nickel eutectoid baths.

White to yellow
iridescent colorBlack

Organic acid type
Ideal for JASCO Stronzinc
202010301 JASCO Nippon Hyomen Kagaku Kabushiki Kaisha 1

[Product Introduction] Tryner Seriespassivation" is one in which a member which is zinc plating

easy to perform automated management.

or zinc alloy plating in a treatment liquid containing trivalentchromium is immersed, and a thin film is formed on theTreatment process

plating surface by a chemical reaction. The treatment

The processing step of the trivalent chromium

appearance is roughly classified into "white system" andpassivation is described (Figure 1). Treatment process is"black system", and those in which a pale iridescent color

different in white and black systems, and post dip treatment

film of blue to yellow is obtained are set as a white system,is necessary for corrosion resistance stabilization and color

and those in which a black film is obtained are set as a blacktone stabilization in the case of black system.

system. There are two main types of white system, anorganic acid type that chelate metal ions in the treatment

Mechanisms

liquid with an organic acid and inorganic silica type that

The trivalent chromium passivation protects the plating

does not contain an organic acid in the treatment liquid andlayer of the base by its own barrier effect. However, sincecontains colloidal silica.

the trivalent chromium conversion film is a thin film,

We have a lineup of the trivalent chromium passivation

microscopic damage due to scratches is unavoidable.

agent is optimized according to the plating type, the plating

Therefore, it has a "self-healing function" in which the film

method, the required performance, etc., as a "Tryner" series.

regenerating component held in the film at the time ofscratching elutes and repairs the damaged portion. Organic

Product Summaryacid type trivalent chromium passivation represented by theJASCO Tryner series is a trivalent chromium passivation

Tryner TR-173 series shows excellent self-healing property

agent for electro-galvanizing/electro-galvanizing alloy

because the existence of organic acid improves the holding

plating. Film appearance such as blue iridescent color,

power of the film regeneration component. On the otherwhite to yellow iridescent color, and black color can behand, the inorganic silica type trivalent chromium

obtained, and it is possible to meet various quality

passivation film represented by the Tryner TR-175 and TR-

requirements (Table 1).

177 series has a stable and high-rust prevention capability
with our proprietary system. The film of the Tryner TR-175

Features of the Tryner Series

and TR-177 has a two-layer structure in which silicon,

・Hexavalent chromium is not contained.

oxygen (present as silica) is present in the upper layer, and・A trivalent chromium coating can be formed only byoxides such as chromium, cobalt, and zinc, and hydroxides

immersion treatment.
・Can accommodate various conditions such as line

are present in the lower layer. It should be noted that a major
feature is that such a two-layer structure can be constructedby one dip2 (Figure 2).

characteristics.
・It can be managed by concentration analysis, and it isWhite
systemBlacksystem

Figure 1: General Post-Treatment Process of Zinc Plating and Zinc Alloy Plating
202010301 JASCO Nippon Hyomen Kagaku Kabushiki Kaisha 2

[Product Introduction] Tryner Series
upper layer

lower layer

silicon and oxygen layer

metal componentlayer

increasing in our lineup.
JASCO Tryner series has evolved through constantzinc plating layer

research and development and continues to respond tochanging market needs.

*1: ELV (End of Life Vehicles) Directive
The EU banned the use of hexavalent chromium, lead,
mercury, and cadmium in marketed vehicles after July 1,2003. As an exception, up to 2 g/unit of hexavalentchromium was permitted until June 2007.
Figure 2: Tryner TR-175 Depth profile by XPS*2: RoHS (Restriction of hazardous Substances) Directive
Electrical and electronic products that will be put on theThe silica rich layer of the upper layer is formed by themarket in the EU since July 2006 should not contain lead,aggregation of colloidal silica, and this lowers the corrosion

mercury, cadmium, hexavalent chromium, polybrominatedratebiphenyls, or polybrominated diphenyl ethers

bydispersing

thecorrosion

current

without

concentrating on the damaged part. The synergistic effect of
this "corrosion

current dispersion

effect" andthe*3: REACH (Registration, Evaluation, Authorization andaforementioned "self-healing function" realizes surprising

Restriction of Chemicals) Regulation

corrosion resistance.

Producers and importers are required to investigate theIn addition, the trivalent chromium black passivation

effects of all chemicals (1 ton/year or more) on humanity

produces a blackening component during the reaction, andand the earth and to apply and register them with theby incorporating it into the film, a black appearance isEuropean Chemicals Agency. Furthermore, it is necessary toobtained. Though trivalent chromium black passivation film

apply for a permit from the European Chemicals Agency foralso has rust prevention mechanism by barrier effect andthe use of the regulated substances that have been publicly

self-healing function, it is necessary to complement these by

disclosed and obtain a permit. It entered into force in 2007.

post dip treatment because rust prevention power and luster
in appearance are deteriorated by the effect of blackening
component incorporated into the film.

References
1. ELECTROPLATER’S TECHNICAL ASSOCIATION;In closing
JASCO Tryner series offers a lineup of products that canGendaimekkikyouhon, first edition 4 printing, p. 371(2014)

meet all the needs of zinc plating and zinc alloy plating over

2. Hideo Susa; J. Surf. Finish. Soc. Jpn. Vol.70, No. 8, pp.

many years of sales, and is used in a wide range of388-393 (2019)

applications, including automobiles, electrical machinery,and building materials, with excellent performance andmanageability.
At present, many trivalent chromium passivation agents
contain cobalt to strengthen their self-healing function, butthe need for cobalt-free treatment is also increasing due toissues such as REACH regulations*3, dispute metals, andrare metals, so the cobalt-free treatment agent is also202010301 JASCO Nippon Hyomen Kagaku Kabushiki Kaisha 3