Nippon Kayaku (Thailand) CO., LTD.
Technical Service Center[Kayacryl ED color fastness to natural sunlight]
Dyeing Recipe: Grey
Trichroma ① (Recommended trichroma)
KAC Yellow 3RL-ED
0.052
KAC Red GL-ED
0.041
KAC Blue BG-ED(N)0.063「Dyeing Conditions」
Material
Liquor ratiopH
Na2SO4Trichroma ②
KAC Yellow 3RL-ED
KAC Red GRL-ED
KAC Blue BG-ED(N)

0.059
0.032
0.061

CDP 100%
20:1
pH 4.2 (acetic acid + sodium acetate) & pH 3.2 (acetic acid 1 cc/L)
0 g/L & 3g/L

「Irradiation Conditions」
・ JIS Carbon-arc:
Grade 4 irradiation
・ JIS Xenon-arc:
Grade 4 irradiation
・ Sunlight
3 days、5 days、7 days (Irradiation time 07:30～15:00)
Sunlight Exposure Condition
Date

Maximum Temperature

WeatherWind

2022/08/03

Clear

Slight winds(Alcohol Thermometer)
50℃ (13:00)

2022/08/09

Clear

Somewhat strong winds

44℃ (12:00)

2022/08/10

Clear

Somewhat strong winds

43℃ (13:00) 3 days

2022/08/19

Clear

Slight winds

45℃ (11:30)

2022/08/29

Clear – Partly Cloudy

Slight Breeze

35℃ (12:00) 5 days

2022/09/05

Clear

Slight winds

42℃ (11:30)

2022/09/12

Clear

No winds to light breeze

38℃ (14:00) 7 days

「Result」
・ The results for both trichroma ① and trichroma ② can be summarized as below:
・ For both trichromas, there is no difference in light fastness with addition of Glauber’s salt for pH 4.2 dyeing(acetic acid + sodium acetate).
・ In the case of pH 3.2 dyeing (1 cc/L acetic acid), the light fastness with addition of Glauber’s salt is considerably
higher than that without addition of Glauber’s salt (caused by CDP embrittlement).
・ On the other hand, comparing both trichromas, they differ in the following properties:➢ Trichroma ①: pH 4.2, 3g/L of Glauber’s salt added, the light fastness after 3 days of sunlight irradiation(high temperature in summer) is grade 3, and grade 2 after 7 days of irradiation (Reference: JIS Carbon
Arc Grade 4, JIS Xenon Arc Grade 4-5).
➢ Trichroma ②: (same conditions as above) pH 4.2, 3g/L of Glauber’s salt added, the light fastness after 3
days of sunlight irradiation (high temperature in summer) is grade 2-3, and grade 1 after 7 days ofirradiation (Reference: JIS Carbon Arc Grade 4, JIS Xenon Arc Grade 2-3).
➢ Trichroma ② has good light fastness of Grade 4 under Carbon Arc Irradiation, but has poor light fastness
NIPPON KAYAKU (THAILAND) CO., LTD.
ADD: 13th Floor, Ramaland Building, 952 Rama IV road, Suriyawongse, Bangrak, Bangkok 10500
TEL: +66-2-235-2843 HP: http://www.kayakuth.co.th

・of Grade 2-3 under Xenon Arc Irradiation, and the hues after discoloration and fading are also verydifferent.
➢ In addition, the sunlight irradiation results of the trichroma ② is similar to the Xenon irradiation result.
This means that the Xenon irradiation result is closer to the phenomenon that can actually occur in market.
The image below shows the discoloration issue that can actually occur in the market introduced in vol.01 ofTechnical Information.
「Consultation: Store with CDP/PET product experienced Red fading」
・ There was a consultation by an apparel store regarding red fading on theirproducts.
・ There was no problem with Carbon-arc light fastness.
・ The dyeing factory and dye used are unknown, possibly overseas.
「Diagnosis」
・ Red is faded and if it is due to heat, the dye responsible for fading is usually
blue cationic dye.
・ This is a common phenomenon that can occur when KAC Red GRL is used
as a Red component for CDP fabrics.
「Comment」
・ This phenomenon cannot be reproduced with Carbon-arc Light fastness
test.
・ This phenomenon can be reproduced with Xenon-arc Light fastness test
or exposure to sunlight.
・ This phenomenon does not occur in Acrylic fabrics.

Red is faded「Consultation: Store with CDP/PET product experienced Red fading」
・ The phenomenon was reproduced with Xenon-arc.
「Recommended Nippon Kayaku trichromatic colors」① KAC Yellow 3RL-ED, KAC Red GL-ED, KAC Blue BG-ED(N)-Generally recommended trichromatic colors② KAC Yellow 3RL-ED, KAC Red GL-ED, KAC Blue TL-ED-High light fastness trichromatic colors

Xenon
irradiated part・・ KAC Red GL-ED is recommended for pale shades to reduce thisproblem for CDP fabrics.

Cationic Red with similar structure as KAC Red GRL-ED is the cause of this phenomenon. When CDP fibers aredyed with this type of Red, it may pass Carbon lightfastness standard, but it will be inferior in lightfastness tosunlight, so there is risk of fading at stores and end users.

「Considering the result of this time」
・ We recommend dyeing at pH 4-5 with addition of Glauber’s salt to reduce CDP embrittlement.
・ Carbon and Xenon lightfastness of trichroma ② (KAC Yellow 3RL-ED, Red GRL-ED, Blue BG-ED(N)) candiffer greatly due to the behavior of the Cationic Red.
・ Cationic Reds similar to Kayacryl Red GRL-ED are widely used for both Acryl and CDP dyeing. At our workplace,
we have received two complaints about discoloration of CDP-dyed fabric caused by these types of reds in the past.
(Curtain material & above image phenomenon)・ In Japan, many apparels use JIS Carbon standard for light fastness, but even if the Carbon light fastness standard iscleared, unexpected fading can occur in actual sunlight. Please see the test results on the next page as reference.

NIPPON KAYAKU (THAILAND) CO., LTD.
ADD: 13th Floor, Ramaland Building, 952 Rama IV road, Suriyawongse, Bangrak, Bangkok 10500
TEL: +66-2-235-2843 HP: http://www.kayakuth.co.thCDP dyeing: Dyeing Condition and Light Fastness (Carbon-arc, Xenon-arc, Sunlight)
Judged with Grey Scale
Recipe: KAC Yellow 3RL-ED 0.052

KAC Red GL-ED 0.041

pH 4.2 (Acetic Acid + Sodium Acetate)
Glauber’s salt: None

Glauber’s salt: 3g/L

KAC Blue BG-ED(N) 0.063 %o.w.f.
pH 3.2 (Acetic Acid 1cc /L)
Glauber’s salt: None

Glauber’s salt: 3g/L

JIS Carbon-arc
Grade 4

JIS Xenon-arc
Grade 4Sunlight
7.5h

3 daysSunlight
7.5h

5 daysSunlight
7.5h

7 dayspH 4.2 (Acetic Acid + Sodium Acetate)

Glauber’s salt: None

Glauber’s salt: 3g/L

pH 3.2 (Acetic Acid 1cc /L)

Glauber’s salt: None

Glauber’s salt: 3g/L

JIS Carbon-arc
Grade 4

JIS Xenon-arc

Grade 4Sunlight
7.5h

3 daysSunlight
7.5h

5 daysSunlight
7.5h

7 daysNIPPON KAYAKU (THAILAND) CO., LTD.
ADD: 13th Floor, Ramaland Building, 952 Rama IV road, Suriyawongse, Bangrak, Bangkok 10500
TEL: +66-2-235-2843 HP: http://www.kayakuth.co.thCDP dyeing: Dyeing Condition and Light Fastness (Carbon-arc, Xenon-arc, Sunlight)Judged with Grey Scale
Recipe: KAC Yellow 3RL-ED 0.059

KAC Red GRL-ED 0.032

pH 4.2 (Acetic Acid + Sodium Acetate)
Glauber’s salt: None

Glauber’s salt: 3g/L

KAC Blue BG-ED(N) 0.061 %o.w.f.
pH 3.2 (Acetic Acid 1cc /L)
Glauber’s salt: None

Glauber’s salt: 3g/L

JIS Carbon-arc
Grade 4

JIS Xenon-arc
Grade 4Sunlight
7.5h

3 daysSunlight
7.5h

5 daysSunlight
7.5h

7 dayspH 4.2 (Acetic Acid + Sodium Acetate)

Glauber’s salt: None

Glauber’s salt: 3g/L

pH 3.2 (Acetic Acid 1cc /L)

Glauber’s salt: None

Glauber’s salt: 3g/L

JIS Carbon-arc
Grade 4

JIS Xenon-arc

Grade 4Sunlight
7.5h

3 daysSunlight
7.5h

5 daysSunlight
7.5h

7 daysNIPPON KAYAKU (THAILAND) CO., LTD.
ADD: 13th Floor, Ramaland Building, 952 Rama IV road, Suriyawongse, Bangrak, Bangkok 10500
TEL: +66-2-235-2843 HP: http://www.kayakuth.co.th