GB/T 21888-2023C.I. Acid red 131 (Acid brilliant red P-9B 150%) (English PDF)

4.1

The quality of C.I. Acid red 131 (Acid brilliant red P-9B 150%) shall comply with Table 1.

Table 1 - Quality requirements for C.I. Acid red 131 (Acid brilliant red P-9B 150%) (No. - item: requirement; test method):

1 - Appearance: deep red uniform powder or granules; 6.1

2 - Strength (relative to the standard), points: 100; 6.2

3 - Shade (compared with the standard), visual: approximately to slightly different; 6.2

3 - Shade (compared with the standard), instrumental (D65 illuminant) (a): DE <= 0.50; DC -0.30 to 0.30; DH -0.30 to 0.30; 6.2

4 - Moisture (mass fraction), % <= 8.0; 6.3

5 - Water-insoluble matter (mass fraction), % <= 0.2; 6.4

6 - Solubility (90 °C), g/L >= 50; 6.5

7 - Dusting behaviour, grade >= 3; 6.6

8 - Harmful aromatic amines (mass fraction), mg/kg: shall comply with GB 19601 and GB/T 24101; 6.7

9 - Heavy metal elements (mass fraction), mg/kg: shall comply with GB 20814; 6.8

(a) Whether the instrumental shade indicator is controlled is agreed between the supplier and the purchaser.

4.2

The colour fastness of C.I. Acid red 131 (Acid brilliant red P-9B 150%) on polyamide fabric shall be not lower than the grades specified in Table 2.

Table 2 - Colour fastness of C.I. Acid red 131 (Acid brilliant red P-9B 150%) on polyamide fabric, at 1/1 standard depth (grades):

Light (xenon arc): 3

Soaping, 50 °C: change in colour 3-4; staining of cotton 4; staining of polyamide 4-5

Perspiration, acid: change in colour 4-5; staining of cotton 4-5; staining of polyamide 4

Perspiration, alkaline: change in colour 4-5; staining of cotton 3; staining of polyamide 3

Water: change in colour 4-5; staining of cotton 3-4; staining of polyamide 3

Rubbing: dry 4-5; wet 4-5

Hot pressing, 180 °C: change in colour (after 4 h) 4-5

Chlorinated water, effective chlorine 50 mg/L: 4-5

Note: 1.0% (owf) corresponds to the 1/1 standard depth.

6.1 Assessment of appearance

Assess visually under natural north daylight.

6.2 Determination of shade and strength

6.2.1 Dye standard

The dye standard is the reference sample used for the determination of shade and strength; it is agreed between the supplier and the purchaser and sealed jointly by them.

6.2.2 Polyamide dyeing method (referee test method)

6.2.2.1 General dyeing conditions

The general dyeing conditions shall comply with the relevant provisions of GB/T 2374-2017. The dyeing is carried out as specified in 6.2 of GB/T 2378-2012.

The dyeing depth is 0.5% (owf); 4 g of polyamide fabric is used (2 g or another mass of fabric may be used if necessary), with a liquor ratio of 1:50 (another liquor ratio may be chosen according to the actual situation, provided level dyeing is ensured).

6.2.2.2 Preparation of the dyebath

Taking 4 g of fabric, a liquor ratio of 1:50 and an ordinary dyeing machine as an example, prepare the dyebaths in 5 dyeing beakers as specified in Table 3.

Table 3 - Preparation of the dyebath (volume of each component in the dyebath, in millilitres, beakers 1 / 2 / 3 / 4 / 5):

0.5 g/L standard solution: 38 / 40 / 42 / - / -

0.5 g/L sample solution: - / - / - / 38 / 40

50 g/L ammonium acetate solution: 4 / 4 / 4 / 4 / 4

Water: 158 / 156 / 154 / 158 / 156

6.2.2.3 Dyeing procedure

Proceed as specified in 6.2.4 of GB/T 2378-2012, raising the temperature at a rate of 1 °C/min, and continue dyeing at 90 °C to 95 °C for 30 min.

6.2.2.4 Assessment of shade and strength

Proceed in accordance with the relevant provisions of 7.1 of GB/T 2374-2017.

6.2.3 Wool dyeing method

6.2.3.1 General dyeing conditions

The general dyeing conditions shall comply with the relevant provisions of GB/T 2374-2017. The dyeing is carried out by the weak acid dyeing method specified in Table 1 of GB/T 2378-2012.

The dyeing depth is 0.5% (owf); 4 g of wool gabardine or wool yarn is used (2 g or another mass of fabric may be used if necessary), with a liquor ratio of 1:50 (another liquor ratio may be chosen according to the actual situation, provided level dyeing is ensured).

6.2.3.2 Preparation of the dyebath

Taking 4 g of fabric, a liquor ratio of 1:50 and an ordinary dyeing machine as an example, prepare the dyebaths in 5 dyeing beakers as specified in Table 4.

Table 4 - Preparation of the dyebath (volume of each component in the dyebath, in millilitres, beakers 1 / 2 / 3 / 4 / 5):

0.5 g/L standard solution: 38 / 40 / 42 / - / -

0.5 g/L sample solution: - / - / - / 38 / 40

100 g/L anhydrous sodium sulfate solution: 4 / 4 / 4 / 4 / 4

10 g/L acetic acid solution: 2 / 2 / 2 / 2 / 2

Water: 156 / 154 / 152 / 156 / 154

6.2.3.3 Dyeing procedure

Proceed as specified in 6.1.4 of GB/T 2378-2012, holding at 90 °C to 95 °C for 30 min of dyeing.

6.2.3.4 Assessment of shade and strength

Proceed in accordance with the relevant provisions of 7.1 of GB/T 2374-2017.

6.3 Determination of moisture

Proceed as specified for the oven-drying method in 3.2 of GB/T 2386-2014.

6.4 Determination of water-insoluble matter

Proceed as specified for water-soluble dyes in GB/T 2381-2013.

6.5 Determination of solubility

Proceed as specified in GB/T 3671.1-1996, at a dissolution temperature of 90 °C ± 2 °C.

6.6 Determination of dusting behaviour

Proceed as specified in GB/T 6693-2009.

6.7 Determination of harmful aromatic amines

Proceed as specified in GB 19601 and GB/T 24101.

6.8 Determination of heavy metal elements

Proceed as specified in GB 20814.

6.9 Determination of colour fastness on polyamide fabric

6.9.1 General

All colour fastness test specimens shall be dyed to the 1/1 standard depth as specified in GB/T 4841.1-2006.

6.9.2 Colour fastness to rubbing

Proceed as specified in GB/T 3920-2008.

6.9.3 Colour fastness to soaping

Proceed as specified in GB/T 3921-2008. The test conditions are those of test method B(2) in Table 2 of GB/T 3921-2008.

6.9.4 Colour fastness to perspiration

Proceed as specified in GB/T 3922-2013.

6.9.5 Colour fastness to water

Proceed as specified in GB/T 5713-2013.

6.9.6 Colour fastness to hot pressing

Proceed as specified in GB/T 6152-1997, dry pressing at 180 °C (assessment after 4 h).

6.9.7 Colour fastness to light

Proceed as specified in GB/T 8427-2019.

6.9.8 Colour fastness to chlorinated water

Proceed in accordance with the relevant provisions of GB/T 8433-2013. The working solution is prepared as specified in 5.3 of GB/T 8433-2013.

7.1 Inspection categories

Inspection is divided into type inspection and delivery inspection.

All the items listed in Clause 4 are type inspection items. Items 1 to 7 of Table 1 are delivery inspection items and shall be inspected batch by batch.

7.2 Type inspection

Under normal continuous production, type inspection shall be carried out at least once a year. Type inspection shall also be carried out in the following cases:

a) when a new product is first finalised;