CN107164979B - A kind of polyimide carrier dyeing method - Google Patents

Abstract

The invention discloses a polyimide carrier dyeing method, which belongs to the technical field of textile printing and dyeing. The present invention adopts the following process: (1) pretreatment of polyimide fiber fabric to remove impurities attached to the fabric during silk making, weaving and storage; (2) using an organic substance containing an amide structure as a carrier for polyimide dyeing (3) Washing, soaping, and washing the dyed fabric to remove the dyed floating color. In the present invention, the polyimide fabric is dyed with carrier and cationic dye under high temperature conditions, the fabric has a certain color yield, and the dyed fabric has high color fastness to washing.

Description

A kind of polyimide carrier dyeing method

technical field

The invention relates to a polyimide carrier dyeing method, belonging to the fields of textile printing and dyeing auxiliaries and textile dyeing and finishing.

Background technique

Polyimide fiber (formula 1) is a high-strength, high-modulus high-performance fiber. Its excellent mechanical properties, high temperature resistance, chemical resistance, radiation resistance and insulation properties make polyimide fibers widely available. Attention, compared with high-performance fibers such as aramid, polyimide has better comprehensive applicability. Polyimide fiber can be used to develop various protective clothing, can be used as high-temperature filter cotton, high-temperature filter felt, and can also be widely used in special application fields such as aerospace, with considerable application prospects.

The main chain of polyimide contains an imide ring, and the structure is shown in the figure below. The molecular structure of the fiber is very tight, the stereoregularity is good, and the glass transition temperature is above 300 °C, so the dyeing of polyimide fiber is very difficult. Under normal high temperature conditions (100-130°C), the dye cannot enter the interior of the fiber to complete the dyeing. Since the imide structure is not resistant to alkali, polyimide fibers can be hydrolyzed under alkaline conditions to generate polar groups, which can be combined with dyes, but after the fibers are hydrolyzed, the polyimide is destroyed. The original regular structure of the fiber will seriously lose the strength of the fiber and lose the meaning of high-performance fiber. Carrier dyeing is a dyeing method in which a small molecule organic solvent close to the fiber structure is used as a dyeing carrier. The carrier and the fiber are combined with van der Waals force or hydrogen bonding, which weakens the bonding force between the molecular chains in the fiber, increases the cavity inside the fiber, and increases the dye diffusivity and dyeing percentage. With the help of the carrier, the dye can be continuously Enter the fiber and complete the dyeing. Carrier dyeing is a common dyeing process for synthetic fibers. For example, the carriers used in the polyester carrier dyeing process are mostly aromatic alcohols and aromatic esters.

In patents CN201410817952.2 and CN201310493553.0, it is mentioned that the carrier is used to dye polyimide fibers, and the carrier used is the general reagent for dyeing polyester carrier, which is benzyl alcohol, methyl benzoate, acetophenone, methacrylic acid Non-amide structure small molecular organic compounds such as methyl ester; polyimide is treated with alkaline solution before dyeing to hydrolyze polyimide molecules to obtain polar groups, but the strength of the fabric will inevitably be affected to a certain extent after the fiber is hydrolyzed damage, does not meet the requirements of high-performance fibers.

SUMMARY OF THE INVENTION

In view of the chemical molecular structure of polyimide fibers, the present invention mainly selects an organic substance containing an amide structure as a carrier for polyimide dyeing, and excellent dyeing effect can be obtained without an alkaline pretreatment process. The carrier used has a similar structure to the polyimide fiber, which has more affinity with the fiber. The cationic dye dyes the fiber with the help of the carrier, and the color of the fabric after dyeing is dark, the color fastness to washing is high, and the fabric strength is maintained well .

The general structural formula of the carrier for polyimide dyeing provided by the present invention is shown in the following formula (2):

The amide structure endows the carrier with a certain affinity for polyimide fibers, and R ₁ in the carrier structure can be hydrogen, alkyl, aryl, alkoxy, or hydroxyl; R ₂ can be hydrogen, alkyl, aryl, or alkoxy group, hydroxyl; R ₃ can be hydrogen, alkyl, aryl, alkoxy, hydroxyl.

The present invention also provides a method for dyeing polyimide by using the carrier, comprising the following steps:

Step 1, remove the impurities attached to the surface of the polyimide fiber, and dry;

Step 2, adding the polyimide fiber after washing to remove impurities into the dye liquor containing cationic dye and carrier, and dyeing;

Step 3: After the dyeing is completed, the polyimide fiber is washed, soaped and washed with water to remove the floating color of the dyeing.

In one embodiment of the present invention, in step 1, the polyimide fiber is added with 2-3g/L nonionic surfactant and 1-2g/L degreasing agent, such as nonionic surfactant AEO- 7, CT-3 degreaser. The liquor ratio is 20-30:1, and it is treated at 85-95°C for 30-60min, fully washed with water and then dried.

In an embodiment of the present invention, in step 2, the dried polyimide fibers are added to a dye liquor containing a carrier and a cationic dye, and the bath ratio of the dye liquor to the fiber fabric is (15:1)～ (30:1); the weight (owf) of the cationic dye to the fiber fabric is 2.5%-10%; the carrier is a compound of one or more of the carriers in the present invention, and the carrier concentration is 10-100g/ L.

In one embodiment of the present invention, in step 2, the polyimide fiber after washing and removing impurities is added to the dye liquor containing carrier and cationic dye, and the temperature is raised to 120-130 °C at a speed of 1.5-3 °C/min. ℃, keep warm for 40-120min.

In an embodiment of the present invention, in step 3, after the dyeing is completed, the polyimide fiber is added to a solution containing soaping agent and sodium carbonate, the bath ratio is 20:1-30:1, and the treatment is carried out at 85°C. Wash thoroughly after 15 minutes. The soaping agent is a nonionic surfactant, such as AEO-7, the concentration is 2-3g/L, and the concentration of sodium carbonate is 2-3g/L.

Using the carrier provided by the invention to dye the polyimide fiber does not require complicated pretreatment process, the dyeing amount is large, the fading fastness of the obtained polyimide fabric is improved, and the strength is not significantly reduced compared with before dyeing .

Detailed ways

Example 1

A substance in which R ₁ is phenyl, R ₂ is methyl, and R ₃ is hydrogen is selected as the carrier.

Take 2g of polyimide knitted fabric, put it into a solution containing nonionic surfactant AEO-7 (2g/L) and degreaser CT-3 (1g/L), the bath ratio is 30:1, at 95 Treated at ℃ for 30min, fully washed and dried.

The polyimide fabric washed and removed from impurities was placed in a carrier dye solution containing 5% cationic red SD-GRL and 50g/L by weight of the fabric, wherein the bath ratio of the dye solution and the fabric was 15:1, and the temperature was 1.5°C. The temperature was raised to 120 °C for 40 min at a rate of /min.

After the dyeing is completed, the fabric is placed in a soaping solution containing 2g/L of nonionic surfactant AEO-7 and 2g/L of sodium carbonate, the bath ratio is 20:1, and the fabric is fully treated at 85°C for 15min. Washed and dried.

The color parameters and washing fastness of the dyed samples are shown in Table 1.

Example 2

A substance in which R ₁ is methyl, R ₂ is methyl, and R ₃ is hydrogen is selected as the carrier.

Take 2g of polyimide knitted fabric, put it into a solution containing nonionic surfactant AEO-7 (2g/L) and degreaser CT-3 (1g/L), the bath ratio is 30:1, at 95 Treated at ℃ for 30min, fully washed and dried.

The polyimide fabrics washed to remove impurities were put into the carrier dye liquor containing 5% cationic blue SD-GSL and 50g/L by weight of the fabric, wherein the bath ratio of the dye liquor and the fabric was 30:1, and the temperature was 3°C. The temperature was increased to 130 °C for 120 min at a rate of /min.

After the dyeing is completed, the fabric is placed in a soaping solution containing 2g/L of nonionic surfactant AEO-7 and 2g/L of sodium carbonate, the bath ratio is 20:1, and the fabric is fully treated at 85°C for 15min. Washed and dried.

The color parameters and washing fastness of the dyed samples are shown in Table 1.

Example 3

A substance in which R ₁ is phenyl, R ₂ is methyl, and R ₃ is hydrogen and a substance in which R ₁ is methyl, R ₂ is methyl, and R ₃ is hydrogen are selected as carriers.

Take 2g of polyimide knitted fabric, put it into a solution containing nonionic surfactant AEO-7 (2g/L) and degreaser CT-3 (1g/L), the bath ratio is 30:1, at 85 Treated at ℃ for 30min, fully washed and dried.

The polyimide fabrics washed to remove impurities were put into a carrier containing 5% cationic red SD-GRL and 5% cationic blue SD-GSL and 100g/L by weight of the fabric (the two carriers were 50g/L each), The bath ratio of dye liquor and fabric was 20:1, and the temperature was raised to 120°C at a rate of 2°C/min for 40 minutes.

After the dyeing is completed, the fabric is placed in a soaping solution containing 2g/L of nonionic surfactant AEO-7 and 2g/L of sodium carbonate, the bath ratio is 30:1, and the fabric is fully treated at 85°C for 15min. Washed and dried.

The color parameters and washing fastness of the dyed samples are shown in Table 1.

Comparative Example 1

Take 2g of polyimide knitted fabric, put it into a solution containing nonionic surfactant AEO-7 (2g/L) and degreaser CT-3 (1g/L), the bath ratio is 30:1, at 95 Treated at ℃ for 30min, fully washed and dried.

Put the washed and removed polyimide fabric into cationic red SD-GRL containing 5% of the fabric weight, in which the liquor ratio of dye liquor and fabric is 15:1, and the temperature is raised to 130 °C at a speed of 1.5 °C/min. 60min.

After the dyeing is completed, the fabric is placed in a soaping solution containing 2g/L of nonionic surfactant AEO-7 and 2g/L of sodium carbonate, the bath ratio is 20:1, and the fabric is fully treated at 85°C for 15min. Washed and dried.

Table 1 CIE Lab, K/S, washing fastness grade and strength after dyeing with polyimide fabric carrier

Note: Color fastness and staining fastness are determined according to the textile color fastness test standard GB/T 3921-2008; the breaking strength is the yarn strength, according to the testing standard GB/T 3921-2008 T 3916-2013 determination.

As can be seen from the data in Table 1, other dyeing conditions are exactly the same, when using carrier (Example 1) and dyeing without carrier (Comparative Example 1), the difference between the CIELab values of carrier-dyed fabrics and undyed fabrics is less than that without carrier dyeing. If the fabric is large, it means that the color change of the carrier-dyed fabric is greater than that of the non-carrier-dyed fabric, that is, the dye uptake is large. At the same time, the fading fastness of carrier dyed polyimide fabric is improved.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Anyone who is familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, The protection scope of the present invention should be defined by the claims.

Claims (5)

1. a method for carrying out carrier dyeing to polyimide, is characterized in that, with the organic substance containing amide structure as the carrier of polyimide dyeing, comprises the steps: Step 1, remove the impurities attached to the surface of the polyimide fiber, and dry; Step 2, adding the polyimide fiber after washing to remove impurities into the dye liquor containing cationic dye and carrier, and dyeing; Step 3: After the dyeing is completed, the polyimide fiber is washed, soaped, and washed to remove the floating color; The general structural formula of the carrier is shown in the following formula (2): wherein, R ₁ is phenyl, R ₂ is methyl, and R ₃ is hydrogen; or R ₁ is methyl, R ₂ is methyl, and R ₃ is hydrogen; or R ₁ is phenyl, and R ₂ is methyl, R ₃ is hydrogen and R ₁ is methyl, R ₂ is methyl, and R ₃ is hydrogen; the carrier is a combination of one or both of formula (2). 2. a kind of method that polyimide is carried out carrier dyeing according to claim 1, is characterized in that, step 1, polyimide fiber adds and contains 2-3g/L nonionic surfactant and 1-2g /L degreaser, the liquor ratio is 20-30:1, treated at 85-95 ℃ for 30-60min, fully washed and dried. 3. a kind of method that polyimide is carried out carrier dyeing according to claim 1 and 2, it is characterized in that, step 2, the polyimide fiber after drying is added to the dyeing containing carrier and cationic dyestuff In the liquid, the bath ratio of the dye liquor and the fiber fabric is (15:1)～(30:1); the weight of the cationic dye to the fiber fabric is 2.5%-10%, and the carrier concentration is 10-100g/L. 4. a kind of method that polyimide is carried out carrier dyeing according to claim 1, is characterized in that, in step 2, the polyimide fiber after washing and removing impurities is added to the dye liquor containing carrier and cationic dye , the temperature was raised to 120-130°C at a rate of 1.5-3°C/min, and the temperature was maintained for 40-120min. 5. a kind of method that polyimide is carried out carrier dyeing according to claim 1 and 4, it is characterized in that, step 3, after dyeing is finished, polyimide fiber is added to containing soaping agent and sodium carbonate In the solution, the bath ratio is 20:1-30:1, and it is fully washed with water after being treated at 85°C for 15min.