JP7828080B2 - Method for pretreating synthetic fiber structures suitable for dyeing with pigment dispersion compositions - Google Patents

Description

The present invention relates to a method for pretreating synthetic fiber structures suitable for dyeing using a pigment dispersion composition for exhaust dyeing containing a cationizing agent.

Pigments have excellent light and chemical resistance and are easy to dye into fibers, so in recent years they have been used to dye various textile materials. Known methods for continuously dyeing (coloring) fibers include (1) the gradual immersion method, in which fibers are immersed in an aqueous pigment dispersion and the pigment is allowed to dye the fibers; and (2) the padding method, in which fibers are immersed in an aqueous pigment dispersion and then pressed with a roll to remove excess dispersion.

In these pigment dyeing methods, the pigment physically adheres to the surface of the fiber, making it prone to falling off during washing and other processes. Therefore, to prevent this, a binder is typically used to fix the pigment. Known methods for using such binders include a method in which the pigment is attached to the fiber material and then brought into contact with the binder (Patent Document 1), and a method in which the binder is mixed into an aqueous dispersion of the pigment when dyeing the fiber material with the pigment (Patent Document 2).

On the other hand, when dyeing a fabric, textile, or other object to be dyed with a dye, there is also a pretreatment method in which the object is first cationized with a pretreatment solution containing a cationizing agent, and then anionized with a pretreatment solution containing an anionizing agent (Patent Document 3). With this method, the anionizing agent can be used to dye, for example, a high concentration of a metal mordant, making it possible to dye plants and trees up to extremely dark colors in a single dyeing process.

Japanese Patent Application Publication No. 10-310718 Japanese Patent Application Publication No. 10-259579 Japanese Patent Application Laid-Open No. 2006-138050

Patent Document 1 describes a process in which a textile material is dyed using a cationic aqueous pigment dispersion composition and then treated with a binder. Specifically, the textile material is dyed with the cationic aqueous pigment dispersion composition and then washed with water. The resulting dyed textile material is immersed in a binder liquid and subjected to a so-called squeezing process, followed by drying and curing, and optionally post-processing using enzymes or other additives, and then dried to obtain a dyed textile product. The squeezing process involves squeezing out excess binder liquid from a large amount of the binder liquid absorbed into the textile material using a roller, centrifuge, or other device to adjust the amount of binder resin adhering to the textile material. However, in general, during the squeezing process, the binder resin contained in the binder liquid ultimately absorbed into the textile material is adsorbed onto the textile material. Therefore, to increase the amount of binder resin adhering to the textile material, it is necessary to increase the amount of binder liquid absorbed or the concentration of the binder resin. However, increasing the absorption amount increases the heating load in the subsequent drying process, and increasing the binder resin concentration increases the amount of raw materials used and the amount of unabsorbed binder resin to be discarded, resulting in problems in terms of production costs and environmental impact. Furthermore, with such conventional binder treatment processes, it is difficult to control the amount of binder resin attached to the fiber material, resulting in problems such as unstable attachment amounts. Furthermore, in terms of quality, there are cases where the binder is not sufficiently effective in fixing the pigment to the fiber.

Patent Document 2 discloses a dyeing process in which cationized textile material is immersed in a water bath containing a synthetic resin emulsion, pigment, and a nonionic surfactant with a cloud point of 25-58°C, and the bath is heated to the cloud point of the nonionic surfactant, causing the synthetic resin and pigment to be adsorbed onto the textile material. However, this method raises concerns about equipment contamination because dyeing with the pigment and binder treatment with the synthetic resin are carried out simultaneously.

In Patent Document 3, the pretreated object to be dyed is made of natural fibers such as cotton fabric or thread, and the pretreated object is immersed in an aqueous solution containing aluminum acetate (mordant solution) to undergo a metal mordant treatment. The pre-mordant product is then immersed in a natural dye solution obtained from dried sophora japonica (Xanthomonas sophora) flower buds to dye it. However, Patent Document 3 does not disclose any dyeing of fiber structures made of synthetic fibers (structures made of fibers such as T-shirts, woven fabrics, or flags) or dyeing using pigments.

Here, structures made of synthetic fibers have low dyeability, not only when using coloring liquids containing dyes but also when using dyeing methods that use pigment dispersion compositions, and are prone to discoloration (color loss) when washed with water after dyeing, resulting in problems such as insufficient final dye concentration and the occurrence of dye spots.

The present invention aims to provide a pretreatment method for synthetic fiber structures that is suitable for dyeing using a pigment dispersion composition, and enables dyeing with little color loss and excellent dye leveling.

The inventors continued to study methods for dyeing synthetic fiber structures using pigment dispersion compositions. They discovered that by first cationic-treating and then anionic-treating a synthetic fiber structure prior to dyeing, dyeing depth can be improved when dyeing using a pigment dispersion composition containing a specific pigment and a tertiary amine cationizing agent, leading to the completion of the present invention.

Specifically, the present invention provides:
1. A method for pretreating a synthetic fiber structure suitable for dyeing with a pigment dispersion composition, comprising:
a step A of immersing a synthetic fiber structure in a cationizing agent to perform a cationization treatment;
and step B of adding an anionizing agent to the cationizing agent in which the synthetic fiber structure is immersed, thereby anionizing the synthetic fiber structure.
The pretreatment method is characterized in that the synthetic fiber structure is not dehydrated or washed between the step A and the step B.

If the pretreatment method for dyed objects disclosed in Patent Document 3 is simply applied to a dyeing method in which a fiber structure made of synthetic fibers such as polyester is dyed with an aqueous pigment dispersion composition, the dyeability of the pigment will be insufficient, causing discoloration upon washing with water and resulting in dye spots. However, with the pretreatment method of the present invention, discoloration of the pigment occurs upon washing with water and dye spots are less likely to occur.

Here, the term "synthetic fiber structure" in this invention includes fiber structures composed only of synthetic fibers, as well as fiber structures composed of both natural and synthetic fibers.

the anionizing agent is a polyester-based anionizing agent,
The cationizing agent is preferably an acrylamide-based cationizing agent.

It is more preferable that the cationizing agent contains a quaternary ammonium salt.

It is preferable that the synthetic fiber structure is composed of one or more fibers selected from the group consisting of polyester fibers, nylon fibers, rayon fibers, acrylic fibers, polyethylene/polyurethane blended fibers, and cotton/polyester blended fibers.

The pigment dispersion composition is
containing at least a pigment, a cationizing agent, a solvent, and water;
the pigment is an organic pigment or carbon,
The cationizing agent is preferably a tertiary amine dispersant from the viewpoints of compatibility with the pigment and the fact that dispersibility decreases at elevated temperatures.

Tertiary amine dispersants for acrylamide, which is a cationizing agent, include, for example:
(a) polymers of alkylaminoalkyl(meth)acrylamides, for example, polymers of dimethyl or diethylaminoethyl(meth)acrylamide, dimethylaminopropyl(meth)acrylamide, or diethylaminopropyl(meth)acrylamide;
(b) polymers of dialkylaminoalkyl (meth)acrylates, for example, polymers of dimethyl or diethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, or diethylaminopropyl (meth)acrylate;
(c) acrylamide-styrene copolymer;
(d) urethane polymers containing tertiary amino groups, etc.

The pigment dispersion composition is
The content of the pigment is 15% by mass or more and 25% by mass or less,
The content of the cationizing agent is preferably 20 % by mass or more and 40 % by mass or less.

According to the present invention, high dyeing density and uniformity can be achieved when dyeing synthetic fiber structures with aqueous pigment dispersions, which was difficult to achieve using conventional methods.

Photographs of the appearance of polyester fabrics of the control example, examples, and comparative examples are shown. The appearance of the residual dyeing liquid after the completion of dyeing and the appearance of the washing water during washing after the completion of dyeing are shown.

Below, we will explain the embodiments of the present invention, with appropriate reference to the drawings.

<Staining stock solution>
EMACOL CT BLUE 4824E (Sanyo Dye Co., Ltd./pigment PB 15:1) was used as the dye concentrate containing a blue pigment.

<Fiber structure>
As the fiber structure, a polyester fabric (100% polyester fiber, 150d/48f) was used.

The pigment content in the aqueous pigment dispersion composition is preferably 12% by mass or more and 30% by mass or less, and more preferably 15% by mass or more and 25% by mass or less. Furthermore, the value of cationizing agent content / pigment content x 100 is preferably 20% by mass or more and 70% by mass or less, and more preferably 30% by mass or more and 50% by mass or less.

The pH of the aqueous pigment dispersion composition is preferably 3.0 or higher and 7.0 or lower, and more preferably 4.0 or higher and 6.0 or lower.

<Pre-wash>
In order to remove foreign matter from the surface of the polyester fabric, the fabric was pre-washed by washing it in hot water at 80°C for 10 minutes.

[Example 1]
A cationization treatment solution was prepared by adding 300 mL of purified water and 0.05 g of a cationizing agent (an acrylamide-based polymer compound having a quaternary ammonium group, manufactured by Sanyo Pigment Co., Ltd., CT F1101) to a 500 mL stainless steel beaker. The pre-washed polyester fabric was immersed in the cationization treatment solution (0.5% owf) and heated at 80°C for 20 minutes (Step A). Then, 0.5 g of an anionizing agent (manufactured by Sanyo Pigment Co., Ltd., CT I1201, a polyester-based anionizing agent) was added to the stainless steel beaker (5.0% owf) and heated at 80°C for 10 minutes (Step B). After dehydration, the fabric was washed twice with tap water and drained, yielding the pretreated polyester fabric of Example 1.

Step A is preferably carried out at a temperature of 75°C to 85°C for 15 to 25 minutes. Step B is preferably carried out at a temperature of 75°C to 85°C for 10 to 15 minutes.

In this specification, "cationization treatment" and "anionization treatment" refer to "treatments in which a cationizing agent is thermally adsorbed onto the fiber surface to form cationic functional groups" and "treatments in which anionic groups from an anionizing agent are adsorbed onto the cationic functional groups formed by the cationization treatment to form anionic functional groups on the fiber surface." Preferred cationizing agents are amine-based cationizing agents (e.g., cationizing agents containing primary amino groups, tertiary amino groups, or quaternary ammonium groups), and preferred anionizing agents are emulsion-based anionizing agents (e.g., anionizing agents that are polyolefin emulsions or polyester emulsions).

The concentration of the cationizing agent used in step A is preferably 10% or more and 20% or less. The concentration of the anionizing agent used in step B is preferably 20% or more and 30% or less. The amount of the anionizing agent used in step B is preferably 10 to 20 times the amount of the cationizing agent used in step A.

The pretreatment method of the present invention significantly differs from conventional pretreatment methods for synthetic fiber structures in that, after immersing the synthetic fiber structure in a cationizing agent (cationization treatment liquid) in step A, an anionizing agent (anionization treatment liquid) is added to the cationizing agent and step B is carried out without dehydrating or washing (rinsing) the synthetic fiber structure.

[Example 2]
A pretreated polyester fabric of Example 2 was obtained in the same manner as in Example 1, except that 0.5 g of UNIKA RESIN PM-110 (Union Chemical Industry Co., Ltd./polyester-based anionizing agent) was used as the anionic treating agent (anionizing agent 5.0% owf).

[Comparative Example 1]
A cationization treatment solution was prepared by adding 300 mL of purified water, 4.8 g of a cationizing agent (3-chloro-2-hydroxypropyltrimethylammonium chloride), and 3.0 g of sodium hydroxide to a 500 mL stainless steel beaker. The pre-washed polyester fabric was immersed in the cationization treatment solution (48% owf) and heated at 80°C for 30 minutes. The polyester fabric was then washed with tap water. An aqueous acetic acid solution was prepared by adding 300 mL of purified water and 0.15 g of 80% acetic acid to a 500 mL stainless steel beaker, and the washed polyester fabric was immersed in this solution. After heating at 50°C for 5 minutes, the fabric was washed with tap water and dehydrated twice.

300 mL of purified water and 4.8 g of anionizing agent (polyacrylic acid) were placed in a 500 mL stainless steel beaker to prepare a cationization treatment solution. The dehydrated polyester fabric was immersed in the cationization treatment solution and heated at 80°C for 30 minutes. After that, washing with tap water and dehydration were repeated twice to obtain the pretreated polyester fabric of Comparative Example 1.

[Comparative Example 2]
A pretreated polyester fabric of Comparative Example 2 was obtained in the same manner as in Example 1, except that 0.4 g of CT FX01 (Sanyo Dye Co., Ltd./aromatic sulfonic acid condensate anionizing agent) was used as the anionic treatment agent (anionizing agent 3.3% owf).

[Comparative Example 3]
A pretreated polyester fabric of Comparative Example 3 was obtained in the same manner as in Example 1, except that 0.5 g of UNIKA RESIN UR-741 (Union Chemical Industry Co., Ltd./polyurethane-based anionizing agent) was used as the anionic treating agent (anionizing agent 5.0% owf).

[Comparative Example 4]
A pretreated polyester fabric of Comparative Example 4 was obtained in the same manner as in Example 1, except that 0.5 g of Sunlife TA-300 (Nicca Chemical Co., Ltd./polyphenol-based anionizing agent) was used as the anionic treatment agent (anionizing agent 3.6% owf).

[Comparative Example 5]
A pretreated polyester fabric of Comparative Example 5 was obtained in the same manner as in Example 1, except that 0.5 g of Poise 530 (Kao Corporation/polycarboxylic acid-based anionizing agent) was used as the anionic treating agent (anionizing agent 5.0% owf).

<Dyeing test>
A dyeing solution was prepared by adding 300 mL of purified water and 0.5 g of dye concentrate to a 500 mL stainless steel beaker. The polyester fabrics of the Examples and Comparative Examples, as well as a control polyester fiber that had not been pretreated, were immersed in this dyeing solution and dyed by gradually increasing the temperature from room temperature to 60°C or 70°C. Completion of dyeing was determined by whether the dyeing solution became transparent or whether there was no decrease in the dyeing solution concentration due to the temperature increase. After dyeing was completed, the polyester fabrics were washed with tap water. The washed polyester fabrics were then centrifuged and dried at 60°C for 10 minutes, followed by another 3 minutes at 100°C. Since dyeing was completed at 60°C for Examples 1 and 2, the temperature was not raised to 70°C during dyeing. However, the temperature was raised to 70°C for the control and Comparative Examples 1 to 5 during dyeing.

Figure 1 shows photographs of the appearance of polyester fabrics from the control, example, and comparative examples. The "Temperature" in the figure indicates the temperature up to which the fabric was immersed in the dye solution during the dyeing test, and the fabric was removed from the dye solution at the indicated temperature and air-dried. The "After Water Wash" in the figure indicates polyester fabric that was heated to 70°C, washed with tap water, centrifuged, and then dried.

The polyester fabrics of Comparative Examples 1 to 5 exhibited particularly high dyeability when dyed at 60°C and 70°C compared to the control polyester fabric that had not been pretreated. On the other hand, the polyester fabric of Example 1 exhibited higher dyeability than the polyester fabrics of Comparative Examples 1 to 5 dyed at 70°C, even when dyed at room temperature. Furthermore, the polyester fabric of Example 2 exhibited higher dyeability than the polyester fabrics of Comparative Examples 1 to 5 when dyed at 50°C or higher. Furthermore, the polyester fabrics of Examples 1 and 2 exhibited significantly less discoloration upon washing with water than the polyester fabrics of Comparative Examples 1 to 5.

Figure 2 shows the appearance of the dyeing residual liquid after dyeing was completed, and the appearance of the washing water (washing wastewater) during washing after dyeing was completed. The washing residual liquid and washing water of the control and comparative example 1 had almost the same appearance, but the washing residual liquid and washing water of example 1 were clearly lighter in blue, confirming that the pigment in the dyeing liquid was fully absorbed into the polyester fabric in example 1. Similar results were obtained for example 2 as for example 1.

The pretreatment method of the present invention is useful in the dyeing, textile or clothing technical fields.

Claims (2)

1. A method for pretreating a synthetic fiber structure suitable for dyeing with a pigment dispersion composition, comprising:
a step A of immersing a synthetic fiber structure in a cationizing agent to perform a cationization treatment;
and step B of adding an anionizing agent to the cationizing agent in which the synthetic fiber structure is immersed, thereby anionizing the synthetic fiber structure.
The synthetic fiber structure is not dehydrated or washed between the step A and the step B,
the cationizing agent is an acrylamide-based cationizing agent containing a primary amino group, a tertiary amino group, or a quaternary ammonium group,
the anionizing agent is a polyolefin emulsion or a polyester emulsion,
The synthetic fiber structure is composed of polyester fibers.
Pretreatment methods. The pigment dispersion composition is
containing at least a pigment, a cationizing agent, a solvent, and water;
the pigment is an organic pigment or carbon,
the cationizing agent is a tertiary amine dispersant;
The pretreatment method according to claim 1 .