JPH0121245B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing colored polyester fibers having a unique surface morphology and improved coloring properties. Polyester fibers are widely used as general clothing materials due to their excellent texture and functionality. However, it has a serious drawback that it is inferior in clarity, depth of color, and especially black color development compared to natural fibers such as wool and silk, and semi-synthetic fibers such as rayon and acetate. These drawbacks are because polyester fibers are dyed with disperse dyes, which are less vivid among dyes, and because polyester fibers have a refractive index of about 1.7, which has a large refractive index difference with air, it is difficult to absorb incident light. This makes it even more difficult to penetrate into the fibers. Recently, roughening the fiber surface has been studied for the purpose of improving gloss and depth of color.
It is stated that a matting effect can be obtained by setting the thickness to about 1μ. However, simply removing the luster does not improve the color development or the depth of the color, as is typical for dyed synthetic fibers containing titanium oxide, which appear pale and dull, or from high-temperature, high-concentration zinc chloride solutions. The surface of the polyester fibers treated with the polyester embrittling agent is rough and dull, but the color of the dyed material appears to be lighter as well. Recently, a method has been developed in which polyester fibers containing fine inorganic powder are subjected to hydrolytic weight loss treatment, and the process of hydrolytic weight loss progresses using the inorganic fine particles as cores to obtain a fiber surface suitable for improving color development. It has been devised. An example of this is described in JP-A-54-120728. However, the method using inorganic fine particles as a core generally results in a randomly uneven surface, and due to the hiding power of the added particles, the transparency of the fiber itself decreases, which has the opposite effect of reducing color development. arise. Therefore, the type of particles added and the amount added must be selected within a very narrow range, and there is a limit to the effect of improving color development. On the other hand, when trying to improve color development by roughening the surface of single fibers, what is important is to efficiently absorb the light incident on the fiber surface, and for this purpose, it is necessary to create deep depressions on the fiber surface. Moreover, it is most effective when the vertically long depressions are arranged in the fiber axis direction. This can be easily understood by considering a field in which light enters the fabric at right angles; in the case of a horizontally long or nearly circular indentation, the light illuminates the entire indentation, whereas in the case of a vertically long indentation, the light illuminates the entire indentation. , shadows are always formed in the depressions on the sides of the fibers. Therefore, it is thought that the color tone appears darker. The present inventors have conducted various studies on processing methods to further improve the color development of polyester fibers containing specific inorganic fine particles compared to the conventional dyeing process, and have found that they are contrary to conventional wisdom. We discovered that by subjecting polyester fibers to hydrolytic weight loss treatment with a solution containing an alkali hydroxide after dyeing, a different surface structure and improved coloring properties could be achieved than when dyeing after weight loss treatment, and we have developed this book. I came up with an invention. That is, the present invention has the following configuration. Inorganic particles with an average primary particle diameter of 100 mμ or less
Polyester fibers polymerized and spun with a content of 0.1 to 5% by weight are stretched to form distortion around the inorganic particles, and then dyed to expand the distortion, and then dyed with a solution containing alkali hydroxide for at least 5% by weight. This is a method for producing colored polyester fibers with improved color development, which is characterized by performing a weight loss treatment to form depressions on the fiber surface. This colored polyester fiber has discontinuous depressions with non-uniform vertical length in the fiber axis direction, and the area of the depressions accounts for 10 to 40% of the fiber surface, and also accounts for 10% to 40% of the fiber volume. It forms a characteristic fiber structure in which the volume ratio of the hollow portion is 3 to 25%, and this structure exhibits excellent coloring properties. Here, the vertically long depression in the fiber axis direction is, for example, as shown in Figs. 1 and 2, and is a light tunnel that allows incident light to efficiently enter the inside of the fiber. The above effect will be more effectively exhibited as the amount of the water increases and the depth increases. That is, the ratio of the recessed portion to the total fiber surface area represents the amount of the recess, and the volume of the recessed portion can be expressed as the ratio of the area of the recessed portion of the same cross section to the area of the cross section perpendicular to the fiber axis,
Good color development can be obtained when the former is 10% or more and the latter is 3% or more. Here, the more vertically long depressions exist in the fiber axis direction, and the deeper the depth, the better the coloring property.The fact that velvet fabrics that exhibit uniquely good coloring property have deep inter-fiber dents. It is obvious that there are many gaps, but when trying to implement this principle on the surface of a single fiber, there is a limit to the mechanical strength, so the ratio of the depressions to the total fiber surface area is 40%, The upper limit of the volume ratio is about 25% of the true fiber volume. Here, the ratio of the concave portion to the total fiber surface area is 100
The area of the vertical depression included in the area corresponding to the side surface of the fiber in square microns is determined by the area weight method, and the proportion of the depression is calculated as the average of 50 locations and expressed as a percentage. In addition, the volume of the hollow part was determined by taking a cross-sectional photograph of the fiber at a magnification of 3000 times, as shown in the model in Figure 2.
Draw a figure B that circumscribes the convex part of the actual cross section A of the fiber shown by diagonal lines, and calculate figure B and figure A with respect to the area of figure A.
The ratio of the difference in area is determined by the area weight method, and is determined as the average for 50 single fibers. Polyester fibers having such a surface are produced by dyeing polyester fibers containing specific inorganic fine particles with a primary particle diameter of 100 mμ or more, and then heating them in an alkaline aqueous solution such as caustic soda to hydrolyze the dyed fiber surface. Obtained by processing. In addition, when performing the hydrolytic weight loss treatment, by performing the hydrolytic weight loss treatment after dyeing, the distortion of the fiber structure that occurs during spinning and drawing that exists around the added inorganic fine particles can be removed by dyeing. The strained area around the inorganic fine particles, which expands due to adsorption and where more dye is adsorbed, is strongly affected by the subsequent hydrolytic weight loss, and the strained area around the inorganic fine particles expands and absorbs more dye. It is believed that it is possible to create a deep recess with a longer vertical length in the axial direction. Here, if the primary particle diameter of the inorganic fine particles exceeds 100 mμ, a surface suitable for improving color development cannot be obtained when the amount is reduced by hydrolysis, which is not preferable. Furthermore, if the amount of the inorganic fine particles added is less than 0.1% by weight, sufficient strain cannot be obtained on the fiber surface, and a rough surface suitable for improving color development cannot be obtained. Further, if the amount added exceeds 5% by weight, the non-uniformity of the fiber surface decreases, and similarly, a surface suitable for improving color development cannot be obtained. The average primary particle diameter constituting the present invention is 100 mμ
The following polyester fiber containing inorganic fine particles can be obtained by adding the inorganic fine particles at any stage to complete polymerization, and then spinning and drawing. Note that the average primary particle diameter of the inorganic fine particles is
A photograph of a powder of inorganic fine particles magnified 100,000 times is taken using an electron microscope, the longest diameter of each primary particle is measured from the obtained image, and the value is determined as the average of 1000 particles. The inorganic fine particles used in the present invention are preferably those that are easily finely dispersed in polyester fibers and have a refractive index close to that of polyester fibers. For example, there is aluminum oxide-containing silicon oxide produced by making aluminum halide exist in silicon halide when silicon oxide is produced by a dry method. The dry method for producing silicon oxide referred to here refers to, for example, "Practical Handbook of Additives for Plastics and Rubber" (Kagaku Kogyosha, August 1971).
This is a method of thermally decomposing general silicon halides together with hydrogen and oxygen in the gas phase, as described on page 524 of the issue published on May 10th. The aluminum oxide content of the aluminum oxide-containing silicon oxide described above must be 0.1 to 5% by weight. That is, the aluminum oxide content is
If the aluminum oxide content is less than 0.1% by weight, it will tend to aggregate during the polyester polymerization reaction, while if the aluminum oxide content exceeds 5% by weight, the yellowing tendency of the resulting polymer will increase (the b value will increase), which is not preferable. In addition, the b value of the polymer is 2.5 to 2.5 in diameter.
It is formed into a cylindrical shape of 3.5 mm and a height of 4.5 to 5.5 mm, and measured using a direct-reading color difference computer manufactured by Suga Test Instruments Co., Ltd. The larger the b value, the greater the yellowing tendency of the polymer. In the present invention, the inorganic fine particles are dispersed in aliphatic glycol, aliphatic alcohol, water, etc. by a known method, and added before the completion of the polymerization reaction, for example, at any stage of the ester reaction, transesterification reaction, or polymerization reaction. be able to.
If it is added after the polymerization is completed, the dispersibility will be extremely deteriorated, which is not preferable. In addition, in order to prevent problems such as clogging of sand or fiber breakage during the spinning process, the inorganic fine particles used in the present invention are classified by a generally well-known method such as natural sedimentation or centrifugation to remove coarse particles as much as possible. It is preferable to use the removed one. The polyester in the present invention refers to a polyester having terephthalic acid or its ester-forming derivative as the dicarboxylic acid component and a glycol selected from ethylene glycol and 1,4-butanediol or its ester-forming derivative as the glycol component. A part of the dicarboxylic acid component may be, for example, a monoalkali metal salt of 5-sulfoisophthalic acid, a dicarboxylic acid such as isophthalic acid, diphenyldicarboxylic acid, naphthalene dicarboxylic acid, adipic acid, sebacic acid, dodecanedioic acid, or an ester thereof, P-
Oxycarboxylic acids such as oxybenzoic acid and P-β-oxyethoxybenzoic acid or esters thereof may be substituted, and a portion of the fatty acid or alicyclic glycol may be replaced with, for example, alkylene glycols having 2 to 10 carbon atoms, 1,4 - Glycols other than the main glycol component may be substituted, such as cyclohexanedimethanol, 1,4-bis(β-oxyethoxy)benzene, bisglycol ether of bisphenol A, and polyalkylene glycol. Furthermore, chain branching agents such as pentaerythritol, trimethylolpropane, trimellitic acid, trimesic acid, monohydric polyalkylene oxide,
It is also possible to use a small proportion of a polymerization terminator such as phenylacetic acid. To produce polyester from such raw materials,
For example, dimethyl terephthalate is transesterified with ethylene glycol, 1,4-butanediol, etc., terephthalic acid is directly esterified with an aliphatic glycol, or terephthalic acid is subjected to an addition reaction with ethylene oxide to produce terephthalate. The most widely used method is to synthesize an aliphatic or alicyclic glycol ester of an acid and/or a low polymer thereof, and then subject the product to a polymerization reaction by a conventional method. Further, in synthesizing the polyester in accordance with the present invention, catalysts, color inhibitors, ether bond by-product inhibitors, antioxidants, flame retardants, etc. well known in the art may be appropriately used. In addition, the fiber of the present invention and its manufacturing method include dyeing the inorganic fine particle-containing polyester fiber and its structure, and then treating it with a solution containing an alkali hydroxide to reduce the weight of the polyester fiber by 5% or more. This can be achieved by Here, the dyeing performed prior to hydrolytic weight loss may be performed by a conventional method. Further, the weight loss due to the hydrolysis treatment performed after dyeing must be 5% or more by weight. This is 5
This is because if the weight loss is less than %, a rough surface with sufficient depth suitable for improving color development cannot be obtained. Although there is no particular limitation in the range of weight loss of 5% or more, a range of 35% or less is preferable since excessive weight loss causes a decrease in the strength of the fiber or its structure. Further, the weight loss due to hydrolysis can be carried out by using caustic soda, caustic potash, etc. as the alkali hydroxide, and treating them in a solution of water, alcohol, or the like. The treatment method is a dipping method in which the fabric is immersed in the alkaline hydroxide solution, a patch method in which the solution is applied to the fabric by a method such as padding, and then the fabric is applied in batches and left to stand, or a method in which the solution is applied to the fabric by a method such as padding. A well-known method such as a padded steam method in which the adhesive is applied to a fabric and then subjected to a steaming process can be employed. In addition, for the purpose of shortening the treatment time, for example, Lauryl dimethyl benzyl ammonium is added to the alkaline hydroxide solution.
Even if an alkaline decomposition accelerator such as chloride is used, the effects of the present invention will not be inhibited. The present invention will be specifically described below with reference to Examples. Example 1 100 parts of dimethyl terephthalate, 60 parts of ethylene glycol, 0.05 part of manganese acetate tetrahydrate, and 0.04 part of antimony trioxide were charged into a transesterification can.
The temperature was raised from 140° C. to 230° C. over 4 hours in a nitrogen gas atmosphere, and the transesterification reaction was carried out while the methanol produced was continuously distilled out of the system. Subsequently, 0.05 part of trimethyl phosphate was added to the obtained product, and silicon chloride and aluminum chloride were further mixed to produce an aluminum oxide product with an aluminum oxide content of 1% and an average primary particle size of 30 mμ. A slurry in which a mixture of aluminum oxide-containing silicon oxide, a 20% aqueous solution of tetraethylammonium hydroxide, and ethylene glycol was dispersed in a weight ratio of 5:2.5:92.5 was mixed with aluminum oxide-containing dry process silicon oxide against the resulting polyester. The aluminum oxide-containing aluminum oxide containing dry process silicon oxide was transferred to a polymerization can. 760mmHg to 1mm over the next 1 hour and 30 minutes
The pressure was reduced to Hg, and at the same time the temperature was raised from 230°C to 285°C over 2 hours from the start of the pressure reduction. Under reduced pressure of 1 mmHg or less, at a polymerization temperature of 285°C for an additional 2 hours, a total of 4
Polymerized for hours. After the reaction was completed, the polymer was discharged into water in the form of a 3 mm rod and cut into 5 mm lengths to obtain polyester chips. The b value of the obtained polyester chips is 3.3 to 8.0
It was within the range of The polyester chip is 180
After drying under reduced pressure at ℃ for 3 hours, spinning was carried out at a spinning temperature of 290℃ and a take-up speed of 900 m/min, followed by a stretching ratio of 3.45.
The yarn was drawn at a pin temperature of 100°C to obtain a drawn yarn of 100 denier/48 filaments. Each of these six types of drawn yarn was made into a tube-knitted fabric using a 27-gauge tricot sock knitting machine, then divided into two parts, and one part was heated to
% caustic soda aqueous solution to reduce the weight by hydrolysis by 25% of the weight before treatment, and then soak it at a concentration of 15% of the weight of the fiber using Dianix Black HG-FS (manufactured by Mitsubishi Kasei). Staining was carried out at 130°C for 60 minutes, and reduction washing was performed at 80°C for 15 minutes with a solution containing 2 g of caustic soda, 1 g of hydrosulfite, and 1 g of nonionic activator. Furthermore, the remaining one was dyed under the same conditions as above, and then hydrolyzed to reduce the weight by 25% under the same conditions as above, and then subjected to reduction washing. The L values of these black dyed products were measured using a digital color measurement color difference calculator (manufactured by Suga Test Instruments Co., Ltd.), and the results of comparing the color depths are shown in Table 1. Here, the L value represents the visual density of a color, and the smaller the L value, the darker the color. In addition, for each dyed product, the ratio of the warp length depression to the total fiber surface (section A in the table) and the volume ratio to the fiber volume (section B in the table) were determined using the above method.
) was calculated and shown in Table 2.

【table】

[Table] From the above results, if the total area of the depressions occupying the fiber surface is 10% or more, and the volume of the depressions is 3% or more of the fiber volume, a remarkable effect of improving color development is observed. . Example 2 The polyester drawn yarn containing 1.0% by weight of silicon oxide containing aluminum oxide used in Example 1 was
The yarn was twisted at 2000T/M to obtain a strongly twisted yarn in the S and Z2 directions. A jersey fabric was woven using the obtained highly twisted yarn. This gray fabric was textured using a washer, dyed in a Dianix Black FB-FS 15% OWF dye bath at a bath ratio of 1:30 for 60 minutes at 130℃, and then a portion was reduced and washed with water. Dry. The remainder was treated by immersing it in a 3% caustic soda aqueous solution at 98°C, and the weight before treatment was 3, 10, 20,
It was subjected to hydrolytic weight loss treatment of 35 and 45% by weight, followed by reduction washing, washing with water, and drying. The L values of these dyed products were measured and are shown in Table 3.

[Table] From the above results, it has been found that when the weight loss is hydrolyzed by 5% or more, a large effect of improving color development can be obtained.

[Brief explanation of drawings]

FIG. 1 is a photograph taken with a scanning electron microscope of the fiber of the present invention at a magnification of 5000 times. FIG. 2 shows a cross-sectional shape of the fiber of the present invention perpendicular to the fiber axis and a figure circumscribing the convex portion of the cross-section.

Claims (1)

[Claims] 1 Polyester fibers containing 0.1 to 5% by weight of inorganic particles with an average primary particle diameter of 100 mμ or less are polymerized and spun, and then stretched to form distortion around the inorganic particles, and then dyed to expand the distortion. 1. A method for producing colored polyester fibers with improved color development, characterized in that the fibers are then subjected to a weight reduction treatment of at least 5% by weight with a solution containing an alkali hydroxide to form depressions on the fiber surface.