JPS6219523B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to polyester fibers having a special surface shape. Polyester fibers are widely used due to their excellent functionality and texture, but one major drawback is that they are difficult to dye, and they can be mixed with natural fibers such as wool and silk, and semi-synthetic fibers such as rayon and acetate. Compared to fibers, it is inferior in clarity, depth of color, and especially black color development. These drawbacks are that polyester fibers are dyed with disperse dyes, which have poor clarity among dyes;
In addition, the refractive index of polyester fibers is approximately 1.7, which is higher than other fibers, and the difference in refractive index with air is large, which inhibits light from entering the fibers. Furthermore, since polyester fibers are manufactured using a melt-spinning method, their smooth surfaces make it more difficult for light to penetrate. Conventionally, the coloring properties of these polyester fibers,
In order to improve the depth of color, a method has been devised to reduce the difference in refractive index between air and fiber by coating the fiber surface with a compound with a low refractive index, thereby reducing light reflection on the fiber surface. However, there are problems with its durability. On the other hand, roughening the fiber surface is considered to improve gloss and color depth. For example, in Tokuko Sho 46-26887, the roughness of the fiber surface was
It is stated that a matting effect can be obtained by setting the thickness to about 0.03 to 1 micron. but,
The fact that simply removing the luster does not improve the color development and depth is that the color of synthetic fibers dyed with titanium oxide appears pale and dull, or that polyester fibers typified by high-temperature and high-concentration zinc chloride dyes. This is evident from the fact that the color of the polyester fiber dyeings treated in the aqueous embrittlement solution also appears lighter. Therefore, when roughening the fiber surface for the purpose of improving color development, the present inventors not only reduce specular reflection on the fiber surface, but also create a light tunnel to assist light penetration into the interior of the fiber. The present inventors have discovered that, in addition to the matting effect, the simultaneous presence of the dyes improves the color development of dyed products, particularly the depth of color and the improvement of black color development, resulting in the present invention. That is, the present invention provides 5 to 100 square microns.
There are 30 discontinuous depressions with a depth of 0.3 microns or more and 0.8 microns or less and vertical length in the fiber axis direction,
Furthermore, the polyester fiber has a surface covered with minute irregularities, and the polyester fiber has an average primary particle diameter of 100 mμ or less at any stage until polymerization is completed, and 0.1 mμ or less.
After completing the polymerization by adding 0.1 to 5% by weight of aluminum oxide-containing dry process silicon oxide containing ~5% by weight of aluminum oxide into the polymer, the fiber surface is coated with an alkaline aqueous solution. A polyester fiber characterized by being hydrolyzed. Here, depressions with a depth of 0.3 microns or more and 0.8 microns or less are considered to be light tunnels that allow light to efficiently penetrate inside the fiber, and microscopic irregularities are defined as those with a depth of less than 0.3 microns. , preferably 0.15 micron or more. The scattering of light by a rough surface is greatest when the unevenness is approximately 40% of the wavelength of the light, that is, the size of the unevenness is 0.15 microns or more and less than 0.3 microns, and the matting effect is also large. However, if it is covered only with irregularities of this size, it is effective in eliminating the specular gloss peculiar to melt-spun polyester fibers, but it is not effective in allowing light to penetrate inside the fibers more efficiently. It won't happen. In addition, if the size of the unevenness is larger than the wavelength of visible light, that is, 0.8 microns or more, it will not be a rough surface for visible light, but will simply increase the light reflection area, and if the surface has a smooth surface. The color of the dyed product will be lighter compared to the original color. On the other hand, when the size of the unevenness on the fiber surface is 0.3 to 0.8 microns, especially when the unevenness is formed as a depression on the fiber surface, light is repeatedly reflected inside the depression on the fiber surface, and the incident light is reflected in the depression. The dyed material appears darker due to the increased light absorption efficiency. Therefore, by coexisting 0.3 to 0.8 micron deep indentations to increase light absorption efficiency and minute irregularities to reduce the specular gloss peculiar to synthetic fibers and give a calming color, we have created a deep flavor. A certain dyeing is obtained. The depth of the depression here is the vertical distance between the tangent line drawn above the depression and the deepest part of the depression,
Determined from electron micrographs of fibers. This depression is a vertical depression approximately parallel to the fiber axis, and it is desirable that the length is 10 microns or less, preferably 5 microns or less, since this provides strength against damage to the fiber surface due to friction. The number of depressions is
If the number is less than 5 per 100 square microns, the effect of improving the depth cannot be obtained, and if it is more than 30, there is a strong tendency to form continuous depressions and the depth is reduced. Furthermore, it lacks resistance to friction, which is undesirable. The reason why vertically long depressions are effective in improving color development is presumed to be as follows. There is a high probability that the fibers are arranged parallel to the plane of the fabric, while the incident angle of light is distributed mainly at right angles to the plane of the fabric. As can be easily understood by considering the case where light is incident on the fabric at right angles, in the case of a horizontally elongated indentation, the light illuminates the entire indentation, whereas in the case of a vertically long indentation, the light illuminates only the side parts of the fibers. A shadow forms in the hollow. Therefore, the color tone appears to be darker. A polyester fiber having such a surface may be prepared by adding 0.1 to 5% by weight of aluminum oxide-containing silicon oxide having an average primary particle size of 100 mμ or less at any stage until the polymerization of the polyester is completed.
It is obtained by adding it to complete polymerization, and then heating it in an alkaline aqueous solution such as caustic soda after spinning and stretching to hydrolyze the fiber surface. The average primary particle size of silicon oxide containing aluminum oxide was measured using the following method. The longest diameter of each primary particle is measured from the image obtained by photographing, and the value is calculated as the average of 1000 particles. The aluminum oxide-containing dry process silicon oxide in the present invention is an aluminum oxide-containing silicon oxide produced by making aluminum halide exist in silicon halide when silicon oxide is produced by a dry process. The dry method for manufacturing silicon oxide mentioned here is, for example, the method described on page 524 of "Practical Handbook of Additives for Plastics and Rubber" (Kagaku Kogyosha, published August 10, 1970). This is a method in which silicon halide is generally thermally decomposed together with hydrogen and oxygen in the gas phase. In the present invention, the aluminum oxide content of the aluminum oxide-containing silicon oxide must be 0.1 to 5% by weight. In other words, if the aluminum oxide content is less than 0.1% by weight, violent agglomeration occurs during the polyester polymerization reaction, making it impossible to obtain fibers with the desired surface roughness after alkali dissolution treatment, resulting in a small effect of improving color development. This is not desirable. On the other hand, if the aluminum oxide content exceeds 5% by weight, the yellowing tendency of the resulting polymer increases (the b value increases), which is not preferable. In addition, the b value of the polymer was measured by the following method. The b value is 2.5 to 3.5 mm in diameter and 4.5 to 5.5 in height.
It is formed into a cylindrical shape of 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. Also, unlike the aluminum oxide-containing silicon oxide produced by a dry process by making aluminum halide exist in silicon halide from the raw material stage as in the present invention, simply mixing aluminum oxide and silicon oxide does not allow the polymerization reaction of polyester. This is not preferable because it causes agglomeration in the fibers, making it impossible to obtain fibers with the desired unevenness after the alkali dissolution treatment, which reduces the effect of improving color development. In the present invention, the aluminum oxide-containing dry process silicon oxide is dispersed in aliphatic glycol, aliphatic alcohol, water, etc. by a known method, and the aluminum oxide-containing dry process silicon oxide is dispersed in an aliphatic glycol, aliphatic alcohol, water, etc. by a known method, and the aluminum oxide-containing dry process silicon oxide is dispersed in an aliphatic glycol, aliphatic alcohol, water, etc. before the polymerization reaction is completed. It can be added at this stage. 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 troubles such as clogging of sand or thread breakage during the spinning process, the aluminum oxide-containing silicon oxide used in the present invention is classified by a generally well-known method such as natural sedimentation or centrifugation to obtain coarse particles. It is preferable to use one from which particles are removed as much as possible. The polyester in the present invention refers to a polyester containing terephthalic acid or an ester-forming derivative thereof as a dicarboxylic acid component and a glycol selected from ethylene glycol and 1,4-butanediol or an ester-forming derivative thereof as a glycol component. A part of this 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 aliphatic or alicyclic glycol may be replaced with, for example, alkylene glycols having 2 to 10 carbon atoms, 1, Glycols other than the main glycol component may be substituted, such as 4-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 may be transesterified with aliphatic or cycloaliphatic glycols, or
An aliphatic or alicyclic glycol ester of terephthalic acid and/or a low polymer thereof is synthesized by directly esterifying terephthalic acid with an aliphatic glycol or by adding ethylene oxide to terephthalic acid, and then The most widely used method is to subject the product to a polymerization reaction using 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. The polyester fiber of the present invention is, for example,
The fiber has a different surface morphology from that disclosed in Japanese Patent No. 54-120728, and has better color development when dyed. The present invention will be specifically explained below with reference to Examples. In addition, parts in the examples are parts by weight, %
means weight %. 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 generated methanol 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 produced by a dry process, which had 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 polymerization ratio of 5:2.5:92.5 was added to the polyester containing aluminum oxide from which dry-method silicon oxide was obtained. It was added at a concentration of 1.0% and transferred to the polymerization can. After that, 760mmHg to 1mmHg over 1 hour and 30 minutes.
230℃ to 285℃ over 2 hours.
The temperature rose to Polymerization temperature under reduced pressure of 1 mmHg or less
Polymerization was continued for an additional 2 hours at 285°C for a total of 4 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 chip was 4.1. After drying the polyester chips under reduced pressure at 180℃ for 3 hours, the spinning temperature was 290℃ and the take-up speed was 900m/min.
Then, the stretching ratio was 3.45 times and the pin temperature was 100.
The yarn was drawn at 100° C. to obtain a drawn yarn of 100 denier/48 filaments. This drawn yarn is referred to as drawn yarn A. Next, in the same manner as above, instead of adding aluminum oxide-containing silicon oxide, 1% of a drawn yarn containing no inorganic fine particles and dry method silicon oxide containing no aluminum oxide and having an average primary particle size of 30 mμ was added. A drawn yarn and a drawn yarn to which silica sol having an average primary particle size of 30 mμ were added were obtained. These drawn yarns are referred to as drawn yarns B, C, and D, respectively. These drawn yarns A, B, C, and D were each made into a tubular knitted fabric using a 27-gauge tricot sock knitting machine, and then immersed in a 3% caustic soda aqueous solution at 98°C.
After hydrolysis loss of 20% relative to the weight before treatment, Dianix Black FB-FS 15% owf acetic acid 0.5cc/L and sodium acetate 0.15g/L in a bath ratio of 1:30. Stain for 60 min at °C.
Thereafter, reduction cleaning was performed according to a conventional method, followed by washing with water and drying. The L value of the obtained black dyed product was measured using a digital color measurement color difference calculator (manufactured by Suga Test Instruments Co., Ltd.), and the color depth was compared. Here, the L value represents the visual density of a color, and the smaller the L value, the darker the color. The results are as shown below, and the drawn yarn A had a deep dark black color. L value of the drawn yarn A dyed product 13.17 〃 B 〃 〃 13.95 〃 C 〃 〃 13.52 〃 D 〃 13.54 In addition, in order to confirm the effect in chromatic colors, the drawn yarn A, B, C and D Each tubular knitted fabric was hydrolyzed to reduce its weight by 20% and dyed at 130°C for 60 minutes in a dye bath containing Kayalon Polyester Blue TS 2.5% owf, acetic acid 0.5cc/L, and sodium acetate 0.15g/L at a bath ratio of 1:30. ,
Reduction cleaning, washing with water, and drying were performed. The L, a, and b values of the obtained dyed product were measured using the digital colorimetric color difference calculator described above, and the L value and (a ² +
^b2 ) ^1/2 values were compared. Here, (a ² + b ² ) ^1/2 is an index that expresses the vividness of the color, and the larger the value, the clearer the color, and the smaller the L value, and (a ² +
b ² ) The larger ^{the 1/2} value, the deeper the dyed product.

[Table] As a result, it was confirmed that drawn yarn A can provide deeper colors even in chromatic colors. Electron micrographs of drawn fibers A, B, C, and D with 20% hydrolytic weight loss at a depth of 0.3 to
The number of depressions with a vertical length of 0.8 microns was determined as follows.

[Table] From these results, it is clear that when aluminum oxide-containing silicon oxide is added, the alkaline hydrolysis treatment generates many 0.3-0.8 μ deep depressions and even minute irregularities, improving color development. be. Example 2 The drawn yarns A and B used in Example 1 were made into a tubular knitted fabric using a 27 gauge tricot sock knitting machine and immersed in a 5% caustic soda aqueous solution at 98°C, and hydrated with the drawn yarns A and B at different times. Prepare products with a decomposition weight loss rate of 2%, 10%, 20%, 30%, 40%, 50% of the weight before treatment, Kayalon Polyester Blue TS 2%owf Acetic acid 0.5cc/l Sodium acetate 0.15g /l in a dye bath with a bath ratio of 1:40 at 130℃ for 60 minutes,
Reduction cleaning, water washing, and drying were performed according to conventional methods. Table 1 summarizes the relationship between the surface condition of the fibers observed in electron micrographs of these dyed products and the L value and (a ² +b ² ) ^1/2 value of the dyed products.

[Table] As a result, a depression with a depth of 0.3 to 0.8 microns is created.
A low L value and a high (a ² + b ² ) ¹ can be obtained only when the fiber surface is formed within the range of the present invention, in which the number of irregularities is within the range of 5 to 30 per 100 square microns, and further minute irregularities coexist. It has been found that colors with a value of ^/2 , ie, deep colors, can be obtained. Moreover, the results of this color measurement were in good agreement with the visual tendency, and the colors of the dyed products within the scope of the present invention had a calm and deep tone. Example 3 Polymerization, spinning, stretching, knitting, and alkaline hydration were carried out in the same manner as in Example 1, except that the aluminum oxide content in the aluminum oxide-containing dry process silicon oxide was changed as shown in Table 2. Decomposition treatment and staining evaluation were performed. The second evaluation result
Shown in the table. It is clear that when the aluminum oxide content in the aluminum oxide-containing dry method silicon oxide is 0.1 to 5% by weight, the b value of the polymer, the surface condition after alkaline hydrolysis treatment, and the depth of the dyed fabric are favorable. .

【table】 [Brief explanation of the drawing]

Figures 1 and 2 are 2800x magnification electron micrographs of the surfaces of polyester fibers containing aluminum oxide and silicon oxide according to the present invention subjected to 10% and 20% alkali hydrolysis treatment, respectively. Third
The figure shows 20% of normal polyester fibers outside the scope of the present invention.
This is an electron micrograph of the surface of the product subjected to alkaline hydrolysis treatment, magnified 1,100 times.

Claims (1)

[Claims] 1 Depth where 5 to 30 particles exist per 100 square microns
A polyester fiber having a surface covered with discontinuous depressions of 0.3 microns or more and 0.8 microns or less in the longitudinal direction of the fiber, and further minute irregularities, the polyester fiber having a surface covered with microscopic irregularities. At any stage until completion, 0.1 to 5% by weight of aluminum oxide-containing dry process silicon oxide having an average primary particle size of 100 mμ or less and containing 0.1 to 5% by weight of aluminum oxide is added to the polymer.
1. A polyester fiber, which is obtained by spinning and stretching a polyester fiber that has been polymerized by adding it, and then hydrolyzing the fiber surface with an alkaline aqueous solution.