JPH0335403B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for efficiently producing polyester fibers with good color development. More specifically, the present invention relates to a method in which polyester containing silica in which the silanol groups on the particle surface are blocked is spun at high speed using a hydrophobic dry method, and then the surface is subjected to surface elution treatment with a solvent. A typical example of the manufacturing process for polyester fibers is
The undrawn yarn spun at a spinning speed of around 1000 m/min is wound up into a package once and is then heat-treated to be stretched 3 to 4 times in the drawing process. Since it requires two steps, in recent years it has become less useful in terms of productivity and thermal energy. As a method of suppressing this increase in energy costs, there is an extremely strong demand for obtaining a yarn that can withstand practical use only through a spinning process. The present inventors investigated a method for manufacturing polyester using only a spinning process, and found that a spinning speed of 5000 m/min or more is required in view of the strength characteristics of the resulting yarn, but it was found that a spinning speed of 5000 m/min or more was required. It has been found that although the yarn has the effect of slightly improving color development compared to ordinary spun/drawn yarn, the color development is still not at a satisfactory level. The reason for this is that ordinary polyester fibers are inferior to other fibers such as acetate, rayon, wool, and cotton in terms of color development (depth of black or sharpness of chromatic colors) of dyed fabrics. In particular, when the single fiber fineness of the polyester fibers constituting the dyed fabric was 1 denier or less, the surface reflectance of light on the fabric surface was high and the color development was poor. Therefore, in order to further improve the color development of the yarn produced only by the above-described spinning process, studies have been conducted on a technique for roughening the fiber surface by surface treatment with an alkaline solvent (hereinafter referred to as alkali treatment). Conventionally, methods for roughening the fiber surface by alkali treatment include (1) alkali treatment of polyester fiber containing 0.5 to 10% by weight of inorganic fine particles such as silica sol with an average particle size of 100 mμ or less, and a specific surface structure (2) Polyester fibers containing 0.5 to 10% by weight of inorganic fine particles such as silica sol with an average particle size of 100 mμ or less are treated with alkali to impart a specific surface structure. Ultrafine fibers with a single fiber fineness of 1 denier or less (Japanese Patent Application Laid-open No. 112306/1983) have been proposed. However, all of the silica-based particles used in the surface roughening technology have the problem that added particles tend to aggregate due to the activity of surface silanol groups, and the agglomerated particles tend to cause coarse particles during spinning. The pressure increase due to yarn breakage and layer clogging was severe, and it could not be put to practical use at all when producing polyester yarn at a speed of 5000 m/min or more. In addition, because there are many aggregated particles, the surface becomes extremely rough after alkali treatment, and when the fabric is rubbed, the vertical depressions are destroyed and it tends to become a mirror surface, which makes it easier to reflect light in parts, causing the color to change. There was a problem. In view of the above-mentioned problems, the present inventors have discovered silica-based particles that can be applied to obtain polyester fibers with good coloring properties only by a spinning process and are free from the problems caused by agglomeration, and have arrived at the present invention. . That is, in the present invention, the average primary particle diameter is 100 m.
5000 m/min or more of polyester containing 0.12% by weight or more and 1.0% by weight or less of hydrophobic dry-method silica particles that have an alkyl group on the particle surface and block 30% or more of the silanol groups on the particle surface. This is a method for producing polyester fibers with good color development, which is characterized in that after spinning the fibers, the fibers are subjected to surface elution treatment with a solvent that is soluble or decomposable. The polyester in the present invention refers to a polyester containing ethylene glycol or 1,4-butanediol as the main glycol component and terephthalic acid or its ester as the main dicarboxylic acid component. A part of this dicarboxylic acid component is, 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 ethylene glycol or 1,4-butanediol may be replaced with, for example, alkylene glycol having 2 to 10 carbon atoms, 1 , 4-cyclohexanedimethanol, 1,4-bis(β-oxyethoxy)benzene, bisglycol ether of bisphenol A, and the like may be substituted with glycols other than the main glycol component. Furthermore, it is also possible to use a small proportion of a chain branching agent such as pentaerythritol, trimethylolpropane, trimellitic acid or trimesic acid, or a polymerization terminator such as monohydric polyalkylene oxide or phenylacetic acid. To produce polyester from such raw materials,
For example, dimethyl terephthalate is transesterified with ethylene glycol or 1,4-butanediol, terephthalic acid is directly esterified with the glycol, or terephthalic acid is added with ethylene oxide to produce terephthalic acid. The most widely used method is to synthesize the glycol ester and/or its low polymer, and then subject the product to a polymerization reaction by a conventional method. Furthermore, in synthesizing the polyester for carrying out the present invention, catalysts, color inhibitors, matting agents, ether bond by-product inhibitors, antioxidants, flame retardants, etc., which are well known in the art, can be appropriately used. In the present invention, the silica particles contained in the polyester need to be hydrophobic dry-processed silica particles having an alkyl group on the particle surface and blocking silanol groups on the particle surface. The hydrophobic dry-processed silica particles are silicon oxide obtained by, for example, reacting dry-processed silicon dioxide with dialkyldichlorosilane, with 30% or more of the silanol groups on the particle surface blocked, and the blocking rate is 50%. % or more is preferable. The method for producing silica particles in the present invention refers to the general method described on page 524 of "Practical Additives for Plastics and Rubber" (Kagaku Kogyosha, published on August 10, 1970). This is a method in which silicon halide is thermally decomposed together with hydrogen and oxygen in the gas phase. Furthermore, the alkali group that blocks the silanol groups on the surface of the silica particles in the present invention is not particularly limited, but methyl groups and ethyl groups are preferred. The reason for using the silica particles whose surfaces are blocked with alkyl groups will be described below. When spinning at a speed of 5,000 m/min or more, it is necessary to increase the discharge amount from the spinning pack spinneret compared to when spinning at a conventional spinning speed. Therefore, clogging in the layers of the spinning pack increases more than before, so in order to prevent an increase in the internal pressure of the spinning pack, it is necessary to minimize the amount of coarse particles trapped in the layers in the polymer from the polyester polymerization stage. There is a need. In addition, when spinning at a high speed of 5000 m/min or higher, deformation and thinning during spinning are performed at extremely high speeds, which makes yarn breakage more likely to occur due to coarse particles passing through the layers and entering the yarn. Therefore, it is necessary to reduce the amount of coarse particles that enter the yarn, and for this purpose it is necessary to strengthen the filter in the spinning pack. At high spinning speeds of 5,000 m/min or higher, even when regular polyester is used, yarn breakage occurs frequently due to foreign matter in the yarn. With silica, etc., it is difficult to spin at a high speed of 5000 m/min or more because the particles are coarse due to agglomeration of silica particles. In other words, the silica sol used in conventional coloring property improvement technology, the ordinary dry process silica, etc., cause severe aggregation during polyester polymerization and produce extremely large numbers of coarse particles. The yarn breaks frequently and cannot be spun at all. Furthermore, when the filtration of the spinning pack is strengthened, coarse particles clog the layers, increasing the internal pressure of the spinning pack, and a portion of the coarse particles pass through the layers, causing yarn breakage. On the other hand, the hydrophobic dry process silica particles used in the present invention have an alkyl group on the particle surface and block the silanol groups on the particle surface.Since the silanol groups on the surface are blocked, aggregation during polyester polymerization is prevented. This hardly occurs and the generation of coarse particles is also slight. Therefore, even if the fiber is strengthened, there is almost no clogging in the spinning pack layer, and since coarse particles that pass through the spinning pack and enter the yarn can be eliminated, pressure increases and
There is no problem of yarn breakage, and high-speed spinning of 5000 m/min or more can be performed. Moreover, since the silica particles in the present invention are uniformly dispersed without particle aggregation, fine irregularities can be uniformly formed after the surface elution treatment, and the effect of improving color development is large. Furthermore, the polyester containing the silica particles used in the present invention was
It was found that when spun at a speed of min or more, the yarn exhibited better color development than yarn obtained by spinning and drawing the same polymer using a conventional method. The average primary particle diameter of the silica particles in the present invention must be 100 mμ or less, preferably 50 mμ or less, particularly preferably 20 mμ or less. If the average primary particle diameter exceeds 100 mμ, there is a drawback that the effect of improving color development is reduced. The primary particle size is
When it is 20 mμ or less, the effect of improving color development is the highest and is more preferable. The content of silica particles in the present invention must be 0.12% by weight or more and 1.0% by weight or less, and 0.3% by weight or more and 0.48% by weight based on the polyester composition to be produced.
Particularly preferred is % by weight or less. If it is less than 0.12% by weight, the number of fine irregularities formed on the surface will be insufficient, and the effect of improving color development will not be sufficient. Moreover, if it exceeds 1.0% by weight, the number of coarse particles in the obtained polymer will increase, the spinning properties will deteriorate, and when it is made into a false-twisted yarn, there will be a drawback that the stretch elongation rate (CR value) will decrease.
Furthermore, the fibrillation properties of the dyed fabric obtained are also deteriorated, which is not preferable. It is more preferably 0.3% by weight or more in view of the effect of improving color development. In addition, from the viewpoints of increased pack internal pressure due to coarse particles, deterioration of yarn reeling properties, and yarn breakage,
More preferably, it is 0.48% by weight or less. Furthermore, in the present invention, it is necessary to set the spinning speed to 5000 m/min or more. If the speed is less than 5000 m/min, polyester fibers equivalent to conventional drawn yarns that can withstand practical use cannot be obtained by just the spinning process. FIG. 2 is a schematic diagram showing the process of the present invention, in which the polyester yarn Y discharged from the nozzle 11 is solidified through the cooling device 12, and then the oil agent applying device 1
3, the oil agent is applied, and the first Godeyroll 1
4 and the second Godey roll 15 to regulate the yarn path and yarn speed, and the yarn is wound up by a winding device 16. The winding speed of the winding device 16 is set to 5000 m/min or more. In this case, the circumferential speed of the second Godey roll 15 will vary depending on the winding tension between it and the winding device, but will be approximately equal to the winding speed. Note that an interlacing device 17 for interlacing the yarn may be installed between the second Godey roll and the winding device if necessary. 18 is a traverse fulcrum guide. The lubricant applying device 13 may be of a guide lubricating type as shown in FIG. 2, an oiling roller lubricating type, a spray lubricating type, or the like. In the method of the present invention, the position of the oil applying device 13 is preferably a position suitable for the ultra high speed spinning proposed in Japanese Patent Application No. 79265/1982. The installation position L of the oil application device 13 is longer than the position where the discharged yarn is cooled and solidified and the yarn temperature is cooled to room temperature, but shorter than 4.26×10 ¹⁰ ×D ^1.61 /V ^1.39 (m). It is preferable to set the winding speed to 5000 m/min or higher and wind the winding speed at 5000 m/min or more. D (cm)...Diameter of single yarn [In the case of irregular cross-section yarn, it is equivalent diameter when converted to a round cross section, that is, (cross-sectional area x 4) / (periphery)] V (cm/sec)... Winding speed If oil is applied at a position where the yarn temperature has cooled to Tg as in the past, single fiber breakage will occur frequently during spinning, and even if oil is applied after Tg to room temperature, the single yarn during spinning will The cutting problem is not resolved. After cooling to room temperature, apply oil,
It turns out that this problem can be solved. The cause of this is not clearly known, but the problem seems to be that until the temperature of the yarn cools down to room temperature, the density of the yarn increases, so the cross-sectional area of the yarn gradually decreases. It is. When the oil is applied during the process of slight deformation of the cross-sectional area of the yarn,
When the spinning speed is 5,000 m/min or more, single fiber breakage becomes noticeable during spinning. The surface elution treatment of the present invention can be applied to basic alkali metal compounds such as alkali metal hydroxides such as caustic soda and caustic potash, alkali metal compounds that form alkali metal hydroxides when dissolved in water, and alkali metal carbonates. This can be achieved by heating the fibers or woven or knitted fabric in a solvent consisting of an aqueous solution, or by subjecting the woven or knitted fabric to a pat/steam treatment with a solvent consisting of an aqueous solution of a basic alkali metal compound. Pat/steam treatment is most preferred. Further, in the alkali treatment, an alkali dissolution promoter such as cetyltrimethylammonium bromide or lauryldimethylbenzylammonium chloride can be used as appropriate. The alkali treatment in the present invention uses the treatment method described above to reduce the weight loss rate to 5 to 50 for fibers or woven or knitted fabrics.
Preferably, it is expressed as % by weight. More preferably 10~
It is 30% by weight. If it is less than 5% by weight, the effect of improving color development is not sufficient, so it is not preferable, and if it is less than 5% by weight,
Exceeding this is not preferable because the strength of the yarn decreases too much. In the polyester of the present invention,
The number of coarse particles of 40 μ or more is 1 g of polymer before spinning.
The number is preferably 150 or less, more preferably 100 or less. If the number exceeds 150 and normal excessive conditions are used when spinning at 5000 m/min or more, which is the objective of the present invention, to produce polyester fibers, thread breakage will occur during spinning, resulting in excessive reinforcement. There is a problem that the pressure rise becomes large. Further, even if the number of coarse particles in the polyester polymer is the same, particles conventionally used in color development improvement technology, such as dry process silica particles, have alkyl groups on the surface that are preferably used in the present invention.
Moreover, the pressure rise is larger than that of silica particles produced using a hydrophobic dry method, in which the silanol groups on the particle surface are blocked.
The layer is often clogged with silica components. The reason for this is thought to be that the agglomerated particles of silica having the alkyl group are easily dispersed by shearing in the layer. Therefore, the hydrophobic dry-processed silica particles having an alkyl group on the surface can be preferably used in the present invention. In addition, if the number of coarse particles is 100 or less per 1 g of polymer, the increase in pressure will be small and ordinary morundum sand etc. can be used as the material for the spinning pack. In some cases, the pressure increase may be large, so it is preferable to prevent the pressure increase using metal sand, a stainless steel nonwoven filter, or the like. When a polyester containing 0.5% by weight or more of silica particles, which has a large effect of improving coloring properties used in the present invention, is polymerized by a normal method, coarse particles are generated violently due to the large amount of silica particles added. Problems such as deterioration in yarn spinning properties, decrease in color development, and decrease in yarn strength are likely to occur. In particular, the production of coarse particles tends to gradually increase as polymerization batches are continued. In order to reduce the generation of coarse particles to 150 or less per gram of polymer, it is preferable to optimize the particle type and amount added, as well as to optimize the polymerization conditions as described below. The number of secondary particles having a diameter three times or more the average primary particle diameter of the silica particles in the present invention is preferably five or more per 10 square microns. If the number is less than 5, the effect of improving color development tends to be small. The reason for this is thought to be that the shape, number, etc. of the vertically long depressions that occur when the fibers are treated with alkali differ. In addition, in the present invention, the number of secondary particles having a diameter that is three times or more the average primary particle diameter is determined by cutting a yarn sample into 100 mμ pieces with a microtome using a HU manufactured by Hitachi, Ltd.
- The number of secondary particles per 7.3cm x 11cm was counted using a photograph taken at 30,000 times using a 12-type transmission electron microscope (acceleration voltage 75KV), and the number was calculated as the average of 20 samples per 10μ ² of polymer. The value obtained as . The intrinsic viscosity [η] of the polyester fiber according to the present invention is preferably 0.36 or more, particularly preferably 0.53 or more. If it is less than 0.36, strength, fibrillation, etc. may become a problem depending on the application, and for this reason, it is more preferable that it is 0.53 or more. Diethylene glycol (DEG) in the present invention
The content is preferably 2% by weight or less, particularly preferably 1% by weight or less. If the amount exceeds 2% by weight, the CR value of the false twisted yarn tends to decrease and the feel of the fabric tends to deteriorate, as described below. DEG content rate 2
In order to keep the amount below % by weight, the selection of polymerization conditions and catalyst system must be considered. In the present invention, the single fiber fineness of the polyester fiber having good coloring properties is not particularly limited. However, in general, when the single fiber fineness of polyester fiber is 1 denier or less, the light reflectance on the fabric surface increases and the depth of the fabric decreases. can. 1
When producing ultrafine fibers of denier or less, there are generally many fiber breakages during spinning or drawing, and over-reinforcement during spinning is required.If there are many coarse particles in the polymer, it is necessary to over-reinforce during spinning. Therefore, there is a problem that the internal pressure at the start is high and the pressure rise during spinning is also large. For example, the known method disclosed in Japanese Patent Application Laid-Open No. 112306/1986 does have a great effect on improving color development, but it has the problems mentioned above.
It has been difficult to stably produce ultrafine fibers of denier or less. Particle type, amount added, number of coarse particles in the present invention,
By optimizing the number of secondary particles that are three times or more the average primary particle diameter, the intrinsic viscosity, etc., it is possible to preferably and stably produce ultrafine fibers of 1 denier or less. The polyester fiber with good color development according to the present invention can be obtained by adding 0.12% by weight or more and 1.0% by weight or less of silica particles with an average primary particle size of 100 mμ or less at any stage until the polymerization of the polyester is completed. Polymerization is completed at 5000m/min.
After spinning as described above, it is obtained by heating in an alkaline aqueous solution such as sodium hydroxide to dissolve the fiber surface. The silica particles in the present invention are dispersed in aliphatic glycol, aliphatic alcohol, water, etc. by a known method, and are dispersed at any stage of the esterification reaction, transesterification reaction, or polymerization reaction before the polymerization reaction is completed. Although it can be added, it is particularly preferable to add it before or after transesterification in terms of the number of coarse particles in the resulting polymer. Generally, when adding silica particles during polyester polymerization, it is necessary to reduce the amount of silica particles added at the time of polymerization because it slows down the reaction rate, increases viscosity, etc. Therefore, the heating coil in the transesterification tank is exposed above the reaction liquid level. Therefore, there is a problem that coarse particles increase. In order to obtain a polyester to which the silica particles of the present invention are added, in which the number of coarse particles of 40 μ or more present in 1 g of polymer is 200 or more, the applicant of the present application has already proposed a patent application filed in 1983-
Particularly preferred is the method described in No. 144020.
Specifically, in order to prevent the formation of coarse particles, it is particularly preferable to adopt a method in which the raw material is charged in a transesterification can such that the heating coil is submerged in the reaction liquid, and the transesterification reaction is carried out. In the present invention, when 0.12% by weight or more and 1.0% by weight or less of silica particles are added, the amount of coarse particles produced can be reduced to 200 or less per gram of polymer by employing the above-mentioned charging method. In addition, in order to prevent problems such as sand clogging or thread breakage during the spinning process, the silica particles in the present invention can be prepared using natural sedimentation methods, centrifugation methods, etc.
It is preferable to use a material that has been classified by a generally well-known method to remove coarse particles as much as possible. Further, in the present invention, when dispersing silica particles in glycol, water, etc., conventionally known dispersants can also be preferably used. Suitable dispersants vary depending on the particle type, but in the case of the present invention, quaternary ammonium compounds such as tetraethylammonium hydroxide are particularly preferred. In the present invention, the transesterification catalyst or polymerization catalyst is not particularly limited, but in the case of the silica particles of the hydrophobic dry process of the present invention, DEG is likely to be generated during polymerization, so the transesterification catalyst may be a lithium, calcium, magnesium compound, etc. Preferably, the polymerization catalyst is particularly preferably an antimony compound. The size of the longitudinal fine depressions on the fiber surface of the fibers obtained by the present invention is determined by the maximum width of 0.05 to 1.5μ and the length/
It is particularly preferable for the maximum width ratio to be 1.5 or more in terms of color development of the fiber. Note that the maximum width of the vertically long recess refers to the maximum width of the recess in the horizontal direction. For example, when the recess is oval, it is referred to as the short axis. Further, the length of the vertically long recess refers to the maximum straight distance of the recess. For example, if the vertically elongated recess is oval, it is referred to as the major axis. The effects of the present invention will be described below. (1) Hydrophobic dry-processed silica particles with alkyl groups on the surface and blocked silanol groups on the surface are used, so there is less aggregation during polymerization, resulting in less yarn breakage during spinning and increased pressure inside the spinning pack. Less is. (2) Since the silica particles are uniformly dispersed,
The surface unevenness that contributes to improved color development is uniformly formed, and large depressions caused by agglomerated particles are not created.
It has a high effect of improving color development and is also advantageous in terms of strong strength. (3) Normally, the smaller the silica particle size, the greater the effect of improving color development, but on the other hand, problems are likely to occur due to particle aggregation. However, since the silica particles of the present invention have little agglomeration during polymerization, it is possible to use silica with a small particle size and good coloring properties. (4) the silica particles act as a crystallization nucleating agent;
It has the effect of forming the internal structure of the thread by crystallization when spinning at 5000 m/min or more. The present invention will be specifically explained below with reference to Examples. In addition, parts in Examples mean parts by weight, and % means weight %. In addition, the average primary particle diameter, intrinsic viscosity [η], diethylene glycol (DEG) content, number of coarse particles, method for creating tube knitting, color development evaluation method, alkaline dissolution conditions,
The fibrillation property evaluation method is as follows. (Average primary particle diameter) This is the value obtained by taking a photograph of silica particles magnified 100,000 times with an electron microscope, measuring the longest diameter of each primary particle from the obtained image, and taking the average of 1000 particles. (Measurement method of intrinsic viscosity [η]) Dissolve the polymer in o-chlorophenol,
Values measured in °C. (Diethylene glycol (DEG) content) Add 2.5 g of monoethanolamine to 1 g of polymer and heat under reflux to depolymerize. After cooling, add 20ml of methyl alcohol, neutralize with acetic acid, and quantify by gas chromatography.
It is expressed as the ratio (%) of diethylene glycol obtained to the polymer. (Number of coarse particles) A polyester chip was formed into a biaxially stretched film with a thickness of 25μ by a conventional method, and this ^25cm2 film was observed with a stereomicroscope (60x magnification) to measure coarse particles with a maximum length of 40μ or more. The number of coarse particles per gram of sample was calculated. The number of coarse particles was measured 10 times per level.
It was expressed as the average value. (Method for Creating a Tube Knit) The filament yarn to be evaluated was used to knit a tube knit fabric using a 27-gauge sock knitting machine (manufactured by Koike Kikai Seisakusho Co., Ltd.). (Color development evaluation method) The fabric to be evaluated was mixed with 0.2% ionic activator [Sandet G-900 (manufactured by Sanyo Kasei Co., Ltd.)] using a conventional method.
% of soda ash for 5 minutes, then washed with water and dried. Next, using a baking test device [MODEL-DK-IH manufactured by Daiei Kagaku Seiki Seisakusho Co., Ltd.] adjusted to 180°C, drying was performed in a non-tensioned state for 30 seconds to set the cylindrical knitted fabric. Next, dyeing was carried out for 60 minutes in an aqueous solution of Sumikaron Black S-BB (disperse dye manufactured by Sumitomo Chemical Co., Ltd.) at 130°C in a bath ratio of 1:30 consisting of 10% owf acetic acid 0.5cc/sodium acetate 0.2g/. Thereafter, according to a conventional method, reduction cleaning was performed for 20 minutes in an aqueous solution of 80 DEG C. containing 2 g of hydrosulfite, 2 g of caustic soda, and 2 g of a nonionic activator (SANDET G-900), followed by washing with water and drying. The color development was evaluated using a digital colorimetric color difference calculator [manufactured by Suga Test Instruments Co., Ltd.] using the L value measured in a state where six or more tube knitted fabrics were stacked and no irradiation light was transmitted.
The darker the color, the smaller the L value, and the lighter the color, the larger the value. (Alkali dissolution conditions) 1 part by weight of the tubular knitted fabric was immersed in 50 parts by weight of a boiling aqueous solution of sodium hydroxide (3% by weight), treated for a predetermined time with stirring, washed with water, and then neutralized with a 1% aqueous acetic acid solution. Then, it was further washed with water and dried. The alkali dissolution treatment time should be examined in advance.
It was set to have a predetermined weight loss rate. In addition, to calculate the weight loss rate, dry the tubular knitted fabric before and after treatment in hot air at 100℃ for 20 minutes, measure the weight [the weights at this time are designated as A and B], and use the formula A-B/A. Calculated from ×100=reduction rate (%). (Fibrillation property evaluation method) Fig. 1 shows a schematic diagram of a fibrillation tester. The wet sample (dyed knitted fabric) 1 is placed on the head 3 so that the friction area with the friction cloth 2 is 12.5 cm ² .
Attach it using holder 4 and place load 5 on it.
Make sure that the sum is 750g. On the other hand, the friction table 6 was attached via sandpaper 7 to prevent slipping, and eccentrically rotated at 85 rpm.
After rubbing for a minute, sample 1 is removed and the degree of fibrillation is visually determined. That is, when fibrillation occurs, the rubbed part looks whiter than the unrubbed part, so we observed the state in which the rubbed part looked white and judged it in the following five stages. Grade 5: Frosting is not allowed. Grade 4: Slight frosting is observed. Grade 3: Slight frosting is observed. Grade 2: Frosting is quite noticeable. Grade 1: Significant frosting is observed. Of the above, grades 3 and above are considered passing levels. 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 a period of 4 hours under a nitrogen gas atmosphere, and the transesterification reaction was carried out while the generated methanol was continuously distilled out of the system. During transesterification, the raw materials were charged so that the heating coil was submerged in the reaction solution. Subsequently, 0.05 part of trimethyl phosphate was added to the obtained product. Furthermore, a mixture of various inorganic fine particles shown in Table 1, a 20% aqueous solution of tetraethylammonium hydroxide, and ethylene glycol in a weight ratio of 5:2.5:92.5 was added.
Janke & Kunkel Ultra Turrax T45DX
(10,000 rpm) for 45 minutes, and the slurry was added to the polyester from which inorganic fine particles were obtained in various amounts. The system was then gradually depressurized from 760mmHg to 1mm over 1 hour and 30 minutes.
The pressure was reduced to Hg, and at the same time the temperature was raised from 230°C to 280°C over 1 hour and 30 minutes. Polymerization was carried out for an additional 2 hours at a polymerization temperature of 280° C. for a total of 3 hours and 30 minutes under reduced pressure of 1 mmHg or less. After the reaction was completed, the mixture was discharged into water and polyester chips were obtained by a conventional method. The obtained polyethylene terephthalate was heated to 160℃
After drying under reduced pressure for 4 hours, the material was spun using the apparatus shown in Figure 2 at a spinning temperature of 305°C and a take-up speed of 6000 m/min using a 36-hole spinneret, 100 mesh sand, and a stainless steel nonwoven filter with an absolute diameter of 20 μ. , a drawn yarn was obtained only by the spinning process of 76 denier-36 filament. Using the obtained drawn yarn, a tubular knitted fabric was prepared by the method described above, and then it was scoured and treated with alkali so that the weight loss rate was 20%, and then the coloring property was evaluated. Table 1 shows the spinning properties in the spinning process and the above color development evaluation results. Note that the methyl group-blocked dry process silica in Table 1 is dry process silica that has methyl groups on the particle surface and has 75% of the silanol groups on the particle surface blocked. Further, the state of dispersion of particles in the thread is the number of particles having a diameter three times or more the average primary particle size, expressed as (particles/10μ ² ).

【table】

[Table] Experiment No. 1, 7, 10, 11 and 12 in Table 1
This is a comparative example for clarifying the effects of the present invention. In Experiment No. 1, which is a comparative example, the amount of added particles was less than 0.12% by weight, the number of particles with an average primary particle diameter of 3 times or more was small, and the color development was poor. In addition, in Experiment No. 7, which is also a comparative example, the amount of particles added exceeds 1.0% by weight, so the spinning property was poor.
The increase in pack internal pressure is also large. In Experiment No. 10, which is also a comparative example, the average primary particle diameter of the particles exceeds 100 mμ, and the number of particles that are three times or more the average primary particle diameter is also small, resulting in insufficient color development. Experiment Nos. 11 and 12, which are comparative examples, use silica that does not block the silanol groups on the surface, so although the effect of improving color development is observed, the spinning property is poor.
The increase in pack internal pressure is also large. On the other hand, Experiment Nos. 2, 3, and 4, which are examples of the present invention,
Samples Nos. 5, 6, 8, and 9 had good spinning properties and a sufficient level of color development. Furthermore, using the drawn yarn of Experiment No. 4, taffeta, strongly twisted fabric, false twisted textured yarn fabric, false twisted textured yarn strongly twisted fabric,
After knitting and weaving, tricots, circular knits, etc. were subjected to weight reduction treatment with alkali, and further dyed and printed using conventional methods. The resulting fabrics, dyed from light to dark colors and dyed black, showed better color development than when drawn yarns obtained by conventional spinning and drawing of the same polymer were used. Example 2 Using the polymers used in Experiment Nos. 5 and 12 of Example 1, a 72-hole cap and an absolute overdiameter were
Uses a 15μ stainless steel non-woven filter
Spinning was carried out under the same conditions as in Example 1 except that the yarn was drawn at 5500 m/min to obtain a drawn yarn of 75 denier-72 filaments. The obtained drawn yarn was made into a tubular knitted fabric by the method described above, and its color development and evaluation were evaluated. Table 2 shows the evaluation results of spinning properties and coloring properties in the spinning process.

[Table] Experiment No. 14 in Table 2 is a comparative example for confirming the effects of the present invention. In Experiment No. 14, which is a comparative example, although the fiber was strengthened, the spinning properties were insufficient and the internal pressure increased significantly. Experiment No. 13, which is an example of the present invention, had satisfactory levels of both color development and thread-spinning performance. Example 3 The polymerization time of the polymer in Experiment No. 4 of Example 1 was changed to obtain polymers with different degrees of polymerization. The obtained polymer was spun in the same manner as in Example 1,
A drawn yarn of 75 denier-36 filaments was obtained. The obtained drawn yarn was processed using a spindle-type false twisting machine with a heater length of 110 cm at a heater temperature of 210°C, a false twisting speed of 100 m/min, a number of false twists of 3450 tpm, and a 3%
The fabric was false-twisted at an underfeed rate of , and then subjected to knitting and alkali dissolution treatment using the method described above, and then evaluated for color development. Table 3 shows the expansion/contraction elongation rate (CR value) of the obtained false-twisted paper and the fibrillation property of the tubular knitted fabric after the alkali dissolution treatment.

[Table] In Table 3, Experiment Nos. 19 to 21 are comparative examples for clarifying the effects of the present invention. Experiment No. 19 had a low degree of polymerization, so the fibrillation property was low. In addition, in Experiment Nos. 20 and 21, the DEG exceeded 2.0% by weight, and the CR of the false twisting process was low. In Experiment Nos. 15 to 18, the CR value of the false-twisted yarn was high and the anti-frosting property was also good, and as a result of dyeing the fabric using this false-twisted yarn after alkali weight reduction treatment, good color development was obtained. It was done.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an apparatus for measuring fibrillation. FIG. 2 is a schematic diagram showing a preferred embodiment of the spinning process of the present invention. 11: Mouthpiece, 12: Cooling device, 13: Oil applying device, 14: First Godey roll, 15: Second Godey roll, 16: Winding device, Y: Yarn.

Claims (1)

[Claims] 1. 0.12% by weight of hydrophobic dry-processed silica particles having an average primary particle diameter of 100 mμ or less, having an alkyl group on the particle surface, and blocking 30% or more of the silanol groups on the particle surface. After spinning polyester containing 1.0% by weight or less at 5000 m/min or more,
1. A method for producing polyester fibers with good color development, which comprises subjecting the fibers to surface elution treatment with a solvent that is soluble or decomposable. 2. The method for producing polyester fibers with good coloring properties according to claim 1, wherein the average primary particle diameter of the silica particles is 50 mμ or less. 3. The method for producing polyester fibers with good coloring properties according to claim 1, wherein the average primary particle diameter of the silica particles is 20 mμ or less. 4. The method for producing polyester fibers with good coloring properties according to claims 1 to 3, characterized in that the content of silica particles is 0.3% by weight or more and 0.48% by weight or less. 5. The method for producing polyester fibers with good color development properties according to claims 1 to 4, characterized in that the number of silica particles of 40 μ or more present in 1 g of polyester is 150 or less. 6. Color development according to claims 1 to 5, characterized in that there are at least 5 secondary particles per 10 square microns having a diameter that is three times or more the average primary particle diameter of the silica particles. A good method for producing polyester fiber. 7 Claims 1 to 5, characterized in that the intrinsic viscosity of the polyester is 0.36 or more
A method for producing a polyester fiber with good coloring properties as described in Section 1. 8 Claims 1 to 6, characterized in that the intrinsic viscosity of the polyester is 0.53 or more
A method for producing a polyester fiber with good coloring properties as described in Section 1. 9. The method for producing polyester fibers with good color development according to claims 1 to 8, characterized in that the content of diethylene glycol in the polyester is 2% by weight or less. 10. The method for producing polyester fibers with good color development according to claims 1 to 8, characterized in that the content of diethylene glycol in the polyester is 1% by weight or less. 11. The method for producing polyester fibers with good coloring properties according to claims 1 to 10, wherein the single fiber fineness after surface elution treatment is 1.0 denier or less. 12. The method for producing polyester fibers with good coloring properties according to claims 1 to 11, characterized in that the solvent for the fibers is a caustic soda solution.