JPS648094B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyester dyed temporary twisted yarn for flat knitting, and particularly for flat knitting which has excellent low-temperature heat setting properties during heat setting to stabilize the form of the knitted fabric obtained from the processed yarn. Concerning polyester dyed temporarily twisted yarn. Polyester fibers, particularly polyethylene terephthalate, have excellent functionality such as wash-and-wear properties, wrinkle resistance, and toughness, and are therefore widely used for clothing such as various textiles, warp knits, and jersey. However, the reality is that it has hardly been used for flat knitting purposes. The reason for this is that it lacks the low-temperature heat setting ability to remove the strain added during knitting with steam at temperatures below 100°C, which is said to be an essential condition for flat knitting materials. The low temperature heat setting properties of knitted fabrics are required for the following reasons. Generally, when a knitted fabric is made, the stitches bend due to the various tensions applied to the yarn during the knitting process, so it is necessary to set the stitches under heat and finish them in the correct direction. For example, sweaters are mainly knitted on a flat knitting machine, and the process is to dye the yarn and then knit it on the flat knitting machine, and then correct any curling up of the edges of the knitted fabric or skewing of the stitches. to heat set and stabilize the shape. However, most of the conventionally well-known bulking processes are performed at 180 to 230℃.
Therefore, if you want to completely heat-set the knitted fabric after that, it is natural that the temperature should be close to the bulking temperature mentioned above, or if moist heat such as steam is used, it should be at a high temperature of at least 130℃. Requires heat setting under high pressure. Furthermore, since polyester is generally difficult to dye, the dyeing temperature must be as high as about 130°C. The problem with dyeing at around 130°C is that even when removing distortions from knitted fabrics made from dyed yarn, it is not effective unless the dyeing is done with moist heat and high temperature at 130°C or higher. Heat setting at such high temperatures uses air heating or radiation, which not only does not allow uniform heat setting, but also has low thermal efficiency, so it can hardly be used. On the other hand, in order to perform steam heat setting, it is necessary to heat set the container by holding it in the shape of a sweater, which results in a huge container and requires a high-pressure container, which is inefficient and extremely economical. It was a disadvantage. Polyester fibers have a high thermal deformation temperature, so in order to impart good crimping, it is common to temporarily twist the fibers at a high temperature of at least 180°C or higher. The processed yarn thus obtained is required to: (1) have a very high thermal history and therefore have no low-temperature heat setting properties for knitted knitted yarns after knitting, and (2) have a thin and cool feel. Since it has too much crimp for flat knitting purposes, it has a strong feeling of thickness and is almost impossible to use for flat knitting purposes. Therefore, many methods have been proposed to improve the drawbacks of such polyester processed yarns. For example, as a proposal to lower the temporary twisting processing temperature, Japanese Patent Publication No. 17214/1972 and Japanese Patent Application Laid-open No. 117719/1982
Publication No. 49-10629, Special Publication No. 10629, Special Publication No. 1987-
There are publications such as Publication No. 12621. In addition, as a proposal to improve dyeing properties,
These include Publication No. 10497 and Japanese Patent Application Laid-open No. 133530/1983. Furthermore, a proposal for imparting low-temperature heat setting properties to knitted fabrics is disclosed in Japanese Patent Application Laid-Open No. 111124/1983. In addition, as a proposal to improve the selvage of knitted fabrics, JP-A-53-
There is a publication number 14891. Although many improvement proposals have been proposed and some have been implemented, none of these conventional techniques are sufficiently effective. A method for obtaining processed polyester yarn suitable for knitting purposes has not yet been found. The inventors of the present invention have made extensive studies to improve the drawbacks of the prior art as described above, and have arrived at the following invention. That is, in the present invention, a yarn made of a copolyester in which 3.5 to 6.0 mol% of the total repeating units of the polyester is ethylene 5-sodium sulfoisophthalate is false-twisted at 100 to 180°C, and then the yarn is twisted without carrier. Polyester false-twisted yarn dyed at 98°C or lower, with a density of 1.375 to 1.405
It is a dyed polyester temporary twisted yarn for flat knitting with a weight of g/cm ³ . In order to dye deep and vivid colors below 98℃,
Processed yarn has 3.5 to 6.0 total repeating units of polyester
It is necessary that the copolymerized polyester contains ethylene 5-sodium sulfoisophthalate in mol%. If the ethylene 5-sodium sulfoisophthalate component is less than 3.5 mol%, there will be no carrier, and the density will change even if dyed at a temperature of 98°C or lower.
The clarity is insufficient. So, I tried to get enough dark colors and sharpness.
If dyed at temperatures above 100°C, the processed yarn cannot be heat set at temperatures below 100°C after knitting. In particular, for fields that require sharpness such as women's use, 4.0 mol% or more is preferable. In addition, when attempting to dye polyester without a carrier at temperatures below 100°C using disperse dyes commonly used for polyester, there are the following drawbacks. Since this is a mere adsorption phenomenon, the dye is easily desorbed and the dye fastness, especially wet fastness, is significantly inferior. Dyeing lacks clarity. In the case of products such as flat knitting, which are mainly intended for women and are highly fashionable, clarity is important.
Disperse dyes cannot provide sufficient clarity. Since disperse dyes are not completely exhaustible, some dye always remains in the dyeing residue even in the case of light colors. Therefore, purification of wastewater is difficult. These three problems can be almost completely solved by making the dye dyeable with basic dyes as in the present invention. In other words, basic dye-dyeable types have ionic bonds, are easily dyed, and are difficult to separate.
This is an essential difference between dyes, and it is a completely exhaust type with excellent color development and excellent clarity.
No dye remains in the residual liquid even at fairly high concentrations. On the other hand, when the ethylene 5-sodium sulfoisophthalate component exceeds 6.0 mol%, the polymer melt viscosity becomes extremely high, which not only reduces the operability in the polymerization and spinning processes, but also reduces the strength of the resulting yarn. Unevenness in strength and elongation increases rapidly.
5.5 mol% for fields that require particularly high strength
The following are preferred. Furthermore, if the ethylene terephthalate component is less than 90 mol%, the toughness and high Young's modulus characteristic of polyethylene terephthalate fibers will be lost, which is not preferable. The second feature of the present invention is that the density of the polyester constituting the dyed temporary twisted yarn is 1.375 g/
cm ³ or more and 1.405g/cm ³ or less. By limiting the density of the dyed temporary twisted yarn in this way, a knitted fabric with unprecedented low-temperature heat setting properties, a texture suitable for flat knitting, and shape retention, which is a characteristic of polyester, has been created. This combination of properties made it possible for the first time to enter the field of flat knitting, which polyester had previously been unable to do. Here, the density of the dyed temporary twisted yarn is 1.405g/cm ³
If the density exceeds 1.405g/ ^cm3, the knitted fabric will have poor low-temperature heat setting properties and cannot be used for flat knitting.
It is necessary to do the following. If the density of the processed yarn is 1.405 g/cm ³ or less, the low temperature heat setting properties of the knitted fabric will be at a level that poses no practical problems. For applications that require even better low-temperature setting properties, the density is preferably 1.400 g/cm ³ or less, so that any knitted structure can almost completely eliminate the curl of the knitted fabric by low-temperature heat setting, and the product will not run skewed. In order to easily correct the problem, the density of the processed yarn is preferably 1.395 g/cm ³ or less. On the other hand, in order to maintain the shape retention of knitted fabrics obtained from polyester processed yarn, the density must be 1.375 g/cm ³
The above is necessary. In the preferred method of producing the dyed and twisted polyester yarn according to the present invention, the copolymer component of the polyester is 3.5 of the total repeating units of the polyester.
As long as ~6.0 mol% is ethylene 5-sodium sulfoisophthalate, the synthesis method and polymerization method are not particularly limited. For example, a monomer may be produced by transesterifying terephthalic acid with ethylene glycol via dimethyl ester, or by esterifying terephthalic acid with ethylene glycol.
Monomers may also be produced. Furthermore, in addition to ethylene 5-sodium sulfoisophthalate, other copolymerization components may be used as a copolymerization component to the extent that the total of ethylene 5-sodiumsulfoisophthalate and other copolymerization components does not exceed 10 mol%. There is no problem in copolymerizing. Examples of other copolymer components include the following. Adipic acid, sebacic acid, isophthalic acid, diethylene glycol, polyethylene glycol, trimethylene glycol, 1,4 cyclohexanedimethanol, benzoylbenzoic acid, benzyloxybenzoic acid, methoxypolyethylene glycol,
Glycerin, trimellitic acid, pentaerythritol, trimesic acid, etc. The polymerization method is not particularly limited, and various stabilizers and matting agents can be used. The obtained polymer may be made into chips or may be processed by continuous polymerization and spinning. Although the spinneret is not limited, it is preferable to use three or more multilobal yarns from the viewpoint of product texture. The multifilament obtained by spinning may be an undrawn yarn or a pre-oriented yarn. The stretching method is not limited, and may be a so-called direct spinning and stretching method in which spinning and stretching are directly connected. The multi-denier of the drawn yarn obtained in this way is 48 to 200 deniers, and the number of filaments is 20.
~80 pieces is preferred. For the temporary twisting process, "IN-DRAW" may be used, in which a multifilament before drawing is used and drawing and temporary twisting are performed simultaneously, but it is also possible to perform only temporary twisting using the drawn yarn. Further, as the temporary twisting means, a spindle method and various friction temporary twisting methods can be used. The thermal history during temporary twisting is important because it affects the heat setting properties of the knitted fabric. In order to impart good heat setting properties to knitted fabrics, it is necessary to keep the heater temperature during temporary twisting, that is, the temperature during temporary twisting, below 180°C.
Preferably it is 170°C or lower. The bulerier processing temperature in the bulerier processing performed subsequent to the temporary twisting processing is preferably 120°C or lower, more preferably 110°C or lower. On the other hand, in order to maintain shrinkage, the temporary twisting temperature needs to be 100°C or higher, and the bulerier processing temperature is preferably 95°C or higher. Such temperature conditions in the temporary twisting process are required not only to improve the setting property but also to improve the texture. In other words, the temporary twisting temperature is set to 180
℃ or less, by setting the buleria processing temperature to 120℃ or less, the stretch recovery rate (CR) of the tentatively twisted yarn after dyeing is 2 to 12%, and the stretch elongation rate (TR) is 0.5 to 0.5.
At 7.0%, it has a very desirable texture with a crisp, cool feel and thin texture, which are necessary requirements for spring/summer flat knitted fabrics. Note that it is not preferable to set the temporary twisting temperature to 100°C or less because the texture will be similar to raw silk. The subsequent staining is preferably cheese staining, but the present invention is not limited to cheese staining, and any technique such as skein staining or muff staining may be used. Furthermore, basic dyes are preferred as the dyes used in terms of color development, sharpness, fastness of dyed products, wastewater treatment, and dyeing cost. Dyeing temperature is very important as it affects setting properties. Since dyeing takes a long time, it is necessary to carry out the dyeing at a temperature substantially lower than the setting conditions, which is at most 98°C or lower. In order to further improve heat setting properties, the temperature is 95°C or lower, more preferably 92°C or lower. It is not recommended to use a carrier during dyeing. This is because even if the dyeing temperature is lowered using a carrier, crystallization of the fibers progresses and the target density cannot be obtained. On the other hand, in order for the dyed product to be dyed sufficiently deep and sufficiently clear, the dyeing temperature needs to be 85°C or higher. The dyed polyester yarn of the present invention has the following advantages and is particularly useful for flat knitting. (1) It has low-temperature setting properties of less than 100°C, which could not be achieved with conventional technology. In other words, in order to impart low-temperature setting properties, it is of course necessary to reduce the heat history through temporary twisting, but rather the heat history during dyeing after temporary twisting is important.
An essential condition is that the heat history during dyeing is lower than the heat history during setting. In other words, in order to fully exhibit the low temperature setting of less than 100°C, a dyeing temperature of 98°C or lower is required, preferably a dyeing temperature of 95°C or lower, more preferably 92°C or lower, and the dyed yarn of the present invention satisfies this requirement. do. (2) The texture of the product is good. In other words, because it has specific shrinkage properties, it eliminates the excessive shrinkage that occurs with conventional polyester processed yarns.
It has the crisp, cool, and thin feel necessary for flat knitting, and the stitches are orderly. (3) Since it can be dyed at a low temperature of 95°C or lower without using a carrier, the dyeing cost is low and the quality is favorable for low-temperature dyeing. The present invention will be specifically described below with reference to Examples, and the methods for measuring each characteristic value in the Examples are as follows. A. Stretch recovery ratio (CR) A skein with a circumferential length of 1 m wound 5 times using a measuring machine is further folded in half and treated with hot water at 90°C for 20 minutes without any load. Leave for at least 12 hours after treatment and air dry. Further, add 102 mg/kg of this in water at 20°C.
Apply a load of d, read the length lo after standing for 2 minutes, further reduce the load to 2 mg/d, read the length l ₁ after standing for 2 minutes, and calculate CR from the following formula. CR (%) = lo-l ₁ / lo x 100 B Stretching and elongation rate (TR) A load of 1/15 g of the indicated denier was applied to a skein with a circumference of 1 m, wound 20 times using a measuring machine, and heated at 90°C.
Treat with hot water for 5 minutes. After processing, leave it for 10 minutes, increase the load to 4 times the indicated denier, read the length l ₁ , and use the following formula.
Find TR. TR (%) = l ₁ - lo / l ₁ × 100 C Selvage degree Yarn dyed processed yarn is knitted into a jersey texture that is well-balanced in the vertical and horizontal directions under conditions that satisfy the following formula. 230＜G√＜370 1.2＜W/D＜1.6 0.5＜W/C＜0.9 [However, G: Gauge of knitting machine (number of stitches per inch) D: Denier of knitting yarn W: After knitting Number of wales per 1 inch of knitted fabric C: Number of courses per 11 inches of knitted fabric after knitting] Next, this knitted fabric was set in steam at 97℃ for 30 seconds, and the knitted fabric was removed from the setting frame and knitted. Mark a distance of 200mm in the vertical direction in the center of the
Cut along the stitches in the vertical direction, 20℃, 65 seconds
Leave it overnight at constant temperature and humidity at RH. As shown in Figure 1, this knitted fabric 1 is placed on a smooth rubber plate 2.
With the back side of the jersey knit facing up, use insect pin 3 to set the distances between D and A, C and B to 50 mm each, and D to C, A.
A, B, C, so that the distance between and B is 200 mm each.
Fix each point of D. The knitted fabric rolls up between AB and presents a crescent-shaped ear wrap 4. At this time, read the length l (mm) of the ear wrap in the vertical direction with a ruler, and calculate the degree of ear wrap using the following formula. Ear wrap degree (%) = l / 200 x 100 There is no practical problem if the ear wrap degree is 10% or less, but it is 2% or less for any knitting structure to not roll up and to easily correct skew. be. D Relative viscosity (ηr) 8 g of polymer are dissolved in 100 ml of O-chlorophenol at 100° C. over a period of 1 hour. The viscosity of this polymer solution and the viscosity of O-chlorophenol itself were measured in the same unit at 25°C and expressed as a ratio. E Density Determined at 25°C by density gradient tube method using normal heptane and carbon tetrachloride. Examples 1 to 5 A polyethylene terephthalate copolymer in which 4.8 mol % of all structural units was ethylene 5-sodium sulfoisophthalate was polymerized by a conventional method to form chips with a relative viscosity of 14.8. Heat this chip to 160℃
After drying under reduced pressure for 5 hours, 55.6 g/min was ejected from a 48-hole nozzle with a pentaloval hole shape consisting of 5 slits and taken at 1400 m/min.
The yarn was drawn at a speed of 700 m/min to obtain a drawn yarn of 150 ^D - 48 ^F. This drawn yarn was subjected to temporary twisting using a spindle method under the temperature conditions shown in Table 1. The obtained processed yarn was wrapped in cheese and scoured using the usual scouring method, and then dyed with malachite green dye, which is a basic dye, 1% OWF and dyeing solution PH5 at a bath ratio of 1:100 as shown in Table 1.
Dyeing was carried out at the dyeing temperature indicated in , followed by air drying. Table 1 shows the properties of the processed yarn and the properties of the knitted fabric obtained by tube-knitting the dyed processed yarn. It can be seen that although the characteristics were good at all levels, Example 2 was particularly excellent. Comparative Examples 1 to 4 Using the same drawn yarn as in Example 1, temporary twisting was performed under the temperature conditions shown in Table 1. Cheese staining was then performed. The dyeing temperature conditions are as shown in Table 1, and the other dyeing conditions are the same as in Example 1. Evaluation of the dyed yarn and evaluation of the knitted fabric of the dyed yarn were carried out in the same manner as in Example 1, and the results shown in Table 1 were obtained. In Comparative Example 1, the temperature of the temporary twisting process was high, so the degree of selvage was large, the heat setting property was poor, and the texture was too loose and was not suitable for spring and summer.
In Comparative Example 2, the dyeing temperature was high, so the heat setting property was poor, the stitch deviation was large, and the texture was rough and hard. Comparative Example 3 had insufficient dyeing properties due to the low dyeing temperature, poor clarity, and was not at the commercial level. In Comparative Example 4, the temporary twisting temperature was low, so the fabric resembled raw silk and had poor texture and appearance. Comparative Example 5 Example 2 except that the ethylene 5-sodium sulfoisophthalate copolymerization rate was changed to 2.8 mol%
Temporary twisting and dyeing were performed under the same conditions as above. The results are shown in Table 1, and the sharpness was extremely poor due to insufficient dyeability. 【table】

[Brief explanation of drawings]

FIG. 1 explains the measurement of the degree of selvage of knitted fabrics. 1: knitted fabric, 2: rubber plate, 3: insect pin, 4: ear wrap, l: ear wrap length.

Claims (1)

[Claims] 1 A thread made of a copolyester in which 3.5 to 6.0 mol% of the total repeating units of the polyester is ethylene 5-sodium sulfoisophthalate,
After false twisting at 100~180℃, 98℃ without carrier
A dyed polyester false-twisted yarn for flat knitting, which is a polyester false-twisted yarn dyed as follows, and has a density of 1.375 to 1.405 g/cm ³ .