JP2903723B2 - Base cloth for adhesive tape - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base fabric for a pressure-sensitive adhesive tape, which comprises a false twisted yarn of a modified polyester. More specifically, the present invention relates to a base fabric for an adhesive tape, which has a good yarn passing property in a high order process, a good cutability of an adhesive tape, a beautiful cut, a smooth surface, and a good appearance.

[0002]

2. Description of the Related Art Spun yarn or vinylon fiber of rayon swoof has been used for a long time as a base material for an adhesive tape, but it has various drawbacks such as a decrease in strength when wet. Many techniques for improving polyester fibers for use as a base fabric for pressure-sensitive adhesive tapes have been disclosed.

[0003] For example, Japanese Patent Application Laid-Open No. 61-75840,
Japanese Patent Application Publication No. -11736 discloses a technique in which physical properties of fibers used for warp of a base fabric are specified in order to improve the hand-cutting property of the adhesive tape and to make the cut beautiful. However, in each case, the elongation of the fiber is low, and there has been a problem that fluff and yarn breakage are apt to occur during warping and weaving as well as during production of the original yarn.

Japanese Patent Application Laid-Open Nos. 63-21950 and 1-104849 disclose the use of a crimped entangled yarn or a bulky yarn having specific physical properties as a warp of a base fabric for weaving or adhesive tape. There have been proposed techniques for improving the hand-cutting properties of these yarns, but these also have low elongation of the yarn and have the same problems as described above.

Further, Japanese Patent Application Laid-Open No. Sho 60-245684,
Japanese Patent No. 20055 discloses a warp of a base fabric comprising a fiber having a specific physical property value and comprising a polymer obtained by copolymerizing a third component such as a compound containing a —SO ₃ M group (M represents hydrogen or a metal atom). The former has the same problem as the above, and the latter has a problem that the base fabric is liable to be clogged because the flat yarn is also arranged on the warp and the weft.

As described above, in the prior art, the production stability of the base yarn for the base fabric, the high process passability, and the necessary properties of the pressure-sensitive adhesive tape, particularly the hand-cutting property, cannot be simultaneously satisfied.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to improve the productivity of the base yarn for the base fabric, the high passability of the high-order process, the excellent hand-cutting of the adhesive tape, the beautiful cut, and the smooth surface. Another object of the present invention is to provide a base fabric for an adhesive tape having a good appearance.

[0008]

The object of the present invention is to provide a modified polyester obtained by copolymerizing an isophthalic acid component having a metal sulfonate group with 1 to 10 mol% based on all dicarboxylic acid components. And (b) a false-twisted yarn that simultaneously satisfies (b) as a warp yarn. (A) 2.5 ≦ strength (g / d) ≦ 4.0 (b) 30 ≤ elongation (%) ≤ 40 (c) 2.0 ≤ boiling water shrinkage (%) ≤ 10.0 (d) 70 ≤ mixed degree ≤ 250.

The warp of the adhesive tape base fabric in the present invention is characterized by using a false twisted yarn made of modified polyester. According to the study of the present inventors, in the case of polyethylene terephthalate having a warp composition, the lower the degree of polymerization of the polymer, the better the hand-cutting property of the pressure-sensitive adhesive tape. However, the modified polyester of the present invention has better hand-cutting properties than polyethylene terephthalate, and the use of false twisted yarn further improves hand-cutting properties. Further, the fine crimp of the single yarn of the false twisted yarn contributes to the improvement of the adhesiveness when the resin layer is laminated on the base fabric in the adhesive tape manufacturing process.

[0010] The false twisted yarn of the present invention must satisfy the following specific physical properties.

First, the strength needs to be in the range of 2.5 to 4.0 (g / d). If it is less than 2.5 (g / d), fluff and yarn breakage are likely to occur during the production of the original yarn, and even if it does not occur, fluff and yarn breakage will occur during warping and weaving, which is not good. In addition, the longitudinal strength of the pressure-sensitive adhesive tape is small and poses a practical problem. When it exceeds 4.0 (g / d), the hand-cutting property of the pressure-sensitive adhesive tape is deteriorated, and the cut after the tear is frayed, so that a beautiful cut cannot be obtained. Therefore, the strength is 2.7 (g / d).
The range of -3.8 (g / d) is preferable.

[0012] The elongation must be in the range of 30 to 40 (%). If the elongation is less than 30 (%), fluff or yarn breakage is likely to occur during false twisting because of the false twisted yarn of the modified polyester. Operation becomes impossible. In addition, warping properties and weaving properties also deteriorate. If it exceeds 40 (%), yarn run-out will occur in the twisting zone during false twisting, and the yarn will come off from the heater or the yarn will break, making stable processing impossible. In addition, the hand-cutting property of the adhesive tape is deteriorated, and the cut after tearing is not clean.

[0013] The boiling water shrinkage must be in the range of 2.0 to 10.0 (%). When the value exceeds 10.0 (%), warp shrinkage and dispersion between warps increase in various heat treatment steps during the production of the pressure-sensitive adhesive tape, the dimensional change rate increases, and process control becomes difficult, so that production is difficult. Not only is the property reduced, but also the surface of the adhesive tape is spotted or wrinkled, resulting in poor product quality. Accordingly, the boiling water shrinkage ratio is preferably low, preferably 8% or less, and more preferably 6% or less. However, in order to produce a raw yarn having a low boiling water shrinkage rate, a high-temperature heat treatment is required in the manufacturing process, but if the heat treatment is performed at an excessively high temperature, the strength and elongation are reduced due to thermal deterioration of the raw yarn, Since the high order workability is lowered and the practical strength as an adhesive tape is lowered, it is necessary to perform heat treatment so that the boiling water shrinkage ratio becomes 2.0 (%) or more.

Further, the false twisted yarn of the present invention must have a specific mixed state of the mixed degree determined by the following measuring method.

[0015] As shown in the measurement method Figure 1 commingled degree, multiplied so as not slide the sample yarn around the central axis 1 to a rotatable grooved pulley 2 to the right and left no resistance, 2
Apply loads 3 and 4 to the location. The loads 3 and 4 are set to the total denier of the sample yarn × 0.4 g.

Next, a fixed needle 5 having an outer diameter of 0.60 mm is pierced at a substantially right angle between the single yarns constituting the yarn and fixed.
Next, a constant load 6 having a weight of the single yarn denier of the sample × 2.0 g is further applied to the load 3 applied to the left side of the sample yarn, and the sample yarn is moved to the left until it stops at the fixed needle 5 where it stops. .

Next, the constant load 6 applied to the load 3 is removed, and the load is applied in addition to the load 4 on the right side so that the sample thread is hooked on the fixed needle 5 and stops naturally. The moving speed of the sample yarn under the constant load 6 is 10 mm / sec. The moving distance L (mm) of the sample yarn to the right side by the above method is obtained, and the degree of fiber mixing is calculated from the following equation. The degree of fiber mixing = 1000 / (L + 0.60) Measured at 10 arbitrary positions in the longitudinal direction of the sample yarn and expressed as an average value.

In the present invention, the degree of mixing must be in the range of 70 to 250. By setting the degree of fiber mixing to 70 or more, the bunching property of the yarn is improved, and the warping property and the weaving property are improved. Furthermore, since the base cloth can be prevented from being twisted or bent, the adhesive tape is not kinked, and the surface flatness of the adhesive tape is improved, and a product having a good appearance and excellent product quality can be obtained. However, when the value exceeds 250, the warping property and the weaving property are deteriorated due to the fluff and the tarmi generated during the fiber mixing, and the thickness unevenness occurs in the yarn longitudinal direction, resulting in poor uniformity.
The mixing degree is preferably from 80 to 230.

Next, the modified polyester of the present invention will be described. In the present invention, the modified polyester is obtained by copolymerizing an isophthalic acid component containing a metal sulfonate group (hereinafter abbreviated as S component) in an amount of 1 to 10 mol% with respect to all dicarboxylic acid components. The S component is a compound represented by the following formula. Specifically, dimethyl (5-sodium sulfo) isophthalate, bis-2-hydroxyethyl (5-sodium sulfo) isophthalate, bis-4-
Hydroxybutyl (5-sodium sulfo) isophthalate and the like can be mentioned.

[0020]

Embedded image

As the preferred S component, dimethyl (5-
Sodium sulfo) isophthalate and bis-2-hydroxyethyl (5-sodium sulfo) isophthalate are exemplified. More preferably, it is dimethyl (5-sodium sulfo) isophthalate.

As described above, the S component must be copolymerized at 1 to 10 mol%. The effect of copolymerizing the S component is that the degree of orientation of the polyester fiber is reduced to decrease the strength or elongation, or both, and that the shearing force, particularly in the direction perpendicular to the fiber axis, is reduced. This has the effect of greatly improving the properties. When the S component is less than 1 mol%, the above effect is small. If it exceeds 10 mol%,
The melt viscosity of the polymer becomes remarkably large, and not only does melt spinning become difficult, but also the strength and elongation become too low, so that false twisting and high-order processability are deteriorated and productivity is impaired. . Therefore, the copolymerization amount of the S component is 1.5 to 8 mol%.
Is more preferable, and more preferably 2.0 to 7.0 mol%.

The adhesive tape base fabric of the present invention can be used for both thin and thick adhesive tapes. For thin materials, the fineness of the false twisted yarn is better.
For a thick material, the fineness is preferably large, and the fineness is preferably in the range of 50 to 250 (denier).
Further, in the case of large fineness, the strength is inevitably increased, and the hand-cutting property of the pressure-sensitive adhesive tape is reduced, so that the strength is preferably low. Conversely, in the case of fineness, the strength is small, and the strength in the warp direction of the pressure-sensitive adhesive tape is too small to cause a problem in practical use. From the above, a false twisted yarn that satisfies the following relational expression for the fineness and strength is preferable.

400-100 × strength (g / d) ≦ fineness (denier) ≦ 500-100 × strength (g / d) The fineness of the single yarn constituting the false twisted yarn is 1 to 10 (denier). Is preferred.
If the denier is less than 1 denier, the operability of the raw yarn deteriorates, and fluff and yarn breakage occur. If it exceeds 10 denier, the rigidity of the yarn will be too strong, and the fiber mixing in the fiber mixing process will be poor,
The hand-cutting property of the adhesive tape becomes poor. The more preferred fineness of the single yarn is 2 to 6 denier.

The weaving density of the warp constituting the base fabric in the present invention is appropriately determined depending on the fineness of the weft, but if the density is too low, clogging occurs.
Since the strength in the warp direction is too high and the hand-cutting property of the adhesive tape is deteriorated, it is preferable that the weaving density satisfy the following expression.

350 / (denier of warp) ^0.5
≤ Weaving density (books / inch) ≤ 550 / (denier of warp (denier)) ^0.5 The weft constituting the base fabric in the present invention is preferably a flat yarn made of polyester, even if a real twist or entanglement treatment is applied. Good. The weft has an effect on the properties of the adhesive tape in the weft direction, hand-cutting properties, cut beauty, and the like, and the fineness of the weft is preferably larger than the warp and not more than three times. Further, the tenacity of the weft is preferably greater than the tenacity of the warp. Also,
Regarding the weaving density of the base fabric, the weaving density of the weft is preferably lower than that of the warp.

As the method for producing the base fabric for an adhesive tape of the present invention, it is preferable to perform weaving without twisting because false-twisted yarn is appropriately blended as a warp. It is preferable to employ it.

The false twisted yarn used in the present invention can be produced, for example, by the following method. After spinning the above-mentioned modified polyester with a usual melt spinning machine, cooling and winding while lubricating, then performing a false twisting while stretching at a desired stretching ratio and temperature, so-called stretch simultaneous false twisting, and then It can be obtained by blending. In the spinning process, since the melt viscosity is high due to the thickening effect of the polymer, the spinning temperature is set to about 10 ° C. or more higher than the normal polyester spinning temperature, and the spinning speed is such as fluff or yarn breakage during simultaneous drawing and false twisting. In order to ensure stable operability without any trouble, the speed is preferably from 2000 m / min to 4000 m / min. More preferably, it is 2500 m / min to 3500 m / min.

In the simultaneous stretching and false twisting process, a processing machine of a two-stage heater type is used as a processing machine, ie, a process of performing false twisting and heat fixing simultaneously with stretching in a one-stage heater zone, and then performing heat treatment with a second-stage heater. Machines are preferred.

In the false twisting device, the yarn contact portion is made of a friction disk made of polyurethane, and a triaxial type rotating the disk in the same direction is a false twist in which a plurality of friction disks partially overlap each other. The device is preferred. The processing temperature is preferably much lower than the normal polyester processing temperature,
50 ° C. or lower is preferred. The temperature is more preferably 130 ° C or lower. As described above, by performing the simultaneous draw-twisting process at a low temperature, the undrawn yarn of the modified polyester of the present invention is free from fluff or breakage, and is free from running yarn detachment from the processing heater and is stable. It becomes possible to operate. For the fiber-mixing treatment, a conventionally known fluid-jet type fiber-mixing device installed subsequent to the simultaneous simultaneous false twisting can be used.

[0031]

The present invention will be specifically described below with reference to examples. Each measurement value in the examples was in accordance with the following method.

A. Strength and elongation Using Toyo Baldwin's "Tensilon" UTM-11, a load-elongation curve (SS curve) was measured under the conditions of a test length of 200 mm and a pulling speed of 200 mm / min. The elongation is read and an average value of 10 times is calculated. The strength is defined as the value obtained by dividing the strength by the fineness.

B. Fineness, boiling water shrinkage rate Measured according to JIS L-1090.

Example 1 Terephthalic acid and dimethyl (5- (5-
The modified polyester obtained by copolymerizing sodium sulfo) isophthalic acid was melt-spun at a spinning temperature of 290 ° C. using a usual spinneret, and wound at 3000 m / min. Subsequently, using a triaxial friction false twist device, the set twist number is 3200 T / m, the speed is 600 m / min, the processing temperature is 130 ° C. (first stage heater), and the elongation of the false twist processed yarn is 35 ± 2%. At the same time, it is stretched and false-twisted at a magnification.
The fiber was mixed at an air pressure of 0 to obtain a false twisted yarn of 75 denier and 24 filaments.

The obtained false twisted yarn is warped and used as a warp. As the weft, a polyester flat yarn of 100 denier 24 filaments (strength 5.1 g / d, elongation 35%) is used. The warp yarn was 50 yarns / inch and the weft yarn was 40 yarns / inch.

Using this greige as a base cloth, a polyethylene film having a thickness of 50 μm was melt-extruded, laminated with the base cloth, and laminated. Next, a release agent was applied to the back side of the laminated base fabric, and an acrylic resin-based adhesive was applied to the back side to obtain an adhesive tape. Table 1 summarizes the properties of the yarn, the yarn operability, the high-order processability, and the properties of the adhesive tape.

Experiment No. Nos. 2 to 6 (the present invention) have a yarn strength of 2.5 to 4.0 (g / d), and particularly impair the yarn operability, high-order processability and hand-cutting property of the adhesive tape. And practical. 3 and 4 were extremely good. The surface of the pressure-sensitive adhesive tape had good flatness and good appearance.

Experiment No. Sample No. 1 (Comparative Example) had a high strength of the original yarn, was difficult to tear in the hand-cutting property of the pressure-sensitive adhesive tape, and was inferior because the cut end was frayed. Experiment No. In No. 7, the polymer viscosity was remarkably increased, the spinning filtration pressure was large, and the spinning filtration pressure rise rate was large. The spinning property was poor, and the spinning was impossible for a long time, and the high-order workability was poor. Was.

[0039]

[Table 1]

Example 2 Experiment No. 1 of Example 1 Using the polymer of No. 3, melt-spinning was performed in the same manner as in Example 1, and the simultaneous draw-twisting with Example 1 was performed except that the draw ratio was set so that the elongation of the false-twisted yarn changed to several levels. A false twisted yarn of 75 denier and 24 filaments was obtained. The strength of the false twisted yarn is 2.8 to 3.5.
(G / d), and the boiling water shrinkage ratio is 5.0 to 6.0.
It was in the range of 5 (%), and the degree of blend was about 90.

The obtained false twisted yarn was warped, woven, and used as an adhesive tape in the same manner as in Example 1. Table 2 shows these evaluation results.
Shown in Experiment No. 9 to 11 (the present invention) had good false twisting property, high order processing property, and hand-cutting property of the pressure-sensitive adhesive tape. Experiment No. No. 8 (Comparative Example) has a high draw ratio, has a low original yarn elongation, and generates fluff during false twisting.
There were also yarn breaks, and therefore, high-order workability was also poor. Experiment No. In No. 12 (Comparative Example), the stretching ratio was set low, the processing tension was low, the yarn runout occurred in the false twisting and twisting zone, and sometimes the processing heater came off, and the yarn was broken. In addition, the physical properties of the raw yarn were high in elongation, and there were large variations in various physical properties in the longitudinal direction of the yarn, poor high-order workability, and poor hand-cutting properties.

[0042]

[Table 2]

Example 3 Experiment No. 1 of Example 1 3 was melt-spun in the same manner as in Example 1, and the processing temperature (first-stage heater) and heat treatment temperature (second-stage) were adjusted so that the boiling water shrinkage of the false twisted yarn changed to several levels. Example 1 except that a heater was set.
In the same manner as in the above, simultaneous stretching and false twisting is performed, and 75 denier 24
A false twisted yarn of the filament was obtained. The strength of the false twisted yarn is in the range of 3.2 to 3.9 (g / d), and the elongation is
It was in the range of 32-38 (%) and the degree of fiber mixture was about 90. The obtained false twisted yarn was formed into a warp, weaving, and adhesive tape in the same manner as in Example 1. Table 3 shows the evaluation results.

Experiment No. Nos. 14 to 17 (the present invention) had good false twisting properties, warping properties, weaving properties, adhesive tape appearance, and good hand cutting properties. Experiment No. No. 13 (Comparative Example) was subjected to a high-temperature heat treatment in order to lower the boiling water shrinkage, and both the strength and the elongation were low, and the warping property and the weaving property were poor. Further, the warp strength as an adhesive tape was low and not practical. Experiment No. Sample No. 18 (Comparative Example) had a high boiling water shrinkage ratio, and therefore spots and wrinkles occurred in the longitudinal direction during the production of the adhesive tape, poor flatness, and poor appearance.

[0045]

[Table 3]

Example 4 Experiment No. 1 of Example 1 Example 3 except that the polymer of No. 3 was melt spun in the same manner as in Example 1 and the air pressure of the fluid injection type fiber mixing apparatus was set so that the degree of fiber mixing of the false twisted yarn changed to several levels. In the same manner, simultaneous false twisting of stretching
A denier 24 filament false twisted yarn was obtained. The strength of the false twisted yarn is in the range of 2.9 to 3.9 (g / d),
The elongation was in the range of 32 to 38 (%), and the boiling water shrinkage was in the range of 5.0 to 6.4 (%). Warping, weaving, and adhesive tape were performed in the same manner as in Example 1. Table 4 shows the results of these evaluations.

Experiment No. Nos. 20 to 23 (the present invention) had an appropriate degree of fineness, good warpability, weaving properties, and good appearance of the pressure-sensitive adhesive tape. Experiment No. No. 19 (Comparative Example) has a low degree of fiber mixing, so that the yarn bunching property is poor, the warpability and the weaving property are poor, and the base fabric is crisp and bent, and therefore the appearance of the adhesive tape is Was not good. Experiment No. 24
(Comparative Example) is one in which the mixed fiber air pressure is set high, and fuzzing or yarn breakage occurs during the mixed fiber, resulting in poor warping property and weaving property, and a thick line in the yarn longitudinal direction. Unevenness occurred, and the flatness of the adhesive tape was poor, and the appearance was poor.

[0048]

[Table 4]

[0049]

The adhesive tape base fabric of the present invention has the following effects. (1) Since the warp is a false twisted yarn of a modified polyester obtained by copolymerizing a specific component and has specific physical properties, the obtained adhesive tape has extremely good hand-cutting properties, and its cut end is extremely small. It is even and beautiful. (2) Although the warp yarn is a false twisted yarn having the specific physical properties of the modified polyester, the productivity of the raw yarn and the high-order processability such as warping and weaving are extremely good. (3) The warp constituting the base fabric is not creased or bent, the adhesive tape is not twisted, and the surface is flat.
The appearance is beautiful. That is, the product quality is extremely good. (4) Weaving is possible without special post-treatment for warp, and the production cost is low. (5) The yarn constituting the base fabric is made of polyester, and the range of use is wide without a drop in strength when wet.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an apparatus for measuring the degree of mixing of false twisted yarn.

────────────────────────────────────────────────── (5) Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI D03D 15/00 D03D 15/00 AC (56) References JP-A-4-136230 (JP, A) JP-A-62-141148 (JP, a) JP Akira 60-245684 (JP, a) JP flat 3-287831 (JP, a) Akira real public 61-20055 (JP, Y2) (58 ) investigated the field (Int.Cl. ⁶ D03D 1/00 D01F 6/84 305 D02G 1/02 D02G 3/04 D02G 3/44 D03D 15/00

Claims (2)

(57) [Claims] 1. A modified polyester obtained by copolymerizing an isophthalic acid component having a metal sulfonate group in an amount of 1 to 10 mol% with respect to all dicarboxylic acid components.
A base fabric for an adhesive tape, wherein a false twisted yarn satisfying (d) is used as a warp yarn. (A) 2.5 ≦ strength (g / d) ≦ 4.0 (b) 30 ≦ elongation (%) ≦ 40 (c) 2.0 ≦ boiling water shrinkage (%) ≦ 10.0 (d) 70 ≦ Degree of blending ≦ 250 2. The weaving density of the warp of the base fabric for an adhesive tape satisfies the following formula: 350 / (denier of warp) ^0.5
≤ Weaving density (book / inch) ≤ 550 / (fineness of warp (denier)) ^0.5 and the weaving density in the weft of the base fabric satisfies the following expression. Warp weaving density (books / inch)> weft weaving density (books / inch)