JPH04240240A - Ground fabric for tacky tape - Google Patents

Abstract

PURPOSE:To obtain ground fabric for tacky tape having excellent cutting properties with hand, beautiful cut end, smooth surface and good appearance. CONSTITUTION:Ground fabric for tacky tape comprising falsely twisted textured yarn of polyester which consists of a modified polyester copolymerized with 1-10mol% based on total dicarboxylic acid components of metal sulfonate group- containing isophthalic acid component and has 2.5-4.0 (g/d), strength, 30-40 (%) elongation, 2.0-10.0 (%) shrinkage percentage in boiling water and 70-250 degree of yarn blending as warp.

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 adhesive tapes comprising a false twisted yarn of modified polyester. More specifically, the present invention relates to a base fabric for adhesive tapes which has good thread passability through higher-order processes, good manual tearability of adhesive tapes, beautiful cut edges, smooth surfaces, and good appearance.

0002

[Prior Art] Spun rayon yarn and vinylon fiber have been used as base fabric materials for adhesive tapes for a long time, but they have various drawbacks such as a decrease in strength when wet. Many techniques for improving polyester fibers have been disclosed for use as base fabrics for adhesive tapes.

For example, Japanese Patent Application Laid-open No. 61-75840,
Japanese Patent Publication No. Sho 64-11736 discloses a technique in which the physical properties of the fibers used in the warp of the base fabric are specified in order to improve the hand-tearability of the adhesive tape and make the cut edges beautiful. However, all of them had the problem that the elongation of the fibers was low, and fuzz and thread breakage were likely to occur not only during raw yarn production but also during warping and weaving.

[0004] JP-A-63-21950, JP-A-1
Publication No. 104849 proposes a technique for improving weavability and hand-tearability of adhesive tapes by using crimped entangled yarns or bulky textured yarns having specific physical properties as the warp yarns of the base fabric. These also have the same problem as mentioned above because the elongation of the yarn is low.

[0005] Furthermore, in JP-A No. 60-245684 and Japanese Utility Model Publication No. 61-20055, a third component such as a -SO3 M group-containing compound (where M represents hydrogen or a metal atom) is copolymerized. This is a technique in which fibers made of a polymer with specific physical properties are used in the warp of the base fabric. There is a problem that the base fabric tends to shift.

[0006] As described above, in the prior art, it has not been possible to simultaneously satisfy the production stability of the base fabric yarn, its passability through higher-order processes, and the required properties of the adhesive tape, especially hand tearability.

[0007]

[Problems to be Solved by the Invention] The objects of the present invention are to provide yarn for base fabric with good productivity and passability through higher-order processes, excellent hand-tearability of adhesive tape, beautiful cut edges, and smooth surface. To provide a base fabric for adhesive tape with a good appearance.

[0008]

[Means for Solving the Problems] The object of the present invention is to provide a modified polyester in which an isophthalic acid component having a metal sulfonate group is copolymerized in an amount of 1 to 10 mol% based on the total dicarboxylic acid component; ) to (b) A base fabric for an adhesive tape characterized in that a false twisted yarn satisfying the following conditions is used as a warp, (a) 2.5≦Strength (g/d)≦4.0 (b)
30≦Elongation (%)≦40 (c) 2.0≦Boiling water shrinkage rate (%)≦10.0 (d)
This can be achieved by setting 70≦mixing degree≦250.

[0009] The warp of the adhesive tape base fabric according to the present invention is characterized in that a false twisted yarn made of modified polyester is used. According to studies conducted by the present inventors, when the warp composition is polyethylene terephthalate, the lower the degree of polymerization, the better the adhesive tape's manual tearability, and for polymers with the same degree of polymerization, false twisted yarn is better than flat yarn. The modified polyester of the present invention has better hand tearability than polyethylene terephthalate, and the use of false twisted yarn further improves the hand tearability. Also,
The fine crimp of the single yarn in the false twisted yarn also contributes to improved adhesion when laminating the resin layer to the base fabric during the adhesive tape manufacturing process.

[0010] The false twisted yarn used in the present invention must satisfy specific physical property values described below.

First, the strength must be in the range of 2.5 to 4.0 (g/d). If it is less than 2.5 (g/d), fuzz and thread breakage are likely to occur during the production of raw yarn, and even if this does not occur, fuzz and thread breakage will occur during warping and weaving, which is not good. In addition, the strength of the adhesive tape in the warp direction is small, which poses a practical problem. If it exceeds 4.0 (g/d), the hand tearability of the adhesive tape deteriorates, fraying occurs at the cut end after tearing, and a beautiful cut cannot be obtained. Therefore, the strength is 2.7 (g/d) ~
A range of 3.8 (g/d) is preferred.

[0012] The elongation needs to be in the range of 30 to 40 (%); if it is less than 30 (%), fluff or thread breakage is likely to occur during false twisting due to the false twisting of the modified polyester, making it difficult to stabilize the elongation. Operation becomes impossible. In addition, the warping properties and weaving properties are also deteriorated. If it exceeds 40 (%), yarn runout occurs in the twisting zone during false twisting, the yarn comes off from the heater, yarn breakage occurs, and stable processing becomes impossible. In addition, the adhesive tape is difficult to tear by hand, and the cut end after tearing is not clean.

The boiling water shrinkage rate must be in the range of 2.0 to 10.0 (%). If this value exceeds 10.0 (%), warp shrinkage and warp-to-warp variation in various heat treatment processes during adhesive tape production will be large, dimensional change rate will be large, and process control will be difficult, making production difficult. Not only does the adhesive tape's properties deteriorate, but it also causes spots and wrinkles on the surface of the adhesive tape, degrading the quality of the product. Therefore, the boiling water shrinkage rate is preferably low, preferably 8% or less, and more preferably 6% or less. However, in order to produce raw yarn with a low boiling water shrinkage rate, high-temperature heat treatment is required in the manufacturing process, but if heat treatment is applied at too high a temperature, the strength and elongation will decrease due to thermal deterioration of the raw yarn. Since the high-order processability is reduced and the practical strength as an adhesive tape is reduced, it is necessary to perform heat treatment so that the boiling water shrinkage rate is 2.0 (%) or more.

[0014]Furthermore, the false twisted yarn in the present invention must have a specific degree of fiber blending as determined by the following measuring method.

Method for measuring the degree of blending As shown in Fig. 1, the sample yarn is hung on a grooved pulley 2 that can rotate left and right around the central axis 1 without any resistance so as not to slip.
Apply loads 3 and 4 to the points. Loads 3 and 4 are the total denier of the sample yarn x 0.4 g.

Next, a fixed needle 5 having an outer diameter of 0.60 mm is inserted substantially perpendicularly between the single threads constituting the yarn and fixed. Next, a constant load 6 whose weight is the single yarn denier of the sample x 2.0 g is 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 catches the fixed needle 5 and stops. .

Next, the constant load 6 applied to the load 3 is removed and applied in addition to the load 4 on the right side, so that the sample thread is caught on the fixed needle 5 and stopped naturally. The moving speed of the sample thread due to the constant load 6 is 10 mm/sec. The distance L (mm) of movement of the sample yarn to the right by the above method is determined, and the degree of blending is calculated from the following formula. Mixing degree = 1000/(L+0.60) Measurements were taken at 10 arbitrary longitudinal positions of the sample yarn and expressed as an average value.

[0018] In the present invention, the degree of blending must be in the range of 70 to 250. By setting the blending degree to 70 or more, the bundling property of the yarn is improved, and the warpability and weavability are improved. Furthermore, since the base fabric can be prevented from shifting or bending, the adhesive tape does not twist, and the surface flatness of the adhesive tape is improved, resulting in a product with good appearance and high quality. However, if the value exceeds 250, warpability and weavability will be poor due to fuzz and sagging generated during blending, and thickness unevenness will occur in the longitudinal direction of the yarn, resulting in poor uniformity. The blending degree is preferably 80 to 230.

Next, the modified polyester in the present invention will be explained. In the present invention, the modified polyester is one obtained by copolymerizing an isophthalic acid component (hereinafter abbreviated as S component) containing a metal sulfonate group in an amount of 1 to 10 mol % based on the total dicarboxylic acid component. The S component is a compound represented by the following formula, and specifically, dimethyl (5-sodium sulfo) isophthalate, bis-2-hydroxyethyl (5-sodium sulfo) isophthalate, bis-4-
Examples include hydroxybutyl (5-sodium sulfo) isophthalate.

[0020]

[Chemical formula 1]

A preferred S component is dimethyl (5-
Examples include sodium sulfo)isophthalate and bis-2-hydroxyethyl(5-sodium sulfo)isophthalate. More preferred is dimethyl (5-sodium sulfo) isophthalate.

As mentioned above, the S component must be copolymerized in an amount of 1 to 10 mol%. The effect of copolymerizing the S component is that the degree of orientation of the polyester fibers decreases, increasing the strength or elongation.
Alternatively, both of them are lowered, and the shearing force in the direction perpendicular to the fiber axis is lowered, which has the effect of greatly improving the hand-tearability of the adhesive tape. When the S component is less than 1 mol %, the above effects are small. Moreover, if it exceeds 10 mol%, the melt viscosity of the polymer will increase significantly, making melt spinning difficult, and the strength and elongation will decrease too much, resulting in poor false twisting and higher process passability. Productivity begins to suffer. Therefore, the copolymerization amount of the S component is preferably 1.5 to 8 mol%, more preferably 2.0 to 7.0 mol%.

The base fabric for adhesive tapes of the present invention can be used for adhesive tapes for both thin and thick materials, but for thin materials, the fineness of the false twisted yarn is preferably smaller;
For thick materials, the fineness is preferably larger, and the fineness is preferably in the range of 50 to 250 (denier). Further, if the fineness is large, the strength will inevitably increase and the adhesive tape will be less easy to cut by hand, so it is preferable that the strength is low. On the other hand, if the fineness is fine, the strength is low, and therefore the strength in the warp direction of the adhesive tape is too small, which poses a practical problem, so it is preferable that the strength is high to some extent. From the above, it is preferable to use a false twisted yarn whose fineness and strength satisfy the following relational expression.

400 -100 x strength (g/d)≦fineness (denier)≦500 -100 x strength (g/d)
In addition, 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 workability of the yarn deteriorates, and fuzz and yarn breakage occur. If it exceeds 10 denier, the stiffness of the yarn becomes too strong, resulting in poor blending in fiber blending processing, and
Poor hand tearability when used as adhesive tape. A more preferable fineness of the single yarn is 2 to 6 deniers.

The weaving density of the warp yarns constituting the base fabric in the present invention is appropriately determined by the fineness of the weft yarns, but if the density is too low, misalignment will occur; on the other hand, if the density is too high,
If the strength in the warp direction becomes too high, the hand-tearability of the adhesive tape will deteriorate, so it is preferable to have a weave density that satisfies the following formula.

350/(Warp fineness (denier)) 0.
5 ≦Weave density (strands/inch) ≦550/(warp fineness (
Denier)) 0.5 The weft constituting the base fabric in the present invention is preferably a flat yarn made of polyester, and may be twisted or entangled. The weft is
It is preferable that the fineness of the weft yarn is larger than the fineness of the warp yarn and within three times that of the warp yarn, since it affects the characteristics of the adhesive tape in the weft direction, the ease of manual cutting, and the beauty of the cut surface. Furthermore, it is preferable that the strength of the weft yarns is greater than that of the warp yarns. Further, regarding the weaving density of the base fabric, it is preferable that the weaving density of the weft yarns is lower than that of the warp yarns.

[0027] As for the manufacturing method of the base fabric for the adhesive tape of the present invention, it is preferable to weave it without any twist or glue since the warp is suitably mixed with false twisted yarn, and the loom is a water jet loom. It is preferable to adopt it.

The false twisted yarn used in the present invention can be produced, for example, by the following method. The above-mentioned modified polyester is spun using a conventional melt spinning machine, wound up while being cooled and oiled, and then false-twisted while being stretched at a desired stretching ratio and temperature, which is called simultaneous stretching and false-twisting. It can be obtained by blending the fibers. In the spinning process, the melt viscosity is high due to the thickening effect of the polymer, so the spinning temperature is approximately 10°C or more higher than the spinning temperature of normal polyester, and the spinning speed is set to avoid problems such as fuzz and yarn breakage during stretching and simultaneous false twisting. In order to ensure trouble-free and stable operability, the speed is preferably 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, the processing machine is a two-stage heater type processing machine, that is, the first stage heater zone performs false twisting and heat setting at the same time as stretching, and then the second stage heater performs heat treatment. Machines are preferred.

[0030] The false twisting device is a triaxial type in which the yarn contacting part is made of polyurethane friction disks and the disks are rotated in the same direction, and a plurality of friction disks partially overlap and intersect. A device is preferred. In addition, the processing temperature is preferably much lower than that of normal polyester, and is approximately 1
The temperature is preferably 50°C or lower. More preferably it is 130°C or lower. As described above, by carrying out the simultaneous stretching and false twisting processing at low temperatures, the undrawn modified polyester yarn of the present invention can be stabilized without fuzz or yarn breakage, and without the running yarn coming off the processing heater. This makes it possible to operate with For the fiber mixing treatment, a conventionally known fluid jet type mixing device installed following the simultaneous stretching and simultaneous false twisting process can be used.

[0031]

[Examples] The present invention will be specifically explained below with reference to Examples. Each measurement value in the examples was determined according to the following method.

A. Strength and elongation The load-elongation curve (S-S curve) was measured using Toyo Baldwin's "Tensilon" UTM-11 under the conditions of a sample length of 200 mm and a tensile speed of 200 mm/min. Read the elongation and calculate the average value of 10 times. Strength is 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-
A modified polyester copolymerized with sodium sulfo)isophthalic acid was melt-spun at a spinning temperature of 290° C. using an ordinary spinneret, and wound at a speed of 3000 m/min. Subsequently, using a triaxial friction false twisting device, the number of twists is set at 3200 T/m, the speed is 600 m/min, the processing temperature is 130°C (first stage heater), and the elongation of the false twisted yarn is 35 ± 2%. False twisting is performed at the same time as stretching at a magnification, and the blending degree is approximately 90 using a fluid jet blending device.
The fibers were mixed at an air pressure of 75 denier and 24 filaments were obtained.

The obtained false twisted yarn was warped and used as the warp, and the weft was a polyester flat yarn of 100 denier 24 filaments (strength 5.1 g/d, elongation 35%), and the weaving density was adjusted. A gray fabric was obtained by weaving in a water jet loom with 50 warps/inch and 40 wefts/inch.

Using this gray material as a base fabric, a polyethylene film having a thickness of 50 μm was melt-extruded and laminated with the base fabric. Next, a release agent was applied to the back side of the laminated base fabric, and an acrylic acid resin adhesive was applied to the back side to obtain an adhesive tape. Table 1 summarizes the yarn physical properties, yarn workability, higher processability, adhesive tape properties, etc.

Experiment No. 2 to 6 (the present invention), the strength of the yarn is 2.5 to 4.0 (g/d), and there are particularly large obstacles in yarn workability, high-order processability, and hand tearability of the adhesive tape. It is very practical, especially experiment No. 3 and 4 were extremely good. Moreover, the surface of the adhesive tape had good flatness and good appearance.

Experiment No. Comparative Example No. 1 (Comparative Example) was poor in terms of the strength of the raw yarn, which made it difficult to tear the adhesive tape by hand, and the cut end was frayed. Also, experiment N
o. In No. 7, the polymer viscosity was significantly increased, the spinning filtration pressure was high, and the rate of increase in the spinning filtration pressure was also large, resulting in poor spinnability, impossibility of long-term spinning, and poor high-order processability. Ta.

[0039]

[Table 1]

Example 2 Experiment No. of Example 1. Using the polymer No. 3, melt spinning was carried out in the same manner as in Example 1, and stretching and simultaneous false twisting was performed as in Example 1, except that the stretching ratio was set so that the elongation of the false twisted yarn varied over 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 rate is 5.0 to 6.5.
(%), and the degree of blending was approximately 90.

The obtained false twisted yarn was warped, woven, and made into an adhesive tape in the same manner as in Example 1. These evaluation results are shown in Table 2.
Shown below. Experiment No. Samples Nos. 9 to 11 (invention) had good false twisting processability, high-order processability, and adhesive tape hand tearability. Experiment No. In No. 8 (Comparative Example), the drawing ratio was set high, the elongation of the raw yarn was low, fuzz was generated during false twisting, there was also yarn breakage, and therefore the higher-order processability was also poor. Experiment No. In No. 12 (comparative example), the stretching ratio was set low and the processing tension was low, causing yarn runout in the false twisting zone, and sometimes the processing heater came off and yarn breakage occurred. In addition, the physical properties of the yarn had high elongation, large variations in physical properties in the longitudinal direction of the yarn, poor high-order processability, and poor manual tearability.

[0042]

[Table 2]

Example 3 Experiment No. 1 of Example 1. Polymer No. 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 heater) were adjusted so that the boiling water shrinkage rate of the false twisted yarn varied over several levels. Example 1 except that the heater) was set.
75 denier 24
A false twisted filament yarn 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 3.
The blending degree was in the range of 2 to 38 (%) and was about 90. The obtained false twisted yarn was warped, woven, and made into an adhesive tape in the same manner as in Example 1. Table 3 shows these evaluation results.

Experiment No. Samples Nos. 14 to 17 (invention) had good false twisting processability, warpability, weavability, and adhesive tape appearance, and also good hand tearability. Experiment No. 13 (Comparative example)
was subjected to high-temperature heat treatment to reduce boiling water shrinkage, resulting in low strength and elongation, and poor warpability and weavability. In addition, the strength in the warp direction as an adhesive tape was low, making it impractical. Experiment No. Sample No. 18 (Comparative Example) had a high boiling water shrinkage rate, so spots and wrinkles occurred in the adhesive tape manufacturing time direction, and the flatness was poor and the appearance was poor.

[0045]

[Table 3]

Example 4 Experiment No. of Example 1. The polymer of Example 3 was melt-spun in the same manner as in Example 1, except that the air pressure of the fluid jet blending device was set so that the degree of blending of the false twisted yarn varied over several levels. Similarly, stretching and simultaneous false twisting were carried out, and
A false twisted yarn having a denier of 24 filaments 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 (%). It was warped, woven, and made into an adhesive tape in the same manner as in Example 1. Table 4 shows these evaluation results.

Experiment No. Samples Nos. 20 to 23 (invention) had an appropriate degree of blending, and had good warpability, weavability, and adhesive tape appearance. Experiment No. In No. 19 (comparative example), due to the low blending degree, the yarns had poor convergence, poor warping and weaving properties, and the base fabric was distorted and bent, so the appearance of the adhesive tape was poor. was not good. Experiment No. 24
In (comparative example), the air pressure for blending was set high, and fluffing and yarn breakage occurred during blending, resulting in poor warping and weaving properties, and the yarn was thick in the longitudinal direction. The flatness of the adhesive tape was poor due to unevenness, and the appearance was poor.

[0048]

[Table 4]

[0049]

[Effects of the Invention] The adhesive tape base fabric of the present invention has the following effects. (1) The warp is a false-twisted yarn made of modified polyester copolymerized with a specific component, and has specific physical properties, so the resulting adhesive tape has extremely good hand-tearability, and its cut edge is extremely sharp. It becomes even and clean. (2) Although the warp is a false twisted yarn having specific physical properties of modified polyester, the productivity of the raw yarn and the passability through higher-order processes such as warping and weaving are extremely good. (3) There is no misalignment or bending of the warp threads that make up the base fabric, there is no twisting of the adhesive tape, and the surface has good flatness.
The appearance is beautiful. In other words, the product quality is extremely good. (4) It is possible to weave without special post-treatment for warp threads, and the manufacturing cost is low. (5) The threads constituting the base fabric are polyester, so there is no loss of strength when wet, and the range of use is wide.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an apparatus for measuring the degree of blending of false twisted yarn.

Claims (2)

[Claims] Claim 1: 1 to 10 mol% of the isophthalic acid component having a metal sulfonate group based on the total dicarboxylic acid component.
Consisting of copolymerized modified polyester, the following (a) to (
A base fabric for an adhesive tape, characterized in that a false-twisted yarn that satisfies (d) at the same time is used as the warp. (a) 2.5≦Strength (g/d)≦4.0 (b)
30≦Elongation (%)≦40 (c) 2.0≦Boiling water shrinkage rate (%)≦10.0 (d)
70≦Mixing degree≦250 [Claim 2] The weaving density of the warp of the adhesive tape base fabric satisfies the following formula, 350/(warp fineness (denier)) 0
．． The base fabric for an adhesive tape according to claim 1, wherein 5≦weave density (strands/inch)≦550/(warp fineness (denier)) 0.5 and the weave density of the warp and warp of the base fabric satisfies the following formula. Warp weaving density (threads/inch) > Weft weaving density (threads/inch)