JP3071957B2 - 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 an adhesive tape having good hand-cutting properties and good dimensional stability of a product.

[0002]

2. Description of the Related Art Conventionally, a spun yarn made of rayon swoof has been used for warp and weft as a base fabric for an adhesive tape. However, the base fabric has unevenness in thickness due to unevenness in the thickness of the yarn. And the surface is not flat.

[0003] Also, Japanese Patent Publication No. 2-39549 discloses that
A base fabric in which ordinary false twisted yarn is woven at a low driving density for the weft has been proposed. However, since the warp is not false twisted, the difference in the torque of the false twisted yarn and the heat shrinkage ecology of the yarn is considered. When the fabric is curled after weaving, or the texture is inclined when exposed to heat, the cut end of the product becomes dirty.

Further, Japanese Patent Application Laid-Open Nos. 62-141148 and 60-71735 propose a base fabric using a polyester multifilament or a modified polyester multifilament yarn entangled in a warp. . These warps have many loops formed by the entanglement treatment, and the adhesiveness to the film is good. However, simply applying the entanglement treatment to the polyester multifilament reduces the strength required to improve the hand-cutting property. Therefore, it was necessary to take a method such as adding a third component to the polyester to reduce the strength of the yarn.

[0005]

SUMMARY OF THE INVENTION The present invention overcomes the above-mentioned problems of the prior art, in which the base fabric does not curl or bend, the surface is flat, there is no uneven thickness, and the hand-cutting property is good. An object of the present invention is to provide a base fabric from which an adhesive tape can be obtained.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems and has the following construction. That is, in the present invention, the strength is 3 g / denier or less, and 25 to 100 strands / m in the lengthwise direction of the yarn are twisted at 5 mm or less.
The part other than the strong twisting point has a base fabric for an adhesive tape, characterized by using a polyester filament crimped yarn in which a part of the filament is wound in an arch shape as a warp. .

In the present invention, the polyester filament crimped yarn used for the warp is a yarn having 25 to 100 strong twisted portions of 5 mm or less in the longitudinal direction of the yarn.
This strong twist has the effect of improving the weaving properties,
If the strong twisting portion has a length of 5 mm or more, unevenness in the thickness of the yarn appears on the tape surface, and the tape surface becomes dirty. If the length of this portion is less than 0.5 mm, the strong twist portion disappears during weaving, which is not preferable. If the number of strong twists is less than 25 / m, the length of the free filaments becomes long, which causes filament breakage during weaving, resulting in a decrease in weaving efficiency. Also, if it exceeds 100 / m,
Since there are too many strong twists and the presence of filaments wound in an arch shape is reduced, the permeability of the adhesive to the base fabric is deteriorated, and the adhesiveness is reduced.

Further, in the polyester filament crimped yarn used for the warp of the present invention, a part of the filament is wound in an arch shape between the strongly twisted portions. As a result, a part of the filaments is released, so that the adhesive easily permeates into the yarn, and the adhesiveness is improved. Further, since the separated filaments are separated and wound in an arch shape so as to surround the yarn, the process passageability is good unlike the protruding loop form of the entangled yarn.

Further, the strength of the polyester filament crimped yarn used for the warp of the present invention must be 3 g / denier or less, and preferably 2.5 g / denier or less.

The yarn used for the weft of the pressure-sensitive adhesive tape base fabric of the present invention is preferably a polyester filament crimped yarn having higher strength than the polyester filament crimped yarn used for the warp and having no entanglement and being entangled. It is preferably at least 0.5 g / denier, more preferably at least 4 g / denier. If the strength of the weft is higher than the strength of the warp, the warp can be cut cleanly when the adhesive tape is cut. Also, a stable cut parallel to the weft can be obtained depending on the strength of the weft and the weft density described later.

The base cloth of the pressure-sensitive adhesive tape preferably has a torque index of 70 times / m or less and a low heat shrinkage rate for both the warp and the weft. In this case, a fabric having good dimensional stability can be obtained without bending or curling due to the torque of the course.

The warp and weft densities are preferably at least 30 yarns / inch, more preferably from 35 yarns / inch to 70 yarns / inch. If the warp density is less than 30 yarns / inch,
The warp strength of the fabric is weakened, and the fabric is torn by pulling in the length direction. In addition, the weft density is 30
If it is less than this per inch, the width of the weft and the weft is too large, the thread end and the adhesive remain at the cut end of the tape, and the cut end becomes dirty. Further, when the weft yarn is entangled, and particularly when the entangled portion is at least 10 pcs / m, it contributes to improvement in weaving.

FIG. 1 is a schematic view showing the appearance of a crimped polyester filament used for the warp of the present invention. FIG. 1A shows a strong twisted portion, and FIG. 1B shows a portion where a part of the filament is wound in an arch shape. . FIG. 2 is a diagram showing a cross section of the strong twisting point (a)
FIG. 3 is a view showing a cross section of a part (b) in which some filaments are wound in an arch shape. Here, the strong twist point (a)
Improves the processability such as weaving, and the part (b) where a part of the filaments are wound in an arch shape serves to improve the adhesiveness. FIG. 4 is a schematic external view of an example of a weft.
(C) is a portion having a gentle crimp shape and good adhesiveness, and (d) is a entangled portion.

Next, a method for producing a thread used for the adhesive tape base fabric of the present invention will be described. As the warp yarn, for example, a polyester highly oriented undrawn yarn having a birefringence Δn of 30 to 80 × 10 ⁻³ is prepared from a false twist temperature of 220 ° C. to 250 ° C. Denier) 2
Stretching false twisting under the conditions of 8000 / D1 / ² to 32000 / D1 / ² (T / M), stretching ratio set to a twisting tension range of 0.1 g / denier to 0.2 g / denier, Next, heat treatment may be performed by setting the overfeed rate between 5% and 20% with the second heater set to a temperature equal to or higher than the first heater temperature. When the false twist temperature is increased from 220 ° C to 250 ° C and the false twist number is increased, a strong twist portion having a twist number approximately corresponding to the false twist number remains in a fused state, and the yarn strength can be reduced. At the same time, some filaments can be formed into arched yarns.

[0015] The weft yarn can be obtained by drawing false twisting of a polyester highly oriented undrawn yarn or false twisting a polyester raw yarn. The processing conditions include, for example, the number of false twists. 30000 / D ^1/2 (T / M)
The lower the number of false twists, the higher strength and gentle crimp morphology can be obtained. Further, the false twist temperature is selected from 230 ° C. or less so as not to cause fusion to the yarn. Stretching ratio,
The false twist overfeed rate is selected in a range where the twisting tension is from 0.1 g / denier to 0.2 g / denier. Next, if necessary, heat treatment is performed by the second heater, and the torque index and the heat shrinkage are selected in the same manner as the above-mentioned warp so that the warp and the weft are almost the same. Further, it is preferable to perform the air entanglement treatment so that the number of entanglements is 10 pieces / m or more at any point before winding.

The number of strong twisting points in the present invention is as follows:
Thread 1m1 on black backing under a load of 0.1g / denier
Paste with a length of 0cm and use a loupe to 0.5mm between 1m
The above-mentioned strong twisting points were measured, and this is an average value measured three times. The torque index is calculated by applying a gripping load of 1/30 g / denier to the yarn, and measuring 1 / m at a sample length of 1 m (reciprocating 2 m).
After applying a yarn turning load of 300 g / denier, the yarn is turned by torque and stabilized, then the torque is untwisted using a twist detection machine, the number of twists is measured, and the average value of five measurements Expressed by The strength is a value obtained by determining the apparent fineness based on JIS-L-1090, measuring the breaking strength with a constant-speed extension type autograph, and dividing by the fineness.

[0017]

According to the present invention, a strong twisted portion having a strength of 3 g / denier or less and a length of 5 mm or less in the longitudinal direction of the yarn is 25 to 10
When a polyester filament crimped yarn is used for the warp of the adhesive tape base fabric, the tear strength of the base fabric is moderate It is possible to obtain a pressure-sensitive adhesive tape with good hand-cutting properties of the tape. In addition, a polyester filament crimped yarn having a strength of 3.5 g / denier or more and having no strong twisting points is used for the weft, and the warp density is reduced. When the weft density is 30 yarns / inch or more, the curl and slant of the base fabric are more stable, the flatness is improved, and there is no unevenness in thickness.
It is possible to obtain an adhesive tape which is parallel to the weft and provides a stable tape cut.

[0018]

EXAMPLE A 110-denier / 36 filament of highly oriented polyester unoriented yarn and a 100-denier / 24 filament of polyester raw yarn were false-twisted with a Mitsubishi Heavy Industries LS-6 type false-twisting machine under the conditions shown in Table 1 for warp. Experiment No.
Polyester crimped yarns of Nos. 1 to 3 and Experiment No. 4 for wefts were obtained. Using the obtained yarns, plain weaves were woven at the densities shown in Table 2 to obtain four types of adhesive tape base fabrics.
A micron polyethylene film was attached to the front side of the base fabric, and a hot-melt adhesive was applied to prepare an adhesive tape.

[0019]

[Table 1]

[0020]

[Table 2]

The pressure-sensitive adhesive tape of Example 1 of the present invention had a good appearance of the product, could be easily torn by hand, and had a beautiful straight cut. On the other hand, in Comparative Example 2, the number of strong twists of the yarn used for the warp was large, and a portion having a length of 5 mm or more was frequently found. It was scattered and the surface was dirty, and the hand-cutting property was the first to feel resistance. In Comparative Example 2, since the number of strong twisted portions of the warp was small, filament breakage occurred during weaving, the weaving efficiency was reduced, and filament balls were scattered on the surface appearance. Also,
In Comparative Example 3, since the weaving density was low, the strength of the base cloth was weak, a part of the tape was stretched while the product tape was being pulled out about 1 m, and the cut edge was left with adhesive and thread ends, and was dirty. Met.

[0022]

As described above, the base fabric for an adhesive tape of the present invention has the above-mentioned structure, so that the weaving efficiency of the base fabric is good, the permeability of the adhesive is good, the dimensional stability is good, and the surface An adhesive tape with a beautiful appearance can be provided. Furthermore, by specifying the strength and density of the warp and weft,
It can provide an adhesive tape with good hand-cutting properties and a clean cut.

[Brief description of the drawings]

FIG. 1 is a schematic external view of a warp of the present invention.

FIG. 2 is a cross-sectional view of a strongly twisted portion (a) of a crimped yarn used for a warp.

FIG. 3 is a cross-sectional view of a part (b) in which a part of filaments of a crimped yarn used for a warp is wound in an arch shape.

FIG. 4 is a schematic external view of an example of a weft yarn.

[Explanation of symbols]

 a strong twisted part b arched part c crimped part d confounding part

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Claims (2)

(57) [Claims] 1. A yarn having a strength of 3 g / denier or less, having 25 to 100 strong twisted portions of 5 mm or less in the longitudinal direction of the yarn, and a part of the filaments other than the strong twisted portions having an arch shape. A base fabric for an adhesive tape, comprising using a wound polyester filament crimped yarn as a warp. 2. A weft yarn comprising a polyester filament crimped yarn having a strength of 3.5 g / denier or more and having no strong twisting points, and having a warp density and a weft density of 30 yarns / weft, respectively.
2. The adhesive tape base fabric according to claim 1, which is not less than inches.