JPS5893770A - Adhesive tape and its preparation - Google Patents

Abstract

PURPOSE:To prepare an adhesive tape which can be torn readily with clean cuts, by laminating a resin layer on a base fabric prepared by using, as warp, a flat yarn made from a polyester having a specified residual group in the molecular chain and applying a release agent on one side and an adhesive on the other side. CONSTITUTION:The base fabric is prepared by using, as warp, a flat yarn made from a polyester having a residual group of the formula in the molecular chain (where X is SO2Na, -X', -OR, -R' or -OAr; -X' is halogen; R and R' are each alkyl; Ar is an aromatic group which may be substit.; bonding chain may be on ortho, meta or para site; m is 1-2; l is 0-2). A resin layer (e.g. polyethylene) is formed on the base fabric, followed by heat treatment (250-350 deg.C for 0.5-5sec) for drying and solidification of the resin and then a release agent is applied on one side and an adhesive on the other side.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention Ij11 relates to a base fabric for adhesive tapes, and its purpose is to use a polyester fiber that has not been widely used in this field and is easy to tear.
To provide a base fabric for an adhesive tape with a beautiful cut surface.

In recent years, adhesive tapes have become widely used as packaging materials.
One of the required properties of the tape is the elongation in the edge direction.
It is necessary to have a tensile strength of ~15-.If it exceeds about 15 ts, the elongation becomes too high and it is difficult to tear, and if it is torn by force, the cut end will not be dirty.

Conventionally, base fabrics for adhesive tapes have been proposed in which the warp and weft yarns are made of rayon fiber or vinylon fiber, and both of them satisfy the elongation characteristics described above.

However, with the former (spun yarn), the strength when wet is reduced to 45 to 55 inches compared to when wet and dry, the base fabric has uneven thickness, the surface is not flat, and the amount of adhesive resin attached is excessive. There are disadvantages such as being prone to
The latter has drawbacks such as being expensive due to the material used, the manufacturing process being complicated, and the wet strength being reduced to 70 to 80 inches.

In order to solve these problems, we developed a new technology that uses untwisted multifilament yarns of 40 denier or less as warp yarns, low-shrinkage untwisted multifilament yarns with a denier of 3 times or more than the warp yarns as weft yarns, and has a weft density of 7 yarns per yarn. Adhesive tape base fabric consisting of a polyester fabric having a polyester of 3 or more.
-71570) has been proposed. This is because the denier of the warp is 40 denier or less, which suppresses the warp strength of the adhesive tape to a level that can be cut, and the use of non-twisted yarn makes it possible to easily cut the warp sequentially. By using a low-shrinkage non-twisted multifilament, the dimensional change of the adhesive tape that occurs when the solvent is dried and removed after applying the adhesive can be prevented. However, even in the above-mentioned invention, there remain drawbacks such as uneven thickness of the base fabric, unevenness of the surface, and unavoidable adhesion spots of the adhesive.

In addition, as a prior art similar to the above-mentioned prior art, "The thickness of the threads constituting the cloth is less than A3, the warp is less than A3, and the weft is less than A3".
Base material for cloth adhesive tape with a rating of S■ or higher. ” (4I introduction 52
-580117 Newsletter), but according to the + example, by making the thickness of the thread thinner, it is possible to increase the strength in the warp direction. However, the elongation in the thread direction was 49 to 62 mm (ToJ).Adhesive tapes with such elongation are difficult to cut, causing #1 kinks at the cut end after tearing, making it impossible to make a beautiful cut. do not have. In addition, the same drawback as the prior art disclosed in Japanese Patent Application Laid-Open No. 71570/1983, which relies on the thickness of the nine-strand and weft threads, remains.

As a result of intensive studies in view of these points, the present inventors have discovered that all the drawbacks can be solved as a base fabric for adhesive tapes by using a specific polyester fiber for the warp yarns, and have arrived at the present invention.

Komuni specific polyester fibers have both strength and elongation necessary for fiber production during the process of weaving them into base fabrics, and are easily torn when the adhesive tape is cut. It is a polyester fiber that has the tear strength and elongation necessary to leave a beautiful cut surface.

To explain this in more detail, weavers need to have a strong elongation that can withstand the tension during weaving, and usually the warp and weft have a strength of about 2 t/d or more and an elongation of about zo% or more. It is said that On the other hand, the strong elongation t required for an adhesive tape is such that the strength in the clay direction is 1 s6/gsm or more, and the elongation f is in the range of 10 to 1 s%. (The strongest one is JI8Z 152
4) Tear strength is JIS L 109
400F or less using method 6.

To obtain an adhesive tape from a base fabric, a resin layer is laminated on at least one side of a woven Kuhei-ori base fabric, heat treated to dry and solidify, and then a release agent is applied to the - side and an adhesive is applied to the other side. Grant.

゛The present inventor focused on heat treatment in the adhesive tape manufacturing process, and developed polyester fibers whose strength and elongation can change to the strength and elongation required for adhesive tapes during this heat treatment as a base fabric for adhesive tapes. The present inventors discovered that the conventional drawbacks could be overcome by applying this method as a warp yarn.This led to the present invention.

The present inventor has confirmed that the strength of certain polyester fibers is reduced by heat treatment during the adhesive tape manufacturing process, similar to that of ordinary polyester fibers, but does not decrease to the point where practicality is lost.

However, it was surprisingly discovered that the elongation of polyester fibers was significantly reduced by heat treatment performed by adhesive tape manufacturers.

The ordinary polyester fibers used in the present invention contain terephthalic acid as the main acid component and contain alkylene glycols having 2 to 6 carbon atoms, such as ethylene glycol, trimethylene glycol, tetramethylene glycol, and pentamethylene glycol.

Hexamethylene glycol The present invention is mainly directed to polyesters containing mineral ethylene glycol as the main glycol component. It may also be a polyester in which part of the terephthalic component is replaced with another difunctional carboxylic acid component, and/or a polyester in which part of the glycol component is replaced with a diol component other than the above-mentioned glycol. .

The difunctional carboxylic acid other than terephthalic acid used here is, for example, isophthalic acid.

naphthalene dicarboxylic acid, diphenyl dicarboxylic acid,
Diphenoxyethane dicarboxylic acid, β-oxyethopenic benzoic acid, P-oxybenzoic acid.

Examples include aromatic, aliphatic, and alicyclic difunctional carboxylic acids such as adipic acid, sepacic acid, and 14-cyclohexanedicarboxylic acid.

In addition, examples of diol compounds other than the above-mentioned glycols include cyclohexane-1,4-dimetatool, neopentyl glycol, bisphenol A, and bisphenol S.
Aliphatics and alicyclics such as.

Examples include aromatic diol compounds.

On the other hand, a polyester fiber having a specific residue has a specific residue in the main chain of the polyester molecule.

Due to the presence of scissor residues, the elongation is rapidly reduced by heat treatment in the adhesive tape manufacturing process 11. Specifically, a dicarboxylic acid or a di-□ residue and L-cd-(.

H*b'SH*"fi- (X is -80BNm+ -X'
+ -OR+ -R't -0Ar, -X' is a halogen group, R and a' are an alkyl group, and %Ar is an aromatic group, which may have a substituent group. It may be in any of the ortho, meta, and para positions of the bond chain.

m jd 1-31. or /1iO-2. ). moreover! Specific polyesters mentioned above include adipic acid, sebacic acid, neopentyl glycol, bisphenols, bisphenols, bisphenols, and 8. Diphenoxyethane dicarboxylic acid, para-hydroxybenzoic acid, etc. may be included as a copolymerizable monomer. Specific polyester fibers may be produced by copolymerization or by blending a specific polyester having the residue defined in the above formula with a normal polyester. The content of the residue can range from 1 to 30% by weight.

It is necessary to use polyester flat yarn having the above-mentioned specific residues in the molecular chain at least as the warp. As the weft, a normal polyester flat yarn may be used, but it is also possible to use an n-flat yarn of polyester fiber having a specific residue.

Warp or weft (Dll 1 degree is not particularly limited, but 5
Preferably, a denier of 0 to 100 is used. It is preferable that the warp and weft have the same denier.

Any fineness that is currently used or that can be manufactured may be used. Similarly, the single yarn denier may be any denier as long as it is compatible with the purpose of the present invention, but a denier of 1 to 5 is usually used.

The warp yarn v11 degree varies depending on the denier used,
The required range of density can be calculated by considering the surface smoothness required for the adhesive tape. The resin layer is laminated on one side or both sides of the base fabric, but olefin-based materials such as polyethylene and polypropylene, vinyl-based materials such as soft polyvinyl chloride, and polyvinyl acetate may be used as the resin layer that is laminated on the base fabric. can.

As for the lamination method, any conventionally used method may be used, such as a method of bonding in the form of a film, a method of dissolving in a solvent to form a dope, and a method of spraying.

The thermal stratum temperature f after laminating the resin layer on the base fabric is 250
~SSO°C range HK is required. Heat treatment time is α5
It is preferable to set it as 5 seconds. The heat treatment can be performed by heating with a hot plate or heating with a hot roller.

If the heat treatment temperature is less than 250°C, the elongation of the base fabric cannot be reduced to the elongation of the adhesive tape while continuously heat treating the laminate.DIf the heat treatment temperature exceeds 350°C, the strength of the base fabric will decrease.

Both elongation and elongation decreased significantly, making it impossible to obtain the strength and elongation required for an adhesive tape.

The same applies to the heat treatment time, and if the time is less than α5 seconds, sufficient heat cannot be applied. If the time exceeds 5 seconds, thermal deterioration will occur.

There are no particular restrictions on the mold release agent or adhesive.

A mold release agent used for adhesive tapes.

Any adhesive may be used.

According to the adhesive tape of the present invention constructed as described in detail above, a) it is inexpensive and economical because it is entirely composed of polyester, b) there is no decrease in strength when wet, and c) a base fabric. There are no thickness unevenness, the surface is smooth, and only a small amount of adhesive is required; 2) It is exceptionally easy to tear in the warp direction, and the cut surface is clean.

Hereinafter, the present invention will be illustrated more specifically with reference to Examples.

Example 1 Modified polyethylene tere-7 tallate flat yarn 75 ds/24 (it (strong f 18 f/de
+ elongation si %) t-a yarn and L (Iik Jk,
11 & 53 pieces/ia) Polyethylene terephthalate flat yarn-775de/3・fi/(strong [
L 1 p/de * elongation j [3(1) was used as the weft, weft density 64/i,] A base fabric was obtained by interweaving. At this time, the elongation of the base fabric in the warp direction was approximately 241 and could not be cut by hand.

Next, as part of the manufacturing process of adhesive tape, even the thickness is determined. At this time, the elongation in the warp direction decreased by about 13 points.

Therefore, it could be easily torn by hand, and the cut was extremely beautiful. Furthermore, a release agent was applied to the front side of the laminated base fabric, and an acrylic acid resin adhesive was applied to the back side to obtain an adhesive tape. The tear strength in the warp direction is 1080 fl for the base fabric.
In contrast, it was 2709 for adhesive tape (-
(according to the measurement method of JI8 L 1096).

Example 2 An adhesive tape was obtained in the same manner as in Example 1 using the modified polyethylene Tele 7 Crate Flat Yarn 7 used in Example 1 for the warp and weft. The obtained adhesive tape was prepared in Example 1.
It exhibited tearability in the warp direction in the same way as in the warp direction, and the tearing cut was extremely beautiful, and it also had the same tearability in the weft direction as in the warp direction.

Examples 3-10. Comparative Example 1 In place of the 5-sodium sulfoisophthalic acid used in Example 1, a polyethylene terephthalate flat yarn to which the residues shown in Table 1 were bonded by copolymerization was used.
An adhesive tape was prepared in the same manner as in Example 1. Table 1 shows the fiber strength and elongation of a nine-base fabric using polyester flat yarns having these specific residues as warp yarns, as well as the tear strength and elongation of an adhesive tape made from it by the method of Example 1.

Table 1 Examples 11-12. Comparative Examples 2 to 3 The characteristics of the base fabric fibers and adhesive tape when only the heat treatment temperature was changed in Example 1 are shown in Table 2.

Table 2

Claims (1)

[Claims] (1) A resin layer is laminated on a base fabric made of polyester flat yarn having a residue represented by the following formula O) in its molecular chain as at least the warp, -mKI1ml agent,
Adhesive tape that has an adhesive on the other side to prevent mold. (Here KX is 180BNa+-')e* OIL+
R'+ OAr*-x' /Ii halogen crystal, 8 and R' are aromatic groups which may have an alkyl group bArti nuclear substituent. The connecting chain may be in the ortho, meta, or para position. m Jd 1 to Suzu-Ku no Kan II $1 The adhesive tape according to item (1). (3) Claim (1) or j in which the flat yarn contains the residue (1) as a fiber made of a copolymer.
(4) The flat yarn is a fiber made of a blend with a copolymer containing the residue (1).
The adhesive tape described in items (1) to (3). (5) After laminating a resin layer on a base fabric made of a polyester flat yarn having a residue shown in the following formula in its molecular chain as at least the warp, the resin layer is heated at 350 to 350°C.
1. A method for producing an adhesive tape, which comprises heat-treating it for several seconds, and then applying a release agent to one side and an adhesive to the other side. (Here KX is 18O1Nar X'l 0RI-R
'lOR'10Ar%X' is a haqgen group, R and R' are an alkyl group, and Ar is an aromatic group that may contain a nuclear substituent. The connecting chain may be in any of the ortho, meta, and para positions. m is 1 to 3, Iltrij is O
~2. )