JP2012122173A - Pretreatment agent used for connecting ends of core rubber-containing braid and pretreatment method for connecting ends of core rubber-containing braid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pretreatment agent for connecting ends of a core rubber-containing braid, the agent being adapted to obtain stable adhesive strength.SOLUTION: When ends of a core rubber-containing braid formed by covering core rubber by a braid cover formed by knitting a fiber in a braid shape are connected with each other using a cyanoacrylate adhesive, the ends of the core rubber-containing braid are solidified using a pretreatment agent obtained by diluting a water soluble chemical paste and ice acetic acid with an alcohol solvent, and the solidified ends are cut off flatly. The pretreatment agent is provided, including, as essential components, 10 to 50 pts.wt. of the water soluble chemical paste and acetic acid having parts by weight equivalent to 1 to 5 pts.wt. of the ice acetic acid, relative to 100 pts.wt. of the alcohol solvent. Preferably, the pretreatment agent is provided, having 0.5 to 5 pts.wt. of a melamine resin adhesive relative to 100 pts.wt. of the alcohol solvent added thereto.

Description

  The present invention relates to a pretreatment agent used for connecting a braid end with a core rubber and a pretreatment method for connecting a braid end with a core rubber, and in particular, the adhesion failure of the braid end with a core rubber due to a cyanoacrylate adhesive is greatly reduced. The present invention relates to a treatment agent and method which can be reduced.

  For example, rubber bands are often used when women tie their hair. For this rubber band, a decorative rubber band is often used in which a core rubber-containing braid covered with a braid cover is manufactured in a ring shape.

  Various methods have been proposed for manufacturing the decorative rubber band. For example, there is known a method in which both ends of a core rubber of a braid containing core rubber are bonded to each other with an adhesive, while fibers at both ends of the braid cover are entangled and bonded to each other (Patent Document 1). However, with this connection method, it is difficult to entangle the fibers at both ends of the braid cover, which increases the manufacturing cost.

  Also, a method is known in which both ends of a braid containing core rubber are cured with an adhesive and cut flat, and the flat cut surfaces are bonded together with an adhesive (Patent Document 2). However, in this connection method, the fibers of the braid cover are not intertwined, the strength of the connection portion depends on the adhesive strength of the adhesive, and when a large load is applied, the adhesion may suddenly come off and break.

  On the other hand, the present inventor, when connecting the ends of the braid containing the core rubber, after bonding the tip surfaces of the core rubber at the two ends of the braid containing the core rubber to each other with an adhesive, A method has been proposed in which the braid cover is placed on the outside of the braid cover at the other end, and the fibers of the braid cover are entangled with each other and bonded with an adhesive (Patent Document 3).

  In the connection method of the braid end with core rubber described in Patent Document 3, since the fibers of the braid cover are entangled and bonded to each other, the fibers of the braid cover are entangled and bonded even if the adhesion of the core rubber is deviated for some reason. As long as it is made, the braid containing the core rubber does not break immediately and has the advantage that it can be used with confidence.

Japanese Patent Laid-Open No. 06-62919 Japanese Patent Laid-Open No. 08-308628 JP 2000-248457 A

  However, in the connection method of the braid end with core rubber described in Patent Document 3, a cyanoacrylate-based adhesive is used as the adhesive, but depending on the solidifying agent used in the previous step, the adhesive strength of the braid cover may be the core rubber. It is not enough compared to the adhesive strength of the end face. For example, when an impact load is applied, the core rubber end face is detached and the braid cover is also detached by the impact of the core rubber end face being detached. was there.

  This invention makes it a subject to provide the connection method of the braid end part with a core rubber which made the stable adhesive strength obtained in view of this problem.

  Accordingly, the pretreatment agent used for connecting the ends of braids with core rubber according to the present invention is 10 to 50 parts by weight of water-soluble chemical glue and 1 to 5 parts by weight of glacial acetic acid with respect to 100 parts by weight of the alcohol solvent. It is characterized in that acetic acid in an amount corresponding to parts by weight is an essential component.

  The present inventors examined the adhesion performance of the cyanoacrylate adhesive to the braid cover fiber, and determined the braid cover according to the type of pretreatment agent used when the end of the braid containing core rubber was solidified and cut flat. When the affinity of the cyanoacrylate adhesive to the fiber is different and this makes it easier for the braid cover to be detached, and when a pretreatment agent in which water-soluble chemical glue and acetic acid are diluted with an alcohol solvent is used, It has been found that the adhesive strength of the braided cover with the acrylate adhesive can be made sufficiently large compared to the adhesive strength of the core rubber, and the adhesive strength of the core rubber can be made sufficiently large.

  Specifically, acetic acid corresponding to 10 to 50 parts by weight of water-soluble chemical glue and 1 to 5 parts by weight of glacial acetic acid is used as an essential component with respect to 100 parts by weight of an alcohol solvent. The reason why the water-soluble chemical glue is 10 to 50 parts by weight is that if the water-soluble chemical glue is less than 10 parts by weight, the fibers of the braided cover cannot be sufficiently solidified. If it exceeds, the braid cover fiber will become too hard and it will take time to loosen in the later process, and the braid cover fiber will become too stiff when bonded with a cyanoacrylate adhesive and lack flexibility. Because it becomes.

  Also, acetic acid corresponding to 1 to 5 parts by weight of glacial acetic acid is used if the glacial acetic acid is less than 1 part by weight, the fiber of the braid cover is not flexible when bonded with a cyanoacrylate adhesive. However, when the glacial acetic acid exceeds 5 parts by weight, the adhesion of the end surface of the core rubber with the cyanoacrylate adhesive is lacking in flexibility. This is because the adhesion is easily removed by pulling.

  According to the tests by the present inventors, the water-soluble chemical glue is preferably 25 parts by weight to 35 parts by weight and acetic acid is glacial acetic acid 2.5 in order to ensure stable adhesion at the end of the braided braid. It was confirmed that parts by weight corresponding to parts by weight to 3.5 parts by weight are preferable.

  When 0.5 parts by weight to 5 parts by weight, preferably 1.0 part by weight to 3.0 parts by weight of melamine resin-based adhesive is added to 100 parts by weight of methyl alcohol to the pretreatment agent described above, cyanoacrylate The adhesive strength of the system adhesive can be increased.

  Further, according to the present invention, the end portion of the braid containing the core rubber is cut flat, the two end surfaces of the core rubber to be connected are bonded to each other with a cyanoacrylate adhesive, and one end When the other braid cover is placed on the outside of the braid cover at the other end, the fibers of the braid cover are entangled in the overlapping range and bonded with the cyanoacrylate adhesive (Claim 1). Or a pretreatment method for the end portion of the braid containing core rubber, wherein the end portion of the braid containing core rubber is solidified using the pretreatment agent described in 2) and then cut flat. can do.

  Hereinafter, the present invention will be described in detail based on specific examples.

Example 1
Pretreatment agent A was produced by diluting 390 g of vinyl acetate polymer and 39 g of glacial acetic acid with 1 liter of methyl alcohol.

(Example 2)
Pretreatment agent B was produced in the same manner as in Example 1 except that 25 g of glacial acetic acid was used.

Example 3
Pretreatment agent C was produced in the same manner as in Example 1 except that 10 g of glacial acetic acid was used.

Example 4
Pretreatment agents D, E, and F were produced in the same manner as in Examples 1, 2, and 3, except that 300 g of vinyl acetate polymer was used.

(Example 5)
Pretreatment agents G, H, and I were produced in the same manner as in Examples 1, 2, and 3, except that 200 g of vinyl acetate polymer was used.

(Example 6)
Pretreatment agents J, K, and L were produced in the same manner as in Examples 1, 2, and 3, except that 80 g of vinyl acetate polymer was used.

(Example 7)
The melamine resin adhesive 4.0g was diluted with 1 liter of methyl alcohol, and this was dripped only 1 drop at the pre-processing agents AL manufactured in Examples 1-6.

(Example 8)
39.5 g of melamine resin-based adhesive was diluted with 1 liter of methyl alcohol, and this was added dropwise to pretreatment agents A to L produced in Examples 1 to 6.

(Comparative Example 1)
Pretreatment agent a was produced in the same manner as in Example 1, except that the vinyl acetate polymer was changed to 50 g.

(Comparative Example 2)
A pretreatment agent b was produced in the same manner as in Example 1 except that the vinyl acetate polymer was changed to 450 g.

(Comparative Example 3)
Pretreatment agent c was produced in the same manner as in Example 1 except that 5 g of glacial acetic acid was used.

[Comparative Example 4]
Pretreatment agent d was produced in the same manner as in Example 1 except that 45 g of glacial acetic acid was used.

(Production example)
After impregnating the ends of the braid containing core rubber with the pretreatment agents of Examples 1 to 8 and Comparative Examples 1 to 4 and drying and curing with room temperature or hot air, the ends of the braid containing core rubber are cut flat. did. Next, rub one end surface of the two ends of the braided cord with core rubber to be connected with sandpaper to loosen the fibers of the cured braided cover, and scrape the end surface of the core rubber to make the tip of the braided cover the core rubber. It was set as the state which protruded 2 mm-5 mm from the end surface.

Next, a cyanoacrylate adhesive was applied to the end faces of the core rubber at the two ends of the braid containing the core rubber to be connected, pressed against each other and held, and the end faces of the core rubber were adhered to each other.
Finally, cover the braid cover fiber that protrudes beyond the end face of the core rubber on the outside of the braid cover at the other end, impregnate the overlapped part with cyanoacrylate adhesive, and rotate while pressing the finger, The braid cover fibers were intertwined with each other, and the adhesive was solidified to bond the braid cover.

(Test example)
The connection strength of the braided cord with core rubber was pulled by assuming a normal use situation, and the connection strength was confirmed by extending the interval of 10 mm to 50 mm. The results are shown in Table 1.

  In the production examples using the pretreatment agents of Examples 1 to 8, there was some variation in connection strength depending on the temperature and humidity, but sufficient and stable strength was obtained for both the connection of the core rubber end surface and the connection of the braid cover. And no adhesion failure was observed.

It was found that the amount of glacial acetic acid affects the connection strength between the braid cover and the end face of the core rubber, and it is necessary to finely adjust the addition amount according to the temperature and humidity of the day.
Moreover, when the melamine resin adhesive diluted with methanol was dropped, even if the interval of 10 mm was extended to exceed 53 mm, no break was observed, and the adhesive strength was very good.

On the other hand, in the production examples using the pretreatment agents of Comparative Examples 1 to 4, the core rubber end surface may break before the 10 mm interval is extended to 50 mm. It was found that the cover was also broken and product defects were likely to occur.

Claims (3)

  A core rubber comprising, as an essential component, 10 parts by weight to 50 parts by weight of a water-soluble chemical glue and 100 parts by weight of acetic acid corresponding to 1 part by weight to 5 parts by weight of glacial acetic acid with respect to 100 parts by weight of an alcohol solvent. A pretreatment agent used to connect the ends of braided braids.   The pretreatment agent used for connecting the ends of braids with core rubber according to claim 1, wherein 0.5 parts by weight to 5 parts by weight of a melamine resin adhesive is added to 100 parts by weight of an alcohol solvent. Cut the end of the braided cord containing the core rubber flatly, and bond the tip ends of the core rubber at the two ends to be connected to each other with a cyanoacrylate adhesive, and attach the braided cover at one end to the other end. When covering the outside of the braid cover of the part, entangle the braid cover fiber in the overlapping range and adhere with the cyanoacrylate adhesive,
A method for pretreating an end portion of a braid containing core rubber, wherein the end portion of the braid containing core rubber is solidified using the pretreatment agent according to claim 1 or 2 and then cut flat. .