JP2001019846A - Nylon 6 composition for tying band - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide nylon 6 compositions having excellent mechanical properties, good flowability, and good mass productivity sufficient to allow multi-cavity injection molding, and tying bands for mailbags using the same. SOLUTION: Nylon 6 compositions for tying bands which are obtained by blending 99-1 pts.wt. nylon 6 having a relative viscosity of not greater than 2.3 and 1-99 pts.wt. nylon 6 having a relative viscosity of not smaller than 2.5. Particularly, the nylon 6 compositions are obtained by blending 99-1 pts.wt. nylon 6 having a relative viscosity of not greater than 2.1 and 1-99 pts.wt. nylon 6 having a relative viscosity of 2.5-5.0.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a nylon 6 composition for a tying band. More specifically, moldability and
The present invention relates to a nylon 6 composition for a binding band, which is excellent in mass productivity and mechanical properties and can be suitably used for a binding band for a postal bag.

[0002]

2. Description of the Related Art A binding band for binding the mouth of a postal bag used for collection and delivery of postal matter (hereinafter referred to as a "binding band for a postal bag") is locked to, for example, a rectangular plate having a thickness of about 1 mm. An opening as a part is provided, and a band-like band part is provided in the rectangular plate part, and the tip of the band part is inserted into the lock part so as to bind the mouth of the bag.

[0003] Such a binding band for a postal bag is required to have excellent mechanical properties so as not to cause cracking of the band portion during binding and breakage of the rectangular plate portion during use. For this reason, it has excellent mechanical properties and is inexpensive. Therefore, usually, nylon 6 having a relative viscosity of 2.5 or more is used, and the nylon 6 is melted and injection-molded into a metal mold. Bands are being manufactured.

[0004] However, a binding band made of nylon 6 having a relative viscosity of 2.5 or more has sufficient mechanical strength, but has poor fluidity, so that a plurality of tying bands are formed at once using a multi-cavity mold at the time of molding. There is a problem that it is impossible to manufacture individual binding bags for postal bags, resulting in poor mass productivity. Therefore, a binding band made of nylon 6 having a relative viscosity lower than 2.5 has been proposed in order to enhance mass productivity.
Such a binding band is inferior in mechanical properties, and has a problem that it breaks or cracks at the time of binding of the band and is not suitable for actual use.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and has excellent mechanical properties, good fluidity, and a mass-produced nylon 6 composition for a tying band capable of realizing multi-cavity injection molding. It provides things.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention. That is, the present invention provides a tying band characterized by blending 99 to 1 part by weight of nylon 6 having a relative viscosity of 2.3 or less and 1 to 99 parts by weight of nylon 6 having a relative viscosity of 2.5 or more. It features a nylon 6 composition.

According to the present invention, the fluidity of a nylon 6 is obtained by blending a low viscosity nylon 6 having a relative viscosity of 2.3 or less and a high viscosity nylon 6 having a relative viscosity of 2.5 or more. Thus, a nylon 6 composition having high moldability, excellent moldability, and excellent mechanical properties can be obtained. As a result, when molding the binding band, high mass productivity injection molding using a multi-cavity mold can be realized, and the obtained binding band has mechanical properties without breaking or cracking at the time of binding. It will be excellent.

According to the present invention, nylon 6 blended with 99 to 1 parts by weight of nylon 6 having a relative viscosity of 2.1 or less and 1 to 99 parts by weight of nylon 6 having a relative viscosity of 2.5 or more and 5.0 or less. It is particularly preferred that it is a composition. The present invention also provides a binding band for use in which 99 to 1 parts by weight of nylon 6 having a relative viscosity of 2.3 or less and 1 to 99 parts by weight of nylon 6 having a relative viscosity of 2.5 or more are blended. Nylon 6 composition, particularly 99 to 1 part by weight of nylon 6 having a relative viscosity of 2.1 or less, and 1 to 99 parts by weight of nylon 6 having a relative viscosity of 2.5 to 5.0. A gist of the present invention is a binding band for a postal bag made of a nylon 6 composition for a binding band.

According to the present invention, it is possible to obtain a binding band for a mail bag, which can realize a large number of pieces, has good mass productivity, and has excellent mechanical properties without breaking or cracking during binding.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The nylon 6 composition for a binding band of the present invention is a low viscosity nylon 6 having a relative viscosity of 2.3 or less.
(Hereinafter, simply referred to as “low-viscosity nylon 6”) and a high-viscosity nylon 6 having a relative viscosity of 2.5 or more (hereinafter, simply referred to as “high-viscosity nylon 6”). There is a need. By blending and using low-viscosity nylon 6 and high-viscosity nylon 6, an improvement in productivity and excellent mechanical properties can be obtained by a synergistic effect of each component. That is, by blending low viscosity nylon 6,
The fluidity at the time of molding is improved, so that injection molding using a multi-cavity mold can be realized, and the binding band can be created with good mass productivity. In addition, by blending high-viscosity nylon 6, mechanical properties, specifically, strength and elongation are increased,
When used, the band portion has both sufficient strength and elongation, so that a banding band that does not crack or break even when bent or subjected to force during banding can be obtained.

[0011] The low viscosity nylon 6 in the present specification is:
Nylon 6 having a relative viscosity of 2.3 or less, more preferably a nylon 6 having a relative viscosity of 2.1 or less, obtained by using 96% by weight concentrated sulfuric acid as a solvent at a temperature of 25 ° C. and a concentration of 1 g / dl. It is. The lower limit is preferably set to 1.5 or more. If the relative viscosity is less than 1.5, the mechanical properties deteriorate, and it becomes difficult to obtain a binding band having a strength enough to withstand actual use.

The high-viscosity nylon 6 in the present specification is:
Nylon 6 having a relative viscosity of 2.5 or more, obtained by using 96% by weight concentrated sulfuric acid as a solvent at a temperature of 25 ° C. and a concentration of 1 g / dl, more preferably a relative viscosity of 2.5 or more and 5.0 or less. And more preferably nylon 6 having a relative viscosity of 2.5 or more and 4.0 or less. When the relative viscosity exceeds 5.0, the moldability rapidly decreases, and it becomes difficult to realize multi-cavity at the time of injection molding, which tends to result in poor mass productivity.

The blending ratio of blending low viscosity nylon 6 and high viscosity nylon 6 is (low viscosity nylon 6) / (high viscosity nylon 6) = 1/99 to 99/1 by weight. More preferably, (low-viscosity nylon 6) / (high-viscosity nylon 6) = 90/10 to 10/90, and still more preferably (low-viscosity nylon 6) / (high-viscosity nylon 6).
= 70/30 to 30/70. If the amount of the low viscosity nylon 6 is less than 1 part by weight, the mechanical strength decreases. On the other hand, if the amount of the high viscosity nylon 6 is less than 1 part by weight, the fluidity decreases and it becomes difficult to take a large number of pieces at the time of molding.

The nylon 6 composition for a binding band of the present invention preferably contains a release agent at a ratio of 1% by weight or less in order to improve the releasability at the time of injection molding. Metal salts of aromatic bisamides and higher fatty acids can be suitably used. Examples of the aliphatic bisamide include methylene bisstearyl amide, methylene bis lauryl amide,
Examples include ethylene bisstearyl amide, ethylene bis lauryl amide, ethylene bis oleyl amide, and ethylene bis behenyl amide, with ethylene bis stearyl amide being particularly preferred.

Examples of the metal salt of a higher fatty acid include metal salts of stearic acid, palmitic acid, lauric acid, mystyric acid, etc. Among them, a metal salt of stearic acid is particularly preferable. Specific examples thereof include magnesium stearate, calcium stearate, barium stearate, aluminum stearate, and zinc stearate.

It is more preferable that the nylon 6 composition for a binding band of the present invention contains a crystal nucleating agent in a proportion of 1% by weight or less, since moldability is improved. Examples of such a crystal nucleating agent include talc, silica, kaolin, graphite, magnesium oxide, aluminum oxide and the like, and talc is particularly preferred. The binding band for a postal bag made of the nylon 6 composition for a binding band of the present invention is often colored orange, but the present invention is not limited to this. The coloring pigment for resin can be blended at a ratio of 3% by weight or less.

For example, dinitroaniline orange, disazo orange PMP, dianisidine orange as an orange pigment, brilliant green PTMA toner, diamond green PTMA toner, phthalocyanine green, phthalocyanine green (yellow mouth) as a green pigment, and Fast Yellow 10G as a yellow brown pigment Disazo yellow AAA, disazo yellow AAAX, disazo yellow AAOT, yellow iron oxide, disazo yellow HR, gold-containing azo yellow, red pigment toluidine red, chlorinated para red, brilliant fast scarlet, pyrazolone red B, barium red 2B,
Calcium Red 2B, Barium Risole Red, Lake Red C, Brilliant Carmine 6B, Pigment Scarlet 3B Lake, Rhodamine 6GPTMA Toner, Bengala, Naphthol Red FGR, Quinacridone Magenta, Quinacridone Red, Rhodamine BPTMA Toner as a purple pigment, Dioxazine Violet,
As a blue pigment, Victoria Pure Blue PTMA toner, phthalocyanine blue (α type), phthalocyanine blue (β type), alkali blue toner, navy blue, ultramarine,
Examples of white pigments include calcium carbonate, barium sulfate, zinc carbonate, titanium dioxide, magnesium carbonate, talc, and black pigments such as carbon black.

The nylon 6 composition for a binding band according to the present invention further comprises a heat-resistant agent, a weather-resistant agent, a bite improver, a plasticizer, a flame retardant, a light stabilizer, an antioxidant, etc., as long as the physical properties are not impaired. You may add things.

[0019]

Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. In addition, the measurement of various physical property values in the following Examples and Comparative Examples was performed by the following methods.

(1) Relative viscosity: The relative viscosity of nylon 6 resin was measured by the following method. That is, 1.0 g of a sample was dissolved in 100 cc of this solvent using 96% concentrated sulfuric acid as a solvent, and the measurement was performed by a conventional method at a temperature of 25 ° C.

(2) Flow length (mm): width 20 mm, thickness 1 mm, gate width 3 m, according to a bar flow measurement method.
m using a spiral mold having a m of 100 m and an IS-100E injection molding machine (manufactured by Toshiba Machine Co., Ltd.)
° C, mold temperature 70 ° C, injection speed 40%, injection pressure 90M
Injection molding was performed at Pa, and the relationship between pressure and flow length, that is, flowability was measured.

(3) Number of multi-cavities: As shown in FIG.
A mold having a cavity such that six binding bands 1 for a mail bag are formed at a time, comprising a rectangular plate portion 2 having a thickness of 1 mm, a width of 93 mm and a length of 160 mm, and a band portion 3 having a thickness of 1 mm and a length of 250 mm. And the resin temperature 26
Molding was performed at 0 ° C., a mold temperature of 80 ° C., an injection pressure of 90 MPa, and an injection speed of 75%. Then, all of the six cavities were filled with the binding band 1 for a mail bag, and the case was evaluated as 、.

(4) Presence or absence of breakage of the band portion and the lock portion: The binding band 1 for a postal bag shown in FIG. 1 was immersed in water at 50 ° C. until the water absorption became 3%. The post-absorbing binding band 1 for a mail bag was cooled to 0 ° C. while being immersed in water, and left for 1 hour. Next, the cooled binding band 1 for a mail bag was taken out of the water, and the tip of the band portion 3 was immediately inserted into the lock portion 4. Then, as shown in FIG. 2, a steel rod 5 having a diameter of 20 mm is passed through the annular band 3 and the band 3 is pulled in the direction of the arrow. The portion 4 was evaluated for damage. The test was performed on 20 binding bands 1 for mail bags, and the band portion 3 or the lock portion 4 was examined for breakage or cracking. Then, those in which no break or crack was generated were evaluated as ○, and those in which even one was cracked were evaluated as x.

Example 1 Nylon 6 having a relative viscosity of 2.05 as a low viscosity nylon 6 (A1015 manufactured by Unitika) and 50 parts by weight of nylon 6 having a relative viscosity of 2.50 as a high viscosity nylon 6 manufactured by Unitika , A1030 JR) and 50 parts by weight of a nylon 6 composition. This nylon 6 composition contains 0.5% magnesium stearate as a release agent.
% And 0.4% of titanium oxide which is a white pigment.

Using the nylon 6 composition blended as described above, a resin temperature of 260 ° C. and an injection pressure of 90 MPa were measured by an FE460S type injection molding machine (manufactured by Nissei Plastics Industries, Ltd.).
a, under the conditions of a mold temperature of 80 ° C. and an injection speed of 75%, using a 6-cavity mold, a thickness of 1 m having a shape as shown in FIG.
m was formed. Table 1 shows the measurement results of the obtained nylon 6 composition and the binding band for a postal bag.

[0026]

[Table 1]

Examples 2 and 3 Nylon 6 having a relative viscosity of 2.05, which is a low viscosity nylon 6
(A1015, manufactured by Unitika) and nylon 6 having a relative viscosity of 2.50, which is a high-viscosity nylon 6 (A1015, manufactured by Unitika)
1030 JR) as shown in Table 1.
Otherwise, a binding band for a mail bag was prepared in the same manner as in Example 1. Table 1 shows the measurement results of the obtained nylon 6 composition and the binding band for a postal bag.

Example 4 70 parts by weight of nylon 6 having a relative viscosity of 2.15 as a low viscosity nylon 6 (A1020BRL, manufactured by Unitika Ltd.)
A nylon 6 composition obtained by blending 30 parts by weight of nylon 6 having a relative viscosity of 2.50 (manufactured by Unitika Ltd., A1030JR) as the high viscosity nylon 6 was used. Otherwise, a binding band for a mail bag was prepared in the same manner as in Example 1. Table 1 shows the measurement results of the obtained nylon 6 composition and the binding band for a postal bag.

The binding band obtained in each of Examples 1 to 4 is a nylon 6 composition obtained by blending low-viscosity nylon 6 and high-viscosity nylon 6 having a relative viscosity within the range of the present invention in a ratio within the range of the present invention. As a result, the flow length was long, the moldability was excellent, and multi-cavity could be realized. Moreover, the obtained binding band for postal bags had no mechanical damage at the time of fastening and was excellent in mechanical properties.

Comparative Example 1 High viscosity nylon 6 was blended without blending low viscosity nylon 6.
Nylon 6 having a relative viscosity of 2.50 (manufactured by Unitika Ltd.)
A1030 JR) alone. Otherwise, a binding band for a mail bag was prepared in the same manner as in Example 1. Table 1 shows the measurement results of the obtained nylon 6 composition and the binding band for a postal bag.

COMPARATIVE EXAMPLE 2 Nylon 6 having a relative viscosity of 2.05, which is a low viscosity nylon 6 without blending the high viscosity nylon 6, (A
1015) alone. Otherwise, a binding band for a mail bag was prepared in the same manner as in Example 1. Table 1 shows the measurement results of the obtained nylon 6 composition and the binding band for a postal bag.

In Comparative Example 1, since only high-viscosity nylon 6 was used without blending low-viscosity nylon 6, the fluidity was poor and a large number of pieces during molding could not be realized. Comparative Example 2
Because only low-viscosity nylon 6 was used without blending high-viscosity nylon 6, the obtained binding band for a postal bag did not have sufficient strength and was likely to be damaged at the time of fastening.

[0033]

According to the present invention, a binding band for 99 to 1 part by weight of nylon 6 having a relative viscosity of 2.3 or less and 1 to 99 parts by weight of nylon 6 having a relative viscosity of 2.5 or more are blended. By using the nylon 6 composition of the above, the flowability is improved, multi-pieces can be obtained at the time of molding, and the obtained binding band has excellent mechanical properties.

Particularly, a nylon for a binding band obtained by blending 99 to 1 part by weight of nylon 6 having a relative viscosity of 2.1 or less and 1 to 99 parts by weight of nylon 6 having a relative viscosity of 2.5 to 5.0. Even when the six compositions are used, the same effects as described above can be obtained. In addition, the binding band made of the nylon 6 composition obtained by blending the low viscosity nylon 6 and the high viscosity nylon 6 can be suitably used as a binding band for a postal bag.

[Brief description of the drawings]

FIG. 1 is a view showing a schematic example of a binding band for a postal bag made of a nylon 6 composition for a binding band according to the present invention.

FIG. 2 is a diagram illustrating a test method for examining whether a band portion and a lock portion are damaged.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Binding band for mail bags 2 Rectangular plate part 3 Band part 4 Lock part

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[Procedure amendment]

[Submission date] August 4, 1999 (1999.8.4)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction contents]

The blending ratio of blending low viscosity nylon 6 and high viscosity nylon 6 is (low viscosity nylon 6) / (high viscosity nylon 6) = 1/99 to 99/1 by weight. More preferably, (low-viscosity nylon 6) / (high-viscosity nylon 6) = 90/10 to 10/90, and still more preferably (low-viscosity nylon 6) / (high-viscosity nylon 6).
= 70/30 to 30/70. If the amount of the high viscosity nylon 6 is less than 1 part by weight, the mechanical strength decreases. On the other hand, if the amount of the low viscosity nylon 6 is less than 1 part by weight, the fluidity decreases and a large number of pieces are formed during molding. Becomes difficult.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Negishi Yukinari 31-3 Uji Hinojiri, Uji-city, Kyoto Unitika Unita Uji Plastics Factory F-term (reference) 3E067 AA12 AB99 BB14A BB22A DA03 EE32 4J002 CL01W CL01X FD090 FD160

Claims (3)

[Claims] 1. A binding band for a binding band, wherein 99 to 1 part by weight of nylon 6 having a relative viscosity of 2.3 or less and 1 to 99 parts by weight of nylon 6 having a relative viscosity of 2.5 or more are blended. Nylon 6 composition. 2. A blend of 99 to 1 part by weight of nylon 6 having a relative viscosity of 2.1 or less and 1 to 99 parts by weight of nylon 6 having a relative viscosity of 2.5 or more and 5.0 or less. Nylon 6 composition for cable ties. 3. A binding band for a postal bag, comprising the nylon 6 composition for a binding band according to claim 1.