JPS6038122B2 - Colored and transparent synthetic resin soles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a synthetic resin shoe sole, more specifically, a shoe sole having moderate rigidity,
The present invention also relates to a lightweight, colored and transparent synthetic resin shoe sole.

In order to simplify the shoe manufacturing process and eliminate the drawbacks of conventional leather shoes in terms of physical properties such as abrasion resistance and moisture absorption resistance,
It has been a long time since the upper part of the shoe was made of various types of artificial leather, and the sole part of the shoe was made of hard natural or synthetic rubber or relatively elastic synthetic resin such as polyurethane.

Polyurethane, which has become the mainstream material for the soles of the above-mentioned improved shoes, has excellent physical properties such as abrasion resistance, flex crack resistance, and elasticity. It is highly prized in the industry because of its strong adhesive strength. However, while polyurethane shoe soles have the above-mentioned advantages, they are too flexible, and in order to provide the appropriate rigidity that is unique to shoe soles, they must be made quite thick. As a result, there is a drawback that the sole of the shoe becomes heavy.

In order to improve the above-mentioned drawbacks, lightweight shoes whose soles are made of a thermoplastic synthetic resin called "ionomer resin" have recently come on the market.

The above-mentioned resin was developed by I.I. DuPont.
This resin is made by crosslinking a copolymer of ethylene or Q-olefin and unsaturated monocarboxylic acid with metal ions, and this resin has very strong rut resistance, as well as moderate elasticity and flexibility, and excellent abrasion resistance. Because of this, it is attracting attention as a suitable shoe sole material to replace polyurethane.

In other words, the soles made from this resin are extremely strong and have excellent abrasion resistance even without the inclusion of reinforcing materials such as carbon black or silica, and therefore have high transparency. Therefore, utilizing this characteristic, sports shoes with innovative designs that have various patterns, marks, trademarks, etc. extracted on the back side of the lower part that can be seen from the outside are becoming popular among consumers. .

However, in such transparent soles, there are some defective products in which semi-transparent or opaque parts are formed in some parts, especially in relatively thick parts, and the decorative effect of the toe pattern etc. is diminished. It's finally happening.

This is thought to be due to the fact that the cooling efficiency in the relatively thick portion is lower than that in other relatively thin portions, and the crystallization start time of the polymer in the former is delayed. If so, it is presumed that the above-mentioned phenomenon can be resolved by blending a crystal nucleating agent to make the polymer crystallization initiation timing as similar as possible and reducing the size of the resulting crystals. However, until now, a crystal nucleating agent suitable for ionomer resins has not yet been known. As a result of various studies based on the above speculations, the present inventors have found that phthalocyanine tsuba salts are suitable crystal nucleating agents for ionomer resins, and that by blending the compounds, semitransparent shoe soles can be made transparent. In addition to avoiding the formation of opaque areas, the soles of the ionomer resin containing the above complex salts are themselves colored in beautiful blue or green. It was discovered that the unexpected effect of making letters and figures stand out clearly could be obtained. As already clear from the above, the purpose of the present invention is to provide a synthetic resin shoe sole that has clear colored transparency, is moderately rigid, and is lightweight. The sole of the shoe is made of a composition containing salts.

The above-mentioned ionomer resin used for manufacturing the sole of the present invention may be a random copolymer whose copolymer molecular chain is composed of various monomers used in the polymerization, or may have an unsaturated monomer in the molecular chain of its polyethylene skeleton. It may also be a graft copolymer produced by polymerizing carboxylic acid monomers.

The graft copolymer is produced by irradiating a mixture of polyethylene and an unsaturated carboxylic acid with Y-rays or ultraviolet light. The ionomeric resins described above may optionally contain small amounts of other monomers, such as alkyl acrylates or alkyl methacrylates, for example in amounts up to 1% by weight.

The aliphatic or aromatic Q-olefin that is a component of the above-mentioned ionomer resin is, for example, propylene, Q-butylene, styrene, etc., and representative examples of the unsaturated monocarboxylic acid include acrylic acid, methacrylic acid, etc. The resin contains 4 to 3 weight %, preferably 15 weight % or less of the unsaturated monocarboxylic acid as a copolymerization component.

Metal crosslinking agents such as zinc, sodium, and magnesium are bonded to the above-mentioned copolymers. As mentioned above, the gist of the present invention is to incorporate phthalocyanine complex salts as a crystal nucleating agent into a transparent shoe sole material made of ionomer resin. As a result of also examining metal salts of organic acids and known sorbitol-based nucleating agents, which have been considered effective as crystal nucleating agents for polypropylene, we found that phthalocyanine complex salts are highly effective. It is.

Incidentally, in conducting these studies, approximately 0.1% by weight of each reagent (methyl terephthalate, tin stearate, sorbitol nucleating agent, phthalocyanine flu, phthalocyanine green) was uniformly dispersed in the ionomer resin compound. Prepare 5 types of samples (Samples 1 to V), heat each sample to 160°C, and after confirming that the crystals have completely melted, reduce the temperature of the product at a rate of 5°C/min. The sample was cooled and the timing of crystallization initiation was measured using a differential scanning calorimeter (DSC). As a result, as shown in Table 1, compared to the standard sample containing no reagent, the crystal initiation time seemed to be slightly accelerated in sample 1. ), no changes were observed at all. On the other hand, in both samples W and V based on the present invention, the crystallization start time was accelerated by about 1 minute.

This can be said to be a significant improvement from the perspective of common sense in the art. Table I Evaluation: ○...Significantly fast △...Slight change ×...No change As is clear from the above results, examples of phthalocyanine salts commonly used for the purpose of the present invention are: In addition to copper phthalocyaniso such as phthalocyanine flu and phthalocyaniso green, those used as subordinate pigments include low chlorinated phthalocyanine, highly halogenated phthalocyanine, sulfonated phthalocyanine, and metal-free phthalocyanine.

Further, instead of copper, it may contain nickel, cobalt, manganese, tin, magnesium, calcium, sodium, potassium, etc., or it may combine iron, aluminum, etc. with other acid plates. Usually, easily available copper phthalocyanine pigments are used. The amount of phthalocyanine salts to be used was determined to be 0 as a result of examining the effects of using various amounts of the compound using the same method as described above.
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It has been found that if the amount is less than 0.005% by weight, the crystallization initiation time cannot be significantly accelerated, and if it is used in an amount of about 1% by weight or more, it is unfavorable in terms of effects on other physical properties and economical efficiency.

According to the present invention, as described in detail above, by blending a very small amount of phthalocyanine rust salts into the pionomer resin, the time at which the resin begins to crystallize during the molding of shoe soles is accelerated, especially in thick parts. To cause crystallization near the surface and in the inner core portion to occur simultaneously as much as possible, and to generate fine crystals in the inner core portion, thereby preventing the generation of translucent or opaque portions in the inner core portion. As a result, it is possible to obtain a shoe sole that has clear colored transparency, is moderately rigid, and is lightweight, taking advantage of the characteristics of the ionomer resin. The present invention will be explained below with reference to Examples.

Example 1 Surlyn 1650 (DuPont ionomer resin)
0.05% by weight of Phthalocyanine Flu BST (manufactured by Sanyo Shiki Co., Ltd.) was thoroughly and uniformly mixed according to a conventional method, and the resulting mixture was subjected to DSSC in the same manner as the above method to determine the temperature at the time of crystallization start and the temperature at the time of crystallization start. When the time was measured, the former was 7.0 minutes and the latter was 17.6 minutes.

Incidentally, in a mixture prepared without mixing the crystal nucleating agent for comparison, the crystal initiation temperature was total °C, and the time until crystal initiation was 18.4 minutes.

Therefore, it can be seen that the crystallization initiation time was significantly accelerated by the present invention.On the other hand, when shoe soles were manufactured using an injection molding machine using the mixture of this example, the color of the soles was bluer than that of the soles made using the standard mixture. A clear and transparent product was obtained.

Example 2 A preparation obtained by mixing 0.1% by weight of cyanine green (phthalocyanine rust salts manufactured by Sanyo Shiki Co., Ltd.) with the same ionomer resin as in Example 1 was subjected to crystallization initiation using the same method as in the previous example. When the temperature and time until crystallization started were measured, the former was 72.500 minutes and the latter was 16.9 minutes.

Claims (1)

[Scope of Claims] 1. The sole is a copolymer of ethylene or α-olefin and at least one unsaturated monocarboxylic acid having 3 to 8 carbon atoms, and the sole is a copolymer of ethylene or α-olefin and at least one type of unsaturated monocarboxylic acid having 3 to 8 carbon atoms, and has a heat-changeable metallic cross-linkage bond. A colored transparent synthetic resin shoe sole, characterized in that it is formed from a thermoplastic resin composition containing a compound having the following: and a phthalocyanine complex salt. 2. The shoe sole according to claim 1, wherein the phthalocyanine complex salt is phthalocyanine blue. 3. The shoe sole according to claim 1, wherein the phthalocyanine complex salt is phthalocyanine green. 4. The shoe sole according to claim 1, which contains at least 0.005% by weight of phthalocyanine complex salts.