JPS61128904A - Shoe sole - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a shoe sole made of stabilized polyurethane resin. More specifically, the present invention relates to a shoe sole made of polyurethane resin that is extremely stable against external factors such as light, heat, moisture, and oxygen.

(Prior art) Polyurethane is a polymer that has excellent impact resistance, chemical resistance, abrasion resistance, cold resistance, etc., so it has traditionally been a material used in various fields and applications. However, on the other hand, polyurethane also has the property of being easily affected by external factors such as light, heat, moisture, and oxygen, and these external factors can cause deterioration of the surface condition of polyurethane molded products. That is, phenomena that are undesirable for the quality of polyurethane products, such as surface peeling, cracking, and changes in hue, occur.

For this reason, various stabilizers have been developed for the purpose of improving polyurethane's poor weather resistance against these external factors.・For example, in JP-A-56-100848, phenylenediamine compounds and sterically hindered phenol compounds, phenylenediamine compounds and phosphite compounds, phenylenediamine compounds and quinoline compounds, phenylenediamine compounds and benzene A triazole compound, a phenylene diamine compound and a thiourea compound, a phenylene diamine compound and a piperidine compound, or a phenylene diamine compound and a metal oxide are used as stabilizers for polyurethane.

Further, in JP-A-57-49653, the weather resistance of polyurethane is improved by using a hindered phenol compound and a phosphorous acid ester.

A variety of molded products are manufactured using polyurethane containing these stabilizers.Recently, polyurethane resins are being used to manufacture various automobile parts, garden chairs, and other products that utilize the design freedom and corrosion resistance of polyurethane resins. Great products are being manufactured.

[Problems to be solved by the invention] However, in the case of polyurethane resins manufactured using stabilizers that have been developed so far, if the polyurethane resin is an uncolored white polyurethane, it is difficult to maintain its whiteness. Polyurethane resins have not always been satisfactory in terms of properties. That is, the stabilizer disclosed in JP-A-56-100848 serves the purpose of preventing gloss fading and cracking of colored polyurethane, but it does not contain a phenylenediamine compound as an essential component. Therefore, if it is used in white polyurethane, it will cause yellowing, which is undesirable.

Furthermore, the stabilizer disclosed in JP-A No. 57-49653 is inferior in terms of sustainability of effect;
It cannot be said to be sufficient.

As mentioned above, various stabilizers for polyurethane are being developed for the purpose of producing polyurethane resins with excellent stability that can withstand long-term use.
This is still not sufficient, and there is a strong desire for the emergence of polyurethane products with excellent weather resistance that can withstand long-term use.

In particular, when a polyurethane resin is used for the sole of a shoe, if the polyurethane has a property of yellowing or fading, the commercial value of the shoe itself will be significantly reduced, which is disadvantageous. Therefore, there is a need for shoe soles made of polyurethane resin that do not discolor or fade.

Means for Solving Problem C] In order to solve the above-mentioned problems, particularly the problem that shoe soles made of polyurethane that are resistant to discoloration and peeling do not yet exist on the market, the present inventors have: As a result of intensive studies, we have arrived at the present invention. That is, the present invention provides: (a) an antioxidant, and (b) general formula (I) (R1, R2, R3 are the same or different alkyl groups,
cycloalkyl group, aryl group, alkylaryl group,
Represents an aralkyl group. ), and the phosphorus content is 4.
To provide a sole made of a polyurethane resin containing a phosphite ester in a range of 0 to 14.0% by weight, and which is resistant to discoloration and peeling.

The polyurethane resin used to manufacture the sole of the present invention is manufactured using an isocyanate compound and an active hydrogen-containing compound, and at that time, an antioxidant and the general formula (I ) is used as a stabilizer.

The antioxidant that can be used in the present invention may be any hindered phenol compound having at least one branched lower aliphatic hydrocarbon group bonded to the ortho position. One having 1 to 4 in one molecule is preferable. When two or more phenol nuclei are present in one molecule, there are no particular restrictions on the bonding state. The branched lower aliphatic hydrocarbon group mentioned above is generally preferably one having 3 to 7 carbon atoms, such as isopropyl group, isobutyl group, t-butyl group, isopentyl group, L-pentyl group, isohexyl group, etc. Among these, a particularly preferred one is a t-butyl group.

Various other substituents may be bonded to the above-mentioned hindered phenol compound.

Specific examples of the above-mentioned hindered phenol compounds include the following compounds.

The above antioxidants can be used in the present invention alone or as a mixture of two or more.

Next, the phosphite compound represented by the general formula (I) above is a compound represented by the general formula (I), provided that R1, R2, and R3 satisfy the above conditions. Any type of material may be used, but the phosphorus content should be 4.0 to 14.
．． 0% by weight, and 6.0 to 8.0% by weight is particularly preferred. Specific examples of these include triisodecyl phosphite, phenyl diisodecyl phosphite, diphenylnonylphenyl phosphite, and triisooctyl phosphite.

These phosphite esters can be used in the present invention alone or as a mixture of two or more.

The phosphorus content of the phosphite used in the present invention is
Although it can be obtained by simple calculation, it can be obtained experimentally as follows.

(I) Preparation of test solution 0.1 g of sample (containing 4 to 16 B as phosphorus) was accurately weighed into a 100 ml Kjeldahl flask, and before adding 2 ml of concentrated sulfuric acid and heating to carbonize, 1 g of 30% hydrogen peroxide solution was added. Add drop by drop to decompose the solution until it becomes clear, then ignite until white fumes of sulfuric acid come out. After cooling, add this solution to 100a
Transfer to a +1 volumetric flask and add water up to the marked line to use as the test solution.

(2) Creation of calibration curve Place phosphorus standard solution (4.3939 g of monopotassium phosphate dissolved in water to make 11) 0.2.4.6.8II11 in a 100a+1 volumetric flask and add 50ml of water to each. . Add 20o+1 molybdovanadate solution to these, add water to make 100ml, and make 30ml.
Leave for a minute. Transfer this solution to a 1On+- cell and
The absorbance at 0 ns is measured using a blank test solution as a control solution, and a calibration curve is created.

(3) Pour 5 ml of the measurement test liquid into a 100 ml volumetric flask, and
0m+1 and molybdovanadate solution 20a+1 were added, and the following operations were performed in the same manner as for creating a calibration curve, and the absorbance was measured.
Calculate the phosphorus content% from the calibration curve.

There is no particular limit to the amount of stabilizer added in the present invention (it is arbitrarily determined depending on the conditions in which the polyurethane composition is used, but usually both the antioxidant and the tertiary phosphite are added to the polyurethane composition). It is in the range of 0.05 to 5% by weight, preferably 0.1 to 3% by weight.If the amount added is less than this range, the stabilizing effect will be low, and if it is more than this range, the strength, elongation, etc. of the product will be affected. It is not preferable because the physical properties of

Regarding the method of adding the stabilizer used when manufacturing the sole of the present invention, it is preferable to disperse the stabilizer in advance into a part of the raw material for producing polyurethane or to dissolve it by heating. It is preferable to blend the phosphite represented by I) into the isocyanate compound.

The stabilizer used when manufacturing the sole of the present invention can be used when manufacturing any generally known polyurethane, and the polyisocyanate compound component is, for example, toluene diisocyanate, m-phenyl diisocyanate, p-phenyl diisocyanate, xylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, polymethylene polyphenylisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 3,3 °-dimethyl-4゜4
“-biphenylene diisocyanate, 3,3°-dichloro-4.4”-biphenylene diisocyanate, 4,4
It can be used when producing polyurethane using polyisocyanate compounds such as ``-biphenylene diisocyanate and 1,5-naphthalene diisocyanate, or mixtures, modified products, or prepolymers thereof.In particular, toluene diisocyanate , 4
．． 4'-diphenylmethane diisocyanate, or
Mixtures, modified products, or prepolymers thereof are preferably used in producing polyurethane.

In addition, examples of active hydrogen-containing compounds used in producing the polyurethane used in the sole of the present invention include:
Ethylene glycol, propylene glycol, 1,4-
Low-molecular polyols such as butanediol, neopentyl glycol, 1,6-hexanediol, glycerin, trimethylolpropane, 1.2.6-hexanediol, pentaerythritol, ethylenediamine, 4.4-hexanediol, etc.
A polyether obtained by adding an alkylene oxide such as ethylene oxide or propylene oxide to an amine compound such as '-methylenebis-2-chloroaniline or 4,4''-methylenebis-2-ethylaniline, or a low-molecular polyol or amine compound. Examples include terboliol and polytetramethylene ether glycol.
In addition, ethylene glycol, propylene glycol,
1. Polyhydric alcohols such as 4-butanediol, phthalic acid, maleic acid, malonic acid, succinic acid, adipic acid,
Examples include polyester polyols, polycaprolactone polyols, polycarbonate polyols, acrylic polyols, castor oil, and tall oil, which are polycondensation products with polybasic acids such as terephthalic acid and have hydroxyl groups at the ends. Furthermore, liquid rubbers having active hydrogen groups such as hydroxyl groups, amino groups, imino groups, carboxyl groups, and mercapto groups at the molecular terminals and mixtures thereof can also be used.

When producing the polyurethane used in the soles of the present invention, a reaction catalyst may be added in order to lower the reaction temperature or shorten the reaction time.Specific examples of reaction catalysts include, for example, Examples include amine compounds such as ethylenediamine, tetramethylethylenediamine, and tetramethylhexanediamine and their salts; organometallic compounds such as dibutyltin dilaurate, tin ofnarate, lead octylate, and manganese octylate; and mixtures thereof. can.

In addition, as auxiliary ingredients, foaming agents such as water and low-boiling organic solvents,
Add colorants such as titanium white, fillers such as calcium carbonate, silica, clay, organic fibers, inorganic fibers, softeners such as process oil, foam stabilizers, antistatic agents, etc. as necessary. You can also do it.

The sole of the present invention can be produced by, for example, mixing and stirring a polyol component containing the above-mentioned antioxidant and an isocyanate component containing a phosphite ester represented by the formula (I), followed by a silicone-based mold release agent. It is manufactured by injecting it into an aluminum shoe sole mold coated with 45°C to 50°C.

[Examples] The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited only to these Examples. Furthermore, in Examples and Comparative Examples, "parts" are all parts by weight.

Examples 1 to 6 Polyester polyol (hydroxyl value 86, average molecular weight 1
300) A predetermined amount of stabilizers other than phosphite esters shown in Examples 1 to 6 in Table 1 were added to 100 parts, and the mixture was heated and stirred at 60 to 80°C for 2 to 6 hours to dissolve. . To this polyol component, 12 parts of ethylene glycol, 0.4 parts of water, 0.8 parts of triethylene diamine, and 1 part of a silicone foam stabilizer were added and mixed, and this was used as a polyol component.

Next, a polyurethane prepolymer (NC0%,
18.5) was added and mixed with a predetermined amount of phosphorous acid ester shown in Examples 1 to 6 in Table 1, and this was used as an isocyanate component.

83 parts of the above polyol component and 10 parts of the isocyanate component
After thoroughly mixing and stirring 0 parts, the mixture was poured into an aluminum shoe sole mold coated with a silicone mold release agent at 45 to 50° C., and taken out after 5 minutes to obtain a shoe sole of the present invention.

After conducting a 30-hour irradiation test on the six types of shoe soles obtained in this way using a carbon arc sunshine weather meter, the degree of yellowing of the test pieces was measured using a colorimeter.
It was indicated by yellow index (Yl value). Results first
Shown in the table.

The test machine used in the experiment is as follows.

(I) Carbon arc weather meter; Suga Test Instruments ■Du Cycle Sunshine Super Long Life Weather Meter WEL-5UN-DC type (2) Colorimeter; Suga Test Instruments■ SM Color Computer SM-3 Comparative Examples 1~ 7 In Examples 1 to 6, a stabilizer was added during the synthesis of polyurethane, but in Comparative Example 1,
Shoe soles were manufactured using polyurethane to which no stabilizer was added during polyurethane synthesis, and tests similar to those in Examples were conducted.

In Comparative Example 2, a shoe sole was manufactured using a polyurethane synthesized by adding only the antioxidant used in Example 1 to the polyol component as a stabilizer during polyurethane synthesis.

In Comparative Example 3, a shoe sole was manufactured using a polyurethane synthesized by adding only the antioxidant used in Example 2 to the polyol component as a stabilizer during polyurethane synthesis.

In Comparative Example 4, a shoe sole was manufactured using a polyurethane synthesized by adding only the phosphite used in Example 1 to the isocyanate component as a stabilizer during polyurethane synthesis.

In Comparative Example 5, a shoe sole was manufactured using a polyurethane synthesized by adding only the phosphite used in Example 2 to the isocyanate component as a stabilizer during polyurethane synthesis.

The specific means of manufacturing soles in Comparative Examples 1 to 5 above are as follows:
All procedures are similar to the examples except for the addition of stabilizer.

Table 1 shows the results of tests conducted on the soles manufactured in Comparative Examples 1 to 5 in the same manner as in the Examples.

〔Effect of the invention〕

As specifically shown in the detailed description of the invention and the examples, the sole of the present invention has excellent performance that conventional shoe soles do not have in terms of its white color retention. It is.

That is, the soles manufactured according to the present invention do not cause discoloration or discoloration, even if they use toluene diisocyanate or 4,4'-diphenylmethane diisocyanate, which are easily colored, as the isocyanate component of the polyurethane raw material.
It has the property of being resistant to peeling, something that could not be achieved with polyurethanes using previously known stabilizers. The sole of the present invention makes it possible to maintain its commercial value at an extremely high level.

Claims (1)

[Claims] 1. (a) Antioxidant, and (b) General formula (I) ▲ Numerical formula, chemical formula, table, etc. ▼ (I) (R_1, R_2, R_3 are the same or different alkyl groups, A sole made of a polyurethane resin containing a phosphite represented by a cycloalkyl group, an aryl group, an alkylaryl group, or an aralkyl group and having a phosphorus content in the range of 4.0 to 14.0% by weight. 2. Phosphite ester represented by general formula (I) is 6
．． The shoe sole according to claim 1, which has a phosphorus content of 0 to 8.0% by weight.