JPH0514564B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a shoe sole made of a stabilized polyurethane resin. For more details,
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 the surface of polyurethane molded products to deteriorate. Phenomena unfavorable to the quality of the polyurethane product occur, such as deterioration of the condition, ie, surface peeling, occurrence of cracks, and change in hue. For this reason, various stabilizers have been developed for the purpose of improving polyurethane's poor weather resistance against these external factors. For example, JP-A-56-
In Publication No. 100848, phenylenediamine compounds and sterically hindered phenol compounds, phenylenediamine compounds and phosphite compounds, phenylenediamine compounds and quinoline compounds, phenylenediamine compounds and benzotriazole compounds, phenylenediamine compounds and benzotriazole compounds, A nylene 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 for various types of automobile parts, garden chairs, and other products that have the freedom of design that polyurethane resins have.
Products that take advantage of their corrosion resistance are 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 were not necessarily satisfactory in terms of properties.
In other words, the stabilizer disclosed in JP-A-56-100848 serves the purpose of preventing the shrinkage 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 Japanese Patent Application Laid-Open No. 57-49653 is inferior in terms of duration of effect and 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, but they are still not sufficient. ,
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 peeling, it is disadvantageous because the commercial value of the shoe itself will be significantly reduced. Therefore, there is a need for soles made of polyurethane resin that do not discolor or peel. [Means for Solving the Problems] In order to solve the above-mentioned problems, particularly the problem that there is no shoe sole on the market that uses polyurethane that is resistant to discoloration and peeling, the present inventors have:
As a result of intensive studies, we have arrived at the present invention. That is, the present invention comprises (a) a benzotriazole ultraviolet absorber, (b) an antioxidant comprising a hindered phenol compound having at least one branched lower aliphatic hydrocarbon group bonded to the ortho position, and (c) a general formula() (R ₁ , R ₂ , R ₃ represent the same or different alkyl group, cycloalkyl group, aryl group, alkylaryl group, or aralkyl group), and the phosphorus content is in the range of 4.0 to 14.0% by weight. The purpose is to provide a shoe sole made of polyurethane resin containing a certain phosphite that 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,
At that time, the above-mentioned specific ultraviolet absorber, antioxidant, and phosphite compound represented by the above-mentioned general formula () are used as stabilizers. In the present invention, a benzotriazole derivative is used as the ultraviolet absorber. Specific examples of benzotriazole derivatives include 2-(2'-hydroxy-5'-methylphenyl)
Benzotriazole, 2-(2'-hydroxy-
5'-t-butylphenyl)benzotriazole,
2-(2'-hydroxy-3',5'-di-t-butylphenyl)benzotriazole, 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-
5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)-5
-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-ditertyabutylphenyl)benzotriazole, and the like. The above ultraviolet absorbers can be used in the present invention alone or as a mixture of two or more. Next, as the antioxidant that can be used in the present invention, any hindered phenol compound having at least one branched lower aliphatic hydrocarbon group bonded to the ortho position may be used, but among them, 1 to 4 phenol nuclei in one molecule
Preferably something that you own. When two or more phenol nuclei exist 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, t-
Examples include pentyl group, isohexyl group, etc.
Particularly preferred is t-butyl group. Various other substituents may be bonded to the above hindered phenol compound. Specific examples of the above hindered phenol compounds include the following compounds.

【formula】

【formula】

【formula】

【formula】

The above antioxidants can be used in the present invention alone or as a mixture of two or more. Next, the phosphite ester compound represented by the above general formula () is a compound represented by the general formula () in which R ₁ , R ₂ , and R ₃ satisfy the above conditions. In that case, either one is fine, but
The phosphorus content is from 4.0 to 14.0% by weight, and from 6.0 to
Particularly preferred is 8.0% by weight. When the phosphorus content in the phosphorous acid ester compound is less than 4.0% by weight, sufficient effects cannot be achieved on the weather resistance of the polyurethane resin. Meanwhile 14.0% by weight
If it exceeds this amount, it is difficult to avoid negative effects such as deterioration of physical properties due to bleeding to the surface and slowing down of reactivity, which is not preferable. Specific examples of these include triisodecyl phosphite, phenyl diisodecyl phosphite, diphenylnonyl phenyl phosphite, triisooctyl phosphite, and the like. 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 can be determined by simple calculation, but can be determined experimentally as follows. (1) Preparation of test solution Accurately weigh 0.1 g of sample (containing 4 to 16 mg of phosphorus) in a 100 ml Kjeldahl flask, add 2 ml of concentrated sulfuric acid, heat and carbonize, and then add 1 ml of 30% hydrogen peroxide solution.
Add drop by drop and let the solution decompose until it becomes clear.
Then heat it until white smoke of sulfuric acid comes out. After cooling, transfer this solution to a 100 ml volumetric flask and add water up to the marked line to use it as the test solution. (2) Creating a calibration curve Take 0, 2, 4, 6, and 8 ml of phosphorus standard solution (4.3939 g of monopotassium phosphate dissolved in water to make 11) in a 100 ml volumetric flask, and add water to each.
Add 50ml. Add 20 ml of molybdovanadate solution to these, add water to make 100 ml, and leave for 30 minutes. Transfer this solution to a 10 mm cell, measure the absorbance at 400 nm using the blank test solution as a control solution, and create a calibration curve. (3) Measurement Pour 5 ml of the test solution into a 100 ml volumetric flask and add approximately 5 ml of water.
Add 50ml and 20ml of molybdovanadate solution,
The following operations are performed in the same manner as in the preparation of the calibration curve, the absorbance is measured, and the phosphorus content percentage is calculated from the calibration curve. The amount of the stabilizer used in the present invention is not particularly limited and is determined arbitrarily depending on the conditions in which the polyurethane composition is used, but usually both the ultraviolet absorber and the tertiary phosphite are added. 0.05-5% by weight of polyurethane, preferably 0.1-3
% 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 physical properties such as strength and elongation of the product will be lowered, which is not preferable. 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. ) is preferably blended 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 stabilizer used when the polyisocyanate compound component is, for example, toluene diisocyanate, m-phenylene 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,
Polyisocyanate compounds such as 3,3'-dichloro-4,4'-biphenylene diisocyanate, 4,4'-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, or mixtures or modified products thereof, or These prepolymers can be used to produce polyurethane. In particular, toluene diisocyanate,
It is preferably used when producing polyurethane using 4,4'-diphenylmethane diisocyanate, a mixture thereof, a modified product, or a prepolymer thereof. In addition, examples of active hydrogen-containing compounds used in producing the polyurethane used in the soles of the present invention include ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, and glycerin. , trimethylolpropane, 1,2,6
-Low molecular polyols such as hexanetriol and pentaerythritol, ethylenediamine, 4,
4'-methylenebis-2-chloroaniline, 4,
Examples include amine compounds such as 4'-methylenebis-2-ethylaniline, or polyether polyols and polytetramethylene ether glycols obtained by adding alkylene oxides such as ethylene oxide and propylene oxide to low-molecular polyols or amine compounds. can be done, and furthermore,
ethylene glycol, propylene glycol,
A polyester polyol that is a condensation product of a polyhydric alcohol such as 1,4-butanediol and a polybasic acid such as phthalic acid, maleic acid, malonic acid, succinic acid, adipic acid, or terephthalic acid and has a hydroxyl group at the end. Examples include polycaprolactone polyol, polycarbonate polyol, acrylic polyol, castor oil, and tall oil. 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 sole 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 amine compounds and salts thereof such as triethylenediamine, tetramethylethylenediamine, and tetramethylhexanediamine, and organic metals such as dibutyltin dilaurate, tin octylate, lead octylate, and manganese octylate. Compounds and mixtures thereof can be mentioned. In addition, as auxiliary ingredients, foaming agents such as water and low-boiling organic solvents, colorants such as titanium white, fillers such as calcium carbonate, silica, clay, organic fibers and inorganic fibers, softeners such as process oil, and foam stabilizers are used. Agents, antistatic agents, etc. may be added as appropriate. The sole of the present invention can be produced by, for example, mixing and stirring a polyol component containing the ultraviolet absorber and an antioxidant, and an isocyanate component containing a phosphite represented by the formula (). It is manufactured by injecting it into an aluminum shoe sole mold coated with a release agent at a temperature of 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 To 100 parts of polyester polyol (hydroxyl value 86, average molecular weight 1300), a predetermined amount of stabilizers other than phosphite esters shown in Examples 1 to 6 in Table 1 was added to 60 to 60 parts. The mixture was heated and stirred at 80°C for 2 to 6 hours to dissolve it. To this polyol component, 12 parts of ethylene glycol, 0.4 parts of water, 0.8 parts of triethylenediamine, and 1 part of silicone foam stabilizer were added and mixed.
This product was used as a polyol component. Next, 100 parts of 4,4'-diphenylmethane diisocyanate and 66.5 parts of polyester polyol (hydroxyl value 56, average molecular weight 2000) were reacted at 60°C for 2 hours to obtain a polyurethane prepolymer (NCO%, 18.5). A predetermined amount of phosphorous acid ester shown in Examples 1 to 6 in Table 1 was added and mixed, and this product was used as an isocyanate component. After thoroughly mixing and stirring 83 parts of the polyol component and 100 parts of the isocyanate component, the mixture is 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. got the sole of the shoe. For the six types of soles obtained in this way,
After conducting a 30-hour irradiation test using a carbon arc sunshine weather meter, the degree of yellowing of the specimen was measured using a colorimeter, and the yellow index (YI
value). The results are shown in Table 1. The test machine used in the experiment is as follows. (1) Carbon arc weather meter; Suga Test Instruments Co., Ltd. Du Cycle Sunshine Super Long Life Weather Meter WEL-SUN-DC type (2) Colorimeter; Suga Test Instruments Co., Ltd. SM Color Computer SM-3

[Table] Comparative Examples 1 to 11 In Examples 1 to 6, a stabilizer was added during polyurethane synthesis, but in Comparative Example 1, no stabilizer was added during polyurethane synthesis. Shoe soles were manufactured using polyurethane that did not contain polyurethane, and the same tests as in the examples were conducted. In Comparative Example 2, a shoe sole was manufactured using a polyurethane synthesized by adding only the ultraviolet absorber used in Examples 1 and 2 as a stabilizer to the polyol component during polyurethane synthesis. In Comparative Example 3, a shoe sole was manufactured using a polyurethane synthesized by adding only the ultraviolet absorber used in Example 3 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 antioxidant used in Example 1 to the polyol component as a stabilizer during polyurethane synthesis. In Comparative Example 5, 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 6 and Comparative Example 7, polyurethane synthesized by adding only the phosphorous ester used in Example 1 and Example 2, respectively, as a stabilizer to the isocyanate component was used. Manufactured shoe soles. In Comparative Example 8, during polyurethane synthesis,
Shoe soles were manufactured using polyurethane synthesized by adding only the antioxidant and phosphite used in Example 1 to the polyol component and the isocyanate component, respectively. In Comparative Example 9, the antioxidant used in Example 4 was added to the polyol component during the synthesis of polyurethane, and the phosphite phenyl diisodecyl phosphite used in Example 4 was added to the isocyanate component. A shoe sole was manufactured using the synthesized polyurethane. In Comparative Example 10, the ultraviolet absorber and antioxidant used in Example 1 were added to the polyol component during polyurethane synthesis, and the phosphorus content of the phosphorous ester was 3.8% by weight. Shoe soles were manufactured using polyurethane synthesized by adding trioleyl phosphite, which is a polyurethane, to an isocyanate component. In Comparative Example 11, during the synthesis of polyurethane, the ultraviolet absorber and antioxidant used in Example 1 were added to the polyol component, and the phenylenediamine compound N,N was added instead of the phosphite ester. Shoe soles were manufactured using polyurethane synthesized by adding '-diphenyl-p-phenylene diamine to an isocyanate component. The specific means for manufacturing soles in Comparative Examples 1 to 11 above are all the same as in the Examples except for the operation related to adding the stabilizer. Table 2 shows the results of tests conducted on the soles manufactured in Comparative Examples 1 to 11 in the same manner as in the Examples.

【table】

〔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 sole manufactured according to the present invention contains toluene diisocyanate or 4, which is easily colored, as the isocyanate component of the polyurethane raw material.
Even shoe soles made with 4'-diphenylmethane diisocyanate, etc., have the property of being resistant to discoloration and peeling, but this is unlike polyurethane using known stabilizers. This would have never been possible. The sole of the present invention makes it possible to maintain its commercial value at an extremely high level.

Claims (1)

[Scope of Claims] 1 (a) a benzotriazole ultraviolet absorber, (b) an antioxidant comprising a hindered phenol compound having at least one branched lower aliphatic hydrocarbon group bonded to the ortho position, and (c) General formula () (R ₁ , R ₂ , and R ₃ represent the same or different alkyl groups, cycloalkyl groups, aryl groups, alkylaryl groups, and aralkyl groups), and the phosphorus content is in the range of 4.0 to 14.0% by weight. Shoe sole made of polyurethane resin containing phosphite. 2. The shoe sole according to claim 1, wherein the phosphite represented by the general formula () has a phosphorus content of 6.0 to 8.0% by weight.