JPH0699628B2 - Polyurethane shoe sole - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyurethane shoe sole which is stabilized by adding a composite stabilizer and has excellent weather resistance.

[0002]

2. Description of the Related Art Polyurethane has impact resistance, chemical resistance,
Since it is a polymer having excellent wear resistance and cold resistance, it is a material that has been conventionally used in various fields and applications. However, on the other hand, polyurethane is
It also has the property of being easily affected by external factors such as moisture and oxygen. Due to these external factors, the surface condition of the polyurethane molded product is deteriorated, that is, the surface is glossed, cracks are generated, and the hue is changed. A phenomenon that is unfavorable to the quality of the polyurethane product, such as a change in the temperature, occurs.

Therefore, various stabilizers have been developed for the purpose of ameliorating the defect of poor weather resistance of polyurethane against these external factors. For example, in JP-A-56-100848, a phenylenediamine compound and a sterically hindered phenol compound, a phenylenediamine compound and a phosphite compound, a phenylenediamine compound and a quinoline compound, a phenylenediamine compound and benzotriazole are disclosed. As a stabilizer for polyurethane, a compound, a phenylenediamine compound and a thiourea compound, a phenylenediamine compound and a piperidine compound, or a phenylenediamine compound and a metal oxide are used.
Further, in JP-A-57-49653, the weather resistance of polyurethane is improved by using a hindered phenol compound and a phosphite. In addition, a white pigment made of titanium white or the like is added to the polyurethane or applied to the surface of the polyurethane to prevent discoloration or fading of the polyurethane.

[0004]

However, the polyurethane resin produced by using the stabilizer for polyurethane that has been developed so far is not always satisfactory in terms of maintaining the whiteness of white polyurethane. It wasn't something. That is, the stabilizer disclosed in JP-A-56-100848 serves the purpose of preventing gloss and cracking of colored polyurethane, but contains a phenylenediamine compound as an essential component. Therefore, if this is used for white polyurethane, yellowing occurs, which is not preferable.

Further, the stabilizer disclosed in JP-A-57-49653 is inferior in terms of the sustainability of the effect, and cannot be said to be sufficient.

The phosphite ester which has been disclosed as a stabilizer component for a polyurethane resin is added to the polyol component to be used, and the phosphite ester is hydrolyzed by water used as a foaming agent in the polyol component. It is decomposed and loses its effect in a short period of time. When a phosphite is used by adding it to the isocyanate component, it reacts with the isocyanate component to cause the system to gel, or even if gelation does not occur, the isocyanate component discolors. It has a drawback that it does.

Particularly, when a polyurethane resin is used for a shoe sole, it is inconvenient if the polyurethane has a property of yellowing or glossing, because the commercial value of the shoe itself is significantly reduced. . Therefore, there is a demand for shoe soles that use polyurethane resin that does not discolor or gloss.

[0008]

DISCLOSURE OF THE INVENTION The inventors of the present invention have found that an excellent stabilizer has not been obtained in view of the above-mentioned problems, that is, the whiteness of white polyurethane. In order to solve the problem that the stabilizers that are present are not always satisfactory in terms of the durability of the effect, as a result of diligent studies, together with an antioxidant and / or an ultraviolet absorber,
The inventors have found that the above problems can be solved by using a specific compound, and have reached the present invention. That is, the present invention provides (a) an antioxidant comprising a hindered phenol compound having at least one branched lower aliphatic hydrocarbon group bonded to the ortho position, (b) a benzotriazole-based ultraviolet absorber, and (c) General formula (I)

[0009]

[Chemical 2]

(R ₁ , R ₂ and R ₃ are hydrogen, an alkyl group, a cycloalkyl group, an aryl group, an alkylaryl group or an aralkyl group, and R ₁ , R ₂ and R ₃ may be the same or different. A composite stabilizer composed of a thiophosphite ester represented by the formula (3) is blended to provide a stabilized polyurethane sole having excellent weather resistance.

The antioxidant used in the present invention may be any one as long as it is a hindered phenol compound having at least one branched lower aliphatic hydrocarbon group bonded at the ortho position, but the phenol nucleus is 1 1 in the molecule
Those having 4 to 4 are preferable. When two or more phenol nuclei are present in one molecule, there is no particular limitation on the binding state. The branched lower aliphatic hydrocarbon group preferably has 3 to 7 carbon atoms,
Examples thereof include an isopropyl group, an isobutyl group, a t-butyl group, an isopentyl group, a t-pentyl group and an isohexyl group, and a particularly preferred one is a t-butyl group. Various other substituents may be bonded to the above hindered phenol compound. Specific examples of the hindered phenol compound as described above include the following compounds.

[0012]

[Chemical 3]

[0013]

[Chemical 4]

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

Next, specific examples of the benzotriazole-based ultraviolet absorber used in the present invention include, for example, 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'
-Dialkylphenyl) benzotriazole and the like can be mentioned.

The above ultraviolet absorbers can be used in the present invention either alone or as a mixture of two or more kinds.

Next, the thiophosphite compound used in the present invention is represented by the following general formula

[0018]

[Chemical 5]

(R ₁ , R ₂ and R ₃ are hydrogen, an alkyl group, a cycloalkyl group, an aryl group, an alkylaryl group or an aralkyl group, and R ₁ , R ₂ and R ₃ may be the same or different. May be any) as long as it is represented by. Examples of such thiophosphite, for example, diethyl hydrogen dithiophosphite, di-n-butyl hydrogen dithiophosphite, dioctyl hydrogen dithiophosphite, didecyl hydrogen dithiophosphite, dilauryl hydrogen dithiophosphite, ditridecyl Hydrogen dithiophosphite, dioleyl hydrogen dithiophosphite, distearyl hydrogen dithiophosphite,
Phenylisodecyl hydrogen dithiophosphite,
Phenyl tridecyl hydrogen dithiophosphite,
Diphenyl hydrogen dithiophosphite, dinonyl phenyl hydrogen dithiophosphite, triethyltrithiophosphite, tri-n-butyltrithiophosphite, trioctyltrithiophosphite, tridecyltrithiophosphite, trilauryltrithiophosphite, tritridecyltrithiophosphite , Trioleyltrithiophosphite, tristearyltrithiophosphite, diphenylisodecyltrithiophosphite, diphenyltridecyltrithiophosphite, triphenyltrithiophosphite, trinonylphenyltrithiophosphite, phenyldiisodecyltrithiophosphite, etc. it can.

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

The amount of the composite stabilizer used in the present invention when added to the polyurethane resin is not particularly limited and may be appropriately determined depending on the conditions under which the polyurethane composition is used. It is preferable to add 0.05 to 5% by weight to the polyurethane resin, and to add 0.1 to 3%.
It is more preferable to blend the composition in a weight percentage. If the addition amount of the composite stabilizer is less than this range, the stabilizing effect is low, and if it is more than this range, the physical properties such as strength and elongation of the product are adversely affected, which is not preferable.

Regarding the method of adding the composite stabilizer used in the production of the shoe sole of the present invention, it is possible to disperse the stabilizer in advance in a part of the raw material for producing polyurethane or to dissolve it by heating. it can.

The composite stabilizer used in the production of the shoe sole of the present invention can be used in the production of any generally known polyurethane, and the polyisocyanate compound component is, for example, toluene diisocyanate or m-phenylene diisocyanate. , P-phenylene diisocyanate, xylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, polymethylene polyphenyl isocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 3,3'- Dimethyl-4,4'-
Biphenylene diisocyanate, 3,3'-dichloro-4,4 '
-Biphenylene diisocyanate, 4,4'-Biphenylene diisocyanate-
, A polyisocyanate compound such as 1,5-naphthalenediisocyanate, or a mixture or modified product of these, or a prepolymer thereof, and can be used when producing a polyurethane. In particular, toluene diisocyanate, 4,4′-diphenylmethane diisocyanate, or a mixture or modified product of these or a prepolymer thereof is preferably used for producing a polyurethane.

Examples of the active hydrogen-containing compound used for producing the polyurethane used for the shoe sole of the present invention include ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol,
Low molecular weight polyols such as 1,6-hexanediol, glycerin, trimethylolpropane, 1,2,6-hexanetriol and pentaerythritol, ethylenediamine,
Obtained by adding an alkylene oxide such as ethylene oxide or propylene oxide to an amine compound such as 4,4'-methylenebis-2-chloroaniline or 4,4'-methylenebis-2-ethylaniline, or a low molecular weight polyol or amine compound. There can be mentioned polyether polyols and polytetramethylene ether glycols,
Furthermore, ethylene glycol, propylene glycol,
Polyester polyol having polyhydric alcohol such as 1,4-butanediol and polybasic acid such as phthalic acid, maleic acid, malonic acid, succinic acid, adipic acid, terephthalic acid and having a hydroxyl group at the terminal And polycaprolactone polyol, polycarbonate polyol, acrylic polyol, castor oil, tall oil and the like. Further, a liquid rubber having a hydroxyl group, an amino group, an imino group, a carboxyl group, an active hydrogen group such as a mercapto group or the like at the molecular end, or a mixture thereof can also be used.

In producing the polyurethane used for the shoe 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 the reaction catalyst include, for example, triethylenediamine, tetramethylethylenediamine, amine compounds such as tetramethylhexanediamine and salts thereof, and dibutyltin dilaurate, tin octylate, lead octylate, organic metals such as manganese octylate. Examples thereof include compounds and mixtures thereof.

Further, as auxiliary components, foaming agents such as water and low boiling point organic solvents, coloring agents such as titanium white and carbon black, fillers such as calcium carbonate, silica, clay, organic fibers and inorganic fibers, process oils and the like. The softening agent, foam stabilizer, antistatic agent, etc. can also be added as necessary.

In carrying out the present invention, the stabilizer is
It can be added to either the polyol component or the isocyanate component, which is adjusted prior to the production of the polyurethane shoe sole. That is, like the stabilizers known so far, there is no fear of being hydrolyzed when used in the polyol component, and the system gels when used in the isocyanate component. By using the stabilizer, it is possible to easily produce a polyurethane shoe sole having excellent weather resistance.
When manufacturing the shoe sole, after adjusting the polyol component and the isocyanate component and adding the auxiliary component, etc., according to the above-mentioned method for producing a polyurethane resin, a polyol component containing a foam stabilizer and an isocyanate component are added. In addition, it can be manufactured by sufficiently stirring and mixing, and then pouring it into a heated aluminum shoe sole mold coated with a silicone type release agent.

[0028]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the examples and comparative examples,
All "parts" are parts by weight.

1. Stability test of thiophosphite ester which is one component in the composite stabilizer used in the present invention in polyol component Polyester polyol (hydroxyl value 86, average molecular weight 130
0) To 100 parts of polyol component prepared by adding 12 parts of ethylene glycol, 0.4 part of water, 0.8 part of triethylenediamine and 1 part of silicon foam stabilizer, 1 part of each thiophosphite ester shown in Table 1 is prepared. Part added (Test Examples 1 to 5), 45 ° C
After being left at the temperature of 2 weeks for 2 weeks, the polyol component was subjected to oxidation measurement and foaming test.

Nothing was added in Comparative Test Example 1 to the same polyol component as in Test Examples, and the phosphite ester shown in Table 1 was added in Comparative Test Examples 2 to 6, and Test Examples 1 to 1 were added. Evaluation was carried out in the same manner as 5. The results are shown in Table 1.

[0031]

[Table 1]

Examples 1 to 4 Polyester polyol (hydroxyl value 86, average molecular weight 130
0) To 100 parts, a predetermined amount of the stabilizer shown in each of Examples 1 to 4 in Table 2 was added, and the mixture was heated and stirred at 60 to 80 ° C for 2 to 6 hours to dissolve the stabilizer. In this polyol component,
12 parts of ethylene glycol, 0.4 part of water, 0.8 part of triethylenediamine, and 1 part of a silicone foam stabilizer were added and mixed, and this was used as a polyol component.

As the isocyanate component, 100 parts of 4,4'-diphenylmethane diisocyanate and 66.5 parts of polyester polyol (hydroxyl value 56, average molecular weight 2000) are added at 60 ° C.
The polyurethane prepolymer (NCO%, 18.5%) obtained by reacting for 2 hours was used.

After 83 parts of the above polyol component and 100 parts of the isocyanate component were sufficiently mixed and stirred, the mixture was poured into an aluminum shoe sole mold of 45 to 50 ° C. coated with a silicone type release agent,
After 5 minutes, the shoe was taken out to obtain a white polyurethane resin shoe sole having a specific gravity of 0.65. The obtained shoe sole was subjected to a 30-hour irradiation test using a carbon arc type sunshine weather meter, and then the yellowing degree of the shoe sole was measured with a colorimeter and indicated by the yellow index (YI value). It was

The test machine used in the experiment is as follows.

(1) Carbon arc weather meter; Suga Tester Co., Ltd. Ducycle Sunshine Super Long Life Weather Meter WEL-SUN -DC type (2) Colorimeter; Suga Tester Co., Ltd. SM Color Computer SM-3 Comparative Examples 1 to 9 In Comparative Example 1, polyurethane shoe soles were manufactured without adding any stabilizer, and the same test as in Examples was conducted.

In Comparative Examples 2 to 6, only one or two of the specific antioxidant, the specific ultraviolet absorber and the thiophosphite used in the present invention were used as stabilizers. A shoe sole made of polyurethane resin was produced using the same, and the same test as in the example was conducted. Further, in Comparative Example 9, in contrast to the combination of the antioxidant and thiophosphite ester of Comparative Example 8, bis (2,2,6,1), which is a kind of hindered amine light stabilizer, instead of the benzotriazole ultraviolet absorber
The results obtained when 6-tetramethyl-4-piperidinyl) sebacate was used as a stabilizer are shown.

The test results are shown in Table 2.

[0039]

[Table 2]

[0040]

EFFECT OF THE INVENTION The polyurethane shoe sole containing the composite stabilizer for polyurethane of the present invention has a YI after 30 hours of irradiation test using a carbon arc type sunshine weather meter, as shown concretely in Examples. Value is about 20 ~
It shows a very low value of 30, and the polyurethane resin of the present invention and the sole made of the polyurethane resin can maintain the extremely high commercial value of urethane products such as sports shoes that require particularly whiteness. It is something to do.

Claims (1)

[Claims] 1. An antioxidant comprising (a) a hindered phenol compound having at least one branched lower aliphatic hydrocarbon group bonded to the ortho position, (b) a benzotriazole-based ultraviolet absorber, and (c) general. Formula (I): (R ₁ , R ₂ and R ₃ are hydrogen, an alkyl group, a cycloalkyl group,
It is an aryl group, an alkylaryl group or an aralkyl group, and R ₁ , R ₂ and R ₃ may be the same or different. ) A shoe sole made of polyurethane containing a thiophosphite ester represented by the formula as a stabilizer.