JPS6348886B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to antioxidant compositions having active groups that can be attached to polymers. More specifically, the present invention relates to an antioxidant composition that can be bonded to polyurethane, which is subject to severe oxidative deterioration due to sunlight, heat, etc., and can prevent the oxidative deterioration thereof. Polyurethanes obtained from polyisocyanates, relatively low molecular weight polymer diols, and low molecular weight polyfunctional active hydrogen compounds have excellent mechanical properties and are easy to process, so they are used for foams, elastomers, paints, synthetic leather, fibers, etc. Although it is used for a wide range of purposes, the use of antioxidants is essential to prevent deterioration and impart durability during processing. Generally, phenolic antioxidants are used as antioxidants for polyurethane because of their excellent effects, and among them, the phenolic compounds represented by the following general formula are: (In the formula, R ₁ represents a group selected from a t-butyl group, a sec-butyl group, and a neopentyl group) It is a preferable antioxidant because it has no side effects such as discoloration due to combustion gas, chlorine, or sunlight. However, when this phenolic compound is blended with polyurethane for textiles, tapes, and artificial leather for clothing, it can be removed from the product during processing steps such as scouring, bleaching, dyeing, and heat treatment leading to the final product, and during home washing and dry cleaning during the use stage. There is a problem in that the antioxidant flows out and loses its antioxidant effect. One possible way to eliminate the leakage of antioxidants from products is to bond them to polymer chains. For example, a prepolymer with an NCO group at the end is obtained from a diisocyanate and a diol, and then this prepolymer solution is mixed with a diamine (chain extender).
In the general method of synthesizing polyurethane by chain extension with
A possible method is to bond the stabilizer to the polymer by reacting the NCO group with the OH group of the phenolic compound. However, in the case of phenolic compounds represented by the general formula, which have excellent antioxidant effects and have no side effects, crosslinking reactions are difficult to avoid because they have three OH groups that can react with NCO groups, as is clear from their molecular structure. If the reaction is carried out in a solution, the polymer solution (dope) will gel, making it impossible to obtain a dope that can be used for molding. The present inventors have conducted extensive research on antioxidants that can be bonded to polyurethane without causing gelation, have excellent antioxidant effects, and have no side effects. It has been discovered that a reaction composition with a specific trifunctional phenolic compound has an excellent antioxidant effect and can be easily bonded to polyurethane molecular chains without causing gelation, etc., and has led to the completion of the present invention. Ivy. That is, in the present invention, the phenol compound represented by the following general formula () and/or the isophorone diisocyanate represented by the following general formula (') is 10% by weight or less, and the compound in which n is 0 represented by the following general formula () is 50% by weight or less.
% by weight or more, and n shown in the following general formula () is 1 to
This is an antioxidant composition comprising 40% by weight or less of the compound No. 3. (In the formula, R ₁ represents a group selected from t-butyl group, sec-butyl group, and neopentyl group) (In the formula, A is CH ₂ NCO group and isophorone diisocyanate residue excluding NCO group, B is OH group 3
Represents the residue of a phenolic compound of general formula () excluding ) The reactive antioxidant composition of the present invention can be obtained by reacting isophorone diisocyanate with a phenol compound represented by the general formula () (hereinafter abbreviated as phenol compound). General formula ()
Examples of the phenolic compound represented by -butyl-3-hydroxy-2,6-dimethylbenzyl)
Examples include isocyanuric acid, 1,3,5-tris(4-neopentyl-3-hydroxy-2,6-dimethylbenzyl)isocyanuric acid, and the like.
Particularly preferable are 1, 3, and 5 from the viewpoint of manufacturing and effectiveness.
-Tris(4-t-butyl-3-hydroxy-
2,6-dimethylbenzyl)isocyanuric acid. The reaction is preferably carried out in a solvent that is inert to isophorone diisocyanate and the phenolic compound and that dissolves the reaction composition. Preferred solvents include N,N-dimethylacetamide, N,
Examples include amide polar organic solvents such as N-diethylacetamide and N-methyl-2-pyrrolidone. In order to avoid a heterogeneous reaction, the phenolic compound is first dissolved in a solvent, and then isophorone diisocyanate is added at once to the solution and reacted with stirring. If the temperature during the reaction is too low, the reaction will take too long, and if it is too high, all three OH groups of the phenolic compound will have reacted, and therefore compounds with no antioxidant effect will be likely to be produced. is preferably in the range of 30°C to 90°C, more preferably 30°C to 70°C. Regarding the reaction ratio of isophorone diisocyanate and phenol compound, as the proportion of isophorone diisocyanate increases, unreacted isophorone diisocyanate tends to remain, and a compound in which two or more OH groups of the phenol compound react is likely to be generated. This is undesirable because it increases the viscosity of the dope when it is bonded to the polymer, and the antioxidant effect becomes poor. Conversely, when the proportion of phenolic compounds increases, the production of compounds with an antioxidant effect that have NCO groups at the end and can be bonded to polymers decreases. This is not preferable because the compound tends to remain and therefore causes gelation etc. when bonding to the polymer. The reaction is usually carried out at a molar ratio (number of moles of phenol compound/number of moles of isophorone diisocyanate) of 1.0 to 2.0, preferably 1.0 to 1.5. The antioxidant composition of the present invention can be attached to a polymer, and as the attached reactive group,
It is characterized by having an NCO group,
Reactants in which NCO groups remain in an amount of 50% by weight or more based on the total NCO group equivalent of the charged isophorone diisocyanate contain a large amount of unreacted isophorone diisocyanate, and therefore dope increases significantly during bonding to the polymer. The amount of the target compound produced is low, and a large amount is required to bind it to the polymer and exert an antioxidant effect, which is not preferable. On the other hand, if the amount of residual NCO groups is small, there will be almost no unreacted isophorone diisocyanate and it can be bonded to the polymer without causing thickening, but the amount of the target component that can be bonded to the polymer will be less, which is not preferable. . The optimal amount varies depending on the charged molar ratio and reaction temperature, but 10 equivalents to 50 equivalents, more preferably 15 equivalents to 45 equivalents, of NCO groups remain based on the total NCO group equivalent of the charged isophorone diisocyanate. A reaction composition. In order to obtain a reaction composition with the desired amount of residual NCO groups, the concentration of residual NCO groups in the reaction form is analyzed by a known method, and heating is stopped when the amount of residual NCO groups reaches the desired amount of NCO groups. Stop the progress of the reaction.
In order to prevent the reaction from proceeding during storage, it is preferable to keep the reaction composition as low as possible, usually at 30°C.
Below, when storing for a long period of time, it is desirable to keep the temperature below 15℃. In addition, avoid bringing moisture into the reaction system as much as possible.
It is preferable that the raw materials are sufficiently dried and dehydrated in advance, and the reaction is carried out under a nitrogen blanket. It is also preferable to keep it sealed with nitrogen during storage. The reactive antioxidant composition of the present invention is The main component is a compound represented by the general formula, where n is O. Generally, when a bifunctional compound (denoted as X) and a trifunctional compound (denoted as Y) are reacted, a one-to-one reaction product of X and Y, that is, Although it is almost impossible to efficiently synthesize -Y, X-Y-X-Y-X-Y, etc.,
Surprisingly, in the case of the reaction between the specific diisocyanate of the present invention and the above-mentioned specific phenolic compound, despite the reaction between a bifunctional compound and a trifunctional compound, a one-to-one reaction between the reactant X-Y ( In the compound represented by the general formula () of the present invention, n=0) is produced extremely efficiently. X-Y-X-Y (corresponding to n = 1), X-Y-X where the reaction has further progressed
-Y-X-Y (where n = 2) compounds are also produced, but these compounds have NCO groups that can be bonded to polymers, and they also directly bond to the benzene nucleus necessary to exert the antioxidant effect. Since it also has an OH group, it also maintains an antioxidant effect, and is a compound that can achieve the object of the present invention. The reactive antioxidant of the present invention is A-NHCO-(O-B-
It is represented by the general formula OOCHN-A-NHCO-) _o OB, where n is a compound in the range of 0 to 3. The reactive antioxidant composition of the present invention will be explained using a reaction formula. The composition formula of the present invention is the following isophorone diisocyanate (hereinafter abbreviated as IPDI). can be reacted with a trifunctional phenol compound to obtain a composition in which the main component is a 1:1 reactant in good yield. This can be expressed as a reaction formula as shown below. Here, the NCO group of IPDI has higher reactivity than the other CH ₂ NCO group, and preferentially reacts with the trifunctional phenol compound. Then, as the reaction progresses further,
The following reaction occurs and the following (b), (c), and (d) are produced. A compound with a large n, that is, a high molecular weight, is not preferable because, when bonded to a polymer, the mechanical properties and heat resistance of the polymer deteriorate. Compounds with a lower n value are preferable because they have less adverse effect on such properties. Particularly preferred is a reaction composition in which the compound represented by the general formula in which n is 0 accounts for 50% by weight or more of the total weight. In order to obtain a reaction composition containing many compounds with low n, the reaction temperature should be lowered and the NCO group
It is preferable to carry out the reaction under mild conditions without using a tin-based or tertiary amine-based catalyst used in the reaction of OH groups. The remaining unreacted phenolic compound and isophorone diisocyanate must be kept to a minimum of 10% by weight of the total weight, as the former causes the dope to gel, and the latter causes the dope to thicken. If it is below, a dope suitable for molding can be obtained. Therefore, a high adduct with n of 1 to 3
The proportion of the compounds (b), (c) and (d) in the composition is 40% by weight or less. Confirmation of whether the target compound is produced can be performed by known methods such as GPC or liquid chromatography. Since the reactive antioxidant composition of the present invention obtained in this way has a reactive NCO group at the end, it can be bonded to any polymer having active hydrogen, but it is particularly effective against oxidative degradation. It is useful for bonding to polyurethanes with strong oxidative properties and imparting resistance to oxidative degradation to polyurethanes. Various bonding methods can be considered depending on the polymer and whether it is carried out during polymer production or after molding. The case of polyurethane will be illustrated below, but the usefulness of the reactive antioxidant composition of the present invention is not limited thereby. In general, polyurethane used for dry molding and wet molding is produced by reacting excess diisocyanate and diol to synthesize a prepolymer with NCO groups at the end, dissolving this prepolymer in a solvent, and then adding diamine as a chain extender and molecular weight It is synthesized by chain-extending the prepolymer by adding an amine solution consisting of a monoamine as a modifier, but when combining during polyurethane synthesis, one method is to add an amine solution consisting of a monoamine as a modifier in advance. Adding the NCO group-terminated reaction composition of the present invention,
A diamine solution containing the monoamine bound to the reaction composition is prepared, and if necessary, other monoamines such as diethylamine are added as a molecular modifier to this solution, and the chain extension of the prepolyurethane is carried out with this amine solution, so that the ends of the polymer are chain-extended. Binding the antioxidant composition of the present invention. Another method is to synthesize a NH2 _- terminated polymer by carrying out chain extension with an excess equivalent of amine than the NCO groups of the prepolymer, and then add the NCO-terminated reaction composition of the present invention to this polymer solution. The antioxidant composition of the present invention is bonded to the end of the polymer. If it is carried out after molding, after molding into fibers, sheets, films, etc.
The molded product is treated with the antioxidant composition solution of the present invention to remove the terminal NH ₂ groups of the polyurethane on the surface of the molded product, -
Bind to NHCOO- bond, -NHCONH- bond, etc. If necessary, known stabilizers, pigments, dyes, extenders, etc. may be added to the polymer to which the reactive antioxidant composition of the present invention is bound. The reactive antioxidant composition of the present invention has an excellent antioxidant effect with no side effects such as yellowing, and since it has a reactive group, it can be bonded to a polymer, so it can be bonded to a polymer without using conventional methods. Since there is no leakage of the antioxidant during the processing process or during the use of the product, unlike in the case of simple blending, its excellent antioxidant effect remains unchanged even when subjected to various treatments. In addition, since the antioxidant does not leak out, a sufficient effect can be achieved by adding a small amount; therefore, since antioxidants are generally expensive, it is economically advantageous to be able to reduce the amount of antioxidant used. It is. Furthermore, the antioxidant composition of the present invention having excellent antioxidant effects has the characteristic that it can be synthesized extremely efficiently. The reactive antioxidant composition of the present invention has a reactive antioxidant composition.
Because it has an NCO group, it is useful when bonded to a polymer containing active hydrogen to provide the polymer with a certain level of oxidative deterioration resistance over a long period of time even after treatment. It is used for a particularly wide range of purposes,
It is useful for imparting durability against oxidative deterioration by bonding it to polyurethane, which is susceptible to oxidative deterioration. That is, when the composition of the present invention is introduced into polyurethane, it is a terminal addition reaction, so firstly, it has a large number of effective hydroxyl groups and has a large antioxidant effect even if the amount used is small, and it has active groups with strong reaction activity. It has the effect of easily attaching to the end of the polymer. In addition, since it is added to the terminal, there is no drawback that if an easily decomposable antioxidant is introduced into the polymer main chain, the polymer main chain will decompose and the physical properties of the polymer will deteriorate. Furthermore, since it is bound by an addition reaction, it has the advantage of providing a product with stable physical properties over a long period of time, without the disadvantage of being washed out during processing, washing, etc., unlike in the case of addition. EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to the scope of these Examples. Note that the characteristic values in the examples were measured as follows. Light embrittlement resistance test After each sample (fibrous or film) was irradiated with ultraviolet rays using a fade meter (manufactured by Suga Test Instruments Co., Ltd.), the breaking strength was measured using a Tensilon tester.
The strength retention rate {(breaking strength of sample after irradiation/breaking strength of sample before irradiation)×100} was determined. Heat Resistance Test Each 100% stretched sample was brought into contact with a cylindrical metal surface with a surface temperature of 180°C, and the time it took for the sample to break was measured. Gas discoloration test Propane combustion gas was introduced into a chamber with a volume of approximately 0.03 m ³ , and each sample was exposed for a certain period of time while maintaining the room temperature at 60°C, and the degree of discoloration was visually judged using the following criteria. 〇: No difference from unexposed sample △: Difference in discoloration compared to unexposed sample ×: Large degree of discoloration Analysis of reaction composition (1) Measurement of residual NCO group A fixed amount of the reaction solution was added to n-butylamine chloride. It was added to a benzene solution, and the remaining amine was determined by neutralization titration with a normal hydrochloric acid solution. (2) Composition Analysis The reaction composition was analyzed using a high performance liquid chromatograph (manufactured by Waters, Model U6K) using chloroform as a liquid medium. In addition, the molecular weight is a polystyrene equivalent molecular weight. Example 1 Thoroughly dehydrated N,N-dimethylacetamide
1000 g and dry powdered 1,3,5-tris (4
-t-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanuric acid 350g (0.5mol)
was charged into the reaction vessel. After the dissolution was completed, 89 g (0.4 mol) of isophorone diisocyanate was added at once and the reaction was started at 50° C. with stirring. After 40 hours, the reaction was stopped by cooling. Residual NCO group equivalent % of the obtained reactant {(Residual NCO group equivalent/
NCO group equivalent at the time of preparation) x 100} was 41.3%. Additionally, as a result of GPC analysis, the reaction product contained approximately 75% by weight of 1:1 reaction products, and approximately 4% by weight of unreacted phenolic compounds remained, but unreacted isophorone diisocyanate was hardly included. In addition, n with a molecular weight of around 3700
Contains about 19% by weight of compounds with n of 1 to 3, and n
Approximately 2% by weight of a polymer having 4 or more was contained. Example 2 An example of bonding the reaction composition obtained in Example 1 to polyurethane is shown. 200 g of polytetramethylene ether glycol having a molecular weight of 2000 and 50 g of 4,4'-diphenylmethane diisocyanate were reacted at 70°C for 1.5 hours to obtain a prepolymer having isocyanate groups at both ends. Add to this 500g of N,N-dimethylacetamide
was added and dissolved to make a homogeneous solution. On the other hand, a solution of 6 g of ethylenediamine and 40 g of N,N-dimethylacetamide was cooled to 5°C, and 30 g of the reaction composition solution obtained in Example 1 was slowly added under vigorous stirring, so that the reaction composition and ethylenediamine were combined. An amine solution containing a monoamine was prepared. The amine solution was added all at once to the prepolymer solution cooled to 5° C. with vigorous stirring to carry out a chain extension reaction, thereby obtaining a polyurethane solution in which the antioxidant of the present invention was bonded to the molecular ends. This polyurethane solution does not gel, and its viscosity at 30℃ is
It had a viscosity of 2500 poise, suitable for molding. The polyurethane solution obtained in this way was cast onto a glass plate and dried at 70°C for 3 hours to a thickness of approx.
A 70μ film was obtained. Some of the films were immersed in Perculen at 50°C for 2 hours and in boiling water for 4 hours. The untreated and treated films were cut into 1 mm wide pieces and then subjected to a light embrittlement test by irradiating them with a fade meter for 20 hours.
The results are shown in Table 1. Comparative Example 1 Using an amine solution consisting of 5.7 g of ethylenediamine, 0.73 g of diethylamine as a molecular weight regulator, and 60 g of N,N-dimethylacetamide, a prepolymer solution prepared under the same conditions as in Example 2 was chain-extended to form a polyurethane solution. Obtained. The viscosity of this polyurethane solution was 2350 poise. Add this solution to 2
One solution contained 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-tris(4-t-butyl-3-hydroxy-2,6-
Polymer dimethylbenzyl) isocyanuric acid
Contains 1.5g per 100g. No antioxidant was added to the other solutions. Films were prepared from these two types of polyurethane solutions, treated in the same manner as in Example 2, and tested for light embrittlement resistance.
The results are shown in Table 1.

[Table] As is clear from Table 1, the film obtained from the polymer solution in which the antioxidant composition of the present invention is bonded to the polymer edge has excellent light embrittlement resistance, and is moreover compared to the comparative example in which a simple antioxidant is blended. It was found that excellent light embrittlement resistance was maintained even after the treatment. Example 3 and Comparative Examples 2 to 4 Isophorone diisocyanate and 1,3,5-tris(4-t-butyl-3-hydroxy-2,6
-dimethylbenzyl)isocyanuric acid by changing the synthesis conditions, the reaction product within the scope of the present invention (Example 3),
A reaction composition (Comparative Example 2) containing a large amount of a polymer with a low content of the compound represented by the general formula () of the present invention and in which the reaction progressed, and a reaction composition containing a large amount of a high molecular weight substance with a low content of the compound represented by the general formula () of the present invention and containing unreacted materials. Reaction compositions containing a large amount (Comparative Example 3, Comparative Example 4) were obtained. Table 2 shows the synthesis conditions and the properties of the reaction composition obtained. Each reaction composition obtained was first added to an ethylenediamine solution in the same manner as in Example 2, and then a prepolymer solution prepared under the same conditions was chain-extended using the obtained amine solution. Polymer solutions that did not gel and had a viscosity suitable for molding were then formed into films, and their light embrittlement resistance and heat resistance were measured. These results are shown in Table 3.

【table】

【table】

[Table] Table 3 shows that the polymer film (Example 3) combined with the reaction composition of the present invention has excellent light embrittlement resistance and good heat resistance. ) In the case of a reaction composition containing a small amount of compounds shown in (Comparative Example 2) and a large amount of high molecular weight substances, the amount of bonding to the polymer is small, and therefore the light embrittlement resistance after perchloren treatment is reduced. If the amount of bonding to the polymer is increased, the light embrittlement resistance will be good even after percuren treatment, but the decrease in heat resistance will be large. In Example 3 and Comparative Example 4), it was found that gelation occurred during bonding to the polymer, making it impossible to obtain a polymer solution suitable for molding. Example 4 and Comparative Examples 5 to 7 A polymer solution in which the antioxidant composition of the present invention obtained in Example 2 was combined, and a polymer solution in which various antioxidants were blended with the polymer solution of Comparative Example 1 (comparison) Examples 5 to 7) from a 4-hole orifice, 220
It was discharged into an atmosphere at ℃, spun, dried, temporarily twisted, oiled, and rolled at 300 m/min to make a 40 denier fiber. A gas color change test was conducted on this fiber.
These results are shown in Table 4.

[Table] From Table 4, it was found that the antioxidant composition of the present invention did not turn yellow even when exposed to gas.

Claims (1)

[Scope of Claims] 1 The phenol compound represented by the following general formula () and/or the isophorone diisocyanate represented by the following general formula (') is 10% by weight or less, and the compound in which n is 0 represented by the following general formula () is 50% by weight % or more, and 40% by weight or less of a compound represented by the following general formula () where n is 1 to 3. (In the formula, R ₁ represents a group selected from t-butyl group, sec-butyl group, and neopentyl group) (In the formula, A is CH ₂ NCO group and isophorone diisocyanate residue excluding NCO group, B is OH group 3
Represents the residue of a phenolic compound of general formula () excluding )