JPH04356494A - Phosphite compound - Google Patents

Abstract

PURPOSE:To provide a new phosphite compound easily synthesizable on an industrial scale, resistant to decomposition, having high stabilizing effect and useful as an antioxidant for organic compounds. CONSTITUTION:The phosphite compound of formula I {R is group of formula II or formula III [R<1> is methylene or ethylidene; R<2> is CnH2n+1 ((n) is l-4)]}. The compound can be produced e.g. by reacting an R-donative phenolic compound such as 2,2'-methylenebis(4-methyl-6-t-butylphenol) with PCl3 in the presence of a base as an acid acceptor and reacting the obtained phosphoryl chloride derivative with a compound having the principal skeleton of formula IV such as alpha,alpha',alpha''-tris(4-hydroxyphenyl)-1,3,5-triisopropylbenzene. In the case of using the compound of formula I as a stabilizing agent for organic material, it is preferable to use the compound in combination with a hindered phenolic compound such as 2,6-di-t-butyl-p-cresol.

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to novel phosphite compounds. This compound is effective as an antioxidant for organic compounds. [Prior Art] Organic substances such as natural polymers, synthetic polymers, oils and fats, lubricating oils, and hydraulic oils are oxidized and their usefulness decreases, so various antioxidants have been devised to treat organic substances. is added inside. For example, it is known that hindered phenols, organic sulfur compounds, organic phosphorus compounds, aromatic amines, and the like are effective when used alone or in combination. [0003] Each of these stabilizers has its own characteristics and is useful, but phosphite compounds based on organic phosphorus compounds are particularly widely used as useful antioxidants. As specific examples of phosphite compounds, compounds described in Japanese Patent Publication No. 33-1641 and Japanese Patent Application Laid-open No. 59-4629 are known and are currently in practical use. In addition, as a specific example of using a phosphite compound and a hindered phenol compound in combination to expect a stabilizing effect,
No. 12373, Japanese Patent Application Laid-Open No. 109050/1983, Japanese Patent Publication No. 21822/1983, and U.S. Patent No. 3558
The proposal is made in the specification of No. 554. [0004] However, conventional phosphite compounds have various problems, and no phosphite compound that is fully satisfactory as a stabilizer has yet been known. Problems with known phosphite compounds include, specifically, that phosphite compounds are susceptible to hydrolysis and thermal decomposition, so not only cannot a sufficient stabilizing effect be expected, but also corrosion and odor generation due to decomposition products. Inconveniences such as these are likely to occur. Furthermore, there is a problem in that phosphites having a structure with a large steric bulk around the phosphite bond are difficult to synthesize. For example, tris(2,4,6-trisubstituted phenyl)phosphite is difficult to synthesize when the substituents at the 2,6-positions are both bulky groups such as tert-butyl groups, The value is small. Therefore, an object of the present invention is to provide a phosphite compound that is industrially easy to synthesize, difficult to decompose, and has a large stabilizing effect. [Summary of the Invention] <Summary> [Means for Solving the Problems] The present inventors have solved the above object by discovering a specific phosphite compound. That is, the novel phosphite compound according to the present invention is represented by the following general formula (I). embedded image [In the formula, R represents either of the following formulas (1) and (2). [0007] [0008] [Formula 6] (In the formula, R1 represents a methylene or ethylidene group, and R2 represents CnH2n+1 (n is 1 to 4). R, R1 and R2 may be the same or different.) <Effects> Although the compound of formula (I) according to the present invention has a large steric bulk around the phosphite bond, it is easy to synthesize. , is difficult to decompose and has a large stabilizing effect. [Specific Description of the Invention] <Compound><BasicStructure> The phosphite compound according to the present invention has a structure represented by formula (I), and the characteristics of this compound are, among others:
It has the structure of formula (II). [0011] In other words, this structure gives the compound of the present invention solubility in the organic material to which it is added when it is used as a stabilizer, and increases the molecular weight of the compound to prevent volatility. This is an important element for achieving this and providing resistance to decomposition. <Definition of Compound> The phosphite compound of formula (I) is as defined above with respect to its substituents R, R1 and R2. The symbol + is a common symbol indicating the structure of an organic compound,
When it exists between benzene rings and is divalent, and when it is monovalent as a substituent for the benzene ring, the following bonds (a) and (b) are shown, respectively. It goes without saying that the group R1 is a methylene group or an ethylidene group, and its structure is the following (c) or (d), respectively. The group R2 is a lower alkyl group represented by CnH2n+1 (n is 1 to 4). Preferably n is 1-2. The compound represented by formula (I) has three substituents R, and the substituent R is a group represented by formula (1) or (2), and has two groups R2. Therefore, the formula (I
In the compound (), a plurality of R, R1 and R2 are present, and each of the plurality of substituents may be the same or different. However, considering the preferred method for synthesizing the compound of the present invention (details will be described later), the groups R, R1 and R2 are usually all the same. <Synthesis of Compound> The phosphite compound of formula (I) according to the present invention can be synthesized by any method suitable for forming bonds or structures. One such method is to use the formula (
This method consists of introducing a group R into a compound that provides a skeleton of the group represented by II). Specifically, formula (II)
Trisphenol having the basic skeleton and a bisphenol compound which is a phenol compound giving the formula R (in the case of formula (1)) or 2 moles of a monophenol compound are combined to form a phosphite bond/group using phosphorus trihalide, for example, PCl3. Binding occurs via the formation of R. The reaction of PCl3 can be carried out in advance on one of the two phenol compounds, specifically, 1 mol of the phenol compound giving the group R (in the case of the bisphenol compound of formula (1))
Alternatively, 2 moles (in the case of the monophenol compound of formula (2)) and 1 mole of PCl3 can be reacted in advance to form a phosphoryl chloride derivative, which can then be reacted with the triphenol having formula (II). Since this reaction is a dehydrohalogenation reaction, it is usually carried out in the presence of a base as an acid scavenger, such as a tertiary amine. This dehydrohalogenation reaction proceeds near room temperature. If this reaction is carried out in a non-polar solvent, by-produced hydrogen halide salts, such as tertiary amine hydrochloride, will precipitate as insoluble matter, and if this is removed by filtration, a solution of the phosphite compound of the present invention can be obtained. The target compound can be obtained by distilling off the solvent used. <Utility of Compound> The phosphite compound of formula (I) according to the present invention is useful as an antioxidant for various organic materials. <Target Organic Materials> The organic materials stabilized by the compound (I) of the present invention are typified by high molecular weight polymers, fats and oils, mineral oils, etc. themselves as well as materials made of these materials. That is, for example, as a polymer, (a) an α-olefin homopolymer such as polyethylene, polypropylene, polybutene, or poly-3-methylbutylene, or an ethylene-vinyl acetate copolymer, an ethylene-propylene copolymer, etc. α-olefin copolymer, (b) polyvinyl chloride, polyvinyl fluoride, polyvinylidene chloride, polyvinylidene fluoride,
Brominated polyethylene, chlorinated rubber, vinyl chloride-vinyl acetate copolymer, vinyl chloride-ethylene copolymer, vinyl chloride-propylene copolymer, vinyl chloride-styrene copolymer, vinyl chloride-isobutylene copolymer, vinyl chloride -
Vinylidene chloride copolymer, vinyl chloride-styrene-maleic anhydride terpolymer, vinyl chloride-styrene-acrylonitrile copolymer, vinyl chloride-butadiene copolymer, vinyl chloride-chlorinated propylene copolymer, vinyl chloride - Vinylidene chloride-vinyl acetate terpolymer, vinyl chloride-acrylic acid ester copolymer, vinyl chloride-maleic acid ester copolymer, vinyl chloride-methacrylic acid ester copolymer, vinyl chloride-acrylonitrile copolymer, Halogen-containing synthetic resins such as internally plastic polyvinyl chloride, (c) so-called petroleum resins such as petroleum resins and coumaron resins,
(d) Polystyrene, polyvinyl acetate, acrylic resin,
Styrene and other monomers (maleic anhydride, butadiene,
copolymers with acrylonitrile, etc.), acrylonitrile-butadiene-styrene copolymers, acrylic acid ester-butadiene-styrene copolymers, methacrylate resins such as polymethyl methacrylate, so-called vinyl resins such as polyvinyl alcohol, polyvinyl formal, polyvinyl butyral, etc. (e) Semi-synthetic resins such as cellulose resins, (f) Saturated polyesters, polyphenylene oxides, polyamides, polycarbonates, polyacetals, polyurethanes, unsaturated polyester resins, phenolic resins, urea resins, melamine resins, epoxy resins, silicones Polycondensation or polyaddition polymers of resins, polyethylene terephthalate, polyphenylene sulfide, polyethylene terephthalate, polysulfone resins, polyethersulfone, polyetheretherketone, polyarylate, polyetherimide, polyimide, polymaleimide, polyamideimide, etc. Can be done. As shown in the above examples, the "high molecular polymer" may be rubbers such as natural rubber, isoprene rubber, butadiene rubber, acrylonitrile-butadiene copolymer rubber, or a blend of rubbers and these resins. . <Concomitant use with other stabilizers> When the compound of the present invention is used as an organic material stabilizer,
Preferably, they are used in combination with hindered phenolic compounds. These phenolic antioxidants are generally monovalent or polyvalent phenol compounds in which at least one of the ortho positions of the hydroxyl group is substituted with an alkyl group, an aralkyl group, or a cycloalkyl group. This substituent preferably has about 3 to 10 carbon atoms, and the alkyl group (including those in aralkyl and cycloalkyl groups) may be unsaturated (in this specification, "alkyl group") shall be used in this sense). This phenol compound may have a substituent other than the above-mentioned substituents, or may have a structure such as bisphenol in which a phenol nucleus is connected with a linking group such as an alkylene group. Specific examples of such phenolic antioxidants include 2,6-di-t-butyl-p-cresol, 2,6-diisobutyl-p-cresol, and 2,6-bis(2-phenyl). isopropyl)-p-cresol, 2
, 6-di-t-butyl-4-nonylphenol, n-octadecyl-β-(3,5-di-t-butyl-4-hydroxy-phenyl)propionate, 2,2'-methylenebis(4-ethyl-6 -t-butylphenol), 2
, 2'-methylenebis(4-methyl-6-α-methylcyclohexylphenol), 4,4'-methylenebis(
2,6-di-t-butylphenol), 4,4'-butylidenebis(2-t-butyl-5-methylphenol)
, 4,4'-butylidenebis(2-t-butyl-5-methylphenol), 4,4'-butylidenebis(2-isopropyl-5-methylphenol), tris(4-t
-butyl-2,6-di-methyl-3-hydroxybenzyl) isocyanurate, 1,3,5-tris(3,5
-di-t-butyl-4-hydroxybenzyl)-2,4
, 6-trimethylbenzene, 3,9-[bis-1,1-
Di-methyl-2-{β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]-2,4,8,10-tetraoxaspiro[5,5
] Undecane, ethylene glycol-bis[3,3-bis(3-t-butyl-4-hydroxyphenyl)butyrate], 1,1,3-tris(5-t-butyl-4-hydroxy-2-methylphenyl) ) Butane, Tetrakis [
Examples include, but are not limited to, 3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionyloxymethyl]methane. <Use as a stabilizer> When the compound (I) of the present invention is used as a stabilizer for organic materials, it is preferably blended in an amount of 0.01 to 5% by weight based on the organic material. In addition, when the compound (I) of the present invention is used as a stabilizer for organic materials in combination with at least one phenolic antioxidant, it may be blended in a proportion of 0.01 to 5% by weight based on the organic material. is preferable, and the ratio of the compound (I) of the present invention to the phenolic antioxidant is 10:1 to 1:5, preferably 5:1 to
1:2 is better. When using the compound (I) of the present invention as a stabilizer, other additives such as ultraviolet absorbers, light stabilizers, sulfur stabilizers, metal deactivators, metal soaps,
Nucleating agents, lubricants, antistatic agents, flame retardants, pigments, pigment dispersants, fillers, and the like may be used in combination. Examples of the ultraviolet absorber and light stabilizer in this case include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2-(2'-hydroxy-5'-methyl phenyl)benzotriazole, 2-(2'-hydroxy-
3'-t-butyl-5'-methylphenyl)-5-chloro-benzotriazole, 2-(2-hydroxyl-3
',5'-di-t-butylphenyl)-5-chloro-benzotriazole, 2-(2'-hydroxy-3',5
'-di-amylphenyl)benzotriazole, [2,
2'-thiobis(4-t-octylphenolate)]butylamine Ni salt, 2,2,6,6-tetramethyl-4
-piperidinylbenzoate, bis(2,2,6,6-
Tetramethyl-4-piperidinyl) sebacate, 2-(
3,5-di-t-butyl-4-hydroxybenzyl)-
2-n-butyl-malonate bis(1,2,2,6,6-
pentamethyl-4-piperidyl), 1-[2-{3-(
3,5-di-t-butyl-4-hydroxyphenyl)propionyloxy}ethyl]-4-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxy]-2,2, 6,6-tetramethylpiperidine,
Dimethyl succinate 1-(2-hydroxyethyl)-4
-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate, tris(1,2,2,6,6-pentamethyl-4-piperidyl)phosphite, poly[{6-(1
,1,3,3-tetramethylbutylimino)-1,3,
5-triazine-2,4-diyl} {(2,2,6,6
-tetramethyl-4-piperidyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidyl)imino}], poly[{6-morpholino-2,4-diyl}{(2, Examples include 2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl)imino}. Examples of sulfur-based antioxidants include dialkyl (dilauryl, dimyristyl, distearyl, etc.) thiodipropionate and alkyl (octyl, lauryl, stearyl, etc.) thiopropionic acid. Examples include esters of polyhydric alcohols (eg, pentaerythritol tetrakis lauryl thiopropionate). <Experimental Examples> The following experimental examples are for explaining the present invention. The present invention is not limited to this. [Synthesis Example 1] 35.5 g of PCl was dissolved in 220 ml of toluene, and after cooling the liquid temperature to 5°C, 2.
13.6 g of 2'-methylenebis(4-methyl-6-t-butylphenol) was added, and 314 g of N(Et) was added.
Slowly drop 6g. Thereafter, the mixture was stirred at room temperature for 3 hours, and then α,α′,α″-tris(4-hydroxyphenyl)-1,3,5-triisopropylbenzene 6.4
g and the reaction is carried out under reflux for 20 hours. After the reaction was completed, the reaction solution was cooled, the generated triethylamine hydrochloride was filtered off, and the solvent was distilled off to obtain a colorless powder with a crude yield of 95%. Furthermore, purification was performed using a column. 1) Melting point 144-145°C2
) Infrared spectroscopy results (KBr method) νP-O: 120
0cm-1 3) Nuclear magnetic resonance analysis results (CDCl3, ppm)
δ1.2-1.3 (s, 54H) δ1.5-1.6 (s, 18H) δ2.2-2.3 (s, 18H) δ4.0-4.1 (d, 6H) δ7. 0 to 7.5 (m, 27H) [Synthesis Example 2] 32.8 g of PCl was dissolved in 150 ml of toluene, and after cooling the liquid temperature to 5°C, 2.
Add 8.4 g of 4-di-t-butylphenol, and then slowly dropwise add 310 ml of N(Et). After that, it was stirred at room temperature for 3 hours, and further α, α′, α″-tris (4
3.2 g of -hydroxyphenyl)-1,3,5-triisopropylbenzene are added and the reaction is carried out under reflux for 20 hours. After the reaction was completed, the reaction solution was cooled, the generated triethylamine hydrochloride was filtered off, and the solvent was distilled off to obtain a colorless powder with a crude yield of 93%. Furthermore, purification was performed using a column. 1) Infrared spectroscopic analysis results (KBr method) ν
P-O: 1210cm-1 3) Nuclear magnetic resonance analysis results (CDCl3, ppm)
δ1.2~1.3 (s, 108H) δ1.5~1.6 (s, 18H) δ7.0~7.8 (m, 33H) [Application example] Measured in tetralin at 135°C The intrinsic viscosity is 1.9 and 98% isotactic.
Each additive shown in Table 1 was added to 100 parts by weight of polypropylene powder, and the mixture was thoroughly mixed with a mixer under a nitrogen atmosphere. And cylinder temperature 260℃, L/D=20,
The mixture was melt-kneaded and granulated using an extruder with a diameter of 20 mm. The MFR (JIS K6758) at 230°C was measured for the pellets thus obtained. MFR is one of the indicators of molecular weight, and a small MFR means that the decrease in molecular weight due to oxidative deterioration in the extruder is small, and it means that the antioxidant effect is large. In addition, the pellets obtained above were compression molded at 230°C into a sheet of 0.5 mm thick x 0.5 mm thick.
It was used as a test piece. Heat aging resistance was determined by heating a test piece in a circulating air oven at 150°C and measuring the time required for the test piece to brown and become brittle due to oxidative deterioration. [0031] Weather resistance is 65/XW-WR manufactured by Atlas Co., Ltd.
Judgment is made by measuring the time required for the test piece to become brittle and crack when the test piece is bent 180 degrees by irradiating light on the test piece using a type xenon weatherometer at a black panel temperature of 80°C. did. The results were as shown in Table 1. Heat resistance was determined by increasing the temperature at a rate of 10° C. for 1 minute in a nitrogen stream using a Thermoflex 8100 model, and measuring the weight loss behavior of the compound. The results were as shown in FIG. The stabilizers used are as follows. (Phenolic antioxidant) "RA" Tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxymethyl]methane (
Product name: Irganox 1010) (phosphorus antioxidant) "P-1" Tris(2,4-di-t-butylphenyl) phosphite (Product name: Irgafos 168) "P-2" Distearylpentaerythritol- Di-phosphite (trade name: Weston 618) "D-1" Compound of Synthesis Example 1 "D-2" Compound of Synthesis Example 2 0034
Table 1


Comparison Phosphorous antioxidant
Other additives MFR Heat aging resistance Weather resistance Comparison agent (Additional thickener
concentration weight%) concentration weight%) (g/10
minutes) (hours) (hours) 1
−
10.3 2 40
2-R
A (0.1) 2.0 600
180 3 P-1 (0.1)
RA (0.1) 1.2 70
0 220 4 P-2 (0.
1) RA (0.1) 1.4
900 200 1 D-1
(0.1) RA (0.1) 0.8
1200 220 2D
-2 (0.1) RA (0.1) 0.9
1000 240 [0035] Effects of the Invention As mentioned above in the section ``Means for Solving the Problems'', the phosphite compound of the present invention is easy to synthesize and has a large stabilizing effect on organic materials.

[Brief explanation of the drawing]

FIG. 1 is a graph comparing the heat resistance of the compound (I) of the present invention and known phosphite compounds.

[Explanation of symbols]

D-1 Compound P-1 of Synthesis Example 1 Tris(2,4-di-t-butylphenyl)
Phosphite P-2 Distearylpentaerythritol-di-phosphite

Claims (1)

[Claims] [Claim 1] A novel phosphite compound represented by the following general formula (I). embedded image [In the formula, R represents either of the following formulas (1) and (2). [Formula 2] [Formula 3] (In the formula, R1 represents a methylene or ethylidene group, and R2 represents CnH2n+1 (n is 1 to 4). R, R1, and R2, which are present in plural numbers, may be the same or the same. It may be different.)]