KR830001190B1 - Process for preparing monoester compound of 2,2'-alkylidene bis (4,6-di-substituted phenol) - Google Patents

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Description

Method for preparing monoester compound of 2, 2'-alkylidenebis (4, 6-di-substituted phenol)

The present invention relates to a process for the preparation of a monoester compound of 2, 2'-alkylidenebis (4, 6-di-substituted phenol). In the past, various synthetic resin stabilizers, including antioxidants and improvements thereof, have been proposed to prevent the synthetic resin products from deteriorating and fading due to heat and light or fumes, thereby reducing the commercial value of the synthetic resin products.

For this purpose, light stabilizers, sulfur-based antioxidants, phosphite compounds and phenolic antioxidants were used alone or in combination with each other.

However, most of these stabilizers are unstable by heat or air oxidation, and some of them stabilize the synthetic resins due to the action of combustion gases in the atmosphere, so that the stability effect of these resin products is insufficient for a long time.

In general, antioxidation deterioration oxidizing agent by the light action which greatly improved the stabilization effect is excellent, but tends to discolor the synthetic resin by the action of heat and light or fumes. On the other hand, antioxidants, which are highly resistant to combustion gases, deteriorate in stability due to sunlight.

Therefore, these stabilizers were not satisfactorily provided with the effects of anti-degradation and anti-coloring. As an example, U.S. Patent No. 3642669 discloses 2- (2'-hydroxy-3'-t-alkylbenzel) -substituted with an alcohol group and steric hindrance as a stabilizer for polyurethane against light and heating air. Phenols with anisoles are described.

Here, the anti-pigmentation effect of these phenols on the combustion fumes in the atmosphere and the anti-degradation effect on light are still not satisfactory enough.

U.S. Pat.No.3428711 discloses a copolymer of diisopropyl amino ethyl methacrylate and decyl methacrylate as a decolorizing agent for combustion gases in the atmosphere and an antioxidant stabilized polyurethane against ultraviolet rays and fumes. 4'-butylidene ratio tm (6-t-butyl-m-cresol) is used.

Furthermore, Japanese Patent Application (OPI) No. 29352/78 describes using a combination of a hydrazino triazine derivative and a sulfuric acid ester compound to stabilize the polyurethane against discoloration. However, this combination did not have a sufficient effect on the preservation of desirable properties such as anti-pigmentation and strength of the original polyurethane.

In Japanese Patent Application (OPI) No. 29850/1977, as a stabilizer of polyurethane, [2- (2 "-hydroxy-3'-t-butyl-5'-methylbenzene) -4-methyl-6-t -Butylphenyl] Leriphthalate describes a polyester which contains a stabilizer that is effective in preventing discoloration but not sufficient.

Moreover, such stabilizers have the drawback of leaking from the surface of the polyurethane product.

Widely used antioxidants include 2, 2'-isobutylidenebis (4, 6-dimethyl-phenol), 2, 2'-methylenebis (4methyl-6-t-butylphenol), 2, 2 '-( 3, 5, 5-trimethylhexylidene) -bis (4, 6-dimethylphenol) and 2, 2'-methylenebis (4, 6-dimethylphenol) can be opened but their compounds are detrimental to bleaching . Therefore, the study was made to study stabilizers that simultaneously improved the anti-degradation effect and the anti-bleaching effect on synthetic resins.

In view of the above drawbacks of the prior art, the present invention relates to an esterification agent selected from the group consisting of compounds of formulas (III) and (IV) in about the same amount in the presence of a reaction medium at a temperature of about 0 ° C to 100 ° C. 2,2'-alkylidenebis (4, 6-) represented by the following general formula (I) prepared by reacting 2,2'-alkylidenebis (4, 6-di-substituted phenol) of formula (II) To prepare a monoester compound of di-substituted phenol).

Expression from R1 and R2 are the same or different in each occurrence C ₁ - ₄ alkyl, C ₅ - ₆ Im kilo alkali or methyl-substituted C ₅ - ₆ show the Im kilo alkyl group and R ₃ and R ₄ is that one is a hydrogen atom The other represents a hydrogen atom or a C1-10 alkyl group and represents these methyl groups. R ₅ is C ₄ - ₉ alkyl group, C ₃ - ₇ cyclo alkyl groups, C ₂ - ₄ alkenyl group, a phenyl group, a C ₁ - ₄ alkyl-substituted phenyl group, a C ₁ - ₄ alkoxy-substituted phenyl group, a mono- or di -C ₁ - ₄ alkyl-substituted hydroxyphenyl groups, stryl groups, benzyl groups

Wherein R ₁ and R ₂ are the same or different C ₁ respectively - ₄ alkyl group, a C ₅ - ₆ cyclo alkyl group, or a methyl-substituted C _{5 6} and cyclo alkyl groups, R ₃ and R ₄ is that one is a hydrogen atom and one Represents a hydrogen atom or a C1 10 alkyl group or both represent a methyl group.

R5COCl (III) (RCO) 20 (IV)

Above equation, R ₅ is C ₄ - ₉ alkyl group, C ₃ - ₇ cyclo alkyl groups, C ₂ - ₄ alkenyl group, a phenyl group, a C ₁ - ₄ alkyl-substituted phenyl, alkoxy-substituted phenyl group, a mono- or di -C ₁ - ₄ alkyl -A substituted hydroxyphenyl group, a stynyl group, a benzyl group or a pyridyl group.

Preferred groups represented by R ₁ and R ₂ in formula (I) are methyl, ethyl, propyl, t-butyl, cyclohexyl and 1-methylcyclohexyl groups.

Preferred groups represented by R ₃ and R ₄ are hydrogen atoms, methyl, ethyl, heptyl and nonyl groups and branched chain alkyl groups such as isopropyl and 2, 4, 4-trimethelpentyl groups.

Preferred groups represented by R 5 are t-butyl, n-octyl, cyclohexyl, vinyl, 1-propenyl, isopropenyl, 2, 2-dimethylvinyl, phenyl, methylphenyl, especially 4-methylphenyl, 4-t-butylphenyl, Bulky groups such as 4-methoxyphenyl, 4-butoxyphenyl, 3, 5-di-t-butyl-4-hydroxyphenyl, benzyl, styryl, pyridyl, especially 2, 3 and 4-pyridyl groups (bulkt group).

Representative of the monoester compound of the present invention includes a monoester compound as shown in Table 1 below.

Note: C ₈ H ₁₇ groups in numbers 9, 10, 11 and 12 are 2, 4, 4-trimethylphenyl groups, and C ₈ H ₁₇ groups in number 4 are n-octyl groups.

In the reaction of the present invention, a large amount of diester compound of the following general formula (V) of 2,2'-alkylidenebis (4, 6-di-substituted phenol) is added to the monoester compound to give 2,2'-alkylidenebis ( 4, 6-di-substituted phenol) can be easily prepared simultaneously in the presence of two phenolic hydroxyl groups having an equivalent value.

(Wherein R 1, R ₂ , R ₃ , R ₄ , and R ₅ , are the same as in general formula (I))

The diester compound of the above formula does not have any antioxidant effect for the synthetic resin.

Furthermore, the idie ester compound is discharged from the synthetic resin when mixed with the synthetic resin.

In particular, the diester compound leaks out as a white powder on the fiber surface, which causes the fiber to break when being knitted, and as a result, has a detrimental effect on the treatment effect.

For this reason, the diester compound should suppress as much of the by-product as possible.

On the other hand, when the by-product of the diester compound is suppressed, the unreacted amount of 2,2'-alkylidenebis (4, 6-di-substituted phenol) remaining in the reaction product is increased.

Thus, a low-purity monoester compound containing an unreacted compound of 2,2'-alkylidenebis (4,6-di-substituted phenol) is extremely advantageous as an antioxidant for synthetic resins and has a significant discoloration of synthetic resins. And discoloration resistance by acting with combustion gases.

The unreacted allowable amount of 2, 2'-alkylidenebis (4, 6-di-substituted phenol) which can be combined with the synthetic resin is unreacted 2, 2-alkylidethene (4, 6-di-substituted phenol), mono It is about 5 wt% based on the total amount of the ester compound and the diester compound.

The amount of unreacted compound 2, 2'-alkylidenebis (4, 6-di-substituted phenol) of 5 wt% or more significantly decolorizes the synthetic resin by exposure to light and fumes.

In the preparation of the monoester compound of the present invention with high purity, the unreacted compound of the diester compound and 2,2'-alkylidenebis (4, 6-di-substituted phenol) is reacted by recrystallization using a suitable solvent. Can be removed from.

According to the present invention, a monoester compound of 2,2'-alkylidenebis (4, 6-di-substituted phenol) having high purity and high yield is prepared in a specific reaction state with 2,2'-alkylidenebis (4, 6- Di-substituted phenol) and an esterification agent.

Examples of suitable 2, 2'-alkylidenebis (4, 6-di-substituted phenols) used in the present invention are 2, 2'-methylenebis (4, 6-dimethelphenol), 2, 2'-methylene Bis (4-ethyl-6-t-butylphenol), 2, 2'-methylenebis- [4-methyl-6 (1-methylcyclonucleosil) phenol], 2, 2'-methylenebis (4-methyl- 6-cyclohexylphenol), 2, 2-methyllinbis (4-methyl-6-t--butylphenol), 2, 2'-ethylidenebis (4, 6-dimethylphenol), 2, 2 ' -Ethylidenebis (4-methyl-6-t-butylphenol), 2,2'-isopropylidenebis (4, 6-dimethylphenol), 2,2'-methylenebis (4-methyl-6-t -Butylphenol), 2,2'-propylidenebis (4, 6-dimethyltylphenol), 2,2'-propylidenebis (4-methyl-t-butylphenol), 2,2'-isobutylidene Bis (4, 6-dimethylphenol), 2, 2'-isobutylidenebis (4-methyl-6-t-butylphenol), 2, 2'-isobutylidenebis (4-ethyl-6-t- Butylphenol), 2, 2'-isobutylidenebis (4-methyl-6-cyclohexylphenol), 2, 2'-octylidenebis (4, 6-dimethylphenol), 2, 2 '-( 3, 5, 5-trimethylhexylidene) -bis (4, 6-dimethylphenol), 2, 2 '-(3, 5, 5-trimethylhexylidene) -bis (4-methyl-6-t- Butylphenol) and 2, 2'-decylidenebis (4, 6-dipropylphenol).

In addition, examples of suitable esterifying agents that can be used in the present invention include C4-9 alkanecarboxylic acid chloride, cyclopropane carboxylic acid chloride, cyclobutane carboxylic acid chloride, cyclopeptane carboxylic acid chloride, cyclohexane carboxylic acid chloride Cyclocyclohetancarboxylic acid chloride, acryloyl chloride, methacryloyl chloride, 3, 3-dimethylacryloyl chloride, benzoyl chloride, toluroyl chloride, pt-butylbenzoyl chloride, p-methoxybenzoyl chloride, 4-hydroxy-3, 5-di-t-butylbenzoyl

The molar ratio of the esterifying agent to 2,2'-alkylidenebis (4, 6-di-substituted phenol) is about 1.0.

Preferred molar ratios are about 1.0 to about 1.3, and more preferred molar ratios are 1.00 to 1.10.

Most preferred molar ratio is 1.02.

The reaction of the present invention is initially carried out in the presence of a reaction medium to form 2, 2'-alkylidenebis (4, 6-di-substituted phenol) in a liquid phase that can be in uniform contact with the esterifying agent. Examples of the reaction medium that can be used in the present invention include dioxane, benzene, chlorobenzene, nitrobenzene, xylene, toluene, pyridine, N, N-dimethylformamide and N N-dimethylacetamide.

The amount of reaction medium that can be used in the present invention is at least about 3 times, preferably about 4 times to about 10, based on the total amount of 2,2'-alkylidenebis (4, 6-di-substituted phenol) and esterifying agent. It is a ship. In order to promote this reaction, it is preferable to carry out the reaction in the presence of a base catalyst.

Examples of such base catalysts include hydrogen and nitrogen atoms such as heterocycleamines such as pyridine, such as triethylamine, triallylamine, tetramethylurea, N, N-dimethylformamide, dimethylacetamide and basic ion exchange resins. There are nitrogen compounds that are not linked.

The amount of base catalyst that can be used in the present invention is typically about 1 mol to about 2 mol per mole of esterification agent, the reaction temperature is typically in the range of about 0 ℃ to about 100 ℃.

Furthermore, about 50% of the 2,2'-alkylidenebis (4, 6-di-substituted phenol) used to prepare the monoester compound of general formula (I) in high yield is represented by general formula (I). It is preferred to maintain at a temperature of about 10 ° C. to about 30 ° C., more preferably at about 20 ° C. until converted to a monoester compound of. In this case, when about 50% of the compound of formula (II) is about 30% or more before conversion to the monoester compound of formula (I), 2,2'-alkylidenebis of formula (V) The diester production of (4, 6-substituted phenol) is increased and disadvantageous. 2, 2'-

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to the following examples, and the parts and percentages of the examples are expressed by weight unless otherwise specified.

Example 1

Preparation of 1- (2-hydroxy-3, 5-dimethylphenyl) -1- (2-benzoyloxy-3, 5-dimethylphenyl) -methylpropane (compound No. 5 in Table 1) Stirrer, thermometer and drip In a 500 ml three-neched flask equipped with a funnel, 2,2'-isobutylidenebis (4, 6-dimethylphenol) was charged with 10 g (126.6 mmol) of pyridine and toloc in the amounts shown in Table 2 below. The benzoyl chloride was added dropwise in a dropping funnel with vigorous stirring for about 30 minutes in the amount shown in Table 2 while being completely dissolved in a mixed solution of 200 g of yen and maintained at 20 ° C. under a dry nitrogen atmosphere, and the mixture was stirred for another 30 minutes. Analysis of the reaction mixture by gas chromatography showed that the mono esterification was 74%, 55.2% and 45% in the treatment Nos. 1, 2 and 3, respectively. The reaction mixture was then heated to 80 ° C. and held at 80 ° C. for 2 hours.

The monoesterification of the resulting reaction mixture was 97%, 75% and 59% in Treatment Nos. 1, 2 and 3, respectively. After the reaction was completed, the precipitated pyridine salt was separated by filtration in the reaction mixture, the toluene layer was washed with a large amount of water to completely remove the by-product and toluene was evaporated to obtain a solid product. As a result of analysis by gas chromatography, the solid product is a monoester compound, which is 1- (2-hydroxy-3, 5-dimethylphenyl) -1- (2-benzoyloxy-3, 5-dimethylphenyl) -2-methyl Propane, 2,2'-isobutylidenebis (4, 6-dimethylphenol) as starting material and 1-bis (2-benzoyloxy- (4, 6-dimethylphenol) and Table 2 as diester compounds of Table 2 The amount of 1-bis (2-benzoyloxy-3, 5-dimethylphenyl) -2-methylpropane was contained as a diester compound.

The melting point of the product was 129-130 ℃ infrared absorption spectrum was characterized by the ^{3530㎝ -I (νOH)), 1735㎝} -I (νC-O), 1250㎝ -I and 1140㎝ ^-I (νC-O).

TABLE 2

Part: * molar ratio of benzoyl chloride and 2,2'-isobutylidenebis (4, 6-dimethylphenol)

Example 2

As shown in Table 2, Treatment No. 1 was carried out in the same manner as in Example 1 except that the temperature and time required to achieve the monoesterification rate of 50% and the temperature and time after achieving the monoesterification rate of 50% were used.

The purity of the product by gas chromatography is shown in Table 3.

TABLE 3

Note: * The reaction continued at 30 hours -5 ° C.

In this treatment, unreacted benzoyl chloride was detected by gas chromatography.

Example 3

Preparation of 1- (2-hydroxy-3, 5-dimethylphenyl) -1- (2-benzoyloxy-3, 5-dimethylphenyl) -2-methylpropane (compound number 5 in Table 1). Dissolve 20 g (67.1 mmol) of 2,2'-isobutylidenebis (4, 6-dimethylphenol) in 200 g of N, N-dimethyl acetamide in a 500 ml three-neck flask equipped with a stirrer, a thermometer and a dropping funnel. The mixture was kept at 20 DEG C in a dry nitrogen atmosphere, and 100 g of N and N-dimethylacetamide in which 15.5 g (68.6 mmol) of benzo anhydride was dissolved was added dropwise, and the mixture was stirred at 20 DEG C for 1 hour.

As a result of analyzing the reaction mixture solution by gas chromatography, the monoesterification rate was 72%. The reaction mixture solution was further heated to 80 ° C. and maintained at 80 ° C. for 4 hours. As a result, the monoesterification rate of the obtained reaction mixture solution was 96%.

After the reaction was completed, N, N-dimethylacetamide was evaporated from the reaction mixture, the residue was first washed with 5% aqueous sodium carbonate solution and the second was sufficiently washed with water.

Then, 50 ml of hexane was added and left to obtain 26.5 g (98.2%) of a powdery product.

The melting point of this product was 129 ° C to 130 ° C.

The infrared absorption spectrum was the same as in Example 1.

As a result of the analysis of purity by gas chromatography, the product was 1- (2-hydroxy 3, 5-dimethylphenyl) -1- (2-benzoyloxy-3, 5-dimethylphenyl) -2-methylpropane as a monoester compound. 97.0 wt%, 2,2'-isobutylidenebis (4, 6-dimethylphenul) as starting material and 0.7 wt% as diester compound 1-bis (2-benzoyloxy-3, 5-dimethylphenyl) -2 -2.3 wt% methylpropane. Furthermore, after completion of the reaction, the N, N-dimethylacetamide amide reaction mixture showed a satisfactory effect as an antioxidant to prevent discoloration for polyurethanes, polystyrenes, polymethylmethacrylates and polyamides.

Example 4

As in Table 1, the monoester compound of the present invention was prepared in the same manner as in Example 1 or 3 with a yield of about 94% to 99%.

Table 4 shows the results of the elemental analysis and the infrared absorption spectrum of the monoester compound.

TABLE 4

Note: Process A is the method according to Example 1, and process B is the method according to Example 3.

Claims (1)

2, 2'-alkylidenebis (4, 6-ter-substituted phenol) of the general formula (II) in a general equimolar amount in the presence of the reaction medium at a temperature of about 0 ℃ to 100 ℃ Method for preparing a monoester compound of 2,2'-alkylidenebis (4, 6-di-substituted phenol) characterized in that the compound of formula (I) is prepared by acting with an esterification agent selected from the group consisting of .

Wherein Rl and R2 are the same or different and each is a Cl-4 alkyl group, a cycloalkyl group or a methyl-substituted C5-6 cycloalkyl group, where R ₃ and R _{4 each} represent a hydrogen atom and the other is hydrogen An atom or a C1-10 alkyl group or both represent a methyl group. R ₅ is C4-9 alkyl, C ₅ - ₆ cyclo alkyl group, C ₂ - ₄ alkenyl group, a phenyl group, a C _l - ₄ alkyl-substituted phenyl group, a C _l - ₄ alkoxy-substituted phenyl group, a mono- or di -C ₁ - ₄ , an alkyl-substituted hydroxyphenyl group, a stryl group, a benzyl group or a pyridyl group is represented.