JPH02202902A - Production of phenol-containing low polymer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a novel phenol group-containing low polymer, and more specifically, to a method for producing a new phenol group-containing low polymer, and more specifically, a low copolymer of ethylene and a vinyl ester of a saturated carboxylic acid, and a phenol group-containing low copolymer. The present invention relates to a method for producing a phenol group-containing low polymer by transesterifying an ester compound contained therein in the absence of a solvent, and particularly relates to a method for producing a substance that is excellent in preventing deterioration when incorporated into synthetic resins.

[Prior Art] Synthetic resins such as polyolefins such as polyethylene and polypropylene are used in many fields due to their excellent mechanical and chemical properties. However, as is well known, during processing or use, the bonds in the molecules of these polyolefins are broken due to the effects of heat, oxygen, light, etc., resulting in crosslinking and lowering of the molecular weight, resulting in softening, embrittlement, and surface cracking. It is well known that its functionality deteriorates due to a decrease in mechanical strength and discoloration.

In order to prevent such deterioration, synthetic resins are often mixed with various additives that take the factors of deterioration into account. , is known to be added during the processing process to prevent deterioration.

Examples of substances that have such antioxidant effects include 2
, 3-di-tert-butyl-4-methylphenol,
2,2'-methylenebis(4-methyl-6-tert-butylphenol), 4゜4'-butylidenebis(3-
Methyl-6-tert-butylphenol), n-octadecyl-8-(3,5-diter-butyl-4-hydroxyphenyl)propionate, L 1,3-)
Phenolic antioxidants such as lith(2-methyl-4-hydroxy-5-tert-butylfer)butane, pentaerythritol tetrakis[3-(3,5-diter-butyl-4-hydroxyphenyl)propionate] These phenolic antioxidants can be used alone, these phenolic antioxidants can be used in combination with phosphorus antioxidants such as tris(nonylphenyl) phosphite, distearylpentaerythritol diphosphite, or the above phenolic antioxidants can be used together. A method of using a sulfur-based antioxidant such as dilaurylthiodipropionate, simiristylthiodipropionate, and distearylthiodipropionate in combination has been carried out.

These treatments are applied to most synthetic resins today by selecting the most suitable additives or by prescribing them in combination, depending on the type of synthetic resin to be treated and the intended use of the processed product, such as synthetic resin.

On the other hand, studies are also being carried out on increasing the molecular weight of antioxidants.

For example, Journal of Polymer Science
In B edition Vol. 10, pages 157-159 (published in 1972), β-vinyloxy (3, Using 5-di-tert-butyl-4-hydroxy)benzoate as a monomer, the synthesis of a homopolymer thereof or a copolymer with styrene or maleic anhydride has been reported.

Furthermore, in Japanese Patent Publication No. 54-956, ethylene-vinyl alcohol copolymer produced by alcoholysis of ethylene-vinyl acetate copolymer and 3-(3゜5-di-tert-butyl-
A method for producing a polymeric antioxidant by transesterifying ethyl 4-hydroxyphenylpropionate using a large amount of benzene solvent in the presence of a para-toluenesulfonic acid catalyst is disclosed.

Furthermore, in JP-A-51-136782, 3-(3-(3)
, 5-ditert-butyl-4-hydroxyphenyl)propionate and a large amount of xylene solvent in the presence of a sodium methylate catalyst to produce a polymeric antioxidant. has been done.

[Problems to be Solved by the Invention] However, as can be inferred from the chemical structure of the aforementioned antioxidants made of low molecular weight compounds, many of them have a basic structure in which the phenol ring has an alkyl group. Many of them are actually used, but because they are low molecular weight substances and contain few polymethylene units, they often have poor compatibility with polyolefins due to differences in molecular weight and polarity.

As a result, after being mixed with a polyolefin, it exhibits separability over time and, for example, migrates to the surface of a molded product (bleeding phenomenon) and is lost, making it difficult to maintain performance.

Furthermore, the method of increasing the molecular weight of antioxidants by polymerizing or copolymerizing them using special comonomers has not been put into full-scale practical use today due to low yields and insufficient antioxidant effects. .

Furthermore, polymer-type antioxidants produced by transesterification using polymer compounds as raw materials as described in Japanese Patent Publication No. 54-956 and Japanese Patent Publication No. 51-136782 have low reaction rates and insufficient antioxidant performance. However, since a large amount of solvent is used, it is difficult to recover the reactant and the production cost is high, making it difficult to accept from an industrial perspective.

Considering the problem further using JP-A-51-136782 as an example, it is found that if the raw material is an ethylene-vinyl acetate copolymer with a melt index (MI') of 30 as seen in that example, It has an extremely high viscosity at a temperature of 200°C, making mixing operations difficult and making it impossible to carry out a uniform transesterification reaction, making it difficult to obtain a high reaction rate.

Furthermore, if the resin is operated at higher temperatures, decomposition of the resin such as deacetic acid reaction will occur, resulting in the formation of unsaturated bonds and coloring, resulting in a significant decline in the quality of the product. Therefore, it is usually necessary to carry out the transesterification reaction in a dilute solution using a large amount of solvent.

The transesterification reaction is an equilibrium reaction, and a high reaction rate can be obtained by actively discharging the by-product methyl acetate out of the reaction system by reducing pressure, etc. However, using a solvent not only makes it difficult to operate under reduced pressure, but also Methyl acetate dissolves in the solution, making it difficult to discharge and slowing down the reaction rate.

In view of these problems, the present invention aims to develop a more effective and economical polymeric antioxidant, which has good compatibility with polyolefins and exhibits excellent antioxidant performance with low bleeding. The purpose is to manufacture and provide substances by an industrially extremely advantageous method.

[Means for Solving the Problems] As a result of intensive studies aimed at solving the problems, the present inventors have found that a polymeric antioxidant produced by an industrially extremely advantageous method has very good performance. I found out that
We have arrived at the present invention.

That is, the present invention has a number average molecular weight of 800 to 5000 and a vinyl ester content of saturated carboxylic acid of 10 to 50% by weight.
A low copolymer (A) of ethylene and vinyl ester of saturated carboxylic acid, which is , Ra is an alkyl group, aryl group, cycloalkyl group, or a bond thereof having 20 or less carbon atoms, and either R2 or R3 may be hydrogen. Also, m is an integer from 0 to 3) This invention relates to a method for producing a phenol group-containing low polymer, which comprises transesterifying the phenol group-containing ester compound (B) represented by the following by melting and stirring at 50 to 200'C in the absence of a solvent. .

Number average molecular weight used in the present invention 800-500
0. Vinyl ester content of saturated carboxylic acid 10-50
The low copolymer (A) of ethylene and vinyl ester of saturated carboxylic acid (% by weight) is produced by a known method.

For example, Tokuko Shou 39-20069, Tokusho 52-17
558, Japanese Patent Publication No. 60-33154, etc., it is produced by free radical bulk polymerization, emulsion polymerization, solution polymerization, etc.

Vinyl esters of saturated carboxylic acids, which are comonomers used in copolymerization, include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl octoate, and vinyl stearate. Good too.

In the copolymerization, a small amount of olefin comonomers other than ethylene such as propylene, butene, hexene, or a small amount of alkyl esters of unsaturated carboxylic acids such as methyl acrylate and methyl methacrylate may be simultaneously copolymerized.

Furthermore, the reaction temperature, pressure, type of solvent, type of molecular weight regulator, etc. in copolymerization are not particularly limited.

The low copolymer (A) of ethylene and vinyl ester of saturated carboxylic acid used in the present invention preferably has a number average molecular weight in the range of 800 to 5,000, and if the number average molecular weight is 800 or less, it is not compatible with polyolefin etc. Oxidation prevention performance may become insufficient or bleed during heating or long-term holding, making it difficult to fully demonstrate antioxidant performance. If the number average molecular weight is 5,000 or more, the viscosity of the reaction system increases and stirring becomes difficult when the phenol group-containing ester compound (B) is introduced by transesterification, which is not preferable.

In addition, the vinyl ester content of saturated carboxylic acid is 10 to 5.
A range of 0% by weight is preferable, and if the content of vinyl ester of saturated carboxylic acid is less than 10% by weight or more than 50% by weight, compatibility with polyolefin etc. may become poor,
The amount of the phenol group-containing compound introduced becomes insufficient, making it difficult to fully exhibit antioxidant performance.

Note that the number average molecular weight is the value obtained by the vapor pressure equilibrium method, and the vinyl ester content is the value obtained by the saponification method.

The phenol group-containing ester compound (B) represented by the general formula used in the present invention is:
It is preferred that R2 and/or R3 are an alkyl group, especially a methyl group and/or a tertiary butyl group, and that R2 and/or R3 are in the ortho position to the hydroxyl group.

Specific compounds used include, but are not limited to, methyl, ethyl, propyl, butyl, octyl, dodecyl, phenyl, and cyclohexyl esters of the following compounds, and two or more of these compounds are used. may also be used.

3-Methyl-4-hydroxybenzoic acid, 3,5-ditertiary
Butyl-4-hydroxybenzoic acid, 3゜5-dimethyl-
4-hydroxybenzoic acid, 3-tert-butyl-4-hydroxybenzoic acid, 3-tert-butyl-6-methyl-4-hydroxybenzoic acid, 3-tert-butyl-6-methyl-4-hydroxybenzoic acid, 3-tert-butyl-5-ethyl-4-
Hydroxybenzoic acid, 3-tert-butyl-6-ethyl-4
-Hydroxybenzoic acid, 3-tertiary octyl-4-hydroxybenzoic acid, 3-tertiary octyl-5-methyl-4-hydroxybenzoic acid, 3-tertiary octyl-5-ethyl-4
-Hydroxybenzoic acid, 3-tert-octyl-6-methyl-4-hydroxybenzoic acid, 2-(3-methyl-4-hydroxyphenyl)acetic acid, 2-(3,5-dimethyl-
4-hydroxyphenyl)acetic acid, 2-(3,5-di-tert-butyl-4-hydroxyphenyl)acetic acid, 2-(3
-tert-butyl-4-hydroxyphenyl)acetic acid, 2-(
3-tert-butyl-5-methyl-4-hydroxyphenyl)acetic acid, 2-(3-tert-butyl-6-methyl-4-hydroxyphenyl)acetic acid, 2-(3-tert-butyl-5-ethyl- 4-hydroxyphenyl)acetic acid, 2-(3-tertiary)
octyl-4-hydroxyphenyl)acetic acid, 2-(3-
tertiary octyl-5-methyl-4-hydroxyphenyl)
Acetic acid, 2-(3-tert-octyl-6-methyl-4-hydroxyphenyl)acetic acid, 3-(3-methyl-4-hydroxyphenyl)propionic acid, 3-(3,5-dimethyl-4-hydroxyphenyl) ) propionic acid, 3-(3,
5-ditert-butyl-4-hydroxyphenyl)propionic acid, 3-(3-tert-butyl-4-hydroxyphenyl)propionic acid, 3-(3-tert-butyl-5-methyl-
4-hydroxyphenyl)propionic acid, 3-(3-tert-butyl-6methyl-4-hydroxyphenyl)propionic acid, 3-(3-tert-butyl-5-ethyl-4-hydroxyphenyl)propionic acid, 3- (3-tert-butyl-6-ethyl-4-hydroxyphenyl)propionic acid, 3-(3-tert-octyl-4-hydroxyphenyl)
Propionic acid, 3-(3-tertiary octyl-5-methyl-
4-hydroxyphenyl)propionic acid, 3-(3-tert-octyl-6-methyl-4-hydroxyphenyl)propionic acid, 3-(3,5-didodecyl-4-hydroxyphenyl)propionic acid, 4-(3 -methyl-4
-hydroxyphenyl)butyric acid, 4-(3,5-dimethyl-4-hydroxyphenyl)butyric acid, 4-(3,5-tert-butyl-4-hydroxyphenyl)butyric acid, 4-(3
,5-di-tert-butyl-4-hydroxyphenyl)butyric acid,
4-(3-tert-butyl-4-hydroxyphenyl)butyric acid, 4-(3,6-tert-butyl-4-hydroxyphenyl)butyric acid, 4-(3-tert-butyl-5-methyl-4-hydroxy phenyl)butyric acid, 4-(3-tert-butyl-5-ethyl-4-hydroxyphenyl)butyric acid, 4-(3-tert.
butyl-6-methyl-4-hydroxyphenyl)butyric acid,
4-(3-tert-butyl-6-ethyl-4-hydroxyphenyl)butyric acid, 4-(3-tert-octyl-4-hydroxyphenyl)butyric acid, 4-(3-tert-octyl-5-methyl-4 -hydroxyphenyl)butyric acid, 4-(3-tertiary octyl-6-methyl-4-hydroxyphenyl)butyric acid.

In the present invention, a low copolymer (A) of ethylene and a vinyl ester of a saturated carboxylic acid having a number average molecular weight of 800 to 5,000 and a vinyl ester content of a saturated carboxylic acid of 10 to 60% by weight, and a phenol group-containing ester compound (
When B) is transesterified to produce a phenol group-containing low polymer, the reaction is carried out in the absence of a solvent at 50 to 200°C.

In other words, in the conventional technology, as shown in the example of JP-A-51-136782, the reaction is carried out using an ethylene copolymer diluted in a solvent, which makes it difficult to separate the target product after the reaction. This is necessary and extremely uneconomical.

According to the present invention, since the reaction is carried out without a solvent, there is no need to separate or recover the solvent, and since a low molecular weight ethylene copolymer having excellent fluidity at the reaction temperature is used, there is an advantage that a high reaction rate can be obtained.

In addition, the volume of the reactor used can be used effectively because there is no solvent, and for example, it is possible to use a small reactor or increase the amount of raw materials charged in a large reactor, allowing efficient synthesis.

Furthermore, by performing transesterification in the presence of an alcohol compound during the reaction, a much higher reaction rate can be obtained.

The presence of the alcohol compound has the effect of simultaneously removing by-product methyl acetate from the system by boiling and distilling it off under high temperature reaction conditions, thereby shifting the equilibrium of the varnish hand exchange reaction to the product side.

Alcohol compounds include methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol,
Addition of amyl alcohol, octyl alcohol, etc. is effective. Moreover, it is also possible to use one or more of these types.

The alcohol compound referred to here is a solvent, i.e., a low copolymer of ethylene and vinyl ester of saturated carboxylic acid (
It has almost no effect on dissolving A) and is added to remove the above-mentioned methyl acetate from the system.

In the reaction of the present invention, catalysts include alkaline metals such as alcolade, acids such as sulfuric acid, hydrochloric acid, phosphoric acid, and p-toluenesulfonic acid, amines, sodium, magnesium, manganese, zinc, palladium, cadmium, tin, and lead. Salts such as acetates, phosphates, and silicates of metals,
Metal halides such as zinc chloride and antimony trichloride can be used.

The reaction temperature in the present invention is suitably higher than the temperature at which the low copolymer of ethylene and vinyl ester of saturated carboxylic acid can be melted and bonded, usually about 50°C or higher, preferably 70°C or higher.
The temperature is preferably 0°C or higher, and 200°C or lower at which the low copolymer of ethylene and vinyl ester of saturated carboxylic acid (A) and the phenol group-containing ester compound (B) are thermally stable.

The reaction pressure in the present invention is preferably carried out under normal pressure or reduced pressure, but it may be under increased pressure if a means for removing by-product methyl acetate from the system, such as purging of the gas phase, is used. .

Although there is no particular restriction on the reaction time in the present invention, it is preferable to terminate the reaction as soon as the target reaction rate is obtained, since keeping it at high temperature for a long time will induce thermal decomposition and side reactions.

In addition, regarding the charge ratio of the low copolymer of ethylene and vinyl ester of saturated carboxylic acid (A), the phenol group-containing ester compound (B), the alcohol compound, and the catalyst in the present invention, the structure of the target transesterified product is determined. The decision can be made with consideration, but in order to produce a phenol group-containing low polymer with excellent antioxidant performance, a low copolymer of ethylene and a vinyl ester of a saturated carboxylic acid (A
) The amount of the phenol group-containing ester compound (B) is in the range of 10 to 200 moles, preferably 50 to 100 moles, per 1.0 mole of the vinyl ester content of the saturated carboxylic acid in (B).

There is no particular limit to the amount of catalyst used, but it is usually 0.1
A range of from 1 to 100 mol, preferably from 1 to 50 mol, is efficient. There is also no particular restriction on the amount of alcohol compound used, but it is usually 0.1 to 2000 moles, preferably 1 to 20 moles.
A range of 0 mole is efficient.

The phenol group-containing low polymer obtained by such a reaction contains a large amount of phenol groups that have antioxidant properties,
And because it has excellent compatibility with polyolefins,
After mixing with polyolefin, it is characterized by eliminating the problem of migration to the surface (bleed phenomenon) and deterioration of performance over time.

In addition, polymer-type antioxidants produced by conventional transesterification of polymer compounds have low reaction rates and insufficient antioxidant performance, and require a large amount of solvent, making it difficult to recover the reactants and resulting in high production costs. However, the method of the present invention can produce phenol group-containing low polymers with a simple process that does not use solvents and at a high reaction rate. It is possible and has high industrial value.

The phenolic group-containing low polymer obtained in the present invention includes polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymer resin, ethylene-butene copolymer resin, ethylene-hexene copolymer resin, polymethylpentene, styrene- By mixing 10 to 110,000 pp of antioxidants into synthetic rubber such as butadiene rubber and ethylene-propylene copolymer rubber using a conventional method such as a mixer, blender, roll, kneader, etc., polyolefin The stability of the species can be increased.

In this case, it may be used in combination with other additives added to polyolefins, such as light stabilizers, copper inhibitors, lubricants, and peroxide decomposers. Can be used in combination with inhibitors.

In this case, it is often the case that an even stronger antioxidant effect can be obtained as a synergistic effect by combining the characteristics of each antioxidant, and the present invention is not limited thereto.

Reference Example-1 (Manufacture of low molecular weight ethylene-vinyl acetate copolymer) Using tert-butyl peroxy-2-ethylhexanoate with ethylene and vinyl acetate as polymerization initiators in a high-pressure continuous reactor, the pressure was 1400. Kg/cm2,
Copolymerization was carried out at a temperature of 190° C. in the presence of propane as a molecular weight regulator.

The obtained ethylene-vinyl acetate copolymer had a vinyl acetate content of 30 wt%, a number average molecular weight of 1900, and a softening point of 30.
It was a highly viscous oligomer with a temperature below ℃.

Example-1 28.7 g of the low molecular weight ethylene-vinyl acetate copolymer produced in Reference Example (100 mmol as vinyl acetate component) and 3-(3-tert-butyl-5-methyl-4-hydroxyphenyl) propion Put 25.0 g (100 mmol) of methyl acid (hereinafter referred to as MBP') into a 250 cc flask, dissolve and mix at 100°C, replace the atmosphere with nitrogen under reduced pressure, and entrain the methyl acid containing 28% sodium methoxide as a catalyst. 0.79 g of alcohol solution (5 mmol as sodium methoxide) was added, and the pressure was gradually reduced while increasing the temperature to 160° C. and finally to 5 mmHg.

The reaction product after 4 hours was analyzed by gel permeation chromatography, and the reaction rate of MBP was determined from the amount of MBP decreased, and was found to be 45.2%.

After 4 hours, the reaction mixture was cooled to 100°C, diluted with 50 g of tetrahydrofuran, and diluted with 500 g of cold methyl alcohol.
cc to precipitate the polymer, purify it, and dry under reduced pressure to obtain a highly viscous yellow-brown phenol group-containing low polymer 36.
4g was obtained.

This low polymer was determined to be 27B by ultraviolet absorption spectrum analysis.
The amount of the component based on the phenol group was calculated from the absorbance around nm, and the content was 0.99 mmol per 1 g. The results are also shown in Table 1.

Example-2 Instead of MBP in Example-1, 3- (3°5-
29°2g (1
The reaction was carried out in the same manner as in Example-1 except that 00 mmol) was used.

When the components vaporized during the reaction were trapped and analyzed by gas chromatography, the presence of components that matched the retention time of methyl acetate was observed.

The reaction product after 4 hours was analyzed by gel permeation chromatography, and the amount of 2,6-BP decreased.
The reaction rate of 6-BP was determined and was found to be 57.8%.

Further, the reaction product after 4 hours was purified to obtain 38.8 g of a yellow-brown phenol group-containing low polymer.

This low polymer contains 1g of constituents based on phenol groups.
The content was 1.16 mmol per portion. The results are also shown in Table 1.

Example 3 A reaction was carried out in the same manner as in Example 1 except that 6.0 g of methyl alcohol was further added after adding the catalyst in Example 1. The results are shown in Table 1.

Example 4 A reaction was carried out in the same manner as in Example 2 except that 6.0 g of methyl alcohol was further added after adding the catalyst in Example 2. The results are shown in Table 1.

Example-δ A reaction was carried out in the same manner as in Example-2 except that 6.0 g of ethyl alcohol was further added after adding the catalyst in Example-2. The results are shown in Table 1.

Example-6 In Example-2, 0°12g of lithium amide was added to the catalyst.
(5 mmol) was added, but the reaction was carried out in the same manner as in Example-2. The results are shown in Table 1.

Example-7 In Example-2, 0 p-toluenesulfonic acid was added to the catalyst.
．． The reaction was carried out in the same manner as in Example 2 except that 86 g (5 mmol) was added. The results are shown in Table 1.

Example-8 Vinyl acetate content 38 wt%, manufactured according to the reference example.
The reaction was carried out in the same manner as in Example 3, except that 22.6 g (100 mmol as vinyl acetate component) of an ethylene-vinyl acetate low copolymer having a number average molecular weight of 2800 and a softening point of 32° C. was used.

The results are shown in Table 1.

Example-9 Vinyl acetate content 24 wt%, manufactured according to the reference example.
The reaction was carried out in the same manner as in Example 3, except that 35.7 g (100 mmol as vinyl acetate component) of an ethylene-vinyl acetate low copolymer having a number average molecular weight of 1500 and a softening point of 40°C was used.

The results are shown in Table 1.

Comparative Example-1 Ethylene-vinyl acetate copolymer resin Sumichy sold by Sumitomo Chemical Co., Ltd. KC-10 (vinyl acetate content 28 wt%, melt index 150, number average molecular weight approximately 7500, softening point Vicat) 30°C
) was used in the same manner as in Example 1, except that 31 g (100 mmol as the vinyl acetate component) was used, but at 160 °C
In this case, entrainment mixing was not possible at all, and it was impossible to synthesize a uniform phenol group-containing polymer. As a precaution, the reaction product after synthesis was analyzed by gel permeation chromatography to determine the amount of MBP that had decreased, but the reaction rate was only 2.8%.

The results are also shown in Table 1.

Comparative Example-2 In Comparative Example-1, the same mole of 2,6-BP was used instead of MBP, and the same procedure as in Comparative Example-1 was performed, but entrainment mixing was not possible at all and a homogeneous phenol group-containing polymer was synthesized. It was impossible to do so. Furthermore, the reaction rate of 2°6-BP was only 3.6%. The results are also shown in Table 1.

Comparative Example 3 The same procedure as Comparative Example 1 was carried out, except that 150 cc of xylene was added to the ethylene-vinyl acetate copolymer resin and MBP in a solution system.

The reaction product after 4 hours was cooled to 100°C, added dropwise to 500 cc of cold methyl alcohol to precipitate the polymer, and purified, and dried under reduced pressure to obtain 37.5 g of a cotton-like white phenol group-containing polymer. .

The amount of constituent components based on phenol groups was calculated by ultraviolet absorption spectrum analysis of this polymer, and the amount was 0.5 per gram.
A content of 5 mmol was obtained.

The results are also shown in Table 1.

Comparative Example 4 The same procedure as Comparative Example 3 was conducted except that 150 cc of xylene was added to the ethylene-vinyl acetate copolymer resin and 2.6-BP in a solution system. The results are shown in Table 1.

Comparative Example-6 26 g (100 mmol as vinyl acetate component) of ethylene-vinyl acetate copolymer resin Evaflex ■ 150 (vinyl acetate content 33 wt%, melt index 30) sold by Mitsui Petrochemical Industries, Ltd. , Add 1000 cc of xylene to 2.6-BP, then add 6.0 g of methyl alcohol after adding the catalyst.
The operation was carried out in the same manner as Comparative Example 3, except that the addition of the following ingredients was carried out. However, 3000 CC of methyl alcohol was used for reprecipitation of the reaction product.

As a result, 38.8 g of cotton-like white phenol group-containing polymer
I got it. The amount of constituent components based on phenol groups in this polymer is 0.00% per 1g. The content was Furomimol.

The results are also shown in Table 1.

Reference Example-2 (Antioxidant performance for polyolefin) Density 0
．． 92 g/em", an ethylene-butene copolymer with a melt index of 7.0 (butene content: 28%), and an antioxidant Sumilizer BHT commercially available from Examples and Comparative Examples or Sumitomo Chemical Co., Ltd. (2,6
-di-tert-butyl-4-methylphenol), Sumilizer〇 BP-101 (tetrakis-[methylene-3-(
0.2 parts by weight of each of 3,5-di-tert-butyl-4-hydroxyphenyl)propionate-toco-methane were added and mixed for 10 minutes at 160°C using a Brabender.
It was pressed at 150°C to form a sheet with a thickness of 600 μm.

Additive-free products were also processed using the same machine.

The mechanical strength of this additive-free product in a tensile test is as follows: tensile strength at break is 195 kg/cm2, and tensile elongation at break is 9.
It was 90%.

After holding the press sheet in air in a gear oven at 190°C for 5 hours, the deformed sheet was pressed again at 150°C to form a sheet with a thickness of 500 μm, and its mechanical strength was measured by a tensile test.

Table 2 shows the results. It can be said that the smaller the numerical values of tensile strength at break and tensile elongation at break, the more the ethylene-butene copolymer tends to deteriorate, but the product of the present invention was excellent in preventing deterioration.

Table 2 [Effects of the Invention] The present invention is similar to the comparative examples shown in Table 1. enough or
This is an improvement on the fact that it is difficult to recover the reactant due to the use of a large amount of solvent, and the production cost is high, making it difficult to accept from an industrial perspective. As is clear from the example, the number average molecular weight is 800 to 500
0, vinyl ester content of saturated carboxylic acid 10-50
A low copolymer (A) of ethylene and a vinyl ester of a saturated carboxylic acid and a phenol group-containing ester compound (B) of 50 to 2% by weight without a solvent were added.
By melt welding and transesterification at 00°C, a phenol group-containing low polymer is produced with a high transesterification reaction rate.

Moreover, as shown in the reference examples, the obtained substance has excellent anti-oxidation properties and is of high industrial value.

Claims (1)

[Scope of Claims] A low copolymer of ethylene and a vinyl ester of a saturated carboxylic acid (A) having a number average molecular weight of 800 to 5,000 and a vinyl ester content of a saturated carboxylic acid of 10 to 50% by weight.
and general formulas ▲ mathematical formulas, chemical formulas, tables, etc. ▼
_2 and R_3 are an alkyl group, an aryl group, a cycloalkyl group having 20 or less carbon atoms, or a bond thereof, and R_
Either one of 2 and R_3 may be hydrogen. In addition, the phenol group-containing ester compound (B) represented by
A method for producing a phenol group-containing low polymer, which comprises performing transesterification by melting and stirring at 200°C.