TW201912634A - Antioxidant agent and plastic article having the same - Google Patents

Abstract

This invention provides antioxidants and plastic products having the same. The antioxidants are polymerizable, phenol-free and low extractable. The antioxidants can be used to prevent or retard the degradation of plastic products induced by heat or external force. The flow properties, color stability and mechanical properties of polymers can be thus maintained and the durability of plastic products can be extended.

Description

 Antioxidant and plastic product having the same  

The present invention relates to an antioxidant, and more particularly to an antioxidant for use in a plastic article to inhibit heat, oxidation or photodegradation.

Many organic synthetic resin products, natural resin products, and polymerizable organic polymer products (hereinafter collectively referred to as "plastic products") are often affected by heat, whether at high temperature manufacturing or processing, or long-term storage at room temperature, thermally induced generation. Active free radicals or peroxides cause the plastic products to become inferior, especially in the high temperature environment. If the active substance is not stabilized or quenched, the inferior plastic products will eventually become brittle and cannot be used. The product has the necessity of adding an antioxidant, wherein the antioxidant is further classified into a carbon-centered radical scavenger and an oxygen-centered radical scavenger according to its active substance. And a hydroperoxide decomposer, which is initiated by the formation of carbon radicals in the auto-oxidation cycle of aging of plastic products, and then reacts with oxygen in the air to generate oxygen radicals. Therefore, a good carbon radical quenching agent can avoid the formation of oxygen free radicals, and the most representative carbon radical quenching agent is the benzofuranone antioxidant. 3-Aromatic benzofuranone was first reported by the MH Hubacher in the journal (J. Org. Chem., 1959, 24, p1949), and the US Patent No. 4,325,863 and 4,338,224 issued to Sandoz in the 1980s. For use as a stabilizer in organic polymers, U.S. Patent Nos. 5,516,920 and 5,607,624 issued to Ciba-Geigy, the disclosure of which are incorporated herein by reference. HP-136). At present, most of the products provided by the prior art are solid-added antioxidants, which have the problems of high relative toxicity and poor heat resistance of the small molecule, and the solid-added antioxidant also has the solubility problem added in the process and the compatibility of the subsequent processing of the finished product. The problem involves a slight migration to the product's migration, which can cause bloating or blooming during severe conditions. The above problems can be solved by the use of liquid macromolecular 3-arylbenzofuranones, which are disclosed in US Patent Nos. 7390912 and 8653284, issued by Milliken & Company, 2004. The lactone composition, however, is caused by the high price of the final commercial product due to the synthesis of the expensive 4-hydroxymandelic acid monohydrate as a reaction precursor.

The present invention provides a novel antioxidant of 3-arylbenzofuranone which has the characteristics of being polymerizable, free of free phenol and low extractability. In addition, the present invention provides a reaction precursor synthesized by inexpensive glyoxylic acid hydrate (compared with TCI reagent, 4-hydroxymandelic acid monohydrate: USD 670/mol; glyoxylic Acid hydrate): USD 13.3/mol), increasing the feasibility of its industrial production applications.

The present invention provides a compound of the formula (I), Wherein R represents a linear or branched C _1-5 alkyl group; and R _{1 -} R ₄ represent a hydrogen atom, a C _1-20 alkyl group, a C _1-20 cycloalkyl group, a C _1-20 alkoxy group, respectively. , phenyl or C _7-20 phenylalkyl; m is an integer from 1 to 10; X represents an oxygen atom; Y represents a divalent oligoester group represented by the following formula (Ia); and Z represents a hydrogen atom, a terminal group of a C _1-20 alkyl group, an alkylcarbonyl group or an arylcarbonyl group; Wherein W represents an oxygen atom; R ₆ and R ₇ each represent a hydrogen atom or a C _1-6 alkyl group; p is an integer of 1 to 10; and q is an integer of 0 to 20.

The compound of the formula (I) can be added during the manufacture of a plastic product or added during the processing of a plastic product as an antioxidant.

The present invention further provides a method of stabilizing a plastic article comprising the compound of the formula (I) as an antioxidant. The plastic product of the present invention contains the compound of the formula (I), so that the plastic product can maintain the original fluidity, color stability and mechanical property maintenance rate, thereby improving the durability of the plastic product.

The embodiments of the present invention are described by way of specific examples, and those skilled in the art can readily understand the advantages and functions of the present invention from the disclosure. The present invention may be embodied or applied by other different embodiments, and the various details of the present invention may be variously modified and changed without departing from the spirit and scope of the invention.

The present invention provides a compound of the formula (I), Wherein R represents a linear or branched C _1-5 alkyl group; and R _{1 -} R ₄ represent a hydrogen atom, a C _1-20 alkyl group, a C _1-20 cycloalkyl group, a C _1-20 alkoxy group, respectively. , phenyl or C _7-20 phenylalkyl; m is an integer from 1 to 10; X represents an oxygen atom; Y represents a divalent oligoester group represented by the following formula (Ia); and Z represents a hydrogen atom, a terminal group of a C _1-20 alkyl group, an alkylcarbonyl group or an arylcarbonyl group; Wherein W represents an oxygen atom; R ₆ and R ₇ represent a hydrogen atom or a C _1-6 alkyl group; p is an integer of 1 to 10; and q is an integer of 0 to 20.

The compound of the formula (I) of the present invention is synthesized by the following synthetic route: Wherein R ₅ represents a hydrogen atom, and R, R _{1 -} R ₄ , m, X, Y and Z are the same as defined in the formula (I).

The reaction precursor is synthesized by the following synthetic route of phenol and glyoxylic acid, the yield is high, the raw materials are relatively cheap, and the cost is lower than that of the synthesis method using 4-hydroxymandelic acid as a raw material. Wherein R ₅ represents a hydrogen atom, and R _{1 to} R ₄ are the same as the formula (I).

In a specific embodiment, in the compound of the formula (I), R ₂ and R ₄ are a hydrogen atom. For example, the compound of the formula (I) of the present invention has the structure of the following formula (I-1):

In still another embodiment, in the compound of the formula (I-1), R is an exoethyl group, m is 1, X is an oxygen atom, Y is a divalent oligoester group, and Z is a hydrogen atom, wherein The divalent oligoester group has p of 5 and R ₆ and R ₇ is a hydrogen atom. For example, the compound of the formula (I-1) of the present invention has the structure of the following formula (II):

In another embodiment, in the compound of the formula (II), R ₁ and R ₃ are a methyl group, and q is 0. For example, the compound of the formula (II) of the present invention has the structure of the following formula (II-1):

In still another embodiment, in the compound of the formula (II), R ₁ and R ₃ are t-butyl groups, and q is 0. For example, the compound of the formula (II) of the present invention has the structure of the following formula (II-2):

In still another embodiment, in the compound of the formula (II), R ₁ is a hydrogen atom, R ₃ is a tert-butyl group, and q is 0. For example, the compound of the formula (II) of the present invention has the structure of the following formula (II-3):

In another embodiment, in the compound of formula (II), q is zero. For example, the compound of the formula (II) of the present invention has the structures of the following formulae (II-4) to (II-6):

In still another embodiment, in the compound of the formula (II), R ₁ and R ₃ are a methyl group, and q is 4. For example, the compound of the formula (II) of the present invention has the structure of the following formula (II-7):

In still another embodiment, in the compound of the formula (II), R ₁ and R ₃ are t-butyl groups, and q is 4. For example, the compound of the formula (II) of the present invention has the structure of the following formula (II-8):

In still another embodiment, in the compound of the formula (II), R ₁ is a hydrogen atom, R ₃ is a tert-butyl group, and q is 4. For example, the compound of the formula (II) of the present invention has the structure of the following formula (II-9):

In another embodiment, in the compound of formula (II), q is 4. For example, the compound of the formula (II) of the present invention has the structures of the following formulas (II-10) to (II-12):

The present invention further provides a method of stabilizing a plastic article comprising the compound of the formula (I) as an antioxidant.

In a specific embodiment, the plastic product comprises the compound of the formula (I), so that the plastic product can maintain the original fluidity, color stability and mechanical property maintenance rate, thereby improving the durability of the plastic product. .

Synthesis Example 1 : Synthesis of 3-(2-hydroxy-3,5-dimethylphenyl)-5,7-dimethylbenzofuran-2-one (Formula A)

12.2 g of 2,4-dimethylphenol, 7.4 g of 50% aqueous glyoxylic acid solution and 40 ml of toluene were added to the reaction flask, stirred at room temperature, and then 0.97 g of methanesulfonic acid was added, and the temperature was gradually raised to reflux. Azeotropic removal of water, the reaction was carried out until it was anhydrous and then azeotropically removed, and no residue of the starting material was detected by thin layer chromatography. After the temperature was lowered to room temperature, the organic layer was washed twice with water (40 mL) and concentrated to remove toluene under reduced pressure. Recrystallization from heptane gave 12.6 g of a white solid product, yield 89%.

Synthesis Example 2 : Synthesis of 3-(2-hydroxy-3,5-di-tert-butylphenyl-5,7-di-tert-butylbenzofuran-2-one (Formula B)

20.6 g of 2,4-di-tert-butylphenol, 7.4 g of a 50% aqueous glyoxylic acid solution and 40 ml of toluene were added to the reaction flask, stirred at room temperature, and then 0.97 g of methanesulfonic acid was added thereto, and the temperature was gradually raised to reflux. The state azeotropically removes water, and the reaction is azeotropically removed until it is anhydrous, and no residue of the starting material is detected by thin layer chromatography. After the temperature is lowered to room temperature, the organic layer is washed twice with water (40 mL) and then concentrated under reduced pressure. Toluene was recrystallized from heptane to give 20.3 g of white solid.

Synthesis Example 3 : Synthesis of 3-(5-tert-butyl-2-hydroxyphenyl)-5-tert-butylbenzofuran-2-one (Formula C)

15.2 g of 4-tert-butylphenol, 7.4 g of 50% aqueous glyoxylic acid solution and 40 ml of toluene were added to the reaction flask, and the mixture was stirred at room temperature, and then 0.97 g of methanesulfonic acid was added thereto, and the temperature was gradually raised to reflux to azeotrope. In addition to water, the reaction was azeotropically removed until it was anhydrous, and no residue of the starting material was detected by thin layer chromatography. After the temperature was lowered to room temperature, the organic layer was washed twice with water (40 mL) and concentrated to remove toluene under reduced pressure. Recrystallization from heptane gave 14.6 g of a white solid product, yield 86%.

Synthesis Example 4 : 3-(2-(2-hydroxyethoxy)-3,5-dimethylphenyl)-5,7-dimethylbenzofuran-2-one (Formula II-1) Synthesis (AO-DME)

 Method 1: Synthesis with ethylene oxide  

5.65 g of 3-(2-hydroxy-3,5-dimethylphenyl)-5,7-dimethylbenzofuran-2-one and 40 ml of dimethylacetamide were added to the reaction flask. After stirring at room temperature, add 0.02 g of anhydrous calcium chloride, slowly introduce 3 equivalents of ethylene oxide, control the temperature below 50 ° C, and maintain the temperature at 50 ° C until the test of thin layer chromatography has no starting material. The residue was cooled under reduced pressure and evaporated to remove dimethylacetamide. ¹ H-NMR (CDCl ₃ , 300 MHz) δ: 2.20 (s, 6H), 2.24 (s, 6H), 3.03 (t, 2H, J = 6.9 Hz), 4.50 (t, 2H, J = 6.9 Hz), 6.42(br s,1H),6.77(s,2H),6.97(s,2H)

 Method 2: Synthesis with 2-chloroethanol  

5.65 g of 3-(2-hydroxy-3,5-dimethylphenyl)-5,7-dimethylbenzofuran-2-one, 3.52 g of 2-chloroethanol, 8.29 g of anhydrous potassium carbonate and 40 ML of methyl cyanide was added to the reaction flask, and the temperature was raised to reflux until no residue of the starting material was detected by thin layer chromatography. After cooling under reduced pressure, the cyanide was removed, diluted with 60 ml of dichloromethane, and the salt was filtered off. After washing twice with water, the organic layer was concentrated under reduced pressure.

 Method 3: Synthesis with ethyl carbonate  

5.65 g of 3-(2-hydroxy-3,5-dimethylphenyl)-5,7-dimethylbenzofuran-2-one and 37.5 ml of dimethylacetamide were added to the reaction flask. After stirring at room temperature, 0.28 g of anhydrous potassium iodide was added, 2.64 g of ethyl carbonate was slowly added, and the temperature was raised to 140 ° C until the residue of the starting material was detected by thin layer chromatography. After the acetamide was diluted with 60 ml of dichloromethane, the salt was filtered off, washed twice with water and then concentrated, and then evaporated to give a white solid.

Synthesis Example 5 : 5,7-di-tert-butyl-3-(3,5-di-tert-butyl-2-(2-hydroxyethoxy)phenyl)benzofuran-2-one (Formula II- 2) Synthesis (AO-DTB)

9.01 g of 3-(2-hydroxy-3,5-di-tert-butylphenyl-5,7-di-tert-butylbenzofuran-2-one and 40 ml of dimethylacetamide were added to the reaction flask. After stirring at room temperature, add 0.02 g of anhydrous calcium chloride, slowly introduce 3 equivalents of ethylene oxide, control the temperature below 50 ° C, and maintain the temperature at 50 ° C until the TLC test has no start. the residue was, after cooling and concentrated under reduced pressure to remove dimethylacetamide to obtain 8.86 g column isolated the product as a white solid, yield ^{87.5% 1 H-NMR (CDCl} 3, 300MHz) δ:. 1.16 (s, 9H) , 1.37 (s, 9H), 1.42 (s, 9H), 1.46 (s, 9H), 2.20-2.30 (m, 1H), 3.29-3.38 (m, 1H), 3.40-3.62 (m, 2H), 6.86 (d, 1H, J = 2.4 Hz), 7.19 (d, 1H, J = 2.1 Hz), 7.32 (d, 1H, J = 2.4 Hz), 7.37 (d, 1H, J = 2.1 Hz), 9.00 (s) , 1H)

Synthesis Example 6 : 5-(tert-butyl)-3-(5-(tert-butyl)-2-(2-hydroxyethoxy)phenyl)benzofuran-2-one (Formula II-3) Synthesis (AO-TBU)

6.77 g of 3-(5-tert-butyl-2-hydroxyphenyl)-5-tert-butylbenzofuran-2-one and 40 ml of dimethylacetamide were added to the reaction flask and stirred at room temperature. After total dissolution, add 0.02g of anhydrous calcium chloride, slowly pass 3 equivalents of ethylene oxide, control the temperature below 50 ° C, hold the temperature at 50 ° C until the test of thin layer chromatography has no starting material residue, cooling down After concentration by pressure and removal of dimethylacetamide, the product was isolated on a column to yield 6.27 g of white solid. ¹ H-NMR (CDCl ₃ , 300 MHz) δ: 1.24 (s, 18H), 3.13 (t, 2H, J = 6.6 Hz), 4.54 (t, 2H, J = 6.6 Hz), 6.85 (m, 2H), 6.89(br s,1H),7.08(m,2H),7.62(m,2H)

Synthesis Example 7 : Synthesis of RTAO-DME (Formula II-7)

8.53 g of 3-(2-hydroxy-3,5-dimethylphenyl)-5,7-dimethylbenzofuran-2-one and 11.95 g of ε-caprolactone were added to the reaction flask, slowly The temperature was raised to 130 ° C, 0.2 g of stannous octoate was added, and the reaction was carried out for 2 hours. After cooling, the mixture was diluted with toluene, washed twice with water, and then azeotropically removed. Finally, the toluene was concentrated under reduced pressure to give 19.46 g of a pale yellow oily mixture. The product, 95% yield, was analyzed by high-resolution mass spectrometry to confirm that the molecular weight of the main product was correct.

HRMS (ESI): Calculated for C ₄₄ H ₆₂ O ₁₂ Na[M+Na]+: 805.4139

Actual value: 805.4146 (error 0.9ppm)

Synthesis Example 8 : Synthesis of RTAO-DTB (Formula II-8)

12.93 g of 3-(2-hydroxy-3,5-di-tert-butylphenyl-5,7-di-tert-butylbenzofuran-2-one and 11.95 g of ε-caprolactone were added to the reaction flask. The temperature was slowly raised to 130 ° C, and after adding 0.2 g of stannous octoate, the reaction was carried out for 2 hours, and the temperature was lowered to dilute with toluene. After washing twice with water, the water was azeotropically removed. Finally, the toluene was concentrated under reduced pressure to give 23.39 g of pale yellow oil. The product of the mixture, 94% yield, was analyzed by high-resolution mass spectrometry to confirm that the molecular weight of the main product was correct.

HRMS (ESI): Calculated for C ₅₆ H ₈₂ O ₁₂ Na[M+Na]+: 973.6017

Actual value: 973.6020 (error 0.3ppm)

Synthesis Example 9 : Synthesis of RTAO-TBU (Formula II-9)

10.00 g of 3-(5-tert-butyl-2-hydroxyphenyl)-5-tert-butylbenzofuran-2-one and 11.95 g of ε-caprolactone were added to the reaction flask, and the temperature was slowly raised to 130 ° C. After adding 0.2 g of stannous octoate, the reaction was carried out for 2 hours, and the temperature was lowered to dilute with toluene. After washing twice with water, the water was azeotropically removed. Finally, the toluene was concentrated under reduced pressure to obtain 21.07 g of a pale yellow oily mixture. 96%, by high-resolution mass spectrometry analysis, confirmed that the main product molecular weight is correct.

HRMS (ESI): Calculated for C ₄₈ H ₇₀ O ₁₂ Na[M+Na]+: 861.4765

Actual value: 861.4762 (error 0.3ppm)

Test Example 1 : Processing fluidity test of polypropylene (PP)

The antioxidants of the above Examples 4 to 9 were mixed with an auxiliary antioxidant (Irganox 1010 and Irgafos 168, BASF Corporation), and added to 100 parts by weight of polypropylene (Yongjiaene 1080, Formosa Plastics Co., Ltd.), and commercially available. 3-arylbenzofuranone antioxidant (Irganox HP-136, BASF) for comparison, the test formulation ratio shown in Table 1, with a twin-screw extruder (PSM30A 鵣 = 31.2mm, L / D = 40, Rotation speed: 105 rpm, test conditions: processing temperature: 190 to 220 ° C; extruder inlet temperature: 190 ° C; extruder die temperature: 205 ° C), after water extrusion, the particles are dried, and then the particles are dried for a second time. Combat, a total of five times. The melted flow index (MFI) was analyzed by using a melt indexer (GT7100-MI, high-speed rail technology) each time the dried particles were extruded, and the results are shown in Table 2.

The larger the melt flow index shown in Table 2, the more severe the situation in which the polypropylene sample was subjected to thermal cracking. A polypropylene sample comprising the benzofuranone antioxidant of the present invention and a commercially available 3-arylbenzofuranone antioxidant product has a melt flow index of less than 14.02, compared to the melt flow of a polypropylene sample of the control group. The low index value indicates that the addition of the antioxidant of the present invention can significantly improve the heat resistance of the polypropylene sample.

Test Example 2: Anti-thermal oxygen aging yellowing test of polyurethane foam

The antioxidants of the above Synthesis Examples 7 to 9 were added to a polyurethane foam while being combined with a commercially available 3-arylbenzofuranone antioxidant (Irganox HP-136, BASF) and a blank group without adding any antioxidant. For comparison, the anti-thermal aging yellowing test of the polyurethane foam was carried out under the same preparation method, and the relevant test procedures and results are described below.

 1. Polyurethane foam formula ratio (as shown in Table 3)  

 2. Polyurethane foam production steps:  

2-1 6.1 g of toluene diisocyanate (TDI-80) and 12 g of polyol (PP-3000) were placed in two A, B beakers, respectively.

2-2 Take 0.02 g of diamine catalyst (33 LV), 0.04 g of organic tin catalyst (T-9), 0.12 g of foam stabilizer (SZ-580), 0.48 g of distilled water and 0.188 g of antioxidant in order. Add to the B beaker.

2-3 Adjust the speed of the high-speed mixer at 3000 rpm, stir the mixture of the B beaker with the rotor, and stir for 30 seconds before stopping the stirring.

2-4 Pour the toluene di-isocyanate in the A beaker into the B beaker, adjust the high-speed mixer rotation speed to 3000 rpm, stir for 15 seconds, stop the stirring, and quickly pour the mixture into the mold to naturally foam.

2-5 After standing at room temperature for 24 hours, the polyurethane foam was taken out to prepare a 20 mm thick, 60 mm diameter foam test piece for thermal oxygen aging and extractability testing.

 3. Thermal oxygen aging yellowing test  

Each of the above foam test pieces was placed in a hot air circulating oven (temperature: 100 ° C) for aging test, and taken out after 72 hours, and subjected to yellowness (YI) and yellowing index (ΔYI) tests. The results obtained are shown in Table 4.

The smaller the ΔYI value shown in Table 2, the better the case where the polyurethane foam test piece is resistant to yellowing. The urethane foam test piece containing the antioxidant of the present invention has a ΔYI value lower than that of the blank group of the polyurethane foam test piece, indicating that the addition of the antioxidant of the present invention can significantly enhance the anti-yellowing of the polyurethane foam. Effect.

Test Example 3: Antioxidant extractability test in polyurethane foam

5 g of each of the polyurethane foam test pieces in the above Test Example 2 was placed in 195 g of ethanol, heated under reflux for 2 hours, and a clear liquid was added and 200 g of ethanol was added to obtain an extract sample of the polyurethane foam containing the antioxidant. The analysis is carried out by liquid chromatography (HPLC), and the analysis methods and results of the liquid chromatograph are described below.

 1. Liquid chromatography analysis method  

Use solvents and instruments:

 2. Inspection process:  

2-1 Standards for the preparation of antioxidants: The antioxidants of Examples 7 to 9 and the commercially available 3-arylbenzofuranone antioxidant (Irganox HP-136, BASF) were separately weighed and diluted with cyanomethane. Standards for each of the antioxidant concentrations of 250 ppm, 125 ppm, 75 ppm, and 25 ppm were prepared.

2-2 The fixed standard injection volume is 10 μL (μL) for testing.

2-3 The above-mentioned antioxidant standard product results are linear regression analysis of the calibration curve with the concentration as the X-axis and the integral area as the Y-axis; and whether the linear correlation coefficient value (R ² ) is above 0.995 (if not reached) This standard must be reconstituted).

2-4 A sample of the extract of the polyurethane foam containing the antioxidant was injected into a volume of 10 μl (μL) for detection.

2-5 The obtained result was substituted into the linear regression formula of the calibration curve, and the concentration of each antioxidant in the sample of the polyurethane foam was determined.

2-6 The percent extractability of each antioxidant was calculated and the results are shown in Table 5.

As can be seen in Table 5, the commercially available 3-arylbenzofuranone antioxidant (Irganox HP-136) can be obtained by ethanol extraction, and is susceptible to high relative toxicity and poor compatibility compared to commercially available 3-aromatics. The benzofuranone antioxidant product, the antioxidant provided by the present invention confirms the low extractability and reduces the application limit of the plastic product.

In summary, the plastic product of the present invention contains the compound of the formula (I), so that the plastic product can maintain the original fluidity, color stability and mechanical property retention rate, thereby improving the durability of the plastic product. And its use.

Claims (8)

a compound of formula (I), Wherein R represents a linear or branched C _1-5 alkyl group; and R _{1 -} R ₄ represent a hydrogen atom, a C _1-20 alkyl group, a C _1-20 cycloalkyl group, a C _1-20 alkoxy group, respectively. , phenyl or C _7-20 phenylalkyl; m is an integer from 1 to 10; X represents an oxygen atom; Y represents a divalent oligoester group represented by the following formula (Ia); and Z represents a hydrogen atom, a terminal group of a C _1-20 alkyl group, an alkylcarbonyl group or an arylcarbonyl group; Wherein W represents an oxygen atom; R ₆ and R ₇ each represent a hydrogen atom or a C _1-6 alkyl group; p is an integer of 1 to 10; and q is an integer of 0 to 20. The compound described in claim 1 is represented by the structure of formula (II): Wherein R represents a linear or branched C _1-5 alkylene group; and R ₁ and R ₃ represent a hydrogen atom, a C _1-20 alkyl group, a C _1-20 cycloalkyl group, a C _1-20 alkoxy group, respectively. , phenyl or C _7-20 phenylalkyl; m is an integer from 1 to 10; q is an integer from 0 to 20.  The compound of claim 2, wherein R is an exoethyl group, m is 1 and q is 0.   A compound according to claim 3, which is selected from one of the following structural formulae:  The compound of claim 2, wherein R is an exoethyl group, m is 1 and q is 4.   A compound according to claim 5, which is selected from one of the following structural formulae:  A plastic article comprising the compound of claim 1 as an antioxidant.    For example, the plastic products mentioned in the scope of claim 7 are polyurethane and polyolefin plastic products.