WO2012115309A1

WO2012115309A1 - Phosphite-based antioxidant agent having good hydrolytic stability and polymer resin composition including same

Info

Publication number: WO2012115309A1
Application number: PCT/KR2011/003233
Authority: WO
Inventors: Dong-Kyung Park; Jong-Cheul KIM; Eun-Hwa Lee; In-Ae Shin; Hee-Jeong KWON
Original assignee: Songwon Industrial Co., Ltd
Priority date: 2011-02-21
Filing date: 2011-04-29
Publication date: 2012-08-30
Also published as: KR20120095670A

Abstract

Provided are a phosphite-based antioxidant having excellent hydrolysis stability and a polymer resin composition including the same, and the antioxidant may be a phosphite-based antioxidant represented by the above Chemical Formula 1.

Description

PHOSPHITE-BASED ANTIOXIDANT AGENT HAVING GOOD HYDROLYTIC STABILITY AND POLYMER RESIN COMPOSITION INCLUDING SAME

A phosphite-based antioxidant having excellent hydrolysis stability and a polymer resin composition including the same are provided.

In general, a resin composition used to manufacture a plastic product needs a stabilizer against oxidation due to undesirable changes such as chain breaking, cross-linking, discoloring, and the like, as well as a mechanical or physical property change of the resin. The stabilizer may in general be an antioxidant for example, a hindered phenol-based or phosphorous antioxidant.

This antioxidant may most effectively and conveniently protect the resin from modification. The phosphorous-based antioxidant is used more, and for example, may include a tertiary (+3) phosphorous compound.

However, the tertiary phosphorous compound is not stable against hydrolysis and thus may undergo hydrolysis due to moisture in the air during storage. Accordingly, the tertiary phosphorous compound may have a deteriorated stability characteristic as it is stored longer.

In order to overcome many problems in preparing, storing, and using a tertiary phosphorous compound for industrial use, much research is being undertaken on improving hydrolysis stability of the tertiary phosphorous compound. Accordingly, an organic phosphite having a hindered aryl group to have hydrolysis resistance is being researched. The organic phosphite having a hindered aryl group has a high melting point of 180℃ or higher.

Because of the high melting point, the organic phosphite is present in the form of solid at room temperature. Accordingly, the organic phosphite has low compatibility with a resin and low solubility to the resin and thus, no problem of plate-out or blooming, after the resin composition with the organic phosphite is processed.

On the other hand, an organic phosphite being liquid at room temperature may be tried as an antioxidant. As for candidates for the organic phosphite, there may be a trisnonylphenyl phosphite (TNPP) which is liquid at room temperature and is widely used. However, a nonylphenol in the trisnonylphenyl phosphite may be estimated as a representative endocrine disruptor material and have low degradable and a highly concentrated characteristic, so that it accumulates in the environment and ecosystem and harms humans and the environment, and thus is restricted in import and use.

Another liquid organic phosphite may include trisphenyl phosphite (TPP), trisisodecyl phosphite (TDP), diphenyldisodecyl phosphite (DPDP), 2-ethylhexyldiphenyl phosphite (EHDPP), poly(dipropylene glycol)phenyl phosphite (DHOP), and the like. However, this liquid phosphite is not stable against hydrolysis and thus research on an alternative is needed.

One aspect of the present invention provides a phosphite-based antioxidant having excellent hydrolysis stability and that is a liquid at room temperature.

Another aspect of the present invention provides a polymer resin composition including the antioxidant.

According to one aspect of the present invention, a phosphite-based antioxidant having excellent hydrolysis stability and that is represented by the following Chemical Formula 1 is provided.

[Chemical Formula 1]

In Chemical Formula 1,

R¹is a substituted or unsubstituted alkyl group, a substituted or unsubstituted cyclo alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted arylalkyl group,

R¹may be a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C7-C20 arylalkyl group.

The substituted alkyl group, substituted cycloalkyl group, substituted aryl group, or substituted arylalkyl group may be functional groups in which at least one hydrogen is substituted with an alkyl group, an aryl group, an alkylaryl group, or an arylalkyl group.

According to another aspect of the present invention, a polymer resin composition including the phosphite-based antioxidant and a polymer resin is provided.

The polymer resin may be selected from the group consisting of polyolefin, polyethylene, polypropylene, polyester, polycarbonate, polyamide, polyurethane, polysulfone, polyimide, polyphenylene ether, polystyrene, acrylic polymer, polyacetal, a halogenated polymer, and a combination thereof.

The phosphite may be included in an amount of 0.01 parts by weight to 0.5 parts by weight based on 100 parts by weight of the polymer resin.

Another aspect of the present invention provides a product molded by using the polymer resin composition.

An antioxidant according to the present invention has high hydrolysis stability and is maintained as a liquid at room temperature, and thus is easy to handle. Accordingly, the antioxidant may be usefully applied for a polymer resin.

Exemplary embodiments of this disclosure will hereinafter be described in detail. However, these embodiments are only exemplary and do not limit this disclosure.

As used herein, when specific definition is not otherwise provided, the term "allkyl group" may refer to linear, cyclic, and branched alkyl groups and the like.

According to one embodiment of the present invention, a phosphite-based antioxidant may be represented by the following Chemical Formula 1.

[Chemical Formula 1]

In Chemical Formula 1,

R¹is a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted arylalkyl group.

In some embodiment, R¹may be a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C7-C20 arylalkyl group.

The substituted an alkyl group, substituted cycloalkyl group, substituted aryl group, substituted arylalkyl group may be functional groups in which at least one hydrogen is substituted with an alkyl group, an aryl group, an alkylaryl group, or an arylalkyl group.

As shown in the above Chemical Formula 1, a phosphite-based antioxidant according to the present invention includes a 2,4-di-t-butyl-6-methyl group or a 2,4-di-t-butyl group and thus has steric hindrance, resultantly having excellent hydrolysis stability. In particular, since three different functional groups are combined with three oxygens when R¹is a substituted or unsubstituted alkyl group, an antioxidant has excellent solubility to a resin and improved compatibility with the resin. When the antioxidant has improved compatibility with the resin and is used therewith, it have no blooming, plate-out, and the like which may occur due to a separation from the resin, and thus maintain excellent properties. In particular, since the phosphite-based antioxidant maintains a liquid state at room temperature, it may have excellent compatibility with a resin.

Accordingly, a phosphite-based antioxidant represented by the above Chemical Formula 1 has excellent thermal safety, low volatility, and excellent stability against hydrolysis and thus may not be hydrolyzed by moisture during storage.

According to another aspect of the present invention, a polymer resin composition including the phosphite-based antioxidant represented by the above Chemical Formula 1 is provided.

The polymer resin composition may include the phosphite-based antioxidant and a polymer resin. Herein, the phosphite-based antioxidant may be included in an amount ranging from 0.01 parts by weight to 0.5 parts by weight based on 100 parts by weight of a polymer resin.

The polymer resin may be selected from the group consisting of polyolefin, polyethylene, polypropylene, polyester, polycarbonate, polyamide, polyurethane, polysulfone, polyimide, polyphenylene ether, polystyrene, an acrylic polymer, polyacetal, a halogenated polymer, and a combination thereof. The acrylic polymer may include polyacrylate, polymethacrylate, polyacrylonitrile, or a combination thereof, and the halogenated polymer may include polyvinylchloride, polyvinylbromide, polyethylene chloride, or a combination thereof.

The polymer may preferably include a polyolefin. The polyolefin may include polypropylene, polyethylene, and the like.

In addition, the polymer resin composition may further include an additive, for example, a heat stabilizer, an antioxidant, and the like. These additives may be used in an amount ranging from 0.01 to 1 parts by weight based on 100 parts by weight of a polymer resin.

Hereinafter, the present invention is illustrated in more detail with reference to examples. However, these are exemplary embodiments of present invention and are not limiting.

Example 1: Preparation of 4-tert-butylphenyl 2,4-di-tert-butyl-6-methylphenyl 2,4-di-tert-butylphenyl phosphite represented by the following Chemical Formula 1a

[Chemical Formula 1a]

396.63 g (1.8mol) of 2,4-di-tert-butyl-6-methyl phenol was put in a four-necked round flask.

Next, a tributylamine (TBA) catalyst was added to the four-necked round flask in an amount of 2.52g (0.24 parts by weight based on 100 parts by weight of the entire reactant) under a nitrogen atmosphere.

The mixture was heated to 60℃, and 164.79g (1.2mol) of phosphorus trichloride was slowly added thereto by using a dropping funnel. The resulting mixture was matured for 5 hours.

Then, 309.48g(1.5mol)of2,4-di-tert-butylphenolwasaddedtothemixture. The resulting mixture was matured for 5 hours again.

In addition, 180.27g (1.2mol) of 4-tert-butylphenol was added to the matured mixture. The resulting mixture was matured for 5 hours again. The matured solution was heated to 200℃ and matured for 20 hours.

The reactant was cooled to 100℃, and 600g of toluene was added thereto. The toluene mixture was cooled to room temperature. Then water-washing process in which water was added thereto at room temperature, and agitated, and the separated water layer was removed, was performed to neutralize. The neutralized product was concentrated under reduced pressure and cooled, acquiring a transparent yellow liquid product (1720.75g, yield: 98.78%).

The product was evaluated regarding physical properties as follows. In the following experiment results, ¹H-NMR was measured by using Varian Gemini-300 (CDCl₃, ppm unit),and IR was measured by using a BIORAD spectrometer.

¹H-NMR (CDCl₃,δ ppm): 7.38 - 7.03 (m, 8H, aromatic protons), 6.82 (d, 1H, aromatic proton), 2.45 (s, 3H, methyl group of 2,4-di-tert-buthyl-6-methyl phenol), 1.47 - 1.46 (d, 6H, tert-butyl group protons), 1.39 - 1.35 (m, 10H, tert-butyl group protons), 1.32 - 1.25 (m, 28H, tert-butyl group protons), 1.21 (d, 1H, tert-butyl group proton).

IR data cm^-1: 3037.0 (w, sp₂C-H), 2961.1-2869.1 (3s, sp³C-H stretch), 1602.61463.5 (v, aromatic C=C), 1396.1 (m, aromatic-CH₃stretch), 1362.3, 1269.7 (m-s,-C(CH₃)₃bend), 1209.6 (s, P-O-aromatic), 1198.7 (s, C-O), 1159.4 & 1118.9 (m, meta disubst. benzene), 1084.1 (s, C-O), 966.1, 924.8 (w, m, meta & tri subst. benzene), 855.5 (s, P-O-aromatic), 771.8 (m, meta disubst. benzene).

Example 2: Preparation of2,4-di-tert-butyl-6-methylphenyl 2,4-di-tert-butylphenyl phenyl phosphite represented by the following Chemical Formula 1c

[Chemical Formula 1c]

396.63g (1.8mol) of 2,4-di-tert-butyl-6-methyl phenol was put in a four-necked round flask.

Next, 2.37g (0.24 parts by weight based on 100 parts by weight of the entire reactant) of a tributylamine catalyst was added to the four-necked round flask under a nitrogen atmosphere.

The mixture was heated to 60℃, and 164.79g (1.2mol) of phosphorus trichloride was slowly added thereto using a funnel. The resulting mixture was matured for 5 hours.

Next, 309.48g (1.5mol) of 2,4-di-tert-butylphenol was added to the mixture. The resulting mixture was matured for 5 hours again.

Then, 112.92g (1.2mol) of phenol was added to the matured mixture. The resulting mixture was matured for 5 hours. The solution was heated to 200℃ and matured for 20 hours.

The reactant was cooled to 100℃, and 600g of toluene was added thereto. The resulting mixture was cooled to room temperature and washed with water at room temperature for neutralization. The neutralized product was concentrated under reduced pressure and cooled, acquiring a yellow liquid product (1140.42g, yield: 86.59%).

The prepared product was evaluated regarding physical properties according to the same method as Example 1. The results are as follows.

¹H-NMR (CDCl₃,δ ppm): 7.35-7.00 (m, 8H, aromatic protons), 6.84 (d, 1H, aromatic proton), 6.41 (d, 1H, aromatic proton), 2.41 (s, 3H, methyl group of 2,4-di-tert-buthyl-6-methyl phenol), 1.44-1.22 (m, 36H, tert-butyl protons).

IR data cm^-1: 3061.1 (w, sp₂C-H), 2960.1-2869.1 (3s, sp³C-H stretch), 1593.5, 1490.0 (s, aromatic C=C), 1396.9 (m, aromatic-CH₃stretch), 1362.0, 1245.4 (m, s, -C(CH₃) bend), 1209.4 (s, P-O-aromatic), 1159.4, 1119.5 (m, meta disubst. benzene), 1193.3, 1084.0 (s, C-O), 959.8, 926.5 (w, m, meta & tri subst. benzene), 853.6 (s,P-O aromatic), 770.7 (s, meta disubst. benzene).

Example 3: Preparation of 2,4-di-tert-butyl-6-methylphenyl 2,4-di-tert-butylphenyl octadecyl phosphite represented by the following Chemical Formula 1d

[Chemical Formula 1d]

121.19g (0.55mol) of 2,4-di-tert-butyl-6-methylphenol, 3g (0.68 parts by weight based on 100 parts by weight of a reactant) of a TBA catalyst, and 264.24g of an Isopar G (SK Chemicals) solvent under a nitrogen atmosphere were simultaneously put in a four-necked round flask.

The prepared mixture was heated to 50℃, and 68.67g (0.5mol) of phosphorus trichloride was added thereto at 50℃ by using a funnel. The resulting mixture was matured for five hours.

Next, 113.48g (0.55mol) of 2,4-di-tert-butylphenol was added to the matured product and then matured for 5 hours again.

Then, the resulting mixture was heated to the reflux temperature of an Isopar G solvent and matured for 20 hours.

The reactant was cooled to room temperature. Next, 50.6g (0.5mol) of a triethylamine catalyst and 300g of an Isopar G solvent were additionally added to the cooled product, and 135.25g (0.5mol) of stearyl alcohol was added thereto. The resulting mixture was heated to 60℃, matured for one hour, and cooled to room temperature.

The cooled solution was filtrated and washed with water. The washed product was concentrated under reduced pressure, acquiring a yellow liquid product (1337.08g, yield: 92.2%).

The product was evaluated regarding physical properties according to the same method as Example 1. The results are as follows.

¹H-NMR (CDCl₃,δ ppm): 7.37-7.25 (m, 2H, aromatic protons), 7.14-7.02 (m, 3H, aromatic protons), 4.07-4.05 (m, 1H, hexadecyl group proton), 3.78 (m, 1H, heyadecyl group proton), 2.47-2.41 (m, 3H, methyl group of 2,4-di-tert-buthyl-6-methyl phenol), 1.53-1.12 (m, 69H, protons of tert-butyl and hexadecyl group), 0.92-0.85 (m, 2H, protons of tert-butyl and hexadecyl group).

IR data cm^-1: 3032.2 (w, sp₂C-H), 2957.6-2854.8 (s, sp³C-H stretch), 1491.6, 1470.0 (br, s, aromatic C=C & sp³aliphatic-CH₂-aliphatic bend), 1394.5 (m, aromatic-CH₃stretch), 1361.7 (m, -C(CH₃) bend), 1211.8 (s, P-O-aromatic), 1159.1, 1118.5 (m, meta disubst. benzene), 1195.9, 1084.8 (s, C-O), 1006.7 (br, m, P-O-aliphatic), 845.3 (s, P-O-aromatic), 770.0 (s, meta disubst. benzene),≒ 720 (w, long-chain band).

Example 4: Preparation of 2,4-di-tert-butyl-6-methylphenyl 2,4-di-tert-butylphenyl octyl phosphite represented by the following Chemical Formula 1e

[Chemical Formula 1e]

290.86g (1.32mol) of 2,4-di-tert-butyl-6-methylphenol, 7.20g (0.68 parts) of a TBA catalyst, and 634.18g of an Isopar G solvent were put in a 4-necked round flask at a time under a nitrogen atmosphere.

The mixture was heated to 50℃, and 68.67g (0.5mol) of phosphorus trichloride was added thereto by using a funnel. The mixture was matured for 5 hours.

Then, 272.34g (1.32mol) of 2,4-di-tert-butylphenol was added to the matured mixture. The resulting mixture was matured for 5 hours.

The matured mixture was heated to the reflux temperature of an Isopar G solvent and matured.

The matured reactant was cooled to room temperature. Then, 121.43g (1.2mol) of a triethylamine catalyst and 100g of an Isopar G solvent were added to the cooled product in a flask, and 156.28g (1.2mol) of n-octanol was added to the product. The resulting mixture was agitated for one hour. The agitated product was put in water and washed therewith.

The reactant was concentrated by removing an organic solvent remaining therein under reduced pressure, acquiring a yellow liquid product (1195.85g, the yield: 96.89%).

The prepared product was evaluated regarding the physical properties according to the same method as Example 1.

¹H-NMR (CDCl₃,δ ppm): 7.37-6.95 (m, 5H, aromatic protons), 4.09-4.01 (m, 1H, hexadecyl group proton), 3.79-3.72 (m, 1H, heyadecyl group proton), 2.44-2.41 (m, 3H, methyl group of 2,4-di-tert-buthyl-6-methyl phenol), 1.56-1.37 (m, 17H, protons of tert-butyl and hexadecyl group), 1.30-1.07 (m, 33H, protons of tert-butyl and hexadecyl group), 0.89-0.84 (m, 2H, protons of tert-butyl and hexadecyl group).

IR data cm^-1: 3032.9 (w, sp² C-H), 2958.4-2868.7 (s, sp³C-H stretch), 1491.4-1480.0 (br, s, aromatic C=C & sp³aliphatic-CH₂-aliphatic bend), 1395.2 (m, aromatic-CH₃stretch), 1361.7 (m, -C(CH₃)₃bend), 1211.7 (s, P-O-aromatic), 1159.0, 1118.6 (m, meta disubst. benzene), 1198.5, 1084.5 (m, C-O), 1015.9 (br, m, P-O-aliphatic), 845.5 (s, P-O-aromatic), 770.2 (m,metadisubst.benzene),≒ 720 (w, long-chain band).

Comparative Example 1

Trisnonylphenyl phosphite represented by the following Chemical Formula 2 was used.

[Chemical Formula 2]

Comparative Example 2

Trisphenyl phosphite (TPP) represented by the following Chemical Formula 3 was used.

[Chemical Formula 3]

[Rectified under Rule 91 01.08.2011]

Comparative Example 3

Trisisodecyl phosphite (TDP) represented by the following Chemical Formula 4 was used.

[Chemical Formula 4]

[Rectified under Rule 91 01.08.2011]

Comparative Example 4

Diphenyldisodecyl phosphite (DPDP) represented by the following Chemical Formula 5 was used.

[Chemical Formula 5]

[Rectified under Rule 91 01.08.2011]

Comparative Example 5

2-ethylhexyldiphenyl phosphite (EHDPP) represented by the following Chemical Formula 6 was used.

[Chemical Formula 6]

[Rectified under Rule 91 01.08.2011]

Comparative Example 6

Poly(dipropylene glycol)phenyl phosphite (DHOP) represented by the following Chemical Formula 7 was used.

[Chemical Formula 7]

[Rectified under Rule 91 01.08.2011]

Analysis result

Thermo-gravimetric Analysis (TGA) Experiment

The compounds according to Examples 1 to 4 and Comparative Examples 1 to 8 were measured regarding TGA to evaluate thermal stability. The results are provided in the following Tables 1 and 2. The results in Tables 1 and 2 were acquired by heating the compounds at a rate of 20℃/min under a N₂atmosphere up a weight loss ratio of 5 wt% and 10 wt% and recording the temperatures. This experiment was performed by using TA INSTRUMENTS TGA (TA 2100: TA Instruments).

Table 1

Weight loss (wt%)	Example1(℃)	Example2(℃)	Example3(℃)	Example4(℃)
5	275.02	265.93	302.52	287.37
10	293.74	285.34	319.77	302.92

Table 2

Weight loss(wt%)	Comparative Example1(℃)	Comparative Example 2(℃)	Comparative Example 3(℃)	Comparative Example 4(℃)	Comparative Example 5(℃)	Comparative Example 6(℃)
5	265.81	211.70	206.70	227.61	208.26	219.11
10	302.88	222.47	238.69	241.14	218.87	241.54

As shown in Tables 1 and 2, the phosphite-based compounds according to Examples 1 to 4 in general had good high temperature stability and low volatility compared with the compounds according to Comparative Examples 1 to 6.

Hydrolysis Safety

The phosphite-based compounds according to Examples 1 to 4 and Comparative Examples 1 to 6 were evaluated regarding hydrolysis safety.

The hydrolysis safety was evaluated by exposing the phosphite-based compounds to atmosphere at 60℃ under relative humidity (RH) of 85% for 48 hours in total, and then measuring acid value every 8 hours. The acid value was measured by titrating the exposed specimens with KOH and measuring the amount of the KOH used up to the neutralizing point based on 1g of the specimens (mg KOH/g specimen). The acid value results are provided in the following Table 3.

Table 3

	0hr	8hr	16hr	24hr	32hr	40hr	48hr
Example1	0.1	4.45	22.13	50.36	76.15	99.61	108.88
Example 2	0.68	8.57	28.94	51.21	73.73	86.98	104.85
Example 3	0.09	0.25	0.28	0.29	0.36	0.35	0.41
Example 4	0.09	0.25	0.34	0.34	0.35	0.35	0.39
Comparative Example 1	0.41	16.36	74.2	110.83	115.95	115.19	115.15
Comparative Example 2	0.07	360.32	361.14	360.89	362.03	371.74	384.89
Comparative Example 3	0.01	4.57	73.66	126.77	163.32	211.28	214.44
Comparative Example 4	0.01	174.74	195.29	219.85	234.12	242.69	248.4
Comparative Example 5	0.01	191.87	230.7	229.55	232.41	251.25	257.54
Comparative Example 6	0.01	194.15	324.92	373.45	395.72	428.84	437.15

In general, better hydrolysis stability may bring about a lower acid value.

As shown in Table 3, the compound according to Comparative Examples 1 to 6 had a higher acid value (i.e., increases in the amount of base used), as the exposure time was increased. On the other hand, the compounds according to Examples 1 to 4 initially had similar or a somewhat higher acid value but a lower acid value than the compounds according to Comparative Examples 1 to 6, as exposure time was increased. In particular, the compounds of Examples 3 and 4 had almost no increased acid value.

As a result, the compounds according to Examples 1 to 4 had excellent hydrolysis stability.

Preparation of a resin composition

Example 5

0.15 parts by weight of the product according to Example 1 and 0.05 parts by weight of Songstab SC-100 (heat stabilizer) were mixed with 1 part by weight of a polypropylene homopolymer, and 99 parts by weight of a polypropylene homopolymer were added thereto. The final mixture was mixed for 30 minutes with a tubular blender, preparing a resin composition.

Example 6

A resin composition was prepared according to the same method as Example 5, except for using the product of Example 2 instead of the product of Example 1.

Example 7

A resin composition was prepared according to the same method as Example 5, except for using the product of Example 3 instead of the product of Example 1.

Example 8

A resin composition was prepared according to the same method as Example 5, except for using the product of Example 4 instead of the product of Example 1.

Comparative Example 7

A resin composition was prepared according to the same method as Example 5, except for using the product of Comparative Example 1 instead of the product of Example 1.

Comparative Example 8

A resin composition was prepared according to the same method as Example 5, except for using tris(2,4-di-tert-butylphenyl)phosphite represented by the following Chemical Formula 8 instead of the product of Example 1.

[Chemical Formula 8]

Melt Flow Index (MFI, no unit) Measurement

The resin compositions according to Examples 5 to 8 and Comparative Examples 7 to 8 were respectively put in a twin-screw extruder with a die diameter of 37mm and L/D 40 at a rate of 10kg per hour.

The extrusion was performed at a top-to-bottom extruder temperature of 190℃/195℃/200℃/205℃/210℃/215℃ under 10,000ccm of nitrogen at an axis rotation speed of 150rpm, preparing a compounding pellet.

The compounding pellet was extruded one to five times by using a single-screw extruder with L/D 25 in the twin-screw extruder. The single-screw extrusion was performed at a top-to-bottom extruder temperature of 230℃/250℃/255℃ at an axis rotation speed of 25rpm in air.

The once-extruded pellet, the three-time-extruded pellet, and the compounding pellet were evaluated regarding melt index at 230℃ under a load of 2.16kg with melt index measuring equipment. The results are provided in the following Table 4. In the following Table 4, pass 1 indicates a once-extruded pellet, and pass 3 indicates a three-time-extruded pellet.

Table 4

(unit: g/10 minute)

	Example 5	Example 6	Example 7	Example 8	Comparative Example 7	Comparative Example 8
Compounding pellet	3.38	3.29	1.92	3.45	3.61	3.94
Pass 1	5.60	4.68	7.60	6.65	6.80	8.13
Pass 3	23.00	17.26	50.45	57.00	59.89	X

As shown in Table 4, the compounding pellets according to Examples 5, 6, and 8 and Comparative Examples 7 and 8 excluding Example 7 all had a similar MFI. However, as for a once-extruded pellet, the one of Comparative Example 7 had a similar MFI to the ones of Examples 5 to 8, while the one of Comparative Example 8 had a somewhat higher MFI than the ones of Example 5 to 8. In addition, as for a three-time-extruded pellet, the one of Comparative Example 8 had a very high MFI, which shows that three-time extrusion was not performed at all. The one of Comparative Example 7 had a very much higher MFI than the ones of Examples 5 to 8. Herein, when an antioxidant works appropriately in a resin composition, more than one extrusion does not increase the MFI much. Accordingly, the compounds according to Examples 5 to 8 had an MFI that was not increased much, which shows that the products of Examples 1 to 4 worked appropriately as an antioxidant in a resin composition. Resultantly, the compounds of Examples 5 to 8 had better anti-oxidation effects than the compound according to Comparative Examples 7 and 8.

Example 9

0.10 parts by weight of the product according to Example 1, 0.05 parts by weight of Songstab SC-100 (heat stabilizer), and 0.05 parts by weight of Songnox 1010 (an antioxidant) were mixed with one part by weight of a polypropylene homopolymer. The mixture was mixed with 99 parts by weight of a polypropylene homopolymer. The final mixture was mixed for 30 minutes with a tubular blender, preparing a resin composition.

Example 10

A resin composition was prepared according to the same method as Example 9, except for using the product of Example 2 instead of the product of Example 1.

Example 11

A resin composition was prepared according to the same method as Example 9, except for using the product of Example 3 instead of the product of Example 1.

Example 12

A resin composition was prepared according to the same method as Example 9, except for using the product of Example 4 instead of the product of Example 1.

Comparative Example 9

A resin composition was prepared according to the same method as Example 9, except for using the product of Comparative Example 1 instead of the product of Example 1.

Comparative Example 10

A resin composition was prepared according to the same method as Example 9, except for using the product of Comparative Example 8 instead of the product of Example 1.

Melt Flow Index (MFI) Measurement

The resin compositions according to Examples 9 to 12 and Comparative Examples 9 to 10 were respectively put in a twin-screw extruder with a die diameter of 37mm and L/D 40 at a rate of 10kg per hour.

The extrusion was performed at a top-to-bottom extruder temperature of 195℃/200℃/205℃/210℃/215℃ under 10,000ccm of nitrogen at an axis rotation speed of 150rpm, preparing a compounding pellet.

The compounding pellet was extruded one to five times by using a single-screw extruder with L/D 25. The extrusion was performed at a top-to-bottom extruder temperature of 230℃/250℃/255℃ in the air at an axis rotation speed of 25rpm.

In addition, a polypropylene homopolymer resin was prepared into a polypropylene homopolymer compounding pellet according to the above compounding pellet process.

Then, the once-extruded pellet, the three-time-extruded pellet, the five-time-extruded pellet, and the polypropylene homopolymer compounding pellet were measured regarding melt index at 230℃ under a load of 2.16kg by using melt index measuring equipment. The results are provided in the following Table 5. In the following Table 5, pass 1 indicates a once-extruded pellet, pass 3 indicates a three-time-extruded pellet, and pass 5 indicates a five-time-extruded pellet.

Table 5

(unit: g/10minute)

	Example 9	Example 10	Example 11	Example 12	Comparative Example 9	Comparative Example 10
Pass 1	5.530	4.990	5.380	4.670	5.540	5.120
Pass 3	8.440	8.460	9.220	7.370	9.560	9.370
Pass 5	12.270	12.780	14.190	11.060	15.660	15.030

As shown in Table 5, as for the once-extruded pellet, the pellets according to Examples 9 to 12 and Comparative Examples 9 and 10 had similar MFI. Comparing MFI of the once-extruded pellet with MFI of the three-time-extruded pellet, the pellets according to Comparative Examples 7 and 8 had much higher MFI than Examples 9 to 12, which is a larger difference than a difference from the five-time-extruded pellet.

Based on the results, the pellets according to Examples 9 to 12 had not much increased MFI despite multiple extrusions, which shows that the products of Examples 1 to 4 appropriately worked as an antioxidant in a resin composition. Resultantly, the pellets according to Examples 9 to 12 had better anti-oxidation effects than the compound used in Comparative Examples 9 and 10

Yellow Index Measurement

When the resin compositions according to Examples 5 to 8 and Comparative Examples 7 to 8 were measured regarding MFI, the once-extruded pellet, the three-time-extruded pellet, and the compounding pellet were measured regarding yellow index by using a spectrophotometer (Hunterlab Ultrascan PRO). The results are provided in the following Table 6. In the following Table 6, pass 1 indicates a once-extruded pellet and pass 3 indicates a three-time-extruded pellet. In addition, a yellow index difference (△YI) between the three-time-extruded pellet and the compounding pellet was calculated and is provided in the following Table 6.

Table 6

(unit: none)

	Example 5	Example 6	Comparative Example 7	Comparative Example 8
Compounding pellet	-1.900	-1.840	-2.430	-2.260
Pass 1	-0.32	-0.32	-0.43	0.04
Pass 3	0.05	0.43	X	0.64
△YI	1.95	2.27	X	2.9

As shown in Table 6, the pellets according to Examples 5 and 6 had a smaller yellow index (△YI) than the ones according to Comparative Examples 7 and 8 and excellent antioxidant effects. Furthermore, the pellet of Comparative Example 7 could not be extruded three times and thus may not be practically applied.

LTTS (Long Term Thermal Stability) Measurement

1) 135℃ Measurement

The compounding pellet was put in an extruder with a top-to-bottom temperature of 220℃/230℃/240℃/245℃, preparing a specimen with length X width X thickness size of 127 X 12.7 X 1.6mm. The specimen was thermally degraded in a 135°C-heated gear type oven and a point where it started to show embrittlement was recorded. The results are provided in the following Table 7.

Table 7

	Comparative Example 7	Comparative Example 8	Example 5	Example 6	Example 7	Example 8
Hour (h)	16.5	16.5	21.5	19	16.5	16.5

As shown in Table 7, the compounding pellets including the resin compositions of Examples 5 to 8 showed embrittlement starting points that were later than the ones of Comparative Examples 7 and 8, and thus had excellent heat resistance.

2) 150℃ Measurement

The compounding pellets prepared according to the above process were put in an extruder with a top-to-bottom temperature of 220℃/230℃/240℃/245℃, preparing a specimen with a length X width X thickness size of 127 X 12.7 X 1.6mm. The specimen was degraded in a 150℃-heated gear type oven and a point where the specimen started to show embrittlement was recorded. The results are provided in the following Table 8.

Table 8

	Comparative Example 7	Comparative Example 8	Example 5	Example 6	Example 7	Example 8
Hour	2.5	1.5	4.5	4.5	2.5	4.5

As shown in Table 8, the compounding pellets including the resin composition according to Examples 5 to 8 started to show embrittlement later than the ones according to Comparative Examples 7 and 8, and thus had excellent heat resistance.

3) 150℃ Measurement

The compounding pellet was put in an extruder with a top-to-bottom temperature of 220℃/230℃/240℃/245℃, preparing a specimen with a length X width X thickness size of 127 X 12.7 X 1.6mm. The specimen was degraded in a 150℃-heated gear type oven and a point where the specimen started to show embrittlement was recorded. The results are provided in the following Table 9.

Table 9

	Comparative Example 9	Comparative Example 10	Example 9	Example 10	Example 11	Example 12
Day	17	16	17	18	23	24

As shown in Table 9, the compounding pellets including the resin composition according to Examples 9 to 12 showed an embrittlement point later than the ones according to Comparative Examples 9 and 10, and thus had excellent heat resistance.

While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Therefore, the aforementioned embodiments are exemplary in every way but are not to be understood to limit the present invention.

Claims

A phosphite-based antioxidant represented by the following Chemical Formula 1:

[Chemical Formula 1]

wherein,

R¹is a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted arylalkyl group.
The phosphite-based antioxidant of claim 1, wherein R¹is a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C7-C20 arylalkyl group.
The phosphite-based antioxidant of claim 1, wherein the substituted alkyl group, substituted cycloalkyl group, substituted aryl group, or substituted arylalkyl group is a functional group in which at least hydrgron is substituted with an alkyl group, an aryl group, an alkylaryl group, or an arylalkyl group.
The phosphite-based antioxidant of claim 1, wherein R²is a substituted or unsubstituted alkylgroup.
A polymer resin composition comprising:

a phosphite represented by the following Chemical Formula 1; and

a polymer resin:

[Chemical Formula 1]

wherein,

R¹is a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted arylalkyl group.
The polymer resin composition of claim 5, wherein the polymer resin is selected from the group consisting of polyolefin, polyethylene, polypropylene, polyester, polycarbonate, polyamide, polyurethane, polysulfone, polyimide, polyphenylene ether, polystyrene, an acrylic polymer, polyacetal, a halogenated polymer, and a combination thereof.
The polymer resin composition of claim 5, wherein the phosphite is included in an amount of 0.01 parts by weight to 0.5 parts by weight based on 100 parts by weight of the polymer resin.
A product molded by using the polymer resin composition according to claim 5.