JPH04308581A - Novel piperazine derivative - Google Patents

Abstract

PURPOSE:To provide the subject novel compound useful as an oxidizing agent for various organic compounds such as polyolefinic resins. CONSTITUTION:A compound of the formula (R<1> is 1-4C alkyl; R<2> is 1-3C alkylene; R<3> is H, methyl). For example, N,N'-bis{2-[2-t-butyl-4-methyl-6-(2- hydroxy-3-t-butyl-5-methylbenzyl)phenyl]oxycarbonylethyl}piperazine. The compound of the formula is obtained by reacting piperazine or 2,5-dimethylpiperazine (R<3> is CH3) having the N-R<2> bond with the corresponding carboxylate, i.e., an ester having [2-t-butyl-5-R<1>-6-(2-hydroxy-3-t-butyl-5-R<1>-benzyl)phenol as the alcohol portion.

Description

Description: BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to piperazine derivatives with a novel structure. The compound of the present invention is useful as an antioxidant for various organic compounds including polyolefin resins. [0002] Organic substances such as natural polymers, synthetic polymers, oils and fats, lubricating oils, and hydraulic oils are subject to oxidation and their usefulness is reduced, so various antioxidants have been devised and added to a substance. For example, it is known that hindered phenols, organic sulfur compounds, organic phosphorus compounds, aromatic amines, and the like are effective when used alone or in combination. A number of compounds have been proposed and put into practical use as phenolic resin additives (Evaluation and Market of Polymer Additives and Modifiers (CMC Publishing, 1984), 1
Table 14 on page 4). Further, Japanese Patent Publication No. 39-21140 discloses a polypropylene composition containing a novolac type dimer of alkyl-substituted phenol as a stabilizer, while Japanese Patent Publication No. 62-30134 discloses a synthetic resin Piperazine derivatives having a hydroxyphenylalkyl group as an N substituent have been disclosed as stabilizers for use in the present invention. [0005] However, to the best of the present inventors' knowledge, conventional antioxidants are not always fully effective under very harsh oxidizing conditions. The present invention aims to provide piperazine derivatives that have a large antioxidant effect under severe oxidation conditions. [Summary of the Invention] [Means for Solving the Problems] <Summary> The present invention has the following features:
We seek to achieve this objective by providing specific piperazine derivatives, and this new piperazine derivative is represented by the general formula (I) below. [0007] [In the formula, R1 is an alkyl group having 1 to 4 carbon atoms, R2 is an alkylene group having 1 to 3 carbon atoms, and R3 is an alkylene group having 1 to 3 carbon atoms.
represents a hydrogen atom or a methyl group. [Effects] The new piperazine derivative according to the present invention exhibits excellent antioxidant ability against various organic substances, and in particular, unlike conventional piperazine derivatives, it has an antioxidant effect under severe oxidation conditions. big. [Specific Description of the Invention] <Compound> The novel piperazine derivative according to the present invention has the general formula (
This is a compound represented by I). In the general formula (I) of the compound of the present invention,
R1 is an alkyl group having 1 to 4 carbon atoms, and specific examples include a methyl group, an ethyl group, a butyl group, and a propyl group. R2 is an alkylene group having 1 to 3 carbon atoms, specifically a methylene group, an ethylene group, and a butylene group. R3 is a hydrogen atom or a methyl group. A plurality of each of R1 to R3 exists, and they may be the same or different. Specific examples of the novel piperazine derivative represented by the general formula (I) of the present invention include the following compounds. Compound 1: N,N'-bis{2-[2-t-butyl-4
-Methyl-6-(2-hydroxy-3-t-butyl-5
-methylbenzyl)phenyl]oxycarbonylethyl}piperazine [Chemical 3] Compound 2: N,N'-bis{2-[2-t
-butyl-4-ethyl-6-(2-hydroxy-3-t
-butyl-5-ethylbenzyl)phenyl]oxycarbonylethyl}piperazine Compound 3: N,N'-bis{2-[2-t
-butyl-4-methyl-6-(2-hydroxy-3-t
-butyl-5-methylbenzyl)phenyl]oxycarbonylethyl}-2,5-dimethylpiperazine 001
7 Compound 4: N,N'-bis{[2-t-butyl-4-methyl-6-(2-hydroxy-3-t-butyl-5-methylbenzyl)phenyl] oxycarbonylmethyl}piperazine [0020] Compound 5: N,N'-bis{1-methyl-
2-[2-t-butyl-4-methyl-6-(2-hydroxy-3-t-butyl-5-methylbenzyl)phenyl]oxycarbonylethyl}piperazine [Chemical formula 7] [0022] The present invention Since the novel piperazine derivatives of Piperazine have basicity as piperazine, their acid addition salts exist. [0023] Therefore, in the present invention, the term "new piperazine derivative" (including when interpreting the scope of the claims) includes those in the form of acid addition salts thereof. Examples of acids in this case include inorganic acids such as hydrohalic acid, such as hydrochloric acid, sulfuric acid, phosphoric acid, and others.
and organic acids such as lower alkane mono- to diacids such as formic acid, acetic acid, oxalic acid, sulfonic acids such as toluenesulfonic acid, and the like. <Production of Compound> The piperazine derivative of the present invention can be produced by any method suitable for forming a bond and introducing or forming a substituent. One suitable method of preparation is to replace the N-R2 bond of general formula (I) with piperazine or 2,5-dimethylpiperazine (R3 = CH3) and the corresponding carboxylate, ie the alcohol moiety is [2-t -Butyl-4-
R1 -6-(2-hydroxy-3-t-butyl-5-
R1 -benzyl) phenol. One of the reactions in that case uses a carboxylate having an ethylenically unsaturated bond,
This is due to an addition reaction with NH in the piperazine ring. Another reaction with carboxylates to form N-R2 bonds is by dehydrohalogenation reaction with NH in the piperazine ring, using esters of halocarboxylic acids as carboxylates. In that case, it is desirable that a base be present as a by-product hydrogen halide scavenger, but the raw material piperazine compound acts as a hydrogen halide scavenger even without using a special base. Therefore, specifically, for example, a carboxylic acid ester such as various acrylates, various crotonates or haloacetates, and piperazine or 2,5-dimethylpiperazine, respectively, in a molar ratio of about 2:1, The reaction may be carried out at room temperature to 100° C. using methylene chloride, ethanol, toluene, or the like as a solvent, and optionally with a base such as pyridine or trimethylamine. [0028] As the raw material carboxylic ester, the following can be exemplified. (1) Acrylates, such as (a) [2-t-butyl-4-methyl-6-(2-
Hydroxy-3-t-butyl-5-methylbenzyl) phenyl]=acrylate, (b) [2-t-butyl-4-ethyl-6-(2-hydroxy-3-t-butyl-5-ethylbenzyl) phenyl] = acrylate, (
c) [2-t-butyl-4-isopropyl-6-(
2-Hydroxy-3-t-butyl-5-isopropylbenzyl)phenyl]=acrylate, (d) [2,
4-di-t-butyl-6-(2-hydroxy-3,5-
(2) Crotonate, such as (a) [2-t-butyl-4-methyl-6-(2-hydroxy-3-t-butyl-5 -methylbenzyl)phenyl]=crotonate, (b) [2-t-butyl-4
-ethyl-6-(2-hydroxy-3-t-butyl-5
-ethylbenzyl)phenyl]=crotonate, (c)
[2-t-butyl-4-isopropyl-6-(2-
Hydroxy-3-t-butyl-5-isopropylbenzyl)phenyl]=crotonate, (d) [2,4-
di-t-butyl-6-(2-hydroxy-3,5-di-
t-Butylbenzyl)phenyl]=crotonate, etc., [
(3) Methacrylate, for example (a)
[2-t-butyl-4-methyl-6-(2-hydroxy-3-t-butyl-5-methylbenzyl)phenyl]=methacrylate, (b) [2-t-butyl-4
-ethyl-6-(2-hydroxy-3-t-butyl-5
-ethylbenzyl)phenyl]=methacrylate, (c) [2-t-butyl-4-isopropyl-6-(2
-Hydroxy-3-t-butyl-5-isopropylbenzyl)phenyl]=methacrylate, (d) [2,
4-di-t-butyl-6-(2-hydroxy-3,5-
(4) Haloacetates, such as (a) [2-t-butyl-4-methyl-6-(2-hydroxy-3-t-butyl- 5-methylbenzyl)phenyl]-2-bromoacetate, (b) [2-t-butyl-4-ethyl-6-(2-hydroxy-3-t-butyl-5-ethylbenzyl)phenyl]-2- Bromoacetate, (c) [2-t-butyl-4-isopropyl-6-(2-hydroxy-3-t-butyl-5-isopropylbenzyl)phenyl]-2-bromoacetate, (d) [2,4 -di-t-butyl-6-(2-
Hydroxy-3,5-di-t-butylbenzyl)phenyl]-2-bromoacetate, etc. <Use of Compound> The compound according to the present invention represented by the general formula (I) is effective in preventing the oxidation of various organic substances, but especially when exposed to harsh oxidizing conditions during molding and product use. It is useful for synthetic polymers that are often used. For example, polyalpha-olefins such as low-density polyethylene, medium-density polyethylene, linear-low-density polyethylene, polypropylene, polybutene-1, ethylene-propylene random or block copolymers, ethylene-butene-1 random copolymers, etc. This piperazine derivative is effective in preventing the oxidation of α-olefin copolymers, copolymers of polyα-olefins and vinyl monomers such as maleic anhydride-modified polypropylene, and mixtures thereof. It is valid. The novel piperazine derivative according to the present invention can also be used for synthetic polymers other than those mentioned above, and examples of these synthetic polymers include polyvinyl chloride, methacrylic resin, polystyrene, high-impact polystyrene, ABS resin, and AE.
Styrene resins such as S resin, polyesters such as polyethylene terephthalate and polybutylene terephthalate,
Examples include polyamide, polycarbonate, polyacetal, polyethylene oxide, polyphenylene ether, polysulfone, polyurethane, and unsaturated polyester resin. Natural organic compounds are also targets to be stabilized by the compounds of the present invention, and specifically, natural polymers such as cellulose, rubber, proteins, or their derivatives such as cellulose acetate, mineral oils, animal and vegetable oils, You can give wax etc. The compound of the present invention is effective even when used alone, but when used in combination with a sulfur-based antioxidant,
Significant synergistic effects can be obtained. These sulfur-based antioxidants include dialkylthiodipropionates such as dilaurylthiodipropionate, dimeristylthiodipropionate, distearylthiodipropionate, and tetrakis{
Methylene (lauryl thiodipropionate)}methane,
Examples include esters of alkylthiodipropionic acids such as tetrakis {methylene (stearyl thiodipropionate)}methane and polyhydric alcohols. When stabilizing the organic compound, other additives such as ultraviolet absorbers, light stabilizers, phosphorus stabilizers,
Phenolic antioxidants, metal deactivators, metal soaps,
Nucleating agents, lubricants, antistatic agents, flame retardants, pigments, pigment dispersants, fillers, and the like may be used in combination. In particular, UV absorbers and hindered amine light stabilizers, such as 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2(2'-hydroxy-5'-
methylphenyl)benzotriazole, 2(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-
5-chloro-benzotriazole, 2(2-hydroxy-3',5'-di-t-butylphenyl)-5-chloro-benzotriazole, 2(2'-hydroxy-3',
5'-di-amylphenyl)benzotriazole, [2
, 2'-thiobis(4-t-octylphenolate)]
Butylamine Ni salt, 2,2,6,6-tetramethyl-
4-piperidinylbenzoate, bis(2,2,6,6
-tetramethyl-4-piperidinyl) sebacate, 2-
(3,5-di-t-butyl-4-hydroxybenzyl)
-2-n-butyl-malonate bis(1,2,2,6,6
-pentamethyl-4-piperidyl), 1-[2-{3-
(3,5-di-t-butyl-4-hydroxyphenyl)
propionyloxy}ethyl]-4-[3-(3,5-
di-t-butyl-4-hydroxyphenyl)propionyloxy]-2,2,6,6-tetramethylpiperidine, tris(1,2,2,6,6-pentamethyl-4-piperidyl)phosphite, poly[ {6-(1,1,3,
3,-tetramethylbutylimino)-1,3,5-triazine-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene{(
2,2,6,6-tetramethyl-4-piperidyl)imino}], poly[{6-monopholino-2,4-diyl}{
The combined use of (2,2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl)imino}) can improve the light resistance of the target organic compound. Useful for improving sexual performance. Further, by using a phosphorus antioxidant in combination, the hue, heat aging resistance, and weather resistance of the organic compound can be improved. Examples of these phosphorus antioxidants include distearylpentaerythritol diphosphite, tris(2,4-di-t-butylphenyl)
Phosphite, tris(2-t-butyl-4-methylphenyl) phosphite, bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite, tetrakis(2,4-di-t-butylphenyl) )-4,4-
Examples include biphenylene diphosphite. Phenolic antioxidants, which are other specific examples of stabilizers that can be used in combination, are generally monovalent or polyvalent antioxidants in which at least one of the ortho positions of the hydroxyl group is substituted with an alkyl group, an aralkyl group, or a cycloalkyl group. Examples include phenolic compounds. In this case, the substituent is
Those having about 3 to 10 carbon atoms are preferred. Note that the "alkyl group" (including those in aralkyl and cycloalkyl groups) may be unsaturated. This phenol compound may have a substituent other than the above-mentioned substituents, or may have a structure such as bisphenol in which a phenol nucleus is connected with a linking group such as an alkylene group. Specific examples of such phenolic antioxidants include 2,6-di-t-butyl-p-cresol and 2,6-di-t-butyl-p-cresol.
-diisonorbonyl-p-cresol, 2,6-bis(
2-phenylisopropyl)-p-cresol, n-octadecyl-β-(3,5-di-t-butyl-4-hydroxy-phenyl)propionate, 2,2'-methylenebis(4-ethyl-6-t- butylphenol), 2
, 2'-methylenebis(4-methyl-6-α-methylcyclohexylphenol), 4,4'-methylenebis(
2,6-di-t-butylphenol), 4,4'-butylidenebis(2-t-butyl-5-methylphenol)
, 4,4'-butylidenebis(2-t-butyl-5-methylphenol), 4,4'-butylidenebis(2-isopropyl-5-methylphenol), tris(4-t
-butyl-2,6-di-methyl-3-hydroxybenzyl) isocyanurate, 1,3,5-tris(3,5
-di-t-butyl-4-hydroxybenzyl)-2,4
, 6-trimethylbenzene, 3,9-[bis-1,1-
Di-methyl-2-{β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]-2,4,8,10-tetraoxaspiro[5,5
] Undecane, ethylene glycol-bis[3,3-bis(3-t-butyl-4-hydroxyphenyl)butyrate], 1,1,3-tris(5-t-butyl-4-hydroxy-2-methylphenyl) ) Butane, Tetrakis [
3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionyloxymethyl]methane, and the like. [0041] The amount of the piperazine derivative and other additives used in combination as necessary is determined depending on the target organic compound to be stabilized and the purpose of use. Generally, about 0.001% by weight of the target organic compound
Amounts ranging from about 10% by weight are used, although amounts ranging from about 0.01 to about 5% by weight are sufficient for most applications. For example, for polyolefins, 0.0
About 1 to 2.0% by weight is sufficient. <Utility of Compound> It has been mentioned above in the <Effects> section of [Summary of the Invention] that the novel piperazine derivative according to the present invention is useful in preventing the oxidation of various organic compounds. EXAMPLES The following examples and application examples are intended to explain the present invention more specifically. <Example 1>N,N'-bis{2-[2-
t-Butyl-4-methyl-6-(2-hydroxy-3-
Production of t-butyl-5-methylbenzyl)phenyloxycarbonylethyl}piperazine (compound 1) [2-
t-Butyl-4-methyl-6-(2-hydroxy-3-
7.90 g (0.02 mol) of t-butyl-5-methylbenzyl)phenyl]acrylate was added to 40 g of methylene chloride.
ml, piperazine 0.86g (0.01
A solution prepared by dissolving mol) in 20 ml of methylene chloride was slowly added under stirring at room temperature, and the mixture was reacted for 1 hour under stirring. After the reaction was completed, the mixture was washed three times with diluted hydrochloric acid and water, dried, and the solvent was removed under reduced pressure to obtain 8.6 g of a colorless powder of the desired product (compound 1). Crude yield is 98%
Met. The product was purified with acetone. Melting point: 196-197°C Infrared spectroscopy (KBr method) νC=O: 1750c
m-1 NMR (CDCl3, ppm): 1.3-1.4 (m, 36H), 2.1-2.3 (t
, 12H), 2.3 to 2.4 (s, 4H), 2.5 to 2.7 (t, 4
H), 3.5-4.0 (t, 8H), 5.3-5.4 (s, 2
H), 6.6-7.1 (s, 8H) <Example 2>N,N'-bis{2-[2-
t-Butyl-4-ethyl-6-(2-hydroxy-3-
Preparation of t-butyl-5-ethylbenzyl)phenyloxycarbonylethyl}piperazine (Compound 2) In Example 1, [2-t-butyl-4-methyl-6-(2
-Hydroxy-3-t-butyl-5-methylbenzyl)
phenyl]acrylate, [2-t-butyl-4-ethyl-6-(2-hydroxy-3-t-butyl-5-ethylbenzyl)phenyl]acrylate 8.4
Using 6 g (0.02 mol), the reaction and post-treatment were carried out in the same manner as in Example 1, and the target product (compound 2) was obtained in a crude yield of 95.
Obtained in %. <Example 3>N,N'-bis{2-[2-
t-Butyl-4-methyl-6-(2-hydroxy-3-
In Example 1 for the production of t-butyl-5-methylbenzyl)phenyloxycarbonylethyl}-2,5-dimethylpiperazine (compound 3), [2-t-butyl-4-methyl-6
-(2-Hydroxy-3-t-butyl-5-methylbenzyl)phenyl]acrylate was dissolved in 40 ml of toluene, and 1.14 g (0.01 mol) of 2,5-dimethylpiperidine was used instead of piperidine. The reaction and post-treatment were carried out in the same manner as in Example 1, except that the compound was dissolved in 20 ml of ethanol, and the target product (compound 3) was obtained in a crude yield of 97%.
I got it from <Example 4>N,N'-bis{[2-t-
Butyl-4-methyl-6-(2-hydroxy-3-t-
In Production Example 1 of butyl-5-methylbenzyl)phenyloxycarbonylethyl}piperazine (compound 4), [2-t-butyl-4-methyl-6-(2-hydroxy-3-t-butyl-5 -methylbenzyl)phenyl]acrylate, [2-t-butyl-4
-Methyl-6-(2-hydroxy-3-t-butyl-5
-Methylbenzyl)phenyl]-2-bromoacetate 9.22 g (0.02 mol) and toluene instead of methylene chloride, reaction and post-treatment were carried out in the same manner as in Example 1 to obtain the desired product (compound 4) with a crude yield of 85%
I got it from <Example 5>N,N'-bis{1-methyl-2-[2-t-butyl-4-methyl-6-(2-hydroxy-3-t-butyl-5-methylbenzyl) phenyl]oxycarbonylethyl}piperazine (compound 5)
In Production Example 1, [2-t-butyl-4-methyl-6
-(2-hydroxy-3-t-butyl-5-methylbenzyl)phenyl]acrylate instead of [2-t-
Butyl-4-methyl-6-(2-hydroxy-3-t-
Using 8.44 g (0.02 mol) of butyl-5-methylbenzyl)phenyl]crotonate, dissolve it in 40 ml of methanol, and add piperidine to 20 ml of ethanol.
The reaction and post-treatment were carried out in the same manner as in Example 1, except that the target compound (Compound 5) was obtained in a crude yield of 68%. <Application example> Intrinsic viscosity measured in tetralin at 135°C is 1.9 and isotactic is 98%
The additives shown in Table 1 were added to 100 parts by weight of the polypropylene powder and thoroughly mixed with a mixer. And cylinder temperature=260℃, L/D=20, and 20m
The mixture was melt-kneaded and granulated using an m-diameter extruder. The pellets thus obtained were compression molded at 230° C. into a 0.5 mm thick sheet to obtain a test piece. [0050] MFR was measured at 230°C based on JIS K7210. Weather resistance: Atlas 65/X
Using a W-WR type xenon weatherometer, the test piece was irradiated with light at a black panel temperature of 80°C.
When the specimen was bent several times, the time required for the specimen to become brittle and crack was measured. The results were as shown in Table 1. [0051] The abbreviations in the table are as follows. (a) Sulfur-based antioxidant DMTDP Dimeristylthiodipropionate (b) Phenol-based antioxidant F-1 Tetrakis [3-(3,5-di-t)
-butyl-4-hydroxyphenyl)propionyloxymethyl]methane (trade name: Irganox 1010
) F-2 Tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate (trade name: MARK AO-20) F-3 3,9-[bis1,1-di-methyl-2 -{β-(3-t-butyl-4-hydroxy-5-
methylphenyl)propionyloxy}ethyl]-2,
4,8,10-tetraoxaspiro [5,
5] Undecan (Product name: MAR
K AO-80) (c) HALS light stabilizer LS770 bis(2,2,6,6-tetramethyl-
4-Piperidyl) sebacate (Product name: Sanol L)
S770)0052]
Table-1


Phenol-based
Other additives MFR
Weather resistance Comparison Antioxidant Example Example (Additional concentration (Additional concentration weight %)
Weight%) (g/10 minutes)
(time) 1 -
−
9.3 40 2
F-1 (0.1)
-3.2
180 3 F-2 (0.1)
−
4.6 300 4
F-3 (0.1)
-2.5
220 1 Compound 1 (0.1)
-2.
1 320 5 F-1
(0.1) DMTDP (0.2)
3.0 180
6 F-2 (0.1)
DMTDP (0.2) 3
．． 5 280 7 F-3
(0.1) DMTDP (0.2
) 2.3 28
0 2 Compound 1 (0.1) D
MTDP (0.2) 1.8
320 8 F-2 (0
．． 1) LS770 (0.2)
3.6 1200 3
Compound 1 (0.1) LS770
(0.2) 1.7
1600


Effects of the Invention The novel piperazine derivative according to the present invention is
The fact that it shows excellent antioxidant ability against various organic substances, and that it has a large antioxidant effect under harsh oxidation conditions, unlike conventional piperazine derivatives, is a ``means to solve problems.'' This is also mentioned above in the section.

Claims (1)

[Claims] [Claim 1] A novel piperazine derivative represented by the following general formula (I). [Formula, R1 is an alkyl group having 1 to 4 carbon atoms, R2 is
represents an alkylene group having 1 to 3 carbon atoms, and R3 represents a hydrogen atom or a methyl group. ]