JPS58201777A - 2,2,6,6-tetramethylpiperidine derivative, its preparation, and additive for rubber comprising it as active ingredient - Google Patents

Abstract

NEW MATERIAL:A compound shown by the formula I (R1 is H, or lower alkyl; R2 is lower alkyl, lower alkenyl, lower alkynyl, cycloalkyl, aralkyl, or aryl; R3 is H or CH3). EXAMPLE:N-(2,2,6,6-Tetramethyl-4-piperidinyl)benzothiazyl-sulfenamide. USE:An additive for rubber. Having improved vulcanization promoting effect and preventing effect on ozone deterioration, useful as a noncoloring and nonstaining vulcanization promotor. The amount of the additive to rubber is 0.3-7pts.wt. PROCESS:2,2,6,6-Tetramethylpiperidine compound shown by the formula II is converted into an acid addition salt of sulfuric acid, etc. and reacted with an alkali metal salt such as sodium salt, etc. of a 2-mercaptobenzothiazole compound shown by the formula III in an aqueous solution in the presence of an oxidizing agent such as sodium hypochlorite, etc. at 10-20 deg.C, to give a compound shown by the formula I .

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is based on the general formula (II-1 (wherein, R1 is a hydrogen atom or a lower alkyl group, R2
represents a lower alkyl group, a lower, 4-alkenyl group, a lower alkynyl group, a cycloalkyl group, an aralkyl group, or an aryl group, and R8 represents a hydrogen atom or a methyl group. ),)
,.

The present invention relates to a 2,2,6,6-titramethylpiperidine derivative represented by the formula, a method for producing the same, and a rubber additive containing the same as an active ingredient.

Various vulcanization accelerators are used for sulfur vulcanization of natural and synthetic rubbers such as styrene-butadiene rubber, nitrile rubber, butadiene rubber, imprene rubber, etc., but most of them are N-cyclohexylbenzothiazyl-2-sulfur. Sulfenamide derivatives such as phenamide and N-L-butylbenzothiazyl-2-sulfenamide. However, these sulfenamide derivatives have the disadvantage of causing color staining on vulcanized rubber products, making them generally difficult to use for white to brightly colored products.

For these reasons, the present inventors conducted various studies to solve these problems, and found that 2 expressed by the general formula +Il
, 2,6,6-titramethylbiperidine derivatives are useful as non-adherent, non-staining vulcanization accelerators, and the vulcanized rubber products made using them have excellent ozone resistance, making them useful additives for rubber. The present inventors have discovered that it has very excellent performance as an agent, and have completed the present invention.

The 2,2,6,6-titramethylpiperidine derivative represented by the general formula (I) is a novel compound synthesized by the present inventors for the first time and has not been described in any literature. 2 ILl (wherein k and R2 have the same meanings as above) and a 2,2,6,6-titramethylpiperidine compound represented by the general formula (lull 1 (wherein R8 has the same meanings as above) 2 denoted by
- It can be produced by reacting mercaptobenzothiazole.

6- Here, in the above formula, the lower alkyl group as the substituent is methyl, ethyl, propyl, etc. In addition, as the lower alkyl group for substituent R2, in addition to unsubstituted lower alkyl groups such as methyl, ethyl, propyl, butyl,
For example, hydroxyalkyl such as 2-hydroxyethyl, alkoxyalkyl such as 2-ethoxyethyl or ethoxyethyl, aryloxyalkyl such as 2-phenoxyethyl, 2-benzoyloxyethyl,
Substituted lower alkyl groups such as aromatic or aliphatic acyloxyalkyl such as 2-acetoxyethyl, halogenoalkyl such as 2-chloroethyl, alkoxycarbonylalkyl such as 2-cyanotoxyluponylethyl, and as a lower alkenyl group. is an unsubstituted alkenyl group such as allyl, as well as substituted lower alkenyl groups such as alkoxycarbonylalkenyl such as 2-ethoxycarbonylvinyl and ■-methyl-2-methoxycarbonylvinyl. Examples of the lower alkynyl group include 2- Propynyl, examples of cycloalkyl groups include cyclohexyl, examples of aralkyl groups include zingyl, P-methylbenzyl, and P-chlorobenzyl, and examples of aryl groups include phenyl and 0-0
m- or P-) diyl, o-, m- or 9-
Methoxyphenyl, α- or β-naphthyl, and the like.

In these reaction raw materials, 4-amino-2,2,6,
6-Titramethylpiperidine is a 4-oxo-2,2 compound obtained by reacting acetone and ammonia.
, 6,6-titramethylpiperidine is converted into an oxime and then reduced to form a 1-lower alkyl-4
-Amino-2,2,6,6-titramethylpiperidine is prepared by combining 4-oxo-2,2゜6.6-titramethylpiperidine and alkyl halides corresponding to each alkyl group in the presence of a deoxidizing agent. 1 obtained by reacting
-Lower alkyl-4-oxo-2゜2.6.6-titramethylpiperidine is obtained by converting it into an oxime and then reducing it.

In addition, the compound in which the substituent R2 represents a group other than a hydrogen atom is 4-amino-2,2,6゜6-titramethylpiperidine or l-lower alkyl-4-amino-2,2,
It is obtained by reacting 6,6-titramethylpiperidine with the corresponding halide in the presence of a deoxidizing agent.

In addition, the 2-mercaptobenzothiazole compound represented by the general formula (song) is specifically 2-mercaptobenzothiazole, 2-mercapto-4-methylbenzothiazole, and these are aniline or 〇-toluidine,
It can be obtained by reacting with sulfur, carbon dioxide and sulfur by a known method.

The reaction between the 2,2,2,6,6-9-tetramethylpiperidine compound represented by [11] and the 2-mercaptobenzothiazole compound represented by the general formula described above is carried out in an aqueous solution, and the reaction temperature is 2° 2.6.6-Tetramethylpiperidine compounds are used in the form of acid addition salts such as hydrochloric acid, sulfuric acid, and P-toluenesulfonic acid. On the other hand, the 2-mer'captobenzothiazole compound is used in the form of an alkali metal salt such as sodium or potassium.

Reaction 2 is carried out in the presence of an oxidizing agent. The oxidizing agent used is one that is generally used in oxidation reactions, such as hydrogen peroxide, hypochlorous acid, etc.
Preferred are umum and iodine.

The amount of oxidizing agent used is about - to 1.5 molar equivalents, preferably about - to 1.1 molar equivalents, relative to the 2.2.6.6-7' Tetramethylpiperidine Compound.

Also, 2,2.6.6-titramethylpipe.

The reaction molar ratio of the lysine compound and the 2-mercaptobenzothiazyl 10--al compound is usually 1:0.8 to 1.3.

The reaction is usually carried out at a temperature of 10 to 50°C, preferably 10 to 20°C.

The reaction is preferably carried out using a solution of an alkali metal salt of a 2-mercaptobenzothiazole compound dissolved in water while the 2.2.6.6-titramethylpiperidine compound is dissolved in water in the form of an acid addition salt. This is carried out by simultaneously dropping an aqueous solution of an oxidizing agent.

After the completion of the reaction, the product can be separated and collected from the reaction mixture according to a conventional method, for example, the reaction mixture is filtered, the filtrate is dried, and then recrystallized with an appropriate solvent to obtain a pure target product. can be obtained.

As the piperidine compound of the present invention that can be produced in this manner,
Typical examples are shown in the table below.

18- 14- When using such a 2.2.6.6-titramethylpiperidine derivative as a rubber additive, it can be used not only in natural rubber but also in styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber , polybutadiene, polyisoprene, polychloroprene, ethylene-propylene copolymer rubber, and other synthetic rubbers. The amount added to rubber is usually 0.8 to 7 parts by weight, and it can be used in the same manner as ordinary vulcanization accelerators or ozone deterioration inhibitors.

Of course, during use, other vulcanization accelerators, ozone deterioration inhibitors, or antiaging agents can be used in combination depending on the respective conditions and purposes.

Thus, the 2.2.6.6-titramethylpiperidine derivative of the present invention has excellent vulcanization accelerating effects and ozone deterioration preventing effects, and exhibits excellent effects as a rubber additive.

The present invention will be explained below with reference to Examples.

Example I Preparation of N-(2,2,g,6-tetramethyl-4-piperidinyl)benzothiazyl-sulfenamide 5.0r( 0,082 mol) was dissolved in 80% by weight aqueous sulfuric acid solution 5.9f (0,018 mol), and 2-mercaptobenzothiazole monosodium salt 5.
．． 7'? (0,080 mol, dissolved in 80 ml of water)
and 14.4% sodium hypochlorite aqueous solution 1
8.2r (0,085 mol) was simultaneously added dropwise over a period of 1 hour. The temperature inside the flask at this time was 40°C.

The solids generated after cooling were washed with water and then heated at a temperature of 50°C for 12 hours.
After drying for a few hours, the desired product 9. Get Of. Yield: 98% The parent ion peak in the mass spectrum was 821.

Elemental analysis value C (HA H (goods) N (goods) S (goods) Experimental value 59.5 7.2
18.1 19.7 Experimental Example 2 N-(1,2,2,6,6-pentamethy18-ru-4-piperidinyl) 6-methylbenzothiazyl-
Preparation of sulfenamide 5.5 r (0,082 mol) of 4-amino-1,2,2,6,6-bentamethylpiperidine was dissolved in 5.9 f (0,018 mol) of an 80% by weight aqueous sulfuric acid solution. , this has 2
-Mercapto-4-methylbenzothiazole sodium salt 6.7F (0,088 mol, dissolved in Boat's water)
and 14.4% by weight sodium hypochlorite aqueous solution 1
8.2F (0,085 mol) was reacted in exactly the same manner as in Example 1 and post-treated to give a melting point of 127 to 12.8.
10.5 t of the desired product is obtained as white crystals at ℃. Yield 9
The parent ion peak in the 1% mass spectrum was 849.

Elemental analysis value C (goods) Usage N (goods) S
(to) 19-Example 8 N-methyl-N-(2,2,6,6-tetramethyl-4
-Piperidinyl) Production of benzothiazyl-sulfenamide 4-N-Methylamino-2,2,6,6-titramethylpiperidine 5.5F (0°032 mol) was dissolved in an 80% by weight sulfuric acid aqueous solution 6.0F (o, ots 2-mercaptobenzothiazole storium salt 5.7 mol)
f (0,080 mol, 8C) dissolved in xl water) and
14.4% by weight hypochlorous acid) IJium aqueous solution 18
．． or (0,085 mol) is reacted in exactly the same manner as in Example 1 and post-treated to obtain the desired product 9.12 as white crystals with a melting point of 140-142°C. Yield: 90% The parent ion peak in the mass spectrum was 885.

Elemental analysis value q%) H (to) N (goods) S
(Foundation) 20- Experimental value 61.1 7.5 12.4 1
8.7 Example 4 Preparation of N-methyl-N-(1,2,2,6,6-bentamethyl-4-piperidinyl) benzothiazyl-sulfenamide 4-N-methylamino-1,2,2,6° 6
- 5.9 f (0,082 mol) of bentamethylpiperidine in an 80% by weight aqueous sulfuric acid solution 6. Of (0,018 mol), to which the sodium salt of 2-mercaptobenzothiazole 6.1 F (0,082 mol, 80 ml
(dissolved in water) and 18.0 r (0,085 mol) of a 14.4 wt.
The desired product 10.5f is obtained as white crystals at 9-140°C. Yield: 94% The parent ion peak in the mass spectrum was 849.

21- Elemental analysis value C (Foundation) ) IN N (G)
S (Incorporated) experimental value 61.9 7.7 11.
8 18.2 Example 5 N-(2-hydroxyethyl)-N- (2,2,6,6-tetramethyl-4-piperidinyl)
Preparation of benzothiazyl-sulfenamide 4-N-(2-hydroxyethyl)amino-2,2,6
, 6-titramethylpiperidine 6.4r (0,082 mol) was dissolved in 80% by weight sulfuric acid aqueous solution 6.0f (0,018 mol), and 2-mercaptobenzothiazole sodium salt 5.7r (0 ,0.80 mol, Bow
Il dissolved in water) and 14.4% by weight aqueous sodium hypochlorite solution18. Of.(0,085 mol) was reacted in exactly the same manner as in Example 1, post-treated, and recrystallized from alcohol to obtain the target product 9.22 as white crystals with a melting point of 14822-149°C. obtain.

Yield 88% The parent ion peak in the mass spectrum was 867.

Elemental analysis value C (goods) H (goods) N (goods)
S (goods) solid line value 59.8 7.7 1
1.2 17.2 Example 6 Preparation of N-ethoxymethyl-N-(2,2,6°6-tetramethyl-4-piperidinyl)benzothiazyl-sulfenamide 4-N-ethoxymethylamino-2,2゜6.6-Titramethylpiperidine 6.92 (0,082
mol) in 6.0f (0,018 mol) of an 80% by weight aqueous sulfuric acid solution, put it in a 100 ml flask, and add 2
- Sodium salt of mercaptobenzothiazole 5.7t
(0,080 mol, dissolved in BOvtl water) Good job. At this time, the temperature inside the flask is maintained at 0 to 10°C. After returning the temperature to room temperature, the same post-treatment as in Example 1 was performed to obtain the desired product 10.6F as white crystals with a melting point of 150-151°C.
get. Yield: 98% The parent ion peak in the mass spectrum was 879.

Elemental analysis value C (goods) H (l N (goods)
S (goods) calculated value 60.1 '1.7
11.1 16.9 (as q-chi, N@S, 0) Experimental value 59.8 7.7 10.8
17.2 Example 7 N-(2-cyanoethyl)-N-(2°2.6.6-tetramethyl-4-piperidinyl) Production of benzothiazyl-sulfenamide □ 4-N-(2-cyanoethyl)- 2,2゜6.6-titramethylpiperidine 6.7f (0.08.2 mol) to 8
The sodium salt of 2-mercaptobenzothiazole 6.1 F (0,082 mol, dissolved in a bowl of water) and 80 wt. Hydrogen peroxide solution 4.0f (0,0
85 mol) was reacted in exactly the same manner as in Example 6, post-treated, and recrystallized from alcohol to form light yellow crystals with a melting point of 146 to 148°C.The parent ion peak in the target mass spectrum was ←-. there were.

Experimental value 60.8 7.0 15.1
17.8 Example 8 N-ethoxycarbonylmethyl-N- (2,2,6,6-tetramethyl-4-piperidinyl)
Production of penzothiazirusulphene 25-amide 4-N-ethoxycarbonylmethylamino-2,2,6
,6-titramethylpiperidine 7,8 f (0,08
2 mol) in a 30 wt% sulfuric acid aqueous solution 5.2 f (0,016
2-mercaptobenzothiazole sodium salt 5.7F (0,080 mol).

(dissolved in 80 m/ml of water) and 18.0 r (0,085 mol) of a 14.4% by weight aqueous sodium hypochlorite solution were reacted in exactly the same manner as in Example 1, and post-treatment was performed.
Target 10.2 as white crystals with melting point 158-154°C
Get an F. Yield: 88% The parent ion peak in the mass spectrum was 407.

Elemental analysis value C (to) H (goods) N (goods)
S (Incorporated) 26- Example 9 N-allyl-N-(2,2,6,6-tetramethyl-4
-Piperidinyl) Production of benzothiazyl-sulfenamide 4-N-allylamino-2,2,6,6-titramethylpiperidine 6,B y (0,082 mol) was dissolved in an 80% by weight sulfuric acid aqueous solution 6.01 (0,018 5 mol) of the sodium salt of 2-mercaptobenzothiazole.
．． 7f (0,030 mol, 80ml (dissolved in D water) and 14.4% by weight hypochlorous acid) 18.0f (0,085 mol) of IJium aqueous solution was prepared in exactly the same manner as in Example 1. React and post-process to achieve a melting point of 181-1
The desired product 9.42 is obtained as white crystals at 32°C. Yield 8
The parent ion peak in the 7% mass spectrum was 861.

Elemental analysis value CP7A [Sound N(l S(
27- Example 10 N-benzyl-N-(2,2,6,6-tetramethyl-
4-Piperidinyl) Production of benzothiazyl-sulfenamide 30% by weight of 4-N-benzylamino-2,2,6゜6-titramethylbiperidine 7,99 (0,082 mol)
5.7 f (0,080 mol, dissolved in 80 tsl water) of the sodium salt of benzothiazole (2-me/L/cuff) dissolved in 6.0 v (0,018 mol) of sulfuric acid/bisulfur solution, and 18.0f (0,085 mol) of a 14.4% by weight aqueous sodium hypochlorite solution was reacted in exactly the same manner as in Example 1 and post-treated to give a melting point of 139 to
The target products tt, 5r are obtained as light brown crystals at 140°C.

Yield 9B% The parent ion peak in the mass spectrum was 411.

Elemental analysis value 0% HPIAN (Foundation) S (Foundation) Experimental value 66.9 ・7, l 10.2
15.9 Example 11 N-7enyl-N-(2,2,,6,6-tetramethyl-4-piperidinyl) Preparation of benzothiazyl-sulfenamide 4-N-phenylamino-2,2,6゜6 -Titramethylviperi, zine 7.4F (0,082 mol) was dissolved in 6.02 (0,018 mol) of 80*wt% sulfuric acid aqueous solution, and 6.02 (0,018 mol) of sodium salt of 2-mercaptobenzothiazole was dissolved therein. 1f (0,082 mol, dissolved in BOml of water) and 80% by weight hydrogen peroxide4. Or (0,085 mol) is reacted in exactly the same manner as in Example 6, and after treatment, the desired product 11.14 is obtained as brown crystals with a melting point of 158-159°C.

Yield 88% The parent ion peak in the mass spectrum was 897.

29- Elemental analysis value experimental value 66.1 6.9 10.8
16.2 Example 12 N-(2-ethoxycarbonylvinyl)-N-(2,2
,6,6-titramethylbiperidinyl)benzothiazyl-sulfenamide 4-N-(2-ethoxycarbonylvinyl)-amino-
2,2,6,6-titramethylpiperidine 8.2r(0
,082 mol) in an 80% by weight aqueous sulfuric acid solution 5.2F(0,082 mol)
016 mol), in which 5.7 f of the sodium salt of 2-mercaptobenzothiazole (0,080 mol m dissolved in 80 ml of water) and 14.4% by weight of sodium hypochlorite. Aqueous solution 18,0f (0,085
Mol) is reacted in exactly the same manner as in Example 1 and post-treated to obtain the target compound 30-10, lf as white crystals with a melting point of 128-129°C. Yield: 80% The parent ion peak in the mass spectrum was 420.

Elemental analysis value 0% H (goods) N (to) S
Experimental value 59.9 7.1 10
．． 2 15.2 Furthermore, r, 4- N-cyclohexylamino-2゜2.6.6-titramethylbiperidine and 2-
Using mercaptobenzothiazole as a raw material, also 4-N
N-cyclohexyl-N -(2,2
,6,6-tetramethyl-4-piperidinyl)benzothiazyl-sulfenamide i and N-(2-propyl)
-N-(2,2,6,6-tetramethyl-4-piperidinyl)benzothiazyl-sulfenamide can be produced.

Example 18 A rubber compound having the following compounding ratio was prepared using an open roll according to a conventional method.

(Composition) Natural rubber 100 parts by weight Stearic acid 2 Zinc white
5 〃Light calcium carbonate 75 〃Process oil
10 Wax
8 Sulfur
2.5 Test Sample Notes - The obtained rubber compound was subjected to a Mooney scorch test in accordance with JISK-6300 and a rheometer vulcanization test to examine the vulcanization rate. In addition, press vulcanization was performed at a vulcanization temperature of 140°C for 60 minutes, and JIS
The hue and physical properties of the vulcanized rubber and ozone deterioration tests were conducted in accordance with K-6801. In addition, the ozone deterioration test was conducted using an ozone weather meter with a temperature of 7 + 11 degrees 50 degrees.
PPha.

At a temperature of 40° C. and a dynamic elongation rate of 20%, the time required for rack to become visible to the naked eye was measured. The results are shown in Table-1.

In addition, the compound Todoroki as a test sample corresponds to the compound point shown in the table in the main text.

Furthermore, cz and os mean the following.

CZ: 5oxinol CZ, Sumitomo Chemical's product (vulcanization accelerator) O8: Antigene os, Sumitomo Chemical's product (ozone deterioration inhibitor) 88--84 - Example 14 Rubber with the following compounding ratio was prepared using an open roll according to a conventional method. The formulation was adjusted.

(Composition) Styrene butadiene rubber 100 parts by weight Stearic acid 3 Zinc white
5 “HAF Black
50 Process oil
5〃Wax
8 Sulfur 2
[Test sample] The obtained rubber compound was subjected to Mooney scorch test and rheometer test in the same manner as in Example 18. Also, vulcanization temperature 1
Press vulcanization was performed at 45° C. for 40 minutes, and the physical properties of the vulcanized rubber and ozone deterioration tests were conducted in the same manner as in Example 18. These results are shown in Table-2. Note that the test sample was the same as in Example 18.

-35"--698-

Claims (1)

[Scope of Claims] (1) General formula (in the formula, R1 is a hydrogen atom or a lower alkyl group, R2
represents a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a cycloalkyl group, an aralkyl group or an aryl group, and R8 represents a hydrogen atom or a methyl group. ) A 2,2,6,6-titramethylpiperidine derivative represented by (2) General formula (in the formula, R1 is a hydrogen atom or a lower alkyl group,
represents a lower alkyl group, lower alkenyl group, lower alkynyl group, cycloalkyl group, aralkyl group or aryl group. ) A 2,2,6,6-titramethylpiperidine compound represented by the following formula is reacted with a 2-mercaptobenzothiazo-j1 compound represented by the general formula (wherein kl represents a hydrogen atom or a methyl group). A method for producing a 2,2.6.6-titramethylpiperidine derivative represented by the following patent kl (wherein R, , R, and R8 have the same meanings as above). (8) General formula (wherein R1 is a hydrogen atom or a lower alkyl group, K,
is a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a cycloalkyl group, an aralkyl group or an aryl group, and k3 is a hydrogen atom or a methyl group. A rubber additive containing a methylpiperidine derivative as an active ingredient.