DE2213933A1 - Method of stabilizing propane sultone - Google Patents

Description

According to the invention, Propansultone is made by adding at least one of the following compounds: aliphatic Asiine, "
alicyclic amines, aralkylamines, non-aromatic cyclic
Amine * ü-alkyl-substituted aromatic amines, aminoalcohols _r amine property containing H * -halt LGE carboxylic acids with .2 to '10' carbon atoms, stabilized their esters amides, pyridines, quinolines, _5, and reaction products of these compounds with Prepansulton. ,. : -. , ■

In particular, the invention relates to a process for stabilizing the color of propane sultone * '

Propane sultone is known to be a colorless liquid or a crystallized substance with a melting point of 51 ^° C. The compound is an important synthetic material that is used extensively to improve the colorability of "synthetic fiber" or as a surface active agent, as an additive for

modified starch and the like. Use. However, when propane sultone is stored or transported at room temperature or when heated, it gradually changes color to light yellow, and in extreme cases to orange or a reddish brown, so that its commercial value decreases. Although already longer "time is intended to prevent the discoloration of propane, no satisfactory method has yet been found. -

After intensive research on preventing the discoloration of propane sultone, it has now been found that the following compounds are excellent for stabilizing propane sultone: aliphatic amines, alicyclic amines, aralkylamines, non-aromatic cyclic amines, N'-alkyl-substituted aromatic amines, amino alcohols, N-containing compounds with amine properties Carboxylic acids with 2 to 10 carbon atoms, their esters, amides, ■ pyridines, quinolines, and reaction products of these compounds with propane sultone. The present invention is based on this finding.

The invention therefore relates to a method for stabilization of propane sultone by adding one or more of these stabilizers to propane sultone, whereby at room temperature or. discoloration and decomposition of propane sultone is avoided for a long time at elevated temperature.

For example, the following compounds can serve as stabilizers according to the invention:

a) Aliphatic amines: primary amines (RNH ₂ ), secondary amines (RR ¹ NH) and tertiary amines (RR'R "N), in which R, R 'and R ^{11 are} each an alkyl radical with 1 to 20 carbon atoms, or * is an allyl radical, for example mono-, di- and triethylamine, n-propylamine, isopropylamine, n-butylamine and the like.

b) Alicyclic amines: primary, secondary or tertiary amines., as listed under a), in which one radical R is a saturated ring with 3 to 7 carbon atoms in the ring, the ring being separated by ' Carbon / hydrogen freezes can be substituted, for example * "■

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Cyclohexylamine, methyl cyclohexylamine and the like.

'c) Aralkylamines: amines _{f as} listed under a) _r in which. ■ a radical B is an (Ar) * (Alk) radical, in which Ar. denotes a phenyl radical and Alk denotes a. Is an alkylene group having T to 6 carbon atoms , for example benzylamine, phenylethylamine and the like. , -: - ■■ -.- · ■ ■ "■■■■ '.''"-"" ^{: i} '. - "· -.

d) non-aromatic cyclic amines; Cyclic compounds, the: bß ring contain at least 1 nitrogen atom, for example Pyrrolidine, morpholine piperidine, piperazine, hexamethylenetetramine, Herarain and the like »· ■.,

e) N ~ alkyl-substituted aromatic amines: Compounds of the formula ArNRjIU, in which Ar is a phenyl radical or one which is substituted by a carbon radical; Phenyl radical, where at least one of the radicals R, and R- is an alkyl radical with 1 to 6 carbon atoms and the other radical of R ₁ and R ₂ e ^{iri is an} alkyl radical with 1 to 6 carbon atoms or hydrogen, for example N-methylaniline and Ιί , Ν-dimethylaniline and the like; '■

f) Amino alcohols: Compounds as listed under a), vio in the case of a hydrogen atom of "R» R * and R "dur, ch -ÖH is substituted | jbeispa ^ lsweis © Konpti Di ^ -und Triätihanölamiiij panolamin, 2- Amino-2Wm, e, t] iylpröpanp ^^

g) amine properties fatoiirön having, nitrogen-containing end carboxylic acids having 2 to 10 Kohlens.tof and esters thereof: liitrJ: lo- 'triacetic acid _{{Wikotinsäure,} Methylliikctiinat Methylpicolihat f * and the _like; "" -: .. _: ,, '. '.-. ".' .-- '.;"V. .. ..

h) ^^ Amides: formamide ^ dimethylformamide, acetamide, acrylamide, p-toluolsilfonamide ^ nicotinic acid amide, o (-pyrrolidone, £ -Cäpro- ^ lactam and the like .. .. · .._. ·, ■

i) Pyridia: Pyridia and subscribed to the ring with alkyl groups of 1 to 6 carbon atoms. Pyridines ^ -Picoline: fa , ρ or. _ ^) J 2-methyl-5- ⁱ 'ethyl-pyridine, and the like.

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• j) Quinolines: Cliinolin and on the ring with alkyl groups from 1 to ' 6 carbon atoms substituted quinolines, for example quinoline, Methylquinoline and the like.

k) reaction products of propane sultone: reaction products of the abovementioned compounds (a) to (j) with propane sultone.

The propane sultone composition stabilized according to the invention can be easily obtained by directly adding and dissolving or partially dissolving the stabilizer in liquid propane sultone.

From the standpoint of the influence of the stabilizer on the purity of the Propane sultons, the stabilizing effect caused by it And economy is the preferred amount of the pro, pansulton added stabilizer at 0.01 to 1% by weight, based on the weight of the treated propane sultone »If necessary, According to the invention, two or more stabilizers can be used together used v / earth.

The most preferred direct method for determining stability the propane sultone or the stabilizing effect of the stabilizer on propane sultone is that you take a sample Let it stand for a long time under the usual storage conditions and measure the color change that occurs. because the determination takes a long time. The stabilizing effects are therefore accelerated accordingly Color test compared under the following special conditions.

Accelerated color test with heating:

30 g of propane sultone are filled into a hard glass ampoule, which is sealed by melting. The ampoule was ^{stored at 120 °} C. for a predetermined time. The color of the sample was then determined by measuring the Gardner number or the APHA number.

The process of the invention is further illustrated by the following examples.

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B e. i s ρ i e 1 1; i - -

Samples were prepared by mixing freshly prepared propane sultone (color: Gardner number 1, purity "about 99 %) with Q, I. percent by weight of the stabilizers listed in Table 1 and these were subjected to the accelerated coloring test with heating. For comparison Propane sultone containing no stabilizer and propane sultone containing the same amount of a "representative phenol stabilizer" were tested in the same manner. The results are shown in Table 1, The. Numerical values in the table are Gardner numbers. In all cases, the temperature was 90 minutes to 120 ^° C.

Table 1

additive Aliphatic amines Benzylamine 2098A0 Color after the test. / 1214 Monoethylamine ·. (70 %) Phenylethylamine Diethylamine '2 - ■■■ "■■■ Triethylamine . '"-' / 3". ■■■ .. "" - '. . ... ■ · ■ n-propylamine .3;. '■ ■;' . isopropylamine .. ■ ■■ ";■"? - - ^ . ^; n-butylamine "" .- "■■■■ -3 -; - · _,. ■;: - _; - Alicyclic amines. . .-; ■■■■ - ".. 3 ■ '■■". ■; : ■■ Cyclohexylamine Zl.-Methylcyclohexylamine ■ .. '"3-" ■■' ,. - - ■ - - ■ ". Aralkylamines - ' ³ ■ "... ■ .. ■■■ ^; • ■ -. - t 2 ■ -. ■ "'; 3 "'... - - .-

Additional color after the 'past Pyrrolidine Amines k Non-aromatic cyclic Morpholine 3 3 Piperidine 5 Piperazine 3 3 Hexamethylenetetramine 3 3 melamine k 3 3 3 * N-alkyl substituted aromatic amines ³ N-methylaniline N-containing
Ester N, N-dimethylaniline 3 Amino alcohols 3 Monoethanolamine 3 Diethanolamine 3 · Triethanolamine Propanolamine 2-amino-2-methylpropanol Having amine property
Carboxylic acids with 2 to 10
Carbon atoms and their Nitrilotriacetic acid Nicotinic acid Methyl nicotinate Methyl picolinate

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Additive · . colour Formamide Pyridine after the test 3; ■ ■■. ·. Amides , Dimethylformamide "-" " c <~ picoline Acetamide ß-picoline - 2 .Acrylamide Y ~ Picoline <"\ : 2 p-toluene sulfonamide 2-methyl-5-ethylpyridine 3 JJikot insäureamid Quinolines 2 K-pyrrolidone Quinoline '' -p- £ -Caprolactam ■
\ Methylquinoline. 2 Pyridines 3 ■ ' 2 ■ ■ .. 2 3 ■ .. "" ■. 3 '"_;; 3. ■ '; ■■■ 2 2 - -.
Reaction products with propane sultone. Reaiition product from propane sultone ^
and triethanolamine Reaction product of propane sultone
and pyridine ^: '· ■

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-"8th

.Additive control Color after the test No addition Hydroquinone 6th 2,3 ~ dimethylphenol 6th control 7th 3,5-dimethylphenol p ~ methoxyphenol ■ *. 9 Gua: jakol 6th ßyrenated phenol 6th Butyl phenol 7th 7th

As is clear from Table 1, the discoloration is of propane sultone, which is any of the stabilizers according to the invention contains less additives than propane sultone without additives. On the other hand, the discoloration of propane sultone was that contained a phenol stabilizer, about the same as or stronger than in a propane sultone containing no additive.

Example 2

Samples of freshly prepared propane sultone (color: Gardner number 2, purity more than 99 %) were each mixed with 0.1 percent by weight of -N, N'-dimethylpiperazine, triethanolamine, methyl picolinate, pyridine and β-picoline and subjected to the accelerated color test with heating . The color change was measured at hourly intervals over a period of 5 hours. The results are shown in Table 2. The numerical values in the table are Gardner numbers.

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Table 2

additive Heating time 1 2 3 Gardner number 3 4th 6th / Hours .." 0 2 2 2 4th k 5 2 2 3 4th No addition -2 2 2 3 * · - - - - · ι
8 TO NjN • -dimethylpiperazine 2 2 2 3 4 5 :, Triethanolamine 2 2 3 - 3 . 5- ■ · -.--. 6 ". '.; - ,.; ■■ · ...- • ·. Methyl picolinate 2 4 5.; ■ ". .- ■ Pyridine 4 5 P-picoline 4 5 ■ ...- ■; ■

game

Samples of freshly prepared propane sultone (color: Gardner number 2, no above 99 %) were added with different amounts in the order of 0.05 Trf-S 1 percent by weight of 1) triethanolamine and 2) pyridine and the accelerated within 5 hours Subjected to coloring test with heating. The results are shown in Table 3. The numbers in the table are Gardner numbers.

Table 3 ':. "■ ^:

Additional amount (%) Heating time / hours
0 12 3 h 5 O
Pri- 0.05
^ä ^ ^a ~ 0.10
aol-
amine .0.50
1.00 Gardner number 2 3 h 6 8 10
2 2 2.5 Λ 5 6
2 2 2 3 4 6
2 2 2 2 3 4-
2 2 2 2 3 3.5
- - ν.

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Additional amount (%) Heating time / hours
0 1. 2 3 . k 5 0
0.05
Pyridine 0.10
0.50
1.00 Gardner number 2 3 if 6 8 10
2 2 2.5 k 5 6
2 2 2 3 4 5
2 2 2 2 2.5 3
2 2 2 2 2.5 2.5

Example 4

The foregoing accelerated color tests were used to obtain samples of propane sultone with different colors.

According to this example, samples were mixed with 0.1 weight percent of 1) triethanolamine and 2) pyridine and stored at room temperature for 200 days. The degree of discoloration was determined at the intervals shown in the table. In the same way, propane sultone, which contained no additive, was measured as a control test. The results are shown in Table k . The numerical values in the table are APHA numbers.

As clearly shown in the table l \. As shown, there is a remarkable correlation between the values obtained after the accelerated heating test and the degree of coloration obtained by storing the samples for an extended period of time. It is found that triethanolamine and pyridine produce an excellent stabilizing effect, that is to say produce a color-preventing effect in the case of propane sultone in a wide quality range.

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Tabel

OO ■ Ρ-O

ι ' D. Starting ■ ■ additive Days 20th 40 60 80, 100 140 - 200 - _ sample Gardner
Number in 0 APHA number. .170 10 pi No addition 20th ■ 20 20th '20 20th 20th 30th 90 Triethanolamiri 10 "10. , 10 10 10 10 10 15th 40: 150 ·] - A. 1 Pyridine 10 10 10 10 10 10 - 10 ■ 10 30th • 80 • No addition 10 50 60 60 ; 60 . 60 / 70 10 .70 Triethanolamine 30th 30th 30th 30th 30th 30th 30th 80 220 B. 2 ■ pyridine 30th '30 30th .30 30th 30th 30th 30th No addition 30th 80 110 110 110 120 120 30- Triethanolamine 50 - 50 5P 60 60 60 '60 130 η 3 Pyridine 50 50 50 50 60 60 ■ 60 '60 130 : No addition 50 120 140 160 160 170 200 60 120 ,; Triethanolamine 70 70 80 80 80 80 90 200 4th Pyridine 70 70 80 80 80 ■ 80. 80 100 70. 90

O CD OO

sample Starting
Gardner
Number in
test additive Days
O 20th 200 60 80 100 lifO 170 200 90 APHA number E. 5 No addition 80 150 80 230 23O 230 2ifO 250 350 Triethanolamine 80 80 280 90 90 90 100 120 180 Pyridine 80 80 120 90 90 90 90 120 I50 F. 8th No addition 100 200 110 320 .330 350 450 500 650 Triethanolamine 100 100 130 1ZfO 150 170 230 300 Pyridine 100 100 130 1i | -0 150 160 200 250-

B e i s ρ i e 1 5

From the stabilizers (a) to (j) reaction products with propane sultone "were prepared in such a way that equimolar amounts of these two components were reacted. To not To remove converted constituents, the reaction products were washed with a nonsolvent. For example-.were Place 4.9 s (0.1 (Xf mole)) propane sultone in a 50 cc conical flask weighed in. 3.2 g (0.0 ^ mol) of pyridine were added dropwise and then stirred the mixture. The mixture was over ~ Left for the night. The crystals formed were washed several times with methanol to remove unreacted substances and then dried under reduced pressure '

By mixing freshly prepared propane sultone (color ": Gardner number 2, purity: above 99 %) with each reaction product in an amount of 0.1 percent by weight, based on the amount of each reaction product (product B / I), or in samples were prepared in an amount of 0.1% by weight based on the amount of each compound reacted with propane sultone (product B / II) j and subjected to the accelerated coloring test with heating - ■ percent of "each of the stabilizers reacted with propane sultone contained, and propane sultone containing no stabilizer, tested in the same way. The "results are" shown in Table 5. The numerical values in the table are Gardner numbers; In all cases it was heated to 120 ^° C. for 90 minutes.

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Table 5

Compound (A) reacted with propane sultone

group

Specially used connection

Solvent used for cleaning the reaction product (B)

Appearance of (B)

Product B / I

Product B / II

Addition of A alone

(a) Aliphatic amines

Triethylamine

n-hexane

white cloudy paste

(b) Alicyclic amines

Cyclohexylamine

Methanol

White dust

(c) aralkylamines

Benzylamine

Diethyl ether

white crystals

(d) Non-aromatic cyclic Ami-

N, N »-dimethylpiperazine

Methanol

yellow PuI

ver

no

(e) W-alkyl substituted aromatic! aniline Amines

NjN-dimethyl-

acetone

White dust

(£) amino alcohols

Triethanolamine

Methanol

White dust

3.5

(g) N-containing compounds having amine properties Carboxylic acids and their esters

Methyl nicotinate

Methanol

light yellow powder

Ch) amides

Formamide

. (i) Pyridines

(i) O-inoli

no

n-hexane

j white cloudy paste

3.5

Pyridine

Methanol

Chinolln

Tuesday Ä thy1-Xther

v / sisses PuIvor

pink 'powder

3.5

3.5

C.

Claims (1)

S- "" ■ "■ '" - ■ - ■ ■ jI Propansülton, the .-. 0,, Q1. up to 1 percent by weight, based on propane sultone, at least one of the following compounds ¹ : aliphatic amines, alicyclic amines, -aralkylamines> non-aromatic cyclic amines, 1-alkyl-substituted aromatic amines, amino alcohols, N-containing amines Carboxylic acids with P to 10 carbon atoms, whose sster, amides, pyridines, quinolines, and reaction products of these compounds with propane sulton contains. . . \ ?., A method for producing the compositions according to claim 1, characterized in that these "stabilizers are mixed with liquid propane nultone. 2O98A0 / 12U ORIGINAL INSPECTED