DE1793458C3 - N-nitroso-4,4'-bis- (2-phenyllsopropyl) -diphenyle min and its use - Google Patents

Description

CH ₃ NO CH,

The present invention relates to a new product,

that acts as a retarder for the vulcanization of natural 15 and has a melting point of 100 C, a

lichen and synthetic rubbers used sorption maximum at 298 ηιμ, Ε}? » = 130 and a

can be and also valuable protective absorption minimum at 275 πιμ., El? «= 124.

This product is a very effective retarder

Aging of vulcanized products. to prevent scorch of mixtures

It is known that during the various *> based on natural rubber or voi,

Processing stages of a mixture based on synthetic elastomers, such as styrene

Rubber that contains all of the butadiene copolymers, butadiene-acrylonitrile copolymers

Union components, in particular sulfur and VuI- mers, polybutadiene, polyisoprene, and generally all

canization accelerator, contains, longer heating, elastomers vulcanizable with sulfur. The

genes occur which lead to an out of time Vulkani- 95 N-Nitroso-4,4'-bis- (2-phenylisopropyl) -diphenylamine

sation. Such scorchings make which is used in an amount that in general

Mixtures unsuitable for their subsequent conversion. between 0.1 and 5 parts by weight (preferably 0.25

The dangers of scorch can down to 2 parts) per 100 parts by weight of unsaturated elasto-

be set by lying an accelerator with meres.

delayed effect, for example an acceleration 30 The N - nitroso - 4,4 '- bis - (2 - phenylisopropyl) - di-

ger from the class of sulfonamides, and / phenylamine does not interfere with the actual vulcanization

or the composition a vulcanization noticeable, both in terms of speed and

retarder, which is also anti-scorch agent in terms of the properties achieved. The invented

is called, adds. The effect of such a VuI- dative product also enables rubber

canization retarder should only be used on the initial vulcanizates, the degradation of which is strongly inhibited

phase and is during vulcanization. The new product has an additional benefit

stop at a higher temperature, so that the vulcani- on: it discolors paints and varnishes much less

sation time of the mixtures is not increased. than the N-nitrosodiphenylatin.

It is also known that vulcanized rubber.

a nitrosation process from 4,4'-bis- (2-phenyl-

suffers, especially due to the action of isopropyl) diphenylamine.

Oxygen and heat, as well as the special con You can, for example, 4,4'-bis (2-phenylisopro-

conditions of use of the finished product. Man pyl) -diphenylamine in water at a suitable

must therefore disperse the vulcanized rubber against temperature and sodium nitrite and a

destructive effect of these various factors 45 strong mineral acid, for example hydrochloric acid or

protection. Sulfuric acid, add in sufficient quantity that

Numerous products are known which carry out the nitration and the product obtained

combat the dangers of scorching in any way such as filtering

Raw mixtures can be used, and one can separate on- or melt-off.

for example the organic acids and acid anhy- 50 The following examples explain the use

dride, for example phthalic anhydride and salicylic of the product according to the invention in mixtures

acid, and nitroso compounds of amines, both based on rubber,

for example nitrosodiphenylamine. _n . · 1 1

All of these products are subject to certain conditions

They are effective, but they are not always completely satisfied. In this example the influence is concentration

because the former, the organic acids on N-nitroso-4,4'-bis- (2-phenylisopropyl) -diphenyl-

and acid anhydrides, not the desired effect amine on scorch in a mixture

on the accelerators of the class of sulfonamides be based on natural rubber with Ruu as

sit and the nitrosodiphenylamine shown the mixtures filler.

litark dyes and these mixtures of lacquers and paints, 60 You put that in a laboratory interior mixer

if they come into contact with these, the following mixtures will discolour:
be able.

Numerous chemical substances are also involved. Natural rubber,

known to protect the vulcanized rubber smoked sheets 100 parts by weight

Anti-aging products are used 65 zinc oxide 5 parts by weight

be able. Stearic acid 2 parts by weight

It would therefore be valuable to have a product with carbon black HAF 50 parts by weight

to be able to use the at the same time valuable delay spruce tar 3 parts by weight

71 93 458

The above mixture is placed on a roller mixer the following components:

sulfur

N-Cyclohexylbenzothiazyl-

sulfenamide

N-nitroso-4,4'-bis- (2-phenylisopropyO-diphenylamine

2.25 parts by weight 0.50 parts by weight

as indicated below

After standing for 24 hours, the scorch time of the mixtures is measured on a Mooney consistometer at 120 and 130 ^° C.

In addition, the mixtures ^{are vulcanized in the press at 143 °} C. in the form of plates 4 mm thick for various periods of time, and the properties of the vulcanizates thus obtained are measured as a function of the vulcanization time.

The results obtained are given in Table I.

Table I. Measured properties N-nitroso-bis- (2-phenyIiso-

propy1) diphenylamine

(Parts by weight)

0 0.50

Scorch time (min)

at 120 ^° C 22.5

at 13O ⁰ C 13.5

Vulcanization at 143 ⁰ C
Tensile strength (kg / cm ² )

after 20 minutes 246

after 25 minutes 246

after 30 minutes 246

Module at 300% (kg / cm ² )

after 20 minutes 110

after 25 minutes 116

after 30 minutes 120

Elongation at break,%

after 20 minutes 550

after 25 minutes 535

after 30 minutes 510

25.00 14.75 The following mixture is prepared on a roller mixer:

Styrene-butadiene copolymer

of type 1502 100 parts by weight

Zinc oxide 5 parts by weight

Stearic acid 2.5 parts by weight

Ultrafine silica 22.5 parts by weight

Kaolin 22.5 parts by weight

ίο titanium oxide 10 parts by weight

Diethylene glycol 3.5 parts by weight

Sulfur 2 parts by weight

Mercaptobenzothiazole,

Zinc salt 1.2 parts by weight

Zinc dimethyldithiocarbamate 0.3 part by weight N-nitroso-4,4'-bis- <2-phenylisopropyQ-diphenylamine as indicated below

ao 24stiradigem After standing for measuring the scorch time of the mixtures on a Mooney consistometer at 120 ⁰ C. In addition to vulcanizing the mixtures at 153 ⁰ C in the press, and measures the properties obtained with optimum Vuikanisationsdauer

»5 shafts (the shortest vulcanization time leads to the

highest modulus at 500%).

Eventually the raw mixes will last 15 days

_! Room temperature stored and their scorch time is measured again at 120 ⁰ C.

The results are compiled in Table II below.

Table II

28.75 16.25

233 “Measured properties N- nitroso-4,4'-bis- (2-phenyl- 24b 243 isopropyO-diphenylamine 248 249 (Parts by weight) 248 0 0.5 1

110 118 123

535 535 510

104 113 117

535 530 530

It can be seen that the N-nitroso-4,4'-bis (2-phenylisopropyO-diphenylamine the scorch time increases without practically affecting the properties of the vulcanizates to change.

If you in the vulcanizable mixture the N-Cyclohexylbenzothiazylsulfenamid by the same Amount by weight of 2 - (N - morpholinothio) - benzothiazole replaced, the relative changes in the scorch time remain depending on the concentration of N-nitroso-4,4'-bis- (2-phenylisopropyl) -diphenylamine of the same order of magnitude.

Scorch time
appendix 20 "C

after preparing the 9 14.50 15.50

Mixtures

after 15 days 7 22.50 28.50

♦ 5 storage

Vulcanization at 153 ° C
optimal duration 15 15 15

(Minutes)

Tensile strength 98 102 103

(kg / cm *)

Module at 500% 28 29 30

(kg / cm *)

Elongation at break (%) 750 765 760 Shore hardness A 54 54 54

6o

Example 2

In this example the influence of N-nitroso-4,4'-bis- (2-phenylisopropyl) -diphenylamine on the vulcanization of a mixture based on butadiene-styrene copolymers, the light-colored fillers contains, shown.

Example 3

This example shows the protective properties of N-nitroso-4,4'-bis (2-phenyliospropyl) -diphenylamine against the heat aging of the vulcanized compounds.

As in Example 1, mixtures are produced which are vulcanized ^{at 145 ° C. for the optimum time.} The vulcanizates obtained are in the form of test specimens in a ventilated oven at 8O ⁰ C

brought in. The course of the tensile strength is measured and elongation at break. One then determines the values measured to achieve a certain reduction in value Properties required time. Furthermore, one sets

Mixtures as in Example 1, but using the N-nitroso-4,4'-bis (2-phenylisopropyl) diphenylamine replaced by N-nitrosodiphenylamine. The results are shown in Table III.

Table III

N-nitroso-4,4'-bis (2-phenylisopropyl) -diphynylamine (WeightsteDc)

0.25

0.50 N-nitrosodiphenylamine (parts by weight)

0.5 1

To achieve a 6Vi days 10 days llV _s days 13 days 7V 8V ₂ days ₂ days

Reduction of tensile strength by 50%
required time

To achieve a 9Vs days 14 days 15 days 16 days 9V ₂ days 10V ₂ days

Reduction of the
Elongation at break
50% time required

The excellent protection that the product according to the invention compared to the comparison as well as versus the nitrosodiphenylamine is clearly evident.

Example 4

This example shows another advantage of N-nitroso-4,4'-bis (2-phenylisopropyl) -diph3nylamine compared to N-nitrosodiphenylamine, namely much less discolouration of varnishes and paints.

Mixtures produced as in Example 1 are vulcanized ^{at 143 ° C. for the optimum time.} Test specimens from these vulcanizates are brought into contact with a white glycerophthalic paint that is applied to a metal base. The time taken for a color to appear on the paint is noted for each of these two diphenylamine derivatives.

comparison

N-nitroso-4,4'-bis (2-phenylisopropyl) diphenylamine

N-nitrosodiphenylamine

90 hours

0.5 part by weight 75 hours
1 part by weight 75 hours

0.5 part by weight 27 hours
1 part by weight 19 hours

Example 5

The following ingredients (parts by weight) are then added on a roller mixer.

Sulfur 1

N-Cyclohexylbenzothiazylsulfen-

amide 2

N-nitroso-4,4 '- (bis- (2-phenyl-

isopropyl) diphenylamine as indicated below

After 24 hours of standing measuring the scorch time of the mixture at a Mooney consistometer at 130 ⁰ C. It also measures the properties of the vulcanized at 153 ⁰ C mixtures as a function of cure time. The results are shown in Table IV below.

Table IV

Time to color: n der FiU ^- De

With the help of a mixer, the following composition is prepared (the numbers express parts by weight):

1,4-cis polybutadiene 100

Zinc oxide 5

Stearic acid 3

Soot ISAF 50

Spruce tar! 0

N-nitroso-4,4'-bis (? .- phenylisopropyl) -diphenylamine 45 Vulcanization (Parts by weight) 1 25th 30th tion time at 0 50 ¹³ O ⁰ C (in minutes) τη 25 134 122 vulcanization 26 25 at 153 ^° C Time (in min 59 60 ten)
CE 20th Tear 20 25 30 525 485 strength 128 (kg / cm ⁸ ) 129 140 133 Module 300% ⁶ ° (kg / cm ² ) 57 fracture 63 63 62 strain (%) 510 500 525 505

Example ό

This example differs essentially from Example 5 in that it replaces the polybutadiene by polyisoprene.

The following mixture (parts by weight) is produced in a laboratory internal mixer:

1,4 cis polyisoprene 100

Zinc oxide 5

Stearic acid 3

Carbon black HAF 50

Dutrex V 10 (plasticizer petrol

Origin) 3

The following ingredients are added to the above mixture on a roller mixer:

Sulfur 2.5

N-Cyclohexylbenzothiazylsulfenamide ... 1
N-nitroso-4,4'-bis- (2-phenylisopropyl) -diphenylamine as indicated

The results are given in Table V.

Table V N-nitroso-4,4'-bis (2-phenylisopropyl) diphenylamine

(Parts by weight)

0 1

Mooney Anvul

canisation time (in minutes)

at 120 ° C f 32 35.75

at 13O ⁰ C \ 17.75 20

vulcanization
at 143 ⁰ C

Time 17.5 20 25 17.5 20 25

(Minutes)

Tensile strength 232 255 232 254 259 234
speed (kg / cm ² )

Module 300% 123 132 138 107 115 127
(kg / cm ⁴ )

Fractional 480 505 445 555 545 475

strain (%)

Example 7

This example differs essentially from the example in that it replaces the polybutadiene by a styrene-butadiene copolymer.

The following mixture (parts by weight) is produced in a laboratory internal mixer:

Styrene-butadiene copolymer of type 1509 ... 100

Zinc oxide 5

Stearic acid 2

Carbon black HAF ⁵ O

Dutrex V10 8

The following ingredients are added to the above mixture on a roller mixer:

Sulfur 2

N-Cyclohexylbenzothiazylsulfenamide ... 1
N-nitroso-4,4'-bis- (2-phenyl-isopropyl) -diphenylamine as indicated

The results are shown in Table VI

Table VI

N-nitroso-4,4'-bis (2-phenylisopropyI) -diphenylamine

(Parts by weight)
0 1

Mooney Anvul
canization time (in minutes) 35 55.25 40 ₁₀ at 120 ° C j 46 184 16.25 182 at 130 ° C I 14.5 93 77 vulcanization
at 153 ^° C 460 35 530 ₁₅ time
(in minutes) 30th Test report 162 Tensile strength
speed (kg / cm ² ) 198 75 "Module 300%
(kg / cm *) 93 525 fracture
strain (%) 495

The compound according to the invention N-nitroso-4,4'-bis (2-phenylisopropyl) -diphenylamine (hereinafter referred to as N-nitrosodicumyldiphenylamine is) has been recognized in terms of its effect as a vulcanization retarder and as an anti-aging agent for vulcanizates with that known from US Pat. No. 1,734,953 N-nitrosodiphenylamine compared.

A rubber mixture of the following composition was used:

Natural rubber 100 parts by weight

Zinc oxide 5 parts by weight

Stearic acid 2 parts by weight

Carbon black HAF 50 parts by weight

Spruce tar 3 parts by weight

Sulfur 2.25 parts by weight

N-Cyclohexylbenzothiazyl-

sulfenamide 0.5 part by weight

Nitroso derivative varying amounts

The various base mixes are made in the Banbury mixer. Just the sulfur that Accelerator and the nitroso derivative were then added on a roller mixer the following tests were carried out on the raw mixes, the vulcanization

time according to M ο ο η ey measured ^{at 120 0} C and 130 ^{0 C.}

MSt + 10 was measured. In general, these times were expressed as a percentage of the time of the mixture that did not contain any nitroso derivative. The following measurements were carried out on the mixtures optimally vulcanized in the press: Measurement of the dynamometric properties on dumbbell-shaped pieces H ₁ (standard NF T 46.002), behavior of the mixtures at different forms of aging.

Behavior in heat and in the oxygen bomb

The bulb-form samples H ₁ were maintained for variable times either in cabinets multicellulären at 8O ⁰ C or in oxygen bomb at 70 ° C (under 21 kg / cm. ¹ One pursued the development of the dynamometric properties over time

709618/89

Behavior when attempting to creep

The development of the elongation of a sample which was kept in a drying cabinet at 100 ^° C. and subjected to a force of 2 kg / cm ² was followed.

^y 9 10

Behavior with repeated bends

The DE MATTIA machine was used in accordance with ASTM D 430, method B.

In all cases the results were expressed in terms of a protection coefficient. This one will calculated as follows:

Value for the mixture containing the compound under investigation Value for the mixture containing nothing

100.

Behavior on light UV component off. It was established: the times which are necessary to prevent the appearance of any staining

Covered panels of vulcanized mixtures 15 were observed to determine the white layer and the coloration of the same after a certain amount of time.

The results are summarized in the following table:

with a layer of a white mixture 2 mm thick. The whole thing was put to an intense exposure with a light apparatus with a strong one

Table VII

Nitroso derivative of dicumyl-diphenylamine

Amount (pcc) ·) in parts 0 0.5

Diphenylamine 0.5

At vulcanization time
at 120 ⁰ C Cm%)
at 130 ⁰ C (in%)

Different ages

(Protection coefficient)
at 8O ⁰ C in air (in%)
at 70 ⁰ C in oxygen (in%)

Creep test (in%)
with repeated bending (in%)

Behavior in light
Time to achieve a discoloration
on the surface (hours)
Coloring after 90 hours of exposure

*) iTozentantcüe rubber.

100 (22.5 min.) 110 128 130 100 (13.5 min.) 115 123 120 100 177 210 108 100 230 250 190 100 135 160 190 100 300 475 150 90 75 75 27 light yellow yellow yellow Brown

It can be seen from the test results that only the N-nitrosodicumyldiphenylamine according to the invention at the same time has good properties both as a vulcanization retarder and as an anti-aging agent. In comparison, the well-known N-nitrosodiphenylamine has no or very little Anti-aging effect (aging in warm air) oiler an at most mediocre protective effect (resistance in oxygen or during repeated bending). These results are achieved when the both nitro derivatives in the same amount by weight (0.5 parts) or in the same molecular amount (0.5 part nitrosodiphenylamine and 1 part nitrosodicumyldäphenylamine) be compared.

Finally, the known compound is highly photosensitive and stain-forming, while that of the invention Connection does not have this disadvantage

Claims (2)

X. properties and protective properties which are essential for a patent claim good preservation of products made from vulcanized rubber. 1. N-nitroso-4,4'-bis- (2-phenylisopropyl) -di- It has now been found that N-nitroso-4,4'-bisphenylamine 5 (2-phenyhsopropyl) -diphenylamm at the same time this 2. Use of the connection in accordance with the on-delay and protective properties,
spoke 1 as a vulcanization retarder in natural- This new product conforms to the formula
borrowed or synthetic rubbers and / or ""
or as an anti-aging agent in vulcanizates. ^a