DD218106A1 - METHOD FOR PRODUCING OXIDATION-STABILIZED REACTIVE CARBON RESISTANT RESINS - Google Patents

Abstract

The preparation of oxidation-stabilized reactive hydrocarbon resins using inexpensive DCPD technical fractions containing at least 60 wt .-% DCPD, succeeded by the cationic polymerization of isoprene-free technical DCPD fraction, which was obtained after gasoline pyrolysis of the C5 fraction by dimerization, the Content of benzene and CPD each less than 1 wt .-%, the stabilizer content between 400-5 000 ppm and their content of C7 / C8 aromatics in the range between 5-25 Ma .-%, optionally other cationically polymerizable components are used can. Such reactive hydrocarbon resins are useful in typical applications such as in the adhesive and coating sectors or for the preparation of polymeric compositions.

Description

Process for the preparation of oxidation-stabilized reactive hydrocarbon resins Field of application of the invention

The invention relates to a process for the preparation of oxidation-stabilized reactive hydrocarbon resins based on a technical DCPD fraction and optionally other cationically polymerizable components. By varying the content of residual double bonds and by adjusting different molecular weights, the reactive hydrocarbon resins are useful in a variety of typical applications, such as in the adhesives and coatings sector, as well as in the preparation of polymeric compositions.

Characteristic of the known technical solutions

The production of reactive hydrocarbon resins based on dicyclopentadiene (DCPD) and DCPD-containing technical fractions is described in the literature and is carried out technically. '

Thus, EP13060 discloses a process for the Friedel-Crafts polymerization of isoprene-containing DCPD / CPD fractions. To prepare the fraction used, a complicated distillation with subsequent dimerization for the recovery of the DCPD is required. The fraction thus obtained is stabilizer-free and is thus used for the polymerization. The resins obtained by this process are extremely sensitive to oxidation, resulting in a limited shelf life. The present in the fraction used cyclopentadiene (CPD) content of more than 1% by mass requires compliance with special reaction conditions to avoid unwanted gelation in the polymerization. In EP23061 a process for the polymerization of high-percentage DCPD concentrate with styrenes with the addition of PhenolerVbzw. Acrylates to increase the product stability described. The approximately 85% DCPD concentrate used is recovered by distillation and has around 2% CPD and benzene and is virtually free of stabilizers. The existing content of CPD and benzene causes an undesirable reduction in the flashpoint of the concentrate and requires increased technological and safety expenditure. The CPD content leads to the above-mentioned limitations in the polymerization implementation. To achieve the necessary product stability with regard to oxidation and crosslinking reactions, the claimed addition of phenols or acrylafen according to the invention is indispensable. The DCPD fractions used here, which are not isoprene-free with a content of 0.5 to 5% isoprene, also contain. n-pentane, η-hexane, dimethylbutane and 15 to 35% benzene and 0.5 to 5% CPD as low-boiling fractions in very large

"Concentration.,

The said method is liable to the common deficiency that for the recovery of the DCPD concentrates in the preceding stages of petroleum processing z. As pyrolysis of ethylene production technologically induced stabilizer contents is lost and thus a re-stabilization during or preferably after the polymerization is required. It is also disadvantageous that these DCPD concentrates, which are generally obtained as top product, are cost-inefficient and also contain appreciable amounts of CPD and benzene, so that the flash point decreases and technological disadvantages arise in the course of the polymerization in the course of gel formation.

Object of the invention

The aim of the invention is the development of a process for the preparation of oxidation-stabilized reactive Kohlenwasserstoffhar.zen using a special low-priced, gel-free polymerisatibnsfähigen DCPD fraction with low content of carcinogenic constituents and higher flash point with concomitant use of other polymerizable monomers. ,

Presentation of the essence of the invention

The object of the invention is the development of a process for the preparation of oxidation-stabilized reactive hydrocarbon resins using inexpensive isoprene-free technical DCPD concentrate with a DCPD content of> 60%, with low content of <100 ° C boiling components benzene and CPD with concomitant use another polymerizable monomer, without subsequent product stabilization is required. The object is achieved in that inexpensive isoprene-free DCPD fractions with a DCPD content> 60% by mass, which are obtained in the gasoline pyrolysis from the C ₅ fraction whose content of benzene and CPD is less than 1% by mass , with stabilizer contents between 400-500OOppm and a content of 5 to 25 M% C ₇ - and / or preferably C ₈ aromatics, optionally polymerized with other polymerizable components, cationic. The DCPD fraction used in the present invention is obtained after distillative separation of an isoprene and benzene fraction.

The separation of the benzene fraction is possible by addition of 8 to 20% by mass, preferably from 10 to 15% by mass of C ₇ and / or C ₈ aromatics, preferably in the form of technical mixtures as a feedstock filler and after passage of steam under atmospheric pressure, at bottom temperatures <120 ° C. Likewise, the substantial removal of the low-boiling, the erfindungsgeniäße utilization of the fraction in the sense of a gel-free polymerizability, a lower carcinogenic hazard and the setting of a flash point of preferably above 21 ° C interfering components CPD and benzene in each case to concentrations of less than 1 Ma-%. C ₇ - and / or C ₈ -aromatics which are contained in the fraction with 5 to 25% by mass for technological reasons correspond to possible solvents in the cationic polymerization. The content of water in the DCPD fraction is 150 to 500 ppm and thus in concentrations necessary for cationic polymerizations without other coinitiator. The technical DCPD fraction also contains exceptionally high concentrations of 400 to 5000 ppm of stabilizer, in particular sterically hindered phenols. For example: '

2,6-di-tert-6-butylphenol 2,4-dimethyl-6-tert-butylphenol '4-tert-butyl catechol

however, 2,6-di-tert-butyl-p-cresol is preferred. - '.

An isoprene-free technical DCPD fraction, which can be used in the inventive polymerization without further pretreatment and is inexpensive, contains essentially the following main constituents of hydrocarbons (gas chromatographic analysis):.

below 100 ° C boiling components

Benzen, CPD: max. 1.0% by mass

, Cy / Ca aromatics: 5 to 25% by mass

i- / n-propylene norbornene: about 2.0 to 5.5% by mass

Dicyclopentadiene:> 60.0% by mass

Methyltetrahydroindene: about 1.5 to 3.5 mole% of methyldicyclopentadiene: about 8.0 to 12.5 mole% of 2,6-di-tert-butyl-p-cresol: 400 to 5,000 ppm

In general, the DCPÖ fraction has a flash point> 21 ⁰ C And due to the low CPD content allow gel-free polymers. '.. ·,'.

To set optimum Doppelbindungsgphalte, the desired molecular weight and to further improve the oxidation stability of this technical DCPD concentrate is copolymerized with olefins, preferably with aromatic unsaturated hydrocarbons, preferably with styrene and / or α-methyl styrene. In carrying out the polymerization according to the invention 90 to 20 parts of vinyl aromatic, in particular styrene and / or α-methylstyrene are preferably added to 10 to 80 parts of DCPD in the form of the technical DCPD concentrate.

To control the molecular weight and to control the flexibility of the polymer, an isobutene oligomerizate may be incorporated into the resin.

In the present invention, diisobutene, preferably Diisobutengemische and in particular technical Isobutenoljgomerisate with η = 2-4, preferably with η = 2-3 are used. Such diisobutenes can be prepared by cationic oligomerization of zeolites or ion exchangers.

The crude products have the following composition depending on the production conditions: C ₈ -lsoolefine 55 to 80%

C ₁₂ -soo deep 10 to 35% *

C ₁₆ -soolefine 1 to 10% '

After distillation of the crude product, it is possible to isolate C ₈ -lsoolefingamic with the following composition: 2,3,3-trimethylpent-1-ene 5 to 15%

2,4,4-trimethylpent-i-ene 50 to 70%.

2,4,4-trimethylpent-2-ene 8 to 20% 2,3,4-trimethylpent-1-ene 5 to 15%

2,3,4-trimethylpent-2-ene 3 to 10% / ''.

other C ₈ -lsoolefine 2 to 15%

In a fine distillation z. B. via a bubble tray column and the individual components with very high purity can be displayed, but preferred for use are technical mixtures with or without prior drying. The concentration ratios used between DCPD and Isobutenoligomerisat are depending on the desired parameters at 10:10 - 10: 0.

As initiators for the cationic polymerization according to the invention, water, alkyl halides or even HCl, HBr, Cl ₂ or Br _{2 can be used} in combination with a series of coinitiators. As such coinitiators acting Lewis acids, preferably AICI ₃ , AIBr ₃ , BF ₃ OEt ₂ , SnCl ₄ or acidic sludges, as they arise in a number of processes are used. Particularly preferred complexes of technical AICI ₃ or AIBr ₃ with HCl, Cl ₂ or ethers in aromatic solvents such as benzene, toluene, o-, m-, p-xylene, ethylbenzene or mixtures of said aromatics. Furthermore, organoaluminum compounds such as AIRCI ₂ , Al ₂ R ₃ CI ₃ or AIR ₂ CI are suitable as initiators, wherein R is a short-chain aliphatic radical, particularly preferably is C ₂ H ₅ , represents. These compounds in combination with water or alkyl halides z. B. t-BuCl also particularly well suitable initiator systems. In the method according to the invention can be worked with Coinitia, torkonzentrationen of 2.5 to 75mmol / l. The ratio initiator / coinitiator can be varied over a wide range. The preferred coinitiator / monomer ratio is in the range of 0.2: 100 to 3: 100. The polymerization is carried out in a conventional solvent for cationic polymerizations. Suitable chlorinated hydrocarbons having 1-2 carbon atoms or mixtures thereof, preferably methylene chloride, but in particular aromatic or aliphatic or cycloaliphatic hydrocarbons wherein mixtures are preferably used, such as. As gasoline fractions different boiling range or aromatic mixtures such. As o-, m-, p-xylene in addition to ethylbenzene. The polymerization temperatures in the process according to the invention are between 273 and 353K, with temperatures between 293 and 333K being particularly preferred.

The monomer concentrations for the polymerization may range between 2 to 8M.

The polymerization is carried out according to the invention, for example, so as to submit the Coinkiator in admixture with the initiator in the solvent or in a certain part of the solvent.

Under certain circumstances, it may be advantageous to allow the mixture of coinitiator / initiator to be prereacted (for a certain time under suitable conditions) before it is introduced into the polymerization vessel.

The solution is then brought to the reaction temperature and the monomer mixture is added with stirring and tempering in such a way that on the one hand the reaction temperature is maintained, on the other hand a structurally homogeneous polymer is formed during the reaction. In continuous reaction, the catalyst is successively added according to the continuous addition of monomer. The reaction can in the process according to the invention after appropriate time z. B. be stopped with a mixture of methanol and ammonia so that the homogeneity of the solution is maintained. After removal of the catalyst traces by filtration, e.g. with filter presses, the polymer can preferably be used directly in the solvent. However, it is also possible that the polymer is precipitated in a precipitant and then isolated. -. , ,

The molecular weights determined for precipitated unfractionated polymers are generally in the range of 600-4000 g / mol.

The determination of the double bond content by measuring the iodine number according to Wijs generally gave values between 40 and 160, preferably between 60 and 130.

The reactive hydrocarbon resins prepared by the process according to the invention have, as undissolved resins or resin solution without further stabilizer addition, excellent long-term stability.

EXAMPLES

The examples given are intended to explain the process according to the invention. .

Example 1 to 7:

In a clean and dry 350ml sulfonating flask 150ml solvent and the initiator are submitted at the selected polymerization temperature. With constant stirring, the monomer mixture with the technical DCPD concentrate, the composition of which is given in Table 1, is added via a dropping funnel over a period of 45 minutes.

Table 1:

Composition of the DCPD concentrate

benzene

isopropenylnorbornene

Methyltetrahydroindene methyldicyclopentadiene 2,6-di-tert-butyl-p-cresyl

• 0.55% by mass. , "

0,50Ma-%

03.45% by mass '/' ''

64.89%

1.60% by mass,

8,90 Ma-%

2,000 ppm

After a further 180 minutes, the reaction is stopped with 5 ml of a mixture of ammonia and methanol. The polymer solution is then freed by filtration of the present in heterogeneous form catalyst residues. The dabai solution is storage stable over a period of 6 months, clear, scarcely darkens after 10 hours of thermal treatment with BOOK, and has no haze or change in chemical or physical behavior within 6 months. :

The concentration ratios and results as well as the other examples are summarized in Tables 2 and 4,

Example 8:

Example 8 is carried out as described in Examples 1 to 7, but, in other words, Bl is SulfurNpen. presented with 76QmI xylene and 0.01 mol of Al ₂ Et ₃ CI ₃ as an initiator. For this purpose, a mixture of bromobenzene, styrene and the technical DCPD fraction described in the table is added successively such that, based on the addition of 0.3 mol of monomer 0.0005 MqJ initiator are added within 150 minutes at a reaction temperature of 303 K. , After a further 120 minutes, the polymerization was stopped, so that the homogeneity of the solution is maintained. The solution thus obtained is storage stable over a period of 6 months, clear, scarcely darkens on thermal treatment of 500K and has no turbidity or changes in the chemical or physical behavior within 6 months.

Example 9: (Comparison) 150 ml of solvent and the initiator are initially charged at 313K in a clean and dry sulfonating flask.

With constant stirring, the monomer mixture of styrene, α-methylstyrene, diisobutene and pure 99.5% DCPD is added continuously over 30 minutes via a dropping funnel. After another 180 minutes, the

Reaction with 5ml of a mixture of ammonia and methanol stopped. · "

The mixture is then precipitated in methanol and dried in vacuo to constant weight

subjected. '

The product obtained is pale yellow, darkens significantly over a period of 6 months, and darkens greatly upon thermal treatment of 500K. Changes in the solubility of the products and in the chemical behavior were observed.

Undissolved resins lose their solubility through oxidation and released products precipitate oxidation products.

Table 2:

No. monomer concentration

IN THE].·. '

DCPD Styrene μ-MS DIB

Q 272) 1.30 0.90 0.2831

2.24 ²¹ 1.30 - -

0.72 ²¹ 2.64 - -

0.72 ² > 2.64 '- -

0.44 ²¹ 1.62 - -

0.44 ²⁾ 1.62 0.44 ²¹ 1.62

2.44 1.30

0.90 0.28 ³⁾

initiator Initiatorkon- tempera solution Zutropf concentration door medium ¹¹ Time [10 " ² M] [K] [Min] Al ₂ Et ₃ Cl ₃ ZH ₂ O 5 333 dichloro- 45 "» methane Al ₂ Et ₃ Cl ₃ / H ₂ O 5 313 methylene 45 ⁴ > chloride Al ₂ Et ₃ Cl ₃ / H ₂ O 5 ' 303 toluene 45 ⁴¹ Al ₂ Et ₃ Cl ₃ / H ₂ O 5 303 petrol 45 ⁴¹ AlCl3 / HCl 1 303 Methylene · 45 ⁴¹ 90% toluene chloride 10% DEE AICI ₃ / HCI / toluene 1 303 methylene 45 ⁴¹ chloride AICI ₃ / Toluen 1 303 methylene 30 ⁴¹ chloride Al ₂ Et ₃ Cl ₃ / H ₂ O 5 , 303 .. xylene 165 ⁵¹ Al ₂ Et ₃ Cl ₃ / H ₂ O 5 313 methylene 30 ⁴¹ chloride

1) All polymerization batches contained 10% bromobenzene for gas chromatographic analysis

2) Composition of the DCPD fraction: see table

3) Technical DIB mixture with Cs-Isobutenoligomerisaten

4) Duration of post-reaction 180min

5) Duration of post-reaction 120min

-4- 251824 7

Table 3 gas chromatography yield Iodine number ³ ' Molekularge Stability of the poly Darkening at No. graphic grav. ²¹ weight ⁴¹ meren at 6 months 'thermal treatment Sales ¹¹ tiger storage of 500 K (%] | Fl] ig / moi) 98.1 59.8 69.5 1 350 Yes No  1 89.3 45.0 122.0 1475 No 2 90.2 60.9 82.0 1840 noiii 3 92.1. 59.1 92.0 2000 Y ^a No 4 92.8 41.9 100.0 1950 Yes No 5 96.0 34.9 88.0 1850 Yes No 6 91.0 40.4 78.0 1960 Yes No 7 93.5 533.0 72.0 950 Yes No 8th 96.6 54.2 65.0 1190 No Yes 9

1) Taking into account all participating monomers i;

2) Determined by precipitation of the polymer in methanol and calculation on the total composition

3) Iodine number according to Wijs

4) Osmometrically determined on the precipitated polymer

Claims (5)

-5- 251824 7 Invention claims: A process for the preparation of oxidation-stabilized, reactive hydrocarbon resins based on technical DCPD fractions containing at least 60 wt .-% DCPD, characterized in that DCPD fractions, which in the
Gasoline pyrolysis from the C ₅ fraction after Isoprenabtrennung be obtained by dimerization, the content of
Each benzene and CPD is less than 1 wt .-%, with stabilizer contents between 400 to 5000 ppm and a content of 5 to 25 wt .-% C ₇ - and / or preferably C ₈ aromatics, optionally with other polymerizable components such as olefins , Preferably unsaturated aromatic hydrocarbons are cationically polymerized. 2. The method according to item 1, characterized in that as stabilizers preferably sterically hindered phenols,
in particular 2,6-di-tert-butyl-p-cresol are included. . '' 3. The method according to item 1, characterized in that the stabilizer contents preferably 1000 to 4000 ppm in the
DCPD fractions amount. 4. The method according to item 1, characterized in that the content of benzene and CPD in the technical DCPD fraction
preferably in each case less than 0.6% by mass. 5. The method according to item 1, characterized in that are used as further cationically polymerizable components preferably styrene, «methylstyrene and Isobutenoligomerisate from technical Butenfraktionen, in particular oligomers of C ₈ -Ci6 or Diisobutengemische.