DD213673A1 - METHOD FOR THE EPOXIDATION OF CYCLOPENTADIENHOLDING MIXED POLYMERISES - Google Patents

Abstract

The preparation of a reactive hydrocarbon resin with optimal oxirane oxygen content succeeded by a process for the epoxidation of cyclopentadiene-containing polymers with peracetic acid, wherein the double bonds of a oxidation-stable cyclopentadiene-containing copolymer partially or completely epoxidized and reactive hydrocarbon resins are obtained with an oxirane oxygen content of 0.1 to 6%. The products are available in a further modification and can be used in a wide variety of applications (paint industry, resin synthesis).

Description

Procedure on? Epoxidation of cyclopentadiene-containing copolymers

Field of application of the invention

The invention relates to a process for the epoxidation of cationically synthesized cyclopentadiene-containing polymers with peracetic acid.The reaction products can be used as reactive hydrocarbon resin by their Eestdoppelbindungsgehalt and their oxirane oxygen content in the known typical applications (paint industry, resin synthesis).

Characteristic of the "known technical solutions

Processes for the epoxidation of unsaturated polymers with peracids are already known. Thus, by epoxidation of polybutadiene or polyisoprene with perbenzoic acid (DE-AS 1,038,283, DE-AS 1,040,794), peracetic acid (US Pat. No. 3,130,207), ionoperphthalic acid (DE-AS 1,111,399, DE-OS 2,542 .709), Per.cyc Io hexancar bonsäure (BeIg.-PS 585,341) et al modified polydienes which are suitable for the preparation of alkyd resins (US Pat. No. 2,893,885) and lubricant additives (DE-OS 2,554.93) are suitable. Higher molecular weight polybutadiene requires the addition of a solvent such as CGI. or CHGIo (US Pat. No. 2,751,322), while low molecular weight polybutadiene can be epoxidized without a solvent (US Pat

2,577,677, us-ps 2,631,175).

A disadvantage of these methods that with polybutadiene and polyisoprene starting materials are used, which could also be processed into valuable Gummier certificates (DE-OS 3,006,001).

The epoxidation of polymethylcyclopentadiene or polycyclopentadiene is described in British Pat. No. 787,293 and in US Pat. No. 3,130,207, in which aliphatic peracids, in particular peracetic acid, are used as the oxidizing agent. It is known that cyclopentadiene or methylcyclopentadiene homopolymers crosslink due to their sensitivity to oxidation in air with loss of their solubility properties. In order to drastically improve the oxidation stability, it is necessary to completely eliminate the double bonds of such polymers, but an excessively high oxirane oxygen content in the polymer would be associated. A prerequisite for the curing of epoxidized hydrocarbon resins is an optimal proportion of oxirane oxygen, which is indeed adjustable in the cyclopentadiene or methylcyclopentadiene polymers used in these inventions, but only while maintaining the sensitivity to oxidation due to incomplete double bond conversion,

Purpose of the invention

The aim of the invention is the preparation of a reactive hydrocarbon resin with an optimal oxirane oxygen content from sometimes not optimally used products of the chemical industry.

Explanation of the essence of the invention

The invention has for its object to develop a rational process for the preparation of oxidation-stable reactive cyclopentadiene hydrocarbon resins with optimal oxirane oxygen content. By choosing the reaction medium and the reaction conditions in the epoxidation of the double bond conversion and thus the oxirane oxygen content in the polymer should be controlled.

The object is achieved in that an oxidation-stable cyclopentadiene-containing copolymer is converted with peracetic acid as the epoxidizing agent in the presence of a solvent or solvent mixture in a reactive hydrocarbon resin with optimal oxirane oxygen content.

The oxidation-stable unsaturated polymers used for the epoxidation, which are preferably composed of 10 to 65% of cyclopentadiene and oc-methyl thy tyrene, according to the invention also know other cationically polymerizable monomers, such as esters, vinyltinol, indene, isobutene or, their mixtures and molecular weight regulators such as isobutene oligomers having preferably 8 to 16 carbon atoms contain "These hydrocarbon resins can be implemented depending on the process with or without prior isolation from the polymerization mixture.

For the epoxidation, a technical mixture of peracetic acid, acetic acid, hydrogen peroxide and water is used, which contains sodium acetate trihydrate as a buffer. 0.1 to 2.0 moles, but preferably 0.5 to 1.0 mole per acetic acid per cyclopentadiene diene compound are used for this purpose.

The concentration of the epoxidizing agent used can be varied within a wide range, wherein preferably a peracetic acid concentration of 20 "to 40% is selected.

The epoxidation is carried out in a solvent. Suitable are aromatic, preferably benzene and loluenes, and cycloaliphatic solvents such as cyclohexane, but also chlorinated hydrocarbons having 1 to 2 carbon atoms, and mixtures can be used.

The concentration of the solution of the polymer to be epoxidized

Depending on its solubility, _1 can be between 60 and 600 g · 1

_1 and is preferably 10Og-I.

The epoxidation temperatures can be between 290 and 340K. The epoxidation is preferably carried out at 300 to 32OK. According to the invention, the procedure is such that the diene polymer is dissolved in a solvent or solvent mixture, or the polymerization mixture is used directly after removal of the initiator residues. To this solution, peracetic acid containing sodium acetate trihydrate as a buffer is added so that the heat of the reaction is preferably not more than %. increases. After completion of peracid addition can

be stirred intensively between 30 minutes and several hours. The reaction can be stopped by adding distilled water. The organic phase is washed successively with saturated aqueous flaCl solution, saturated aqueous KaCl solution containing KOH and washed neutral with water, dried and concentrated to remove the solvent in vacuo. The epoxidized polymer can also be isolated by precipitation in a non-solvent such as methanol.

Depending on the reaction conditions, the polydiene epoxides obtained contain from 0.1 to 6% oxirane oxygen at double bond conversions of from 10 to 95%. White reaction products which are compatible with paraffins and other hydrocarbon resins and have optimum stability to air and pure oxygen are obtained distinguished. They are accessible for subsequent modification.

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

Exemplary embodiments 1 to 4

In a temperature-controlled 500 ml glass flask equipped with stirrer, dropping funnel, internal thermometer and argon connection, 30 g of a cyclopentadiene cation produced by cationic polymerization are

»G-methylstyrene copolymers (characteristic data in Table 1) dissolved in 300ml benzene. The contents of the flask are brought to the reaction temperature of 30 ° C. and then slowly an amount of 40% strength technical peracetic acid with 3% by weight of sodium acetate trihydrate corresponding to the number of cyclopentadiene-terminated indigents is added so that the temperature does not rise above 3OSK. After completion of peracid addition, the reaction mixture is stirred for 3 hours at 3O3K intensive. Then distilled water is added in the same Yolumen, the benzenic phase separated and washed successively with saturated aqueous sodium chloride solution, saturated aqueous sodium chloride solution with 5 weight percent potassium hydroxide and several times with distilled water until the aqueous phase is neutral. The organic phase is dried with sodium sulfate, filtered and concentrated at 303K in a water-jet vacuum. Process data of the epoxidation and characteristic values of the polymers epoxidized in these examples are summarized in Table 2.

Example 5

For the epoxidation, a polymer is used, which consists of 44.6% cyclopentadiene, 29.2% ^ methylstyrene, 16.5% styrene and 9j7% diisobutene, an iodine number of 163 and a

- 1 average molecular weight of 2700g · mol.

611 g of the polymer are dissolved in 1500 ml of toluene and the solution is brought to a temperature of 303K. With vigorous stirring, 467 g of a 40% technical peracetic acid with 14 g of sodium acetate trihydrate are added slowly. The molar ratio of added peracid to double bond content

in the polymer in this case is 0.72 to 1. After the addition is stirred for 5 hours and the reaction is terminated by adding 800mi of distilled water. The work-up of the reaction product s is carried out as described in Examples 1 to 4. In this case, 564 g of epoxidized polymer (86.7% of theory) having an average molecular weight of 3200 g · mol and a zodzahl of ^ Z are obtained. The double bond conversion is 68.1%. The product contains 3j4% oxirane oxygen.

Example 6 to 9

The epoxidation is carried out as described in Examples 1 to 4, but the solvent used is not benzene but cyclohexane, methylene dichloride, 1,2-dichloroethane or 1,4-dioxane

 The test results are compiled in 'labeile 3

Example 10 to 17

The epoxidation is carried out as described in Examples 1 to 4, but different amounts of peracetic acid are used with respect to the content of cyclopentadiene double bonds and the concentration of peracid is varied

 The results are summarized in Table 4.

Table 1 ϊ Characteristic data of the cyclopentadiene used for epoxidation

© υ-Methylstyr en-Copo lynier e

Ref. Iodine number med. Molar mass Mo1% cyclopentadiene in

g · mol copolymer (a)

Number of double bonds per

-1 Po Iy note te (mol)

A1 134 3600 A2 84 37OO A3 132 43OO A4 140 3IOO

55.1 30.0 50.1 53.9

20.9

7.4

22.4

18.4

(a) H ~ determined by NMR spectroscopy

Table 2: Process data of the epoxidation and characteristics of the epoxidized polymers

Example Peracetic Sodium Acetate Used Yield Iodine Double Binder Oxirane Copolymer Acid Trihydrate _; environment-

(g) (g) (%) rate (%)% (%)

1 A1 35.0 1.1 89.4 13 90.4 5.3 2 A2 16.7 0.5 93.4 11 86.9 2.3 3 A3 30.9 0.9 87.6 19 85.6 5.1 4 A4 34.1 1.0 82.0 66 52.9 3.9

TabeU-Θ 3 * · Results of the solution te! Variation in the epoxidation of cyclopentadienes-Me thy 1st yr en copolymer isates

Peracid used peracid amount of peracid

Intermediate copolymer (mol per cent

(a) per double (%)

b indg.)

Yield iodine number doublebran oxirane

Density- (%) Rate (%) Substance (%)

6 cyclo A2 hey xan 7 methylated A1 lendi- chloride 8th 1,2-di- A1 chlorine- ethan 9 1,4-di- A1 oh xan

1.00 0.80

1.00 1.00

40 10

40 40

90.8 27

89.0

88.3

90.1

79.8

76.4

90.6

91.5

4.8

2.7

3.0

3.2

(a) For the characteristics, see Table 1

Table 4:

Results of the epoxidation of cyclopentadiene-oC-methylstyrene copolymers "using different peracid levels and concentrations

example

used copolymer (a)

Precursor moles (mol per acid per double bond)

P er sic econcentration (%)

iodine

Doppe Ib indungsumsatz

oxirane

10 A2 0.15 40 72 14.3 0.3 11 A1 0.25 40 100 25.0 1.6 12 A1 0.50 40 68 49.3 3.8 13 A2 1.50 40 10 88.1 2.9 14 A2 2.00 40 5 94.0 2.8 15 A1 1.00 5 82 38.8 2.5 16 A1 1.00 10 67 50.0 3.4 V A1 1.00 20 23 82.8 5.0

(a) For the characteristics, see Table 1

Claims (5)

1. A process for the epoxidation of cyclopentadiene-containing polymers with peracetic acid, characterized in that the double bonds of an oxidation-stable cyclopentadiene-containing copolymer are partially or completely epoxidized, whereby the polymer is converted into a reactive hydrocarbon resin having an oxirane oxygen content of 0.1 to 6 % . 2. The method according to item 1, characterized in that are used as oxidation-stable unsaturated copolymers cationically prepared hydrocarbon resins having 10 to 65 Mo1% cyclopentadiene, in addition to cyclopentadiene and ^ -methylstyrene also styrene, Vinyltoluen, indene, isobutene u.a. can contain. 3 «method according to item 1 and 2, characterized in that the molecular weight regulation in the preparation of the polymers to be epoxidized Isobutenoligomerisate preferably having 8 to 16 carbon atoms are used. 4 «method according to item 1, characterized in that the epoxidation of isolated and purified hydrocarbon resins is carried out or takes place without prior separation of the polymers from the polymerization mixture Process according to item 1, characterized in that peracetic acid is present in an amount of 0.1 to 2.0 mol, but preferably in an amount of 0.5 to 1.0 mol per cyclopentadiene double bond and a concentration of preferably 20 to 4 -0 % is used.