DE1106499B - Process for polymerizing an ester of methacrylic acid with a monohydric alcohol having up to 4 carbon atoms - Google Patents

Description

GERMAN

The present invention relates to a method after the linear, head-to-tail polymers from esters of methacrylic acid and monohydric alcohols can be made with up to 4 carbon atoms. Under the designation "Polymers" are in the present Case also to understand copolymers. The invention Polymers are normally essentially not branched, but copolymers are used have branches with difunctional monomers.

According to the present invention, an ester of methacrylic acid with a monohydric alcohol which is up to has to 4 carbon atoms, polymerized by a process in which the ester to form a compound of Formula RMgX, in which R is an alkyl, cycloalkyl, aryl or aralkyl radical and X is a chlorine or bromine atom, is added, this compound may optionally be mixed with a liquid that the Able to dissolve esters. The constituents should be homogeneously homogeneous with regard to the greatest possible yields be mixed, e.g. By stirring or agitation, and the homogeneous mixing is further also preferably continued during the onset of the polymerization reaction. To the profitability with To combine maximum effect of the process, alkylmagnesium bromides with up to are preferred 4 carbon atoms applied.

The magnesium compounds mentioned are known to be expedient as solutions in one Ether, e.g. B. in an ether of the formula R '- O - R ", wherein R' and R" are alkyl, cycloalkyl or aryl groups mean, which can be the same or different, or prepared in a mixture of such ethers. The connections can also be used as a solution in a tertiary amine, e.g. B. dimethylaniline, or an N-alkylmorpholine be generated.

In one embodiment of the present process, the stated liquid is not a solvent for the magnesium compound, and this compound is precipitated from a solution in an ether by adding a liquid paraffinic hydrocarbon or a petroleum fraction or a liquid synthetic hydrocarbon, which consists essentially of paraffinic hydrocarbons. The temperature and pressure used in this precipitation should of course be chosen so that the hydrocarbon used is liquid. The magnesium compound is usually obtained in the form of an oil upon precipitation. This can be used as such or in conjunction with a diluting liquid with which it is immiscible but in which the methacrylate is soluble. A very suitable dilution liquid is a mixture of an ether, as it is also used as a solvent in the production of the magnesium process for polymerizing
an ^ ester ^ of methacrylic acid
with a monohydric alcohol
with up to 4 carbon atoms

Applicant:

Imperial Chemical Industries Limited,
London

Representative: Dr.-Ing. H. Fincke,

Berlin-Lichterfelde, Drakestr. 51,

Dipl.-Ing. H. Bohr and Dipl.-Ing. S. Staeger,

Munich 5, patent attorneys

Claimed priority:
Great Britain March 20 and September 4, 1957

Peter Markey, Harrogate, Yorkshire, Brian Mills,
Percy Arthur Small, Welwyn Garden City,

Hertfordshire,

and Annette La Touche Turner-Jones,

Barnet, Hertfordshire (UK),

have been named as inventors

compound is applied, and a hydrocarbon in such an amount that the magnesium compound is precipitated.

The method can also be carried out in a liquid in which both the magnesium compound as well as the methacrylate is soluble. In this embodiment, the methacrylate forms practically immediately is added, a precipitate, and preferably the amount of methacrylate added is less than that Amount of the listed liquid present.

In order to obtain good yields of the said polymers at the same time reasonable reaction rates, the temperature of the polymerization reaction between -25 and + 5O ⁰ C should lie and pressure and temperature are combined so that both the methacrylate and optionally applied diluents are virtually completely in the liquid Form.

Since the magnesium compounds are sensitive to oxygen, carbon dioxide and moisture, will their preparation and the process according to the invention preferably in an inert atmosphere, e.g. B. in a Nitrogen or argon atmosphere.

109 580/445

According to the invention it has also been found that a new form of methyl methacrylate polymer can be produced by the process according to the invention. This new polymer form differs from the known methyl methacrylate polymers in the infrared absorption spectrum and also in that it can be crystallized. Such polymers also include copolymers which contain a small proportion of copolymerized monomer, as is explained in Examples 14 to 16. The special distinguishing feature in the infrared absorption spectrum is an absorption band at 955 cm " ^1. It was also found that the polymers according to the invention have weak absorption bands at 1063, 965, 913, 825 and 809 cm- ¹ Methyl methacrylate polymers are recycled, and therefore ^{the band at 955 cm "1} must be regarded as specific for the new polymers. These new polymers also show the absorption bands at 990, 840 and 747 cm " ¹ , which are also found in the known methyl methacrylate polymers.

Polymer produced 'C predominantly the novel form of the ^polymer: Although this new Methylmethacrylatpolymerisate can be obtained by the inventive process at temperatures of less than 15 ³ C, which is above 15.

^{The polymer which is produced above 15:} C by the process according to the invention is generally obtained directly in crystalline form. The crystallinity of such a polymer can be improved by tempering, which is preferably carried out for at least 2 hours. The tempering can be effected at a temperature between the rubber-glass transition point of the polymer (60 to 80 ° C.) and the melting point of a polymer to be treated, the temperature preferably being 15 to 25 degrees Celsius below the melting point of the polymer to be treated The maximum melting points that were obtained are 150 ³ C (not tempered) and 160 ⁰ C (tempered), as was determined with the aid of a polarizing microscope provided with a heatable table.

After the polymers according to the invention have been melted once, they normally crystallize not. To restore their crystallinity after they have been melted, the following can be used Procedures are used:

1. A sample with fresh surfaces is marked with a 5a Liquid that is able to swell the polymer, e.g. B. with diethyl ether, at room temperature or with boiling Treated diisopropyl ether. After this treatment, tempering can be carried out in order to achieve the crystallinity achieved raise.

2. The polymer is at a temperature at which it is a rubber-like melt, pressed, quickly stretched, quenched and - while shrinkage is prevented - at a temperature between its rubber glass transition point (60 to 80 ⁼ Cj and its melting point, ie its melting point after quenching and prior to this tempering, the temperature is maintained and preferably at 90 to 120.degree. C. Very suitable temperatures for stretching and tempering are 240 or 110.degree. C. Often at least 1 hour must be tempered so that the greatest possible crystallinity occurs If rubber-like melt is required for this crystallization process, it is of course only suitable for high molecular weight polymers, in particular for polymers with a reduced viscosity of not less than 0.5, the reduced viscosity being the specific viscosity divided by 0.6 at 20 ^° C. of a solution in chloroform containing 0.6 g / cc. This second crystallis ation processes can be used to produce crystalline fibers and films with an oriented crystal structure. The fiber pitch of this crystal structure is 10.5 ± 0.1 Å. The strongest reflections that can be seen on X-ray interference photographs are as follows:

4th layer line intensity S. * r 0 0.147 d (A) visual S.
S. 0
0 0.257
0.295 estimate VW 0 0.390 10.4 c VS 0.147 0.196 6.0
5.2 Equatorial layer < W.
^W l doublet ί 0.147
0.147 0.271
0.323 3.95 [ Wj ^{υοηοιβτ} ^ 0.147 0.334 6.3 c VW
M. 0.293
0.293 0.344
0.391 5.0
4.34 1st layer line < MS 0.440 0.214 4.22 [ MS 0.440 0.266 3.41
3.15 2nd layer line I MS 0.440 0.325 3.15 [ M. 0.586 2.99 3rd layer line < 2.82 I. Meridional strip

The symbols have the usual meaning given in the textbooks for crystallography, ζ and ξ are the cylindrical coordinates of the reciprocal lattice, where ζ is measured parallel to the fiber axis and ξ perpendicular to the fiber axis.

ξ 2 = 2sina,

2 sin σ

σ = Bragg angle of reflection.

d = distance of the plane (or planes) which are to

Reflection contributes.
2 = wavelength of the X-rays, Cu K ₀ ,

= 1.542 Å.

Some of the reflections were diffuse and may have been caused by one or more overlapping reflections. The accuracy of the f-values is ± 2% in the equator, but decreases to about ± 5 ° / ₀ towards the third slice line.

The photographic diagrams show a strong, amorphous band at 6.6 Å and two weaker bands at about 3.0 Å and 2.15 Å.

The X-ray interference images of well-crystalline polymers without the orienting crystallization process C method 2) showed powder-like rings with maxima at the following distances:

intensity Distance (d in Ä) MS 10.3 VS 6.15 MS 5.15 W. 4.3 M. 3.15 W. 2.8 VW 2.5 VW 2.1

In this table, S means intense, MS less intense, VS very intense, M medium, W weak and VW very weak.

The new crystalline polymers according to the invention are transparent, stiff solids that are opposite Oxidation and degradation by light and alkaline liquids are resistant. They show one low water absorption and are hardly wetted by water. The permeability for gases and oils is small amount. They can be of different molecular weights, e.g. B. molecular weights in excess of 10,000 and are generally most useful when their molecular weights are above 50,000. It should be noted that they represent high-melting, thermoplastic materials that are used in the synthetic resin industry. They can also be used as reinforcing fillers for butadiene-acrylic acid nitrate rubber can be applied, as the following results show:

A mass of the following composition was prepared, parts being parts by weight:

Components Blind
sample Mass A Mass B Polymethyl methacrylate ge
according to the invention;
average mole
kular weight (viscosi
determination)
~ 135,000
Bis (2-hydroxy-3 «-methyl -
cyclohexyl-5-methyl-
phenyl) methane
Zinc oxide
Stearic acid
Benzthiazyl disulfide
sulfur 1
3
0.5
1.0
1.5 1
3
0.5
1.0
1.5 20th
1
3
0.5
1.0
1.5

Components Blind
sample Mass A Mass B Copolymer from 66 ° / ₀
Butadiene and 32 ° / ₀ acrylic
acid nitrile
Polymethyl methacrylate ge
according to the invention;
average mole
kular weight (viscosi
determination)
~ 50000) 100 100
20th 100

These masses were produced by rolling the rubber on a mill at 160 to 165 ° C, adding the bis (2 - hydroxy - 3α - methylcyclohexyl - 5 - methylphenyl) methane and then the polymethyl methacrylate - if used - and then adding the mixture it was ground for a long time until it looked homogeneous. The mixture obtained was then cooled and ground at 50 to 70 ^° C. with the other constituents of the mass. Test pieces were molded from the mass at 150 ^° C. for 25 minutes. The following results were obtained:

material

tensile strenght
(kg / cm =)

Elongation to break

(1) (2) 9.9 14.8 (3) (4) (5) 5 100 300 8.5 12.0 Elasti Permanent 5 6.7 8.5 H ity Strain ("/") 10 (kg / cm ² ) Where) 15 sec. 1 hour 48 52V ₈ 30th 48.5 53 25th 41 59 35

Mass A ..
Mass B ..
Blank sample

90

87.2

21

860
880
677

(1) Tensile force at an elongation of 100 ° / ₀ .

(2) Tensile force when stretched by 300 »/«.

(3) hardness.

(4) At 20 ⁰ C.

(5) Remaining elongation in ⁰ I ₀ after the sample has been _{stretched by 30 ° / 0 for} 1 hour and allowed to contract for the specified time.

The following examples were carried out in a nitrogen atmosphere.

example 1

0.5 mol of ethylmagnesium bromide in 300 ecm of ether was treated with 325 ecm of petroleum ether (boiling point 100 to 120 ° C.), whereupon a dark oil separated off. 1.0 mol of methyl methacrylate was added to the well-stirred mixture, the temperature being kept below 40.degree. After 1 V ₂ hours stirring the thick suspension was diluted with 100 cc of n-hydrochloric acid treated and collected for a grayish solid.

Inorganic material was removed by mixing this solid in a mixture of 200 ecm of methanol, 190 ecm of water and 10 ecm of concentrated hydrochloric acid was stirred. After drying in vacuo, 29.6 g of a hard, white solid were obtained, the ash content of which was 0.4%.

Example 2

0.1 mol of ethyl magnesium bromide in 100 ecm of ether was treated with 400 ecm of petroleum ether (b.p. 60 to 80 ° C). An oily layer was formed. Within 30 minutes, 30 g of methyl methacrylate were slowly added added, the temperature slowly rising to 40 ° C. After stirring for 2 hours, the suspension became treated with 50 ecm n-hydrochloric acid and 50 ecm methanol. The white polymer was collected and in a mixture of 2N hydrochloric acid (150 ecm) and methanol (250 ecm) for 1 hour Removal of inorganic material stirred up.

After drying in vacuo, 10.7 g of a hard, white powder were obtained.

55

Example 3

0.1 mol of n-propyl magnesium bromide was used in 100 ecm Ether prepared and mixed with 200 ecm petroleum ether (b.p. 60 to 80 ° C). The resulting suspension of the oily Compound was added with 25 g of methyl methacrylate at such a rate that the temperature did not rise above 35 ° C.

The product was isolated as in the previous example to give 14.0 g of a white powder became.

65

Example 4

25 g of methyl methacrylate were added to a solution of

0.1 mole of n-butylmagnesium chloride in 100 cc of ether and 200 cc of petroleum ether (bp. 60 to 8O ⁰ C) was added and the biphasic mixture stirred for 2 hours. Thereafter

7 8

6.9 g of polymer were in the form of a white, granular with 5.9 g of polymer (20%, based on monomer) Solids isolated. as a white, granular solid.

Example 5 Example 10

0.1 mol of n-amylmagnesium bromide in 100 ecm of ether 5 As in Example 8, 0.243 mol of methyl methacrylate was mixed with 200 ecm of petroleum ether (b.p. 60 to 80 ° C.) and 0.023 mol of ethylmagnesium bromide in 50 ecm of iso. Then 25 g of methyl methacrylate were added to the propyl ether and 100 ecm of methylcyclohexane stirred together mixture, the temperature being given, the mixture being stirred for 2 ¹ I for ₂ hours and kept at 40 ° C. as in. Worked up shortly after the start of conversion example 1. 8.2 g of polymer formed two liquid phases in the mixture. After io as a white granular solid obtained I ¹ / "hour stirring the thick suspension (34% yield based on monomer). 100 ecm n-hydrochloric acid treated and a. .

greyish solid collected. Inorganic material. Example II

was removed from this solid by using a As in Example 8 0.159 mol of methyl meth-

Mixture of 200 ecm of methanol, 190 ecm of water and 15 acrylate and 0.016 mol of ethylmagnesium bromide in 50 ecm of 10 ecm of concentrated hydrochloric acid, diethylaniline and 100 ecm of petroleum ether (b.p. 60 to 80 ° C) was stirred. Then 4.1 g of an almost white powder were combined. The mixture was then kept at room temperature for 3 hours, stirred at temperature and worked up as in Example 1. • D ··, g This gave 1.4 g of polymer as a white, granular ^b P 20 solid (9% yield, based on 0.309 mol of methyl methacrylate used, monomer added dropwise). within 12 minutes in a well-stirred solution Example 12 of 0.05 mol of ethylmagnesium bromide in 50 ecm of ether

given. The temperature was increased by cooling to 20 ° C. As in Example 8, 0.3 mol of methyl methacrylate was used

held. Towards the end of the addition, an oil and ethylmagnesium bromide in 42 ecm of phenetol had separated out and soon solidified. The mixture was combined with 84 ecm of cyclohexane and stirred for 2 hours for a further 2 hours, then slowly stirred under. Then, as in Example 1, cooling was carried out with 50 ecm of methanol and then with 100 ecm. 5.3 g of polymer were added as white, n-hydrochloric acid. After a further ¹ Z ₂ Stun- granular solid obtained (18% yield, based on digem stirring, the mixture was nitrated and the solid monomer). substance stirred with methanol, with a mixture from Example 13

50 parts by volume of methanol and 50 parts by volume of normal hydrochloric acid Washed well, again with methanol Petroleum ether dried over sodium (b.p. 60 bis washed and dried in vacuo at 60 ° C. In the process 80 ° C) became a solution of 0.05 mol of ethyl 17.1 g ^ 55% yield) of a similar white 35 magnesium bromide in 50 ecm of dry ether. Powder received. The resulting dark emulsion became within

15 minutes with 20 ecm (0.17 mol) of freshly distilled

Example 7 Ethyl methacrylate added. The temperature of the reac

tion mixture did not noticeably increase. The GE-

An ethereal solution of 0.05 mol of ethyl 4.0 mixture was then ^{stirred for 2 hours at 20 =} C-, magnesium bromide was removed by distillation of the largest part of the ether, which was then added with 50 ecm of 0.1 N hydrochloric acid. The obtained solid was. The sticky precipitate thus formed was dissolved in 50 ecm of benzene. Left dissolved in hot methanol within 20 minutes; After cooling this one 0.309 mol of methyl methacrylate solution in this solution, a gummy precipitate formed, which dripped while it was stirred well and, after drying over sulfuric acid, kept a yellow-brown color at 23-30 ° C. A rubber-like mass (5.3 g) collected on the wall of the flask and soon a gray, sticky solid formed. The mixture.

was stirred for 2 hours and as in Example 1 - Example 14

works, with a similar white powder (5.1 g; 17% 28.1 g (0.281 mol) methyl methacrylate and 1.28 g

Yield; was obtained. 50 (0.0153 moles, 5.4 mole percent) methyl isopropenyl ketone

were slowly a mixture of 0.05 mol of ethyl

Example 8 magnesium bromide in 20 ecm ether and 40 ecm petrol

ether (bp. 60 to 80 ° C), which is mixed with 0.18 g of water

0.295% of ethyl methacrylate were added within 27 minutes to a well-stirred mixture of 0.1 mol of 55 at 20 ° C. with stirring and in a nitrogen atmosphere. The mixture was stirred for 2 hours ge-phenylmagnesium bromide, 42 ecm ether and 85 ecm, 50 ecm methanol and 50 ecm 2N chlorine water-petroleum ether (boiling point 60 to 80 ^: Cj at 16 to 25 ° C) were added The polymer was filtered off, the mixture was stirred for 2 hours at room temperature with a mixture of 20 percent by volume of methanol and worked up as in Example 1, with 5.5 g of 20 percent by volume of 2N hydrochloric acid being stirred, good polymer (19%, based on monomer) as white , 60 washed with methanol and obtained in a vacuum at 60 ^: C granular solid.

3.5 g of a white crystallizable powder of Example 9 were obtained, which is based on a yield of 12%

total monomer.

0.3 moles of methyl methacrylate were used within 65

32 minutes to a well-stirred mixture of 0.1 mol of Example 15

Cyclohexylmagnesium bromide, 59 ecm ether and 118 ecm A mixture of 28 g (0.28 mol) methyl methacrylate

Petroleum ether (b.p. 60 to 80 ^c C) given at 16.22 ° C. and 1.76 g (0.026 mol, 9.3 mol percent, based on "The mixture was stirred for a further 2 hours at room temperature methyl methacrylate) methacrylic acid nitrile and worked up as in Example 1, stirring slowly at 20 ° C. in a nitrogen atmosphere

10

added to the catalyst mixture described in Example 14, stirred for 2 hours and worked up as in Example 14.

There were 12.4 g of a white powder (42 ° / _0, based on the total amount of monomers) was obtained which is in the X-ray analysis to be crystalline and was found 0.3 ° / ₀ containing nitrogen (corresponding to 1.8 ° / ₀ methacrylonitrile) .

Example 16

A mixture of 30 g (0.30 mole) methyl methacrylate and 0.219 g (0.0011 mole, 0.367 mole percent) glycol dimethacrylate slowly under nitrogen at 20 ° C to a well-stirred mixture of 0.05 ecm mol Ethylmagnesium bromide, 21 ecm ether and 42 ecm Petroleum ether (b.p. 60 to 80 ° C) given. The reaction mixture was stirred for 2 hours and as in Example 14 worked up.

15.6 g of a white crystallizable powder which was practically insoluble in chloroform were obtained. This corresponds to a yield of 52 ° / _0, based on the total monomers.

Example 17

100 g (1 mol) of methyl methacrylate were added dropwise to a well-stirred mixture of 0.4 mol of ethylmagnesium bromide, 400 ecm of ether and 800 ecm of petroleum ether (b.p. 60 to 80 ° C) under nitrogen, the temperature being kept at 20 to 30 ° C became. The mixture was stirred for I ¹ Z ₂ hours as in Example 14, but using about four times the amount of methanol and hydrochloric acid, worked up.

12.5 g of a white crystallizable powder were obtained; this corresponds to a yield of 12.3 ° / _0, based on the monomers. After tempering at 130 ° C. for 3 hours, the crystalline melting point was 160 ° C., as was determined with the aid of the birefringence.

n-Propyl methacrylate within 15 minutes Room temperature. A white, sticky solid precipitated out.

The mixture was stirred for a further 3 hours at room temperature and then 50 ecm of 2N hydrochloric acid were added, whereupon two clear layers formed; the upper layer was _{washed acid-free with NaHCO 3} solution and water, dried and concentrated to a yellow, viscous oil by evaporation in vacuo at room temperature. This oil was soluble in methanol.

Example 20

The procedure was as in Example 19, except that 20.5 ecm of freshly distilled isopropyl methacrylate were used. After isolating the product in the manner described above, approximately 18 cc slightly yellow, gummy mass soluble in methanol was obtained.

Example 18

40

0.15 mol of n-butyl methacrylate were added dropwise under nitrogen at -60 to -50 ° C. to a well-stirred mixture of 0.028 mol of n-butyl magnesium chloride, 20 ecm of ether and 40 ecm of petroleum ether (b.p. 60 to 80 ° C.). The mixture was stirred for 2 hours at −50 ° C., 50 ecm of methanol and then 50 ecm of 2N hydrochloric acid were added. No precipitate formed. The upper layer of the mixture was separated and evaporated in vacuo to give a clear gum, soluble in methanol composition was (80 ° / ₀ yield based on monomer) was obtained.

Example 19

0.05 mol of ethylmagnesium bromide were in 50 ecm made of dry ether. Then 100 ecm of dry petroleum ether were iKp. 60 to 80 ° C) added and the mixture obtained with 20.0 ecm freshly distilled

Example 21

By adding 20 ecm of freshly distilled isobutyl methacrylate to 0.05 mol of ethylmagnesium bromide according to the manner described in Example 19 was 6.0 g a discolored syrup which dissolved smoothly in warm methanol.

Claims (6)

Patent claims: 1. A process for polymerizing an ester of methacrylic acid with a monohydric alcohol having up to 4 carbon atoms, characterized in that this ester is added to a compound of the formula RMgX, where R is an alkyl, cycloalkyl, aryl or aralkyl radical and X is a Means chlorine or bromine atom and this compound can be mixed with a liquid that is able to dissolve the ester. 2. The method according to claim 1, characterized in that that when the ester is added to the magnesium compound, the ingredients together be mixed homogeneously. 3. The method according to any one of the preceding claims, characterized in that the ingredients are mixed during the polymerization. 4. The method according to any one of the preceding claims, characterized in that the magnesium compound an alkyl magnesium bromide with up to 4 carbon atoms is used. 5. The method according to any one of the preceding claims, characterized in that the magnesium compound is mixed with a liquid that is able to dissolve the ester, but in which the Magnesium compound is almost insoluble. 6. The method according to claim 5, characterized in that the liquid is a mixture of one Ether and an aliphatic hydrocarbon. When the notification was announced, four priority documents were displayed. 10Ϊ 580/445 5.61