DE2023303A1 - Crosslinked styrene acrylate polyalkylene oxide ester copolymers - - having outstanding low-temp impact strength - Google Patents

Abstract

Styrene and/or a low alkyl (meth)acrylate are copolymerised, in known manner, with 1-80 weight % of polyalkylene oxide esters of formulae (Ia) and/or (Ib), The products are impact resistant even at temps. at about -50 degrees C, have good antistatic characteristics, and adhesion to surfaces of inorg. materials, e.g. glass, metals, in presence of free hydroxyl groups.

Description

Elastic Crosslinked Polymers It is known that polystyrene is used for a number of application areas is too brittle. That's why you have to deal with different ones Way tried modified polystyrenes with better elastic properties to manufacture. One has, for example, by polymerizing styrene in the presence of Butadiene-styrene rubber made of impact-resistant polystyrene. The resulting product however, it is a two-phase system and is not transparent.

Furthermore, z. B. Acrylonitrile-butadiene-styrene terpolymers (ÄBS polymers) in trade. Copolymers of styrene with unsaturated polymers (unsaturated Polyester resins) have already been proposed. For many areas of application, especially if the plastics are used at low temperatures, however, are the The elastic properties of these known polymers are insufficient. Particularly the impact resistance of the known products can be at temperatures of z. B. -500C to be desired.

It has now been found that polymers with excellent elastic properties can be obtained obtained when styrene and / or (methyl acrylate in the presence of polyepoxides polymerized with polymerizable end groups. The resulting copolymers are crystal clear and their elasticity properties are similar to those of the plastics known up to now, especially at lower temperatures, clearly superior. The copolymers show in addition, a very favorable antistatic behavior, which is mainly due to the Hydrophilicity of the epoxy component or the free Carboxyl groups (in some of the new copolymers) is influenced. The copolymers according to the invention with free carboxyl groups are also characterized by excellent adhesive strength on surfaces of inorganic products, e.g.

on glass or metal.

C-object of the invention is thus a process for the production of crosslinked polymers with favorable elastic properties, which consists in that styrene and / or lower alkyl esters of acrylic or methacrylic acid with 1-80, preferably 10-60 wt .-% of Polyalkylene oxide esters of the formulas Ia and / or Ib R1 is hydrogen or methyl R2 is hydrogen or lower alkyl with 1-4 carbon atoms n1-, n2, n3 integers, where n1 + n2 + fl = n 1 2 3 n 4-1000, preferably 4-500, in itself copolymerized in a known manner.

The invention also relates to elastic, crosslinked polymers, produced by copolymerization of styrene and / or lower Alkyl esters of acrylic or methacrylic acid with 1 - 80, preferably 10 - 60% by weight the esters of the formulas I a and I b.

The starting material used is monomeric styrene and / or commercially available available lower alkyl ester of acrylic or methacrylic acid is used. Particularly are easily accessible e.g.

Methyl methacrylate, butyl methacrylate, methyl acrylate and butyl acrylate.

Polyepoxides come as polyethylene oxides and polypropylene oxides as well Their copolymers are considered, in particular the types with degrees of polymerization between 4 and 1000, preferably between 10 and 500, are suitable. The most common types of polyethylene oxides or glycols are those with medium molecular weights from 200, 300, 400, 600, 1000, 1500, 3000, 4000, 5000, 10,000 and 20,000. Polypropylene glycols are most easily available with average molecular weights of 250, 3000 and 4000. Mixtures can of course also be used.

The triesters of the formula I b are formed from polyalkylene oxide triols, which is known to be accessible by polyaddition of alkylene oxides with glycerol as a starter are.

The two terminal hydroxyl groups of these polyepoxides (starting material for the bis-esters according to formula I a) or the three terminal hydroxyl groups of the polyalkylene oxide triols (starting material for the tris-ester according to formula I b) are then esterified in a manner known per se, either with acrylic or methacrylic acid residues or with maleic acid or its lower alkyl monoesters. It is essential that esters of polyepoxides are used whose end groups are polymerizable Groups included.

The production of these esters succeeds, for. B. very easy by implementation of the corresponding polyepoxides with (meth) acrylic acid chloride or maleic anhydride according to standard methods.

The reaction with (meth) acrylic acid chloride takes place in a manner known per se Manner, expediently in the presence of strong bases, e.g.

Trimethylamine, triethylamine, pyridine, potassium carbonate.

The reaction advantageously takes place in the presence of solvents, z. B. benzene, toluene, xylene and / or butyl acetate.

The reaction temperatures are usually between 0 and 1000C, advantageous at about 10 - 5000. The reactants are expediently brought together slowly, in order to be able to better control the heat development that occurs during the reaction, In In some cases it is advantageous to clean the products obtained using exchangers, the use of strongly basic ion exchangers is preferred. At this Further solvents are often added to the purification, e.g. B. water, methanol, Ethanol, acetone, or other ketones.

It is also advisable to use the di- or triesters of the polyepoxides obtained to stabilize, e.g. 3. by adding radical scavengers such. B. Hydroquinone, the are usually added in a known manner in amounts between 0.01 and 5% by weight. In addition, care must be taken to exclude light during production to avoid polymerizations to prevent.

Also the implementation of the polyepoxides or the polyalkylene oxide triols bis- or tris-maleic acid esters are carried out in a manner known per se, preferably via maleic anhydride. The reaction can be carried out in the presence or absence of solvents take place. The temperatures can be between room temperature and approximately 10000 can be varied; the reaction can also be carried out using catalysts (acidic or basic catalysts) can be carried out. Succeeds particularly advantageously the reaction with acidic ion exchangers, which are in the H + form and preferably in the dried form May be used. You can then get by without any difficulty Product can be separated.

The easiest way to implement it is to boil the reaction partner under reflux, usually for about 5-20 hours.

Alcohol and acid anhydride are used in approximately equivalent amounts, so that the ratio in the diols (formula I a) is about 1: 2, while in the triols (formula I b) use 3 moles of maleic anhydride to 1 mole of alcohol are. Products are obtained in which R2 is hydrogen. these can in a manner known per se, for. B. by reaction with lower alkanols in the presence an acidic catalyst such as HOl or H2S04, in the corresponding lower alkyl esters (R2 = alkyl with 1 - 4 carbon atoms) are converted.

The diesters obtained are, depending on the molecular weight, those used Polyepoxides, viscous to waxy products.

The maleic acid esters of polyethylene glycols of higher molecular weight can also be obtained in crystalline form.

The polymerization itself can be carried out according to all the usual methods described in the literature procedures described. So the polymerization e. B. in substance, be carried out in solution, in emulsion or as precipitation or bead polymerization. As a rule, a radical initiation is preferred, the z. B.

by oxidizing agents such as peroxides, especially dibenzoyl peroxide, Dilauroyl peroxide, di-o-tolyl peroxide, hydrogen peroxide or salts of peroxydichulphuric acid or in particular can also be caused by azoisobutyrodinitrile. Even one Redox initiation is possible, e.g. B. by using the systems sodium dithionite / alkali peroxydisulfate or dibenzoyl peroxide / dimethylaniline. The initiators will be handed over to Sr Ch Way used in concentrations of 0.01 to 10%, preferably 0.1-2%. the Polymerization itself is generally in the temperature range of about 20-1200C carried out and, as is known, depends on the initiator system used.

Often the esters of the polyepoxides are directly incorporated into those to be copolymerized Monomers dissolved .. After the addition of the initiator, the polymerization then takes place in in a known manner, preferably at temperatures of about 50 - 120 ° C. Many times it is advantageous to let the copolymerization take place in forms from which the end products can then be removed with ease.

However, the copolymer can also be used before the end of the polymerization smear out and then get on the surface after the polymerization has ended elastic and scratch-resistant covers on the coated surface.

In addition, of course, those in the case of solution polymerization can also be used obtained flakes by mechanical action, for example by higher temperatures (e.g. 100 - 30000) and higher pressures (e.g. 2 - 100 atü) to end products with the desired elastic properties are converted.

The copolymers according to the present invention are in standard tests have been investigated for their special mechanical properties. With increasing Crosslinker content results in an increase in the elongation at break, the Shore hardness and the Impact strength.

The Shore hardness A was determined in accordance with DIN 53 505.

Sheets produced by bulk polymerisation with a Height of 4 mm tested with the Shore hardness A tester.

The measurement is made at different points on the plate.

The impact strength is determined in accordance with DIN 53 453 as a function on the temperature. Tempered standard small rods are used on the pendulum impact tester Fracture brought. The impact energy consumed by the test specimen is measured.

The elongation at break is determined in accordance with DIN 53 455. A shoulder rod is used as the test body, which is machined was made from a plate. Before the measurement, the test specimen is left for 24 hours stored in the climate specified during the measurement (60% rel. humidity). The shoulder rod is clamped in the jaws of the tensile tester. The cheeks will at the speed of 100 mm / min. pulled apart. The force-displacement diagram is recorded. The elongation at break results from the measured values of the length of the rod at break (measured between the two points at which it is clamped war) and the length of the clamped rod before the tensile load.

The new copolymers are suitable, for. B. for the production of laminated glass panes or resistant transparent coatings and molded parts (e.g. aircraft cockpits, Rear light caps for motor vehicles), which then also work at lower temperatures do not lose elastic properties. The coatings (lacquers) are particularly notable when using the products with free carboxyl groups by an exceptional Adhesive strength on the base. Also their high compatibility with the most diverse Pigments deserve to be highlighted.

The connection of the new copolymers with, in particular, inorganic ones Fibers, e.g. B. Glass, leads to products that can be used anywhere with advantage can be used where glass fiber reinforced plastics are required.

The new plastics themselves are used in a more usual manner Way. Because of the elastic properties of the new products, the manufacture in the form of threads and foils of particular interest.

Example 1 a) 1000 g of a polyepoxide (polyethylene glycol with a average molecular weight of 1000) are dissolved in about 3 liters of benzene. It will 253 g of triethylamine are added, and then the solution is slowly added at 200 220 g of methacrylic acid chloride are added. The reaction mixture is about 15 hours stirred at room temperature. The reaction mixture is filtered off with suction and the filtrate after adding 300 ml of methanol with 800 g of a strongly basic ion exchanger (Ion exchanger III "Merok") added and stirred for one hour.

After suction, the filtrate is stabilized with 0.1 ffi hydroquinone and freed from the solvent at 25-3000 under reduced pressure. You get Polyethylene glycol bis methacrylate as a waxy product.

b) In 90 g of methyl methacrylate, 10 g of the example 1 a prepared polyethylene glycol bis-methacrylate dissolved. The mix will be 0.1 g of azoisobutyrodinitrile was added. The mixture is in a polymerization mold given (2 held at a certain distance and sealed glass plates) and im Polymerized in a water bath at 600C. After about 4 hours the mold is opened. Man receives a crystal-clear plate of high impact resistance.

Example 2 1000 g of butyl methacrylate are mixed with 300 g of the after Example 1 a prepared polyethylene glycol bis-methacrylate added. The mixture is poured into a hinged hollow mold.

The polymerization is after the addition of 1 g of azoisobutyrodinitrile 600 carried out in the heating cabinet. An elastic copolymer with excellent mechanical properties.

Example 3 98 g of monomeric styrene and 2 g of that prepared according to Example 1a Polyethylene glycol bis methacrylate are polymerized with the addition of 0.2 g of benzoyl peroxide. The temperature during the polymerization is between 50 and 600. The polymerization takes place analogously to Example 1b in a form consisting of sealed glass plates instead of. The plate obtained is crystal clear and clearly shows a contrast to polystyrene increased impact strength.

Example 4 A mixture of 70 parts of methacrylic acid methyl esters r and 30 parts of polyethylene glycol bis methacrylate (average molecular weight of Polyethylene glycol 600) is in a flask with 0.1 fo azois azoisobutyrodinitrile added and kept at 60 ° C. for one hour with stirring. The so obtained, easily viscous solution is spread on metal plates and at 600C to complete Brought polymerization. A coating is obtained that is more elastic and more scratch-resistant is available as a polymethyl methacrylate coating.

Example 5 45 g of methyl methacrylate, 5 g of polypropylene glycol bis-methacrylate (average molecular weight of the polypropylene glycol 1500) and 1 g of azoisobutyrodinitrile in 100 g of methanol and 50 g of water stirred. The mixture is polymerized in a water bath at 70 ° with stirring. at If the contents of the flask begin to become cloudy, 150 ml of water are run in and the mixture is heated then another 3 hours at 70 °. The precipitated, flaky polymer is Sucked off, washed with water and dried. By pressing this product at 2000 and 100 kp / cm2 pressure one obtains a plate with its mechanical properties correspond approximately to those of the plate described in Example 1 b).

Example 6 Analogously to Example 1a, 300 g of polyethylene oxide (M. 3000), 25.3 g of triethylamine and 22 g of methacrylic acid chloride are reacted in 1 l of benzene and worked up.

20 g of the product thus obtained are put together between glass plates with 20 g of methyl methacrylate and 20 g of styrene for 24 hours at 50 ° C. and 10 hours 800C copolymerized. 0.2 g of azoisobutyronitrile serve as initiator. You get a disc of a transparent polymer with high elasticity.

Example 7 a) 240 g of a polyepoxide (polyethylene glycol with a average molecular weight of 600) and 78.4 g of maleic anhydride are in 500 ml of absolute benzene dissolved. There are 5 g of a strongly acidic, anhydrous ion exchanger (based on polystyrene sulfonic acids) is added in the H + form and the mixture is made Boiled under reflux for 15 hours. After cooling, the ion exchanger is filtered off and the filtrate is concentrated to constant weight under reduced pressure. There remain 321 g of a light yellow, highly viscous oil.

To characterize the product obtained, a sample is used in given a little water and stirred for 1 hour at room temperature to remove the unreacted To hydrolyze maleic anhydride. This mixture is then with 0.1 N Titrated with NaOH. From, the consumption of caustic soda is the turnover due to the not converted maleic anhydride, calculated to be 89.4%.

b) A mixture of 50 g of destabilized styrene, 10 g of the after Example 7 a) obtained polyethylene glycol bis-hydrogen maleate and 0.2 g of azoisobutyrodinitrile is first 12 hours at 60 ° C and then in a polytetrafluoroethylene form Polymerized at 80 ° C for 12 hours. A crystal-clear molding is obtained, which is can be easily machined and can be polished.

Example 8 a) Analogously to Example 7 a), 1 mol of a polyethylene glycol is used reacted with an average molecular weight of 1500 with 2 moles of maleic anhydride. The polyethylene glycol bis-hydrogen maleate obtained is slow at room temperature crystallizing oil.

The conversion is determined analogously to Example 7 a) and is calculated to 84%. The maleic anhydride still present in the reaction mixture can with increased Temperature are removed under reduced pressure.

Half of the product thus obtained is boiled for 5 hours converted into the corresponding methyl ester with methanolic hydrochloric acid (about 1%) (Formula I a, R2 = Roh3).

b) Analogously to Example 7 b), 40 g of destabilized styrene, 20 g of the polyethylene glycol bis-hydrogen maleate (obtained according to Example 8a)) and 0.2 g Azoisobutyrodinitrile between glass plates at temperatures of 600C for 3 days polymerized. A crystal-clear elastic product is obtained that has great adhesiveness on glass and post-processed by machining and polishing can be.

The methyl ester of polyethylene glycol bis-hydrogen maleate is used in a corresponding manner polymerized. This also creates a very elastic, transparent product. 6 Example 9 50 g of destabilized styrene, 10 g of that obtained according to Example 8 a) Polyethylene glycol bis-hydrogen maleate and 0.2 g of azoisobutyrodinitrile are initially Polymerized between glass plates for 12 hours at 600C and then for 12 hours at 800C.

The resulting crystal clear polymrisate is characterized by great adhesive strength on glass and good elasticity as.

Example 10 The mixture obtained according to Example 8 b) is on a Sheet steel applied thinly. Polymerize at 800 ° C. for 12 hours.

The result is a very firmly adhering, scratch-resistant, transparent lacquer coating.

If desired, the polymerization mixture can also contain pigments can be added.

Example 11 Analogously to Example 1 b), 90 g of methyl methacrylate are obtained and 10 g of polyethylene glycol bis-hydrogen maleate (according to Example 8 a) in the presence of 0.1 g of azoisobutyrodinitrile copolymerized.

The mixture is kept at 65 ° C in a water bath. The emerging Product has good elasticity and high impact resistance.

Example 12 a) Analogously to Example 7a), 1 mol of polyethylene glycol is added an average molecular weight of 5000 to 6000 with about 2 moles of maleic anhydride implemented. The product obtained slowly crystallizes at room temperature. Of the Conversion is calculated analogously to Example 7 a) to 81.

b) The polymerization of the polyethylene glycol bis-hydrogen maleate obtained according to Example 12 a) with destabilized styrene is carried out analogously to Example 8 b). An elastic one is obtained Product that has high impact resistance.

Example 13 a) 1500 g of polypropylene oxide triol with an average molecular weight of 3000 are dissolved together with 160 g of triethylamine in 6 l of dry benzene. 158 g of methacrylic acid chloride are added dropwise over the course of one hour while cooling with ice.

The mixture is then stirred at room temperature for 20 hours. The precipitated triethylammonium chloride is filtered off with suction. The filtrate is after addition concentrated from 0.1% hydroquinone with exclusion of light under reduced pressure.

The obtained polypropylene oxide triol trimethacrylate is weak yellow colored solid product.

b) The product obtained according to example 13 a) is analogous to example 1 b) copolymerized with methyl methacrylate and azoisobutyrodinitrile as initiator. An elastic, glass-clear product is obtained. Example 14 a) Analogously to Example 7 ajw is 1 mole of polypropylene oxide triol with an average molecular weight of 3000 with about 3 moles of maleic anhydride reacted. The tris hydrogen maleate obtained crystallizes slowly at room temperature. The conversion is around 80% (calculated analogously to the example 7 a).

b) The polymerization of the polypropylene oxide-triol-tris-hydrogen maleate obtained according to Example 14 a) with destabilized styrene is carried out analogously to Example 8 b. The received, transparent In addition to good elasticity, the product has excellent adhesive properties on smooth Surfaces.

Example 15 a) Analogously to Example 7 a), 1 mol of polypropylene glycol is added reacted with an average molecular weight of 3000 with about 2 moles of maleic anhydride. The product obtained crystallizes after some time at room temperature.

b) The polypropylene glycol bis-hydrogen maleate obtained is analogous Example 8b copolymerized with styrene. The copolymer provides a firmly adhering, transparent coating -on a pane of glass.

Claims (9)

PATENT CLAIMS 1. Process for the production of crosslinked polymers with favorable Elasticity properties, characterized in that one styrene and / or lower Alkyl esters of acrylic resp. Methacrylic acid with 1-80, preferably 10-60% by weight of polyalkylene oxide esters of the formulas I a and / or I b where R R1 is hydrogen or methyl R2 is hydrogen or lower alkyl with 1-4 carbon atoms n1, n2, n3 integers, where n1 + n2 + n3 = nn 4-1000, preferably 4-500, are copolymerized in a manner known per se. 2. The method according to claim 1, characterized in that the Copolymerization carried out at temperatures between 50 and 120 ° C. 3. The method according to claim 1, characterized in that as Esters of the formula I a polyethylene glycol bis-methaorylate are used. 4. The method according to claim 3, characterized in that one Polyethylene glycol bis methacrylate with an average molecular weight between 200 and 20,000 used. 5. The method according to Ahsprtichen 1 and 2, characterized in that that a polyethylene glycol bis-hydrogen maleate of the formula I a is used. 6. Process according to claims 1-5, characterized in that one uses styrene or methyl methacrylate. 7. Elastic, crosslinked polymers, produced by copolymerization of styrene and / or lower alkyl esters of acrylic or. Methacrylic acid with 1-80, preferably 10-60% by weight of polyalkylene oxide esters of the formulas I a and / or I b R1 is hydrogen or methyl R2 is hydrogen or lower alkyl with 1 to 4 carbon atoms n1, n2, n3 are whole numbers, where n1 + n2 + n3 = nn 4-1000, preferably 4-500. 8. Polymers according to claim 7, characterized in that they are prepared are by copolymerization of styrene with 10 -60 wt. of a polyethylene glycol bis-methacrylate with an average molecular weight between 200 and 20,000. 9. Polymers according to claim 7, characterized in that they are prepared are r £ lat by copolymerization of styrene or methyl methacrylate with a polyethylene glycol-bis-hydrogen maleate of formula I a.