WO2012151596A2

WO2012151596A2 - Expandable polymers consisting of cellulose acetate butyrate and a styrene polymer

Info

Publication number: WO2012151596A2
Application number: PCT/AT2012/000102
Authority: WO
Inventors: Roman Eberstaller; Gerhard Hintermeier
Original assignee: Sunpor Kunststoff Gesellschaft M.B.H.
Priority date: 2011-04-18
Filing date: 2012-04-17
Publication date: 2012-11-15
Also published as: WO2012151596A3; EP2699628A2; AT511509A1

Abstract

The invention relates to expandable polymers or polymer granules and polymer foams consisting of a polymer mixture containing a cellulose acetate butyrate (CAB) and a styrene polymer. The invention also relates to the production thereof.

Description

Expandable polymers of Celluioseacetatbutyrat and Styroipolymerisat

The invention relates to expandable polymers or polymer granules of a polymer mixture comprising a cellulose acetate butyrate (CAB) and a styrene polymerate and corresponding polymer foams.

STATE OF THE ART

Celluioacetate butyrate (CAB) is a biopolymer based on cellulose. It is an ester of cellulose with aliphatic carboxylic acids. Whereas, for example, in the case of cellulose acetate the esterification takes place only by acetic acid, esterification with acetic acid and butyric acid takes place with cellulose acetate butyrate.

The celulose acetate butyrate polymer may be generally represented by the formula

symbolized, where each R in the Poiymer independently from the group of -

OH (hydroxyl), -OOCCH ₃ (acetate), and -OOCCH ₂ CH ₂ CH ₃ (Butyrai).

Cellulose fermentate butyrate has a relatively low density as compared to cellulose acetate and cellulose propionate and has high strength, hardness and toughness. It is dimensionally stable in the temperature range of - 45 ° C to 1 15 ° C, has high temperature and UV resistance and is resistant to moisture and a variety of chemicals and environmental factors.

As industrially manufactured plastic Celluioseacetatbutyrat is since 1946 in the trade. Celluioseacetatbutyrat is used for the production mainly as granules, which is suitable for both extrusion and injection molding.

The range of applications of Celluioseacetatbutyrat ranges from Griffbeschichtun- gene, such as handles of the Swiss Army Knives, Klarsichtkuppein, toys, cable conduits, coatings and paints, for example in the automotive and automotive industry, explosion-proof windows, vehicle lighting, automotive accessories, contact lenses and office equipment to films and packaging material or as part of nail varnishes, printing inks, known trade names are Cellidon®, Tenite® and Tenex®. The use of polymer foams based on fossil raw materials, such as EPS (Expandable Polystyrene), for packaging, insulation and a number of other applications has a long tradition and is well established.

The aim is to completely or partially replace fossil raw materials with renewable raw materials and to maintain the good mechanical, thermal and processing properties.

Various applications of biopolymers are known in the art. Thus, US Pat. No. 6,221,924 describes a process for producing foams of cellulose acetate having good mechanical properties. The moldings produced from it are biodegradable. WO 2008/130226 describes a process for the preparation of foams from polylactic acid, which also show good biodegradability.

Biodegradability has great advantages for short-lived consumer goods, for durable goods such as thermal insulation panels in and on buildings - the use of polymer foam as thermal insulation has a long tradition and is well established - but this is an exclusion criterion.

For reasons of sustainability and resource security, it is therefore desirable to use the highest possible proportion of raw materials from renewable raw materials, which, however, show no biodegradability and as close as possible to the properties of existing fossil-based materials, such as those of expandable polystyrene ( EPS).

Such expandable polymer granules should be reliable and easy to process foamed foam moldings with good welding, which have a Gietchmäßige cell structure with average Zelfgrößen between 20 and 500 pm and a density of 8 to 250 kg / m ³ . However, the polymer granules and the foam moldings produced therefrom should not show any biodegradability according to EN 13432: 2000 (requirements for the recycling of packaging due to composting and biodegradation).

Furthermore, the expandable polymer granules should be processible in equipment such as is commonly used to process expandable particulate foams, e.g. of EPS, are used, in particular in commercially available pre-expanders and molding machines or block molds.

A further important criterion is the shelf life of the polymer granules during transport and during storage to processing and the processing parameters during the pre-expansion, intermediate storage and sintering, which should be as close as possible to those of EPS. Furthermore, the foam parts produced from the granules described must meet the requirements of Formstabiiität, eg Nachblähen, shrinkage, cutability with hot wire and mechanical Schneideantagen. In the not yet published application A 2054/2009 the applicant is the

Use of CAB as a raw material for the production of expandable polymers or polymer granules described. However, it has been found that the CAB materials produced in this way have certain disadvantages with regard to their processability and achievable product properties in comparison with fossil source-derived products. Here are in particular the lower Lagerfähsgkett the propellant loaded granules, as well as the limited possibility of multiple foaming and thus the achievable lowest densities of the polymer particles, by the lower retention capacity of the blowing agent in the Poiymermatrix, compared to for example EPS, lead.

In addition, polymer particles whose polymer matrix consists largely of CAB tend to collapse, i. a shrinkage of the prefoamed beads during or immediately after the Vorschäumprozess, at the usual for example EPS pentane content of 6 wt .-%. This can be solved by lower pentane contents, but has the negative effect of a lower frothing performance towards lower densities and a deteriorated sintering of the foam beads in the production of molded parts.

It is therefore an object of the present invention to provide expandable polymers or polymer granules which do not have the disadvantages described above, but nevertheless consist at least in part of renewable raw materials.

DISCLOSURE OF THE INVENTION

This object is solved by the features of claim 1. According to the invention, it is provided that the polymers are formed from a polymer mixture comprising a cellulose acetate butyrate (CAB) and a styrene polymer.

It has surprisingly been found in experiments that suitable granules or advantageous polymer foams can thereby be obtained for optimum foam production. It was possible to produce expandable polymers having advantageous and suitable properties, which can be processed into polymer granules with the customary blowing agents in an industrial process and which yield polymer foam parts having the desired properties. In this way results an expandable polymer granulate, which can be stored for several weeks without difficulty, can be foamed to low densities in several foaming passages and still exhibits good welding properties. The terms "expandable polymers" or "expandable polymer granules" are to be understood as meaning expandable particulate particles comprising or consisting of CAB and polystyrene or CAB / PS particles of relatively small size, similar to commercially available EPS perienes Storage and transport normal conditions and froth by selecting the processing parameters to various densities and sizes, which are then sintered into moldings. These particles are thus easily expandable by increasing the temperature. It is both the production of open-cell and gesch geschossenzelligen foams and all intermediates possible. Advantageous embodiments or further developments of the invention are defined by the features of the dependent claims:

Thus it is possible for at least one further compatible polymer to be present in the polymer mixture when cellulose acetate butyrate (CAB) and styrene polymer together constitute more than 80% by weight, preferably more than 90% by weight, of the total mass of the polymer mixture. Here, for example, polyurethane, polylactide or other thermoplastic polymers are possible.

Particularly advantageous polymers are obtained when the polymer mixture consists exclusively of a cellulose acetate butyrate (CAB) and a styrene polymer.

It is advantageous if the proportion of cellulose acetate butyrate (CAB) is between 5 and 95% by weight, preferably between 10 and 90% by weight, particularly preferably between 40 and 90% by weight, based on the total mass of the polymer mixture. Surprisingly, the advantageous properties occur even at low contents of styrene polymers from about 5% by weight.

Particularly advantageous polymers are obtained when the cellulose acetate butyrate (s) used have a molecular weight average of Mn> 30,000 g / mol, in particular> 40,000 g / mol, in particular from 30,000 to 70,000 g / mol. The method and the test conditions for determining the molar mass distribution and the molar mass Mn (number average) were chosen analogously to the standard DIN 55672-1, for tetrahydrofuran (THF) -soluble polymers by Geipermeationschromatographie (GPC). The calibration was done with commercially available, linear and polystyrene standards characterized according to independent absoluivery.

The molecular weight number center! or the number average molecular weight n is the weighted arithmetic mean of the moimasse of a polymer sample. Mn is identical to the mean value of the molecular weight distribution of the polymer.

An advantageous butyryl content, determined according to ASTM 0817-96 (2010) (Standard Test Methods of Testing Cellulose Acetate Propionate and Ceilulose Acetate Butyrate), is between 30 and 60% by weight, based on cellulose acetate butyrate.

Furthermore, it is advantageous if the weight of hydroxyl groups on cellulose acetate butyrate, determined according to ASTM D8 7-96 (2010) (Standard Test Methods of Testing Cellulose Acetate Propionate and Ceilulose Acetate Butyrate), about 0.5 to about 2.5 wt .-%, preferably about 0.8 to about 1, 8 wt .-% based on cellulose acetate butyrate, is. Here, too, the reference quantity for the data in% by weight is the cellulose acetate butyrate as such, and not the weight of the polymers.

With regard to the styrene polymer used, it is advantageous to have a molecular weight or molecular weight average (Mn) between 140,000 and 350,000 g / mo! provided.

According to the invention, homopolymers and copolymers of styrene, preferably glass-clear polystyrene (GPPS), toughened polystyrene (HIPS), anionically polymerized polystyrene or toughened polystyrene (A-IPS), styrene-alpha-methylstyrene copolymers, acrylonitrile-butadiene-styrene polymers (ABS) are used as the polystyrene polymers. , Styrene-acrylonitrile (SAN) acrylonitrile-styrene-acrylic ester (ASA), methylacrylate-butadiene-styrene (MBS), methylmethacrylate-acrylonitrile-butadiene-styrene (MABS) -polymerizates or mixtures thereof or with polyphenylene ether (PPE) and expandable styrene polymers (EPS) prepared therefrom. In addition, the addition of other thermoplastic polymers, such as thermoplastic polyurethane or polylactic acid, is possible to modify the mechanical or chemical properties.

According to an advantageous further development of the invention, it is provided that the propellant-free CAB / PS polymer mixture has a glass transition temperature Tg in the range from 90 ° C. to 145 ° C. A propellant-free polymer mixture is obtained, for example, by adding no propellants for comparison or that the propellants are completely outgassed by prolonged storage at elevated temperature.

In order to ensure a good and simple foamability, it is advantageous if at least one blowing agent is contained in the particles themselves or as part of the particle, in particular pentane or vanillin, preferably in a concentration of 3 to 10 wt .-%, based on the total weight of the polymer. An elaborate im- It is not necessary to use supercritical C0 ₂ under pressure. The CAB / PS particles are thereby ready to be processed and can be readily and easily expanded at any time by increasing the temperature.

In order to meet the necessary fire protection standards, advantageously at least one flameproofing agent may be contained. Depending on the intended use, the flameproofing effect or environmental aspects, the flameproofing agent is a halogenated organic compound, for example a bromine compound, preferably with a halogen content of at least 50 wt .-%. Optionally, a thermal Radikaibildner such as dicumyl peroxide, di-tert-butyl peroxide or dicumyl may be included as a synergist.

Alternatively or additionally, a halogenated or non-halogenated organic phosphorus compound, for example 9,10-dihydro-9-oxa-10-phospha-phenanthrene-10-oxide (DOPO) or 9, 10-dihydro-9-oxa-10-phospha- phenanthrene-0-sulfide (DOPS) and derivatives thereof, for example, 10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO-OH), (10-hydroxy-9,10-dihydro -9-oxa-10-phosphaphenanthrene-10-oxide ammonium salt (DOPO-ONH), triphenyl phosphate (TPP), etc., or one or more further anti-fouling agents may be added from the list of claim 10. Advantageous amounts are about 0.5 to 25 Wt .-%, in particular 3 to 15 wt .-%, based on the total weight of the polymer.

Optionally, elemental sulfur or a sulfur compound, e.g. Melamine thiosulfate [bis (1,3,5-triazine-2,4,6-triamine) thiosulfate] or para-tertiobutylphenol disulfide polymer (Vultac TB7 from Arkema Inc.) may be included as a synergist.

In this connection, it is particularly advantageous if the flame retardant system comprises a combination of at least one phosphorus compound as flame retardant and at least one sulfur compound as additional flame retardant agent or synergist.

The effect of the flame retardant system can be further increased if, in addition to the gas-phase-active flame retardant, flame retardants such as aluminum hydroxide, magnesium hydroxide, borates, boron salts, melamine cyanurate, meiamine, ammonium phosphate, ammonium polyphosphate, ammonium succinate, trisodium phosphate, hexamate phosphate, dipentaerythydrite, in each case alone or be added in mixtures.

In order to obtain a reduced thermal conductivity, it is advantageous if 1 to 10% by weight, based on the total weight of the polymer, of at least one infrared opacifier, preferably selected from the group of carbon black, metal oxides, Metal powder, petroleum coke, anthracite and / or graphite. Advantageous polymers are characterized in that the individual granules have an average particle size of 0.2 to 5 mm and / or that the granules are substantially round.

In order to prevent the polymers from sticking together, it may be provided that they have a coating layer, in particular of glycerol stearates, metal stearates, silicates, etc.

According to an advantageous further development of the invention, 0.05 to 3% by weight of a nucleating agent are present, preferably selected from the group of polyolefin waxes, paraffins, Fischer-Tropsch waxes, the esters and amides of fatty acids or inorganic particles with a particle size between 1 and 20 μm or combinations thereof. Subsequently, an advantageous process for the preparation of the above-mentioned polymers is proposed. An advantageous process procedure provides that a polymer melt containing cellulose acetate butyrate and polystyrene, and a blowing agent mixed by means of a dynamic or static mixer and then granulated, wherein the Granuiierung of the particles using a pressurized Unterwassergranuiierers at a pressure greater than 3 bar and A water temperature between 20 and 100 ° C takes place.

Alternatively, it can be provided that cellulose acetate butyrate and polystyrene are melted by means of a dynamic or static mixer, and the melt is subsequently mixed with propellant and granulated, the granulation of the particles being effected with the aid of a pressurized underwater granulator at a pressure of greater than 3 bar and a water temperature between 20 and 100 ° C takes place.

Alternatively, it can further be provided that the cellulose acetate butyrate is mixed with a mixer into still granular expandable polystyrene (EPS) and then the mixture is melted, optionally with additional Treibmiitel and granulated, the granulation of the particles by means of a pressurized Unterwassergranuiierers at a pressure greater than 3 bar and a water temperature between 20 and 100 ° C takes place.

Alternatively, it can further be provided that the granules are produced by suspension polymerization of styrene in aqueous suspension in the presence of cellulose acetate butyrate and a propellant. Furthermore, according to the invention, a polymer foam is proposed, which consists of a mixture of cellulose acetate butyrate and a styrene polymer or of a a polymer mixture containing a Celluioseacetatbutyrat (CAB) and a Styrolpolyme- risat is formed.

The polymer foam advantageously has all those characteristics which are predetermined by the polymers, for example special polymer mixtures, concentration ratios, types, ingredients or additives of the polymers or CA8 and / or the styrene polymers. Advantageous polymer foams therefore have the features of at least one of claims 1 to 7 and 9 _> 10, 11 and 14.

Accordingly, a foam which is formed from the expandable polymers according to one of claims 1 to 14, in particular by foaming and sintering these polymers into a particle foam, is particularly advantageous. However, an advantageous foam can also be obtained by extrusion of the polymer mixture, analogously to XPS.

The foam may be open-cell, closed-cell or mixed. Such a foam has the initially mentioned advantages of a good

Dimensional stability, ease of processing, cuttability, etc., and is advantageously used in particular for foam moldings for packaging, insulation materials, technical materials, protective helmets, insulation boards, etc.

The polymer foam can be prepared either by extrusion. Alternatively, it is advantageously also possible to form the polymer foam in the form of a particle foam. In this case, the expandable polymers described above by means of conventional methods, in particular by foaming and sintering of the particles, further processed to foam.

In this context, it is advantageous if the foam has a uniform cell structure with average cell sizes between 20 and 500 pm.

According to a further embodiment of the invention it is provided that the foam has a density of 8 to 250 kg / m ³ .

In order to enable the use of durable products, such as insulation boards, it is advantageous if it is provided that the foam is non-biodegradable according to EN 13432: 2000.

A particularly advantageous embodiment of the polymer foam provides that particles and particles containing infrared opacifying agents without infrared opacifiers are sintered with one another in regular or irregular distribution. Such a foam has a low thermal conductivity, combined with a high dimensional stability, especially in sunlight. Preparation of Meiaminiumthiosuifat and the aforementioned phosphorus compounds:

The preparation of some of the phosphorus compounds mentioned initially results, for example, from AT 508.507, AT 508.304 or WO 2011/000018 A1. The phenylphosphonate salts are prepared according to WO 201 1/003773, the oligophosphorus compounds or oiigophosphines according to WO 201/029901.

Further phosphorus compounds as well as meiaminium thiosuifate are prepared as follows:

1. Preparation of 9,10-dihydro-10-hydroxy-9-oxa-10-phosphaphenanthren-10-one or 10-oxide (DOPO-OW a) Preparation of DOPO-OH in an aqueous medium:

In a multi-necked bowl equipped with a stirrer, reflux condenser and thermometer, 302.6 g of 9-O-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide powder (DOPO) were suspended in 327.6 g of water Heated to 90 ° C and treated within 6 h at a temperature of 90-99 ° C with 190.5 g of 30% hydrogen peroxide. The suspension was then cooled to room temperature, the precipitate was filtered off and washed with water. The drying of the filter residue took place at 150.degree. The crude yield was 312.2 g [96.1% d. Th.]. After recrystallization from acetic acid, the following data were determined:

Mp: 203 ° C (Lit: 203-204 ° C, J. Cadogan, supra)

Elemental Analysis C ₁₂ HgO ₃ P (M: 232.17 g / mol):

over, C: 62.08%; H: 3.91%; P: 13.34%

gef. C: 61.5%; H: 4.2%; P: 13.2% b) Preparation of DOPO-OH in alcoholic-aqueous medium:

In a multi-necked flask equipped with a stirrer, reflux condenser and

Thermometer, 302.6 g of DOPO in 200.0 g of methanol were pre-dissolved at 25 ° C and treated within 3 h with continuously increasing to 80 ° C temperature with 3 7.5 g of 30% hydrogen peroxide. The resulting suspension was cooled to room temperature, the precipitate was filtered off and washed with methanol. The drying of the filter residue was carried out at 150 ^C C. The crude yield was 277.1 g [85.3% d. Th.]. After Umkristailisation from acetic acid, the following data were determined:

Mp: 203 ° C (lit .: 203 - 204 ° C); Phosphorushali: gef. 13.3%, over 13.34%. c) Preparation of DOPO-OH in an aromatic-aqueous medium:

in a multi-necked flask equipped with a stirrer, reflux condenser and thermometer, 302.6 g of DOPO were dissolved in 150.0 g of toluene at 70 ° C. and at a continuously increasing temperature of 85 ° C. within 7 h with 204.1 g 30% hydrogen peroxide added. Subsequently, 183.7 g of toluene-water mixture were distilled off. The residue was cooled to room temperature and filtered. Drying of the filter residue was carried out at 150 ° C. The crude yield was 314.9 g [96.9% d. Th.]. After recrystallization from acetic acid, the following data were determined:

Mp: 202-203 ° C (lit. 203-204 ° C); Phosphorus content: gef. 13.2%, over 3.34%.

2. Preparation of 9,1-O-Dihydro-10-hydroxy-9-oxa-10-phosphaphenanthrene-10-one or 10-oxide ammonium salt (DQFO-ONH, t a).

In a multi-necked flask equipped with stirrer, reflux condenser and thermometer, 232.1 g of 9,10-dihydro-10-hydroxy-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO-OH) in 216.0 g of water suspended and mixed at 25 ° C with 71, 5 g of 25% ammonia. Subsequently, the suspension was heated to 98 ° C and then cooled to room temperature. The entire contents of the flask were emptied onto a drying cup and dried at 120 ° C. The yield was 248.4 g [99.7% d. Th.] Of a white, crystalline solid.

Mp .: 234-240 ° C (decomp.)

Elementary analysis C ₁₂ H ₁₂ N0 ₃ P (M: 249.20 g / mol):

calc. C: 57.83%; H: 4.85%; N: 5.62%; P: 12.43%

gef. C: 57.5%; H: 5.1%; N: 5.5%; P 12.4% b) solid process:

232.0 g of dry and ground DOPO-OH with a particle size of <45 μm were placed in a closed mash chamber and, while the shearing mechanism was running, 78.3 g of ammonia, 25% in water, were added slowly. At the end of the ammonia addition, the millbase had heated to 77 ° C, without losing the powdery state of matter. After a 5-minute mixing time, the shearing mechanism was turned off and the millbase was allowed to rest for one hour. Thereafter, the mixture was reground again for 5 min and then emptied onto a drying cup, distributed and dried at 140 ° C. The yield was 242 g [97.2% d. Th.] Of a white, crystalline solid, the data of which substantially corresponded to those of Example 1. 3. Preparation of 9,1Q-Dihydro-10-hydroxy-9-oxa-10-phosphaphenanthrene-10'On or 10-oxide melamine salt (DOPO-QMel) in a multi-necked flask equipped with a stirrer, reflux condenser and

Thermometer, 92.8 g of DOPO-OH were suspended in 400 g of water and treated at 25 ° C with 50.4 g of melamine. Subsequently, the suspension was heated to 90 ° C and held for 4 h at this temperature. Thereafter, it was cooled to room temperature. The precipitate was filtered off and washed with water. The drying was carried out at 160 ° C, and the yield was 141, 4 g [98.7% d, Th.] Of a white, crystalline solid.

Mp .: 246-250 ° C (decomp.)

Elemental Analysis C ₁₅ H ₁₅ N ₆ O ₃ P (Mr. 358.29 g / mol):

Calc. C: 50.28%; H: 4.22%; N: 23.46%; P: 8.64%

gef. C: 49.8%; H: 4.5%; N: 23.3%; P: 8.5%

4. Preparation of 9,10-dihydro-10-hydroxy-9-oxa-O-phosphaphenanthrene-O-or -10-oxide-guanidinium salt (DOPO-OGua) in a multi-necked flask equipped with a stirrer, reflux condenser and

Thermometer, a mixture of 100.0 g of water, 100 g of ethanol and 36.0 g of guanidinium carbonate was prepared and heated to 75 ° C. Subsequently, 92.8 g of DOPO-OH were added in portions over a period of 5.5 h. After CO evolution was no longer detectable, the reaction mass was concentrated by distillation. The remaining Rohkristailbrei (135.6 g) was applied to a drying cup and dried at 1 10 ° C. The yield was 100.5 g [86.0% d. Th.] Of a white, crystalline solid.

Mp .: 278-280 ° C (Zers.)

Elemental analysis 0 ₃ Η ₁₄ Ν ₃ θ ₃ Ρ (M: 291, 24 g / mol):

calc. C: 53.61%; H: 4.84%; N: 14.42%; P: 10.63%

gef. C: 53.3%; H: 5.1%; N: 14.3%; P: 10.5%

5. Preparation of Melaminium Thiosulfate (MelTS a) In a multi-necked flask equipped with a stirrer, reflux condenser and thermometer, 1218.7 g of distilled water containing 147.8 g of conc. Hydrochloric acid (37%) and 189.1 g melamine mixed. The suspension was heated to reflux temperature. After a clear solution, the flask contents were cooled to 96 ° C and 348.6 g of a 34% sodium thiosulfate solution. This was followed by a precipitation reaction. The precipitate was cooled with stirring to room temperature, filtered off and washed thoroughly with distilled water. The drying of the filter residue was carried out at 1 10 ° C. The yield was 265.1 g [96.5% d. Th.] Of a white, crystalline solid.

Mp .: 178-180 ° C (Zers.)

Eiementaranalyse

(M: 366.38 g / moi):

Calc. C: 19.67%; H: 3.85%; : 45.88%; O: 13.10%; S: 17.50%

gef. C: 19.8%; H: 4.0%; N: 45.6%; O: 13.5%; S: 17.2% b) In a multi-necked flask equipped with stirrer, reflux condenser and thermometer, 1200.0 g of distilled water were added to 252.2 g of meiamine and 158.1 g of sodium thiosulfate. The suspension was heated to 95 ° C. Subsequently, at a metering rate of 0.9 g / min 197, 1 g of conc. Hydrochloric acid (37%) was added dropwise. Thereafter, the reaction mass was cooled with stirring to room temperature, the precipitate was removed and washed with distilled water. The filter cake was taken up again in 1100 g of distilled water, stirred vigorously and filtered off. The filter residue was dried at 110 ° C. The yield was 356.8 g [97.4% of theory]. Th.] Of a white, crystalline solid, the data of which substantially corresponded to those of Example 1. c) In a multi-necked flask equipped with a stirrer, reflux condenser and thermometer, 1 130 g of distilled water, 252.2 g of meiamin and 158.1 g of sodium thiosuifate were mixed and heated to 90 ° C. Within 1, 5 hours, 174.2 g of 37.5% phosphoric acid were added dropwise to the presented suspension at 90-93 ° C. Thereafter, the precipitate was cooled while the agitator was running to room temperature and filtered through a Blaubandfiiter. The fiiter cake was washed with water and then dried at 1 10 ° C. The yield was 328.5 g [89% d. Th. | of a white, crystalline solid whose data were substantially identical to those of Example 1.

As synergists in the comparative examples, elemental sulfur, Vultac TB7®, a pt-butylphenol disulfide polymer (Arkema), melaminium thiosulfate (bis [(2,4,6-amino-1, 3,5-triazinium) thiosulfate, MelTS) ( manufactured by Krems Chemie Chemical Services AG) and ammonium thiosulfate ((NH ₄ ) 2S ₂ O ₃ ; ATS, Sigma Aldrich). These examples enable the person skilled in the art to prepare or obtain the desired flame retardants as such, any required starting materials and also elaminium thiosulfate and weather synergists. Production of Expandable Polymers or Polymeric Foams

The preparation of flame-retardant expandable polymers, e.g. of EPS, in the form of granules or beads is known per se to those skilled in the art. The preparation of the polymers according to the invention with the above flame retardants and optionally sulfur compounds functions essentially analogously. For example, the embodiments of WO 2006/027241, AT 508.304 or AT 508.507 can be used. The same applies to the polymer foams or XPS. EXAMPLES

The invention is illustrated below with reference to some particularly advantageous, non-limiting examples: Example 1

A mixture of 10% cellulose acetate butyrate (Eastman CAB-500-5, chain length Mn - 57,000 g / mol, butyryl content: 51% by weight, acetyl content: 4% by weight of hydroxyl content: 1.0% by weight) and 90% of styrene polymer (SUNPO EPS-STD: 6% by weight of pentane, chain length MW = 200,000 g / mol, non-uniformity MW / Mn = 2.5) was melted together in a twin-screw extruder and 3% by weight of pentane was added to the melt. The polymer melt thus contained was conveyed through a nozzle plate at a throughput of 20 kg / h and granulated with a pressurized underwater granulator (7 bar) to form compact polymer granules. Example 2

However, as in Example 1, 50% cellulose acetate butyrate and 50% styrene polymer Example 3

However, as in Example 1, 90% cellulose acetate butyrate and 10% styrene polymer

Example 4

As in Example 1, however, 95% Ceuuioseacetatbutyraf and 5% styrene polymer Example 5 (comparison)

However, as in Example 1, 100% cellulose acetobutyrate and 0% styrene polymer. Example 6 (comparison)

However, as in Example 1, 0% cellulose acetate butyrate and 100% styrenic polymer

Example 7

Analogously to Example 2, however, metered addition of 10% by weight of DOPO-OH-NH and 5% by weight of methyl-thiosulphate based on the polymer mixture

Example 8

However, as in Example 2, metered addition of 4% graphite The polymer granules from Examples 1 to 6 were analyzed by gas chromatography for their pentane retention capacity. The pentahands were determined at intervals of 24 hours. The results are shown in Table 1. The starting contents of the granules were all at 5.5% by weight and the initial value was calculated as 100%. The granules were stored in open packaging.

The polymer granules obtained from experiments 1 to 8 were prefoamed by means of a pressure prefoamer (Kurtz X1.5). After an intermediate storage time of 6 hours, plates of approx. 30 x 30 x 5 cm were produced in a molding machine (Erlenbach C87 / 67/1). These were tested for weld quality with a FA meter. Erlenbach (welding measuring device type EM 840 / PE from Erlenbach). The results are shown in Table 2.

The foam samples of Example 7 thus obtained were tested in accordance with DIN 4 02-B2 and according to EN 13501 (fire class E) in order to check the fire protection properties.

The foam samples of Beispie! 8 were tested according to EN 2667 to check the thermal conductivity. Table 1 :

Fig. 1 shows the diagram to Tabe

Table 2:

Table 3:

2 shows the diagram for Table 3. Evaluation and discussion of the results:

Experiments 1 to 6 show that, surprisingly, the pentane ratio does not increase proportionally with the proportion of CAB on the polymer. Even relatively small concentrations of polystyrene (Example 3) were able to slow down the pentane conversion, so that it is possible to store for several weeks in the usual packaging used for EPS granules (gas-impermeable packaging). Also, Examples 1-6 show that the achievable minimum densities do not decrease proportionally with the level of CAB on the polymer. Above all, the possibility of carrying out two foaming operations is due to the retention capacity of pentane. Examples 1 to 6 further show that even with a small addition of polystyrene, the weldability increases disproportionately.

The molded parts produced from Examples 7 and 8 passed the small burner tests according to DIN 4102-B2 and according to EN 13501.

The molded article produced from Example 8 achieved a thermal conductivity of 30.4 mW / (m ^* K) at a density of 20 kg / m ³ .

Claims

claims:

1 . Expandable polymers or polymer granules of a polymer mixture containing a Celluioseacetatbutyrat (CAB) and a styrene polymer.

2. Expandable polymers according to claim 1, characterized in that in the polymer mixture at least one further compatible polymer, for example polyurethane or polylactic acid, is contained, wherein Celluioseacetatbutyrat (CAB) and styrene polymer together more than 80 wt .-%, preferably more than 90 wt .-%, make up the total mass of the polymer mixture.

3. Expandable polymers according to claim 1 or 2, characterized in that the polymer mixture consists exclusively of a Celluioseacetatbutyrat (CAB) and a styrene polymer.

4. Expandable polymers according to one of the preceding claims, characterized in that the proportion of Celluioseacetatbutyrat (CAB) between 5 and 95% by weight, preferably between 10 and 90 wt .-%, particularly preferably between 40 and 90 wt .-% , based on the total mass of the polymer mixture.

5. Expandable polymers according to one of the preceding claims, characterized in that the cellulose acetate butyrate (s) used have a number average molecular weight of Mn> 30,000 g / mol, in particular> 40,000 g / mol, in particular from 30,000 to 70,000 g / mol, further comprising a butyryl content between 30 and 60 wt .-% based on Celluioseacetatbutyrat and further the weight fraction of the hydroxyl groups on Celluioseacetatbutyrat about 0.5 to about 2.5 wt .-%, preferably about 0.8 to about 1, 8 wt .-% based on Celluioseacetatbutyrat, is.

6. Expandable polymers according to one of the preceding claims, character- ized in that the one or more styrene polymer (s) used have a molecular weight or molecular weight average (Mn) between 140,000 and 350,000 g / mol.

7. Expandable polymers according to one of the preceding claims, character- ized in that the styrene polymer or polymers used (e) homopolymers and / or copolymers of styrene, preferably glass clear polystyrene (GPPS), impact polystyrene (HIPS), anionically polymerized polystyrene or impact polystyrene (A-IPS), styrene alpha-methylstyrene copolymers, acrylonitrile-butadiene-styrene polymers (ABS), styrene-acrylonitrile (SAN) acrylonitrile-styrene-acrylic esters (ASA), methyl acrylate-butadiene-styrene (MBS), methyl methacrylate-acrylonitrile-butadiene-styrene (MABS) - polymers or mixtures thereof or with polyphenylene ether (PPE), or mixtures with thermoplastic polymers such as thermoplastic polyurethane, polylactic acid, etc., are.

8. Expandable polymers according to one of the preceding claims, characterized in that at least one blowing agent, in particular pentane or vanillin, is present, preferably in a concentration of 3 to 10 wt .-%, based on the total weight of the polymer mixture.

9. Expandable polymers according to one of the preceding claims, characterized in that the polymer mixture in propellant-free state, for example after a complete outgassing of the blowing agent, a glass transition temperature Tg in the range of 90 ° C to 145 ° C.

10. Expandable polymers according to one of the preceding claims, characterized in that at least one flame retardant is contained, in particular in an amount of 0.5 to 25 wt .-%, in particular 3 to 15 wt .-%,

for example, a halogenated organic compound, for example a bromine compound, preferably having a halogen content of at least 50 wt .-%,

and or

at least one halogenated or non-halogenated organic phosphorus compound selected from:

9, 10-Dihydro-9-oxa-10-phosphaphenantrene-O-oxide (DOPO), 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-thione or -10-sulfide (DOPS), 9, 10-Dihydro-10-hydroxy-9-oxa-10-phosphaphenanthrene-10-thione or -10-sulfide (DOPS-OH), 9,10-dihydro-10-hydroxy

9-oxa-10-phosphaphenanthrene-10-thione or -10-sulphide ammonium salt (DOPS-ONH ₄ ), 9,10-dihydro-10-mercapto-9-oxa-10-phosphaphenanthrene-10-thione or 10-sulfide (DOPS-SH), 9,10-dihydro-10-mercapto-9-oxa-10-phosphaphenanthrene-10-thione or

10-sulfide triethylammonium salt (DOPS-SNH (Et) ₃ ), 9,10-dihydro-10-hydroxy-9-oxa-10-phosphaphenanthrene-10-thione or -10-sulfide triethylammonium salt (DOPS-ONH ( Et) ₃ ), 9, 10-dihydro-10-hydroxy-9-oxa-10-phosphaphenanthrene-10-thione or -10-sulfide melaminium salt (DOPS-OMel), 9,10-dihydro-10-hydroxy -9-oxa-10-phosphaphenanthrene-10-thione or -10-sulfide-guanidinium salt (DOPS-OGua), 9,10-dihydro-10- (9,10-dihydro-9-oxa-10-phosphate) 10-thioxophenanthren-10-ylthio) -9-oxa-10-phosphaphenanthrene-10-one or 10-oxide (DOPS-S-DOPO), bis (9,10-dihydro-9-oxa-10-phosphate) 10- thioxophenanthren-10-yl) sulfide (DOPS-S-DOPS), bis (9,10-dihydro-9-oxa-10-phospha-10-thioxophenanthren-10-yl) disulfide (DOPS-S ₂ -DOPS), bis (9,10-dihydro-9-oxa-10-phospha-10-thioxophenanthren-10-yl) tetrasulfide (DOPS-S ₄ -DOPS), di (9,10-dihydro-9-oxa-0-phospha-10 thioxophenanthren-10-yl) ether (DOPS-O-DOPS) or 9, 10-dihydro-10- (9, 10-dihydro-9-oxa-10-phospha-10-thioxophenanthren-10-yloxy) -9- oxa-10-phosphaphenanthrene-10-one or -10-oxide (DOPS-O-DOPO), triphenyl phosphate (TPP), tetraphenyldiphosphine monoxide, tetraphenyldiphosphine monosulfide, tetraphenyldiphosphine dioxide, tetraphenyldiphosphine disulfide, tetraphenyldiphosphine oxide sulfide, pentaphenylpentaphospholane, 1, 1, 3, 3-tetramethoxy-2-phenyltriphosphine 1, 3-dioxide, 1,1,3,3-tetraethoxy-2-phenyltriphosphine-1,3-dioxide, 1,1,3,3-tetraallyloxy-2-phenyltriphosphine-1, 3-dioxide,

Melamine Phenylphosphonate salts of the formula

where x is a number between or from 1 and 2,

Guanidine phenylphosphonate salts of the formula H

where x is a number between or from 1 and 2,

Tetraphenyl resorcinol diphosphate (Fyrolflex® RDP, Akzo Nobel), resorcinol diphosphate oligomer (RDP), triphenyl phosphate, tris (2,4-di-tert-butylphenyl) phosphate, ethylenediamine diphosphates (EDAP), ammonium polyphosphate, diethyl-N, N-bis ( 2-hydroxyethyl) -amino-methylphosphonate, hydroxyalkyl esters of phosphoric acid, salts of di-C 1 -C ₄ -alkylphosphine acids and hypophosphorous acid (H ₃ PO ₂ ), in particular the Ca ²⁺ , Zn ²⁺ , or Al ³⁺ salts, tetrakis (hydroxymethyl) phosphonium sulfide, triphenylphosphine and / or phosphazene derivatives,

and optionally containing elemental sulfur or one or more sulfur compounds as Flammschutzsynergist, in particular melamine thiosulfate and / or para-Tertiobutylphenoldisulfid polymer.

1 1. Expandable polymers according to one of the preceding claims, characterized in that 1 to 10 wt .-%, based on the total weight of the polymer mixture, of at least one infrared opacifier is preferably selected from the group of carbon black, metal oxides, metal powder and / or Graphite.

12. Expandable polymers according to one of the preceding claims, characterized in that the individual granules have an average particle size of 0.2 to 5 mm and / or that the granules are substantially round or approximately spherical.

13. Expandable polymers according to one of the preceding claims, characterized in that they have a coating layer, in particular of glycerol stearates, tallstearaten metal, silicates, etc., have.

14. Expandable polymers according to one of the preceding claims, characterized in that they contain 0.05 to 3 wt .-% of a nucleating agent, preferably selected from the group of polyolefin waxes, paraffins, Fischer-Tropsch waxes, the esters and amides of fatty acids or inorganic particles having a particle size between 1 and 20 μιτι or combinations thereof.

15. A process for the preparation of expandable polymers or polymer granules according to any one of claims 1 to 14, with the addition of a blowing agent to the melt of the polymer mixture, wherein the granulation of the particles by means of a pressurized underwater granulator at a pressure greater than 3 bar and a water temperature between 20 ° and 100 ° C takes place.

16. A polymer foam comprising a polymer mixture comprising a cellulose acetate butoxide (CAB) and a styrene polymer having the features of at least one of claims 1 to 7 and 9, 10, 11 and 14, optionally obtained by extrusion of the polymer mixture.

17. Polymer foam, in particular in the form of a particle foam, obtainable from the expandable polymers according to one of claims 1 to 14, in particular by foaming and sintering of the polymers.

18. Polymer foam according to claim 16 or 17, characterized in that it has a uniform cell structure with average cell sizes between 20 and 500 pm.

19. Polymer foam according to one of claims 16 to 18, characterized in that it has a density of 8 to 250 kg / m ³ .

20. Polymer foam according to one of claims 16 to 19, characterized in that it is non-biodegradable according to EN 13432: 2000.

21. A polymer foam according to any one of claims 16 to 20, in the form of a particle foam obtainable from the expandable polymers according to any one of claims 1 to 14, characterized in that particles containing infrared opacifying agent and particles without infra-red opacifying agents are sintered together in regular or irregular distribution.

22. Use of the expandable polymers according to one of claims 1 to 14 or of the polymer foam according to one of claims 16 to 21, for the production of or for foam moldings for packaging, insulation materials, technical materials, protective helmets or insulation boards.