The subject of the invention is the method of production of heat insulating composite materials, from two basic widely available components, that is PUR polyurethane systems and/or PIR polyisocyan urate and EPS polystyrene „beads", filled with pentane isomers. The composite material in accordance with the invention can be used as unique insulating material which combines high insulation and mechanical parameters of rigid polyurethane or polyisocyanurate foams with the low price of foamed polystyrene materials. The unique properties of the composite allow for a more extensive use of this material when compared to the above mentioned classic heat insulating materials. The composite material in accordance with the invention can be successfully used as heat insulating material in building construction, power industry, refrigeration, in the building of caravans, house trailers, Nissen huts, sentry boxes, holiday cottages/cabins, animal sheds, superstructures on ships, especially the inland ones, facings and building blocks, insulation of refrigerating pipelines, insulation of cold stores, refrigerator wagons, tank cars and the like.

It is a well-known fact that physical and mechanical properties of heat insulating materials made from polyurethane foam depend on the raw materials used for producing them. What influences these properties are starting compounds, i.e. compounds under the general name of polyols, and in particular their molecular weight, the number of functional groups in the particle as well as their distribution, moisture content and others. Knowing the constitution of these compounds, their mass fraction in the mixture and selecting the appropriate polyisocyanate, as the second component of the system, makes it is possible to predict and design the chemical properties of the obtained polyurethanes. Additionally, the properties of polyurethane plastics can be modified by means of adding other reagents and additives, such as plasticizers, antipyrines and fillers to the reaction mass. These additives should be used according to strictly determined quantities, which make it possible to receive plastics of desired properties. On the basis of literature and the Applicants' own experience it is known that the absence of appropriate proportions between the modifying additives has a negative effect on the properties of the obtained plastics. For instance, if antipyrines, which are typical additives used in order to reduce inflammability and combustibility of plastics such as aluminium hydroxide, triethyl phosphate (TEP) and tris (1 -chloro-2-propyl) phosphate, are added in quantities larger than 15% of the total mass of the components of polyurethane they cause loss of porosity of foam materials.

In order to obtain cheaper polyurethane materials there are used methods of producing heat insulating composite materials, in which rigid polyurethane foam is the base phase. In these methods fillers such as rubber granulate, sawdust, granulated waste products made from polyurethane foam, PVC or saturated polyesters are introduced into the polyurethane reaction mass. The disadvantages of composite materials received in such a way are the following: accelerated ageing processes occurring in the composite, deterioration of heat insulation and mechanical parameters.

The first time that polystyrene used for foaming (EPS) as filler found application was in the process of obtaining phenol-formaldehyde foams. Obtaining such composite material, consisting of foamed polystyrene granules and phenol- formaldehyde foam filling spaces between the granules, was proposed in the Polish patent specification PL 73751 . In order to make the core of the laminar elements from the foam obtained in this way foamed polystyrene granules are to be mixed with phenol-formaldehyde resin prepared for cold foaming. The foamed phenol-polystyrene plastic has good attrition strength as well as high modulus of elasticity. Moreover, there is a possibility of easy shaping of the above mentioned properties by way of using a different degree of expanding of the granulated polystyrene. The absorbability of plastic obtained in this way is lower than the absorbability of pure phenol-formaldehyde foam. What is more, the technological contraction is low, which allows for obtaining automatic adhesion of the plastic to facings during foaming.

The application of polystyrene for foaming (EPS) as filler in rigid polyurethane foams was described in the Polish patent specification No. PL 189498. The heat of polyurethane production allows for creating partial plasticity and expansion of the volume of EPS beads. In this way what is obtained is composite heat insulating material containing up to volumetric 50% of foamed polystyrene phase which has got physical and mechanical parameters as near as possible to foamed polystyrene. However, the achieved results applied to free foaming, i.e. the rank of raw materials selection was not taken into account, and therefore the transfer of results from laboratory scale to commercial scale was made impossible.

In the US patent specifications Nos. 6,605,650 and 6,727,290 a way of utilizing the heat of polyurethane polymerization reaction for expanding and melting of polystyrene "beads" (EPS) was disclosed, as a result of which rigid polyurethane foam was obtained, in which the inside part of cells was covered with a thin layer of polystyrene plastic. The polystyrene layer was to delay the process of diffusion of the expanding agent from the inside of polyurethane foam cells, and therefore the process of deterioration of thermal conductivity of the foam caused by diffusion exchange of expanding agents for the air was to be delayed. The addition of polystyrene beads did not exceed 5% of the total weight of polyurethane components.

In the Polish patent specification No. P 379672 there was described a method of obtaining rigid polyurethane foams based on polyurethane system, to which as early as in the liquid phase polystyrene beads for foaming (EPS) are added. The beads expand under the influence of the produced heat in the exothermic process of forming the structure of the foamed polyurethane. What is more, liquid glass in the weight ratio of 0% to 5% or/and pre-polymer in the weight ratio of 0% to 30% to the total weight of polyurethane system were added to polyol. In the Polish patent specification No. P 387535 there was disclosed a method of production of heat insulating material, in which its components making up polyurethane structure and polystyrene beads expand together in the process of foaming. Before the process of foaming the surface of the polystyrene beads was covered with graphite dust in the weight ratio of 0,8% - 5,6% to the weight of the used beads or it was wetted with any pre-polymer. When using this method in bench tests during free foaming materials of a density ranging from 30 to 40 kg/m ³ were obtained.

The aim of the invention is to develop a method of producing heat insulating composite materials with excellent physical and mechanical properties, based on polyurethane or/and polyisocyanurate systems including chemical expanding agents (C0 ₂ ) and polystyrenes (EPS) performing the function of an expanding filler during the process of forming rigid polyurethane-polystyrene foam, characterised by a high fraction of the filler at a high degree of its expansion and free from defects connected with the degradation of EPS "beads", which is appropriate for using on commercial scale, selecting the right conditions of mutual expansion of both phases, as well as obtaining composite heat insulating material, which, despite a high fraction of the polystyrene phase, is characterised by properties similar to those of rigid polyurethane foams.

The present invention refers to the method of producing heat insulating composite materials based on polyurethanes or/and polyisocyanurates obtained from polyols and isocyanates with the addition of catalysts, surfactants, optionally antipyrines, and those containing fillers from polystyrene for foaming, which is characterized by the fact that

- to the isocyanate component there are introduced polystyrene beads for foaming (EPS) with the softening temperature of between 80 and 90 °C, external and structural moisture content of between 0,2 and 1 ,2% by weight, in the ratio from 20 to 120% by weight to the weight of the polyurethane system including the isocyanate and polyol components, while the amount (weight) of the added EPS beads as compared to the total weight of components of the above mentioned polyurethane system is to be selected in such a way, that the maximum reaction temperature does not exceed the degradation (collapse) temperature of the EPS beads during and after their expansion, and, at the same time, so that the temperature is higher than the polystyrene plastic softening temperature, that is so that it ranges between 80 to 120^, and depending on the amount of the heat energy generated by the applied polyurethane system, the mentioned amount (weight) of the EPS beads based on the total weight of components of the mentioned polyurethane system should preferably amount to specified above 20 to 120% by weight;

- then the polyol component having a hydroxyl number ranging from 100 to 450 mg KOH/g is added, which contains water as chemical expanding agent, from 4 to 8% by weight based on the total weight of the polyol component, while the viscosity of the polyol component should amount to no more than 1000 mPa-s.

Preferably 0,2 to 4 mm diameter polystyrene beads for foaming (EPS) are used.

Preferably 0,5 to 1 ,0% external and structural moisture weight content polystyrene beads for foaming (EPS) are used.

Preferably expanded polystyrene beads (EPS) are added, which previously are subjected to the process of removal of anti-adhesive coating in order to ensure the appropriate cohesion of the polystyrene and polyurethane porous structures.

The present invention refers to the heat insulating composite material based on polyurethanes or/and polyisocyanurates, obtained from polyols and isocyanates with the addition of catalysts, surfactants, optionally antipyrines, and containing fillers from polystyrene for foaming, characterized by the fact that it consists of polyurethane phase from 40 to 85% by weight and polystyrene phase from 15 to 60% by weight, and despite considerable polystyrene phase fraction, has got properties similar to rigid polyurethane foams, such as thermal conductivity coefficient ranging from 0,024 to 0,032 W/mK at the temperature of 10 ^< Ό, thermal stability up to Ι ΟΟ 'Ό, compression strength at 10% deformation ranging from 100 to 400 kPa, absorbability up to 2%, dimensional stability up to 1 %, and due to specific cell structure shows more favourable sound absorbing parameters in comparison to foamed polystyrene materials and rigid polyurethane foams. The heat insulating composite material according to the invention is obtained through adding to the isocyanate component of 80 to 90 °C softening temperature polystyrene beads for foaming, which have got external and structural moisture weight content of between 0,2 and 1 ,2%, in the ratio from 20 to 120% by weight to the weight of the polyurethane system including the isocyanate and polyol components, and then adding the polyol component having a hydroxyl number ranging from 100 to 450 mg KOH/g , which contains water as chemical expanding agent, from 4 to 8% by weight based on the total weight of the polyol component, while the viscosity of the polyol component should amount to no more than 1000 mPa-s.

Preferably in order to obtain heat insulating composite material according to the invention 0,2 to 4 mm diameter polystyrene beads for foaming (EPS) are used.

Preferably in order to obtain heat insulating composite material according to the invention polystyrene beads for foaming (EPS) are used which have got 0,5 to 1 ,0% external and structural moisture content by weight.

Preferably in order to obtain heat insulating composite material according to the invention expanded polystyrene beads for foaming (EPS) are used which previously are subjected to the process of removal of anti-adhesive coating.

As opposed to the earlier attempts to obtain polystyrene-polyurethane composites the Applicants suggest introducing polystyrene beads (EPS) to the isocyanate component which is characterized by viscosity minimum twice as low as that of the polyol components available on the market. As a result of chemical reactions of -OH groups contained in polyol component as well as the surface and structural water of EPS beads, with -NCO isocyanate groups, the generated heat causes evaporation of low-boiling expanding agents contained in EPS beads structures. Moreover, during chemical reactions of -NCO groups with water, carbon dioxide C0 ₂ (chemical expanding agent) is liberated, forming the structure of polyurethane foam material. The application of chemical expanding agent as foaming agent, as opposed to physical expanding agents (that is n-pentane, cyclopentane, fluorohydrocarbons), does not cause reduction in the polyurethane polymerization heat energy, and the porous structure of the foam allows for obtaining larger volume fractions of EPS beads which expand in the structure of the foam after exceeding the softening temperature of polystyrene plastic. This way a porous material of diversified structure as well as physical and mechanical properties is formed.

The introduction of EPS beads to the mixture reacting in this way causes their growth at the expense of the heat energy which is generated in the process of polyurethane components reacting, while surprisingly it was found that the growth is considerably higher when chemical expanding agents are used as opposed to the situation in which physical expanding agents are used. Additionally, the expanding EPS beads by filling free spaces in the polyurethane foam reduce the contraction of the material and improve their strength, as well as favouring isotropic structure formation.

Moreover, based on temperature measurements and heat flux density during polymerization of polyurethanes, made by means of using an innovative method worked out by the Applicants it was found, that there is a possibility of classification of polyurethane raw materials in terms of generated amount of heat energy. It was found, that, to the PUR/PIR systems classified as "low- energy", which are characterized by maximum reaction temperatures below 140 °C, it is preferable to add EPS filler within the range of 20 to 50% by weight, while the systems classified as "high-energy", characterized by maximum reaction temperatures over 140 °C, it is preferable to add EPS filler within the range of 40 to 1 20% by weight. Strict monitoring of the foaming process conditions, the selection of appropriate components of polyurethane raw material and the appropriate, in accordance with the above described principle, amount of EPS filler, allows for obtaining materials which are free of defects connected with the degradation of EPS "beads", as well as characterized by a high degree of expansion of polystyrene phase.

Compared with the above mentioned solutions in this application there are described possibilities of selection of polyurethane systems with regard to energy together with an adequate, for the heat energy generated by them, amount of polystyrene filler. Moreover a range of important parameters from the point of view of processing was pointed out. The method of producing composite material according to the invention allows for obtaining materials characterized by the following properties: • density ranging from 40 - 100 kg/m ³

• thermal conductivity coefficient ranging from 0,024 to 0,032 W/mK at the temperature of 10°C,

• thermal stability up to the temperature of 100 °C,

• compression strength at 10% deformation ranging from 100 to 400 kPa,

• absorbability below 2%,

• dimensional stability below 1 %

and because of special cell structure these materials show more favourable sound absorbing parameters compared with classic foamed polystyrene materials and rigid polyurethane foams.

Examples

Example 1

In order to obtain composite material the following components have been prepared:

- 178 g of polymeric phenyl diisocyanate (PMD) with -NCO groups content at 26% and viscosity of 250 mPa-s,

- 180 g of polystyrene for foaming beads OWIPIAN FS 1325 produced by Synthos S.A. of 1 ,3 - 2,5 mm grain size, containing approximately 6% by weight of pentane mixture (64 - 75% of n-pentane and 25 - 34% of isopentane) and 1 ,0% by weight of moisture.

The above components are mixed together with the use of a stirrer (about 600 rpm) after being heated to the temperature of 20 ^q C, and then 1 19 g of polyol component WG 2034 NF manufactured by Polychem Systems Ltd. with a viscosity of 400 mPa-s, which contains 5,2% of chemical expanding agent by weight is added to the mixture, and after the next, this time very vigorous stirring (about 1200 rpm) the mixture was transferred to a 9 dm ³ volume mould heated to the temperature of 50 °C. The composite was left for about 20 minutes, enabling the mixture to rise freely in the mould.

The material obtained this way was characterized by the following properties: apparent density of 50 kg/m ³ , thermal conductivity coefficient of 0,024 W/rn-K at the temperature of 10°C, parallel compressive strength of 100 kPa, and volume fraction of polystyrene phase of 30%.

Example 2

The components were prepared as in Example 1 , except that the expanded polystyrene beads (EPS) had previously been subject to the process of removal of anti-adhesive coating in order to ensure the appropriate cohesion of the porous structures of polystyrene and polyurethane.

The material obtained in this way was characterized by the following properties: apparent density of 48 kg/m ³ , thermal conductivity coefficient of 0,024 W/m-K at the temperature of Ι Ο 'Ό, parallel compressive strength of 120 kPa, volume fraction of polystyrene phase of 32%.

Example 3

The following components were prepared in order to obtain composite material:

~ 224 g of polymeric phenyl diisocyanate (PMD) with -NCO groups content at 26% and a viscosity of 250 mPa-s,

- 360 g of polystyrene for foaming beads OWIPIAN FS 1325 produced by Synthos S.A. of 1 ,3 - 2,5 mm grain size, containing approximately 6% by weight of pentane mixture (64 - 75% of n-pentane and 25 - 34% of isopentane) and 0,2% by weight of moisture.

The above components were mixed together with the use of a stirrer (about 600 rpm) after being heated to the temperature of 20^, and then 172 g of polyol component IZOPIANOL 22/33 OT-P manufactured by Purinova Ltd. with a viscosity of 500 - 700 mPa-s, which contains about 2,0% of chemical expanding agent by weight and 15 - 20% by weight of physical expanding agent in the form of HFC 365/227 is added to the mixture, and after the next, this time very vigorous stirring (about 1200 rpm) the mixture was transferred to a 9 dm ³ volume mould heated to the temperature of 50 °C. The composite was left for about 20 minutes, enabling the mixture to rise freely in the mould.

The material obtained in this way was characterized by the following properties: apparent density of 80 kg/m ³ , thermal conductivity coefficient of 0,028 W/m-K at the temperature of 10°C, parallel compressive strength of 260 kPa, and volume fraction of polystyrene phase of 39%.

Example 4

The components were prepared as in Example 3, except that 0,3 - 0,8 mm OWIPIAN FS0308 expanded polystyrene beads (EPS) manufactured by SYNTHOS S.A, which contain about 6% of pentane mixture by weight (64 - 75% of n-pentane and 25 - 34% of isopentane) and 0,5% moisture by weight, were used.

The material obtained in this way was characterized by the following properties: apparent density of 80 kg/m ³ , thermal conductivity coefficient of 0,031 W/rn-K at the temperature of 10°C, parallel compressive strength of 260 kPa, and volume fraction of polystyrene phase of 32%.