DE102016001029A1 - Manufacturing Process for Flame Retardant Phase Change Materials (PCM) including PCM composites, PCM objects and PCM systems with microencapsulated organic latent heat storage material - Google Patents

Abstract

Organic phase change material (PCM) for flame retardant PCM composites, PCM objects and PCM systems with microencapsulated organic PCM, characterized in that a flame retardant PCM composite consisting of PCC calcium carbonate, microencapsulated organic PCM, potassium water, urea and Nature Graphite, earth-moist clay, was produced.

Description

The present invention relates to a production process for organic phase change material (PCM), flame retardant PCM composite, PCM objects and PCM systems with microencapsulated organic PCM characterized in that the PCM composite is classified as non-burning dripping / decaying.

State of the art and definition in the context of this invention

To RAL-GZ 896 Edition September 2009 In the following, phase change material is referred to as PCM. For this purpose, the terms phase change materials or latent heat storage materials are common. ( Phase change material, quality assurance, RAL-GZ 896 Edition September 2009, Deutsches Institut für Gütesicherung und Kennzeichnung e. V ).

PCM in the context of this invention are materials that change their state of matter from solid to liquid or their state of crystallization from solid to firm in a defined temperature range (phase transition). This process is reversible (reproducible phase transition) and can be used thermally.

PCM composites in the context of this invention, consist of material composites that always contain PCM components. The combination of PCM and at least one other material adds a new or changed property to the PCM. These property changes can also be determined on small samples.

PCM objects according to this invention have specific properties, i. H. Properties that can not be determined on parts of an object but only on the entire object, as is the case for example for macroencapsulation.

PCM systems in the context of this invention are products that are positively influenced by PCM in a significant function such as heating and air conditioning systems and textiles.

Properties of PCM and PCM composites (PCM-V) for the purposes of this invention are those properties that depend only on the internal composition. Examples include the thermal conductivity and the flammability of a material. These properties can also be determined on small sample quantities.

Properties of PCM objects (PCM-O) in the sense of this invention are those properties which do not depend solely on the internal composition but are determined by the external shape and environmental conditions. An example is the heat dissipation of a plate. It depends on the shape and size of the plate and the environmental conditions.

Properties of PCM systems (PCM-S) in the sense of this invention are those properties which only become apparent during use.

PCM ingredients in PCM-S for the purposes of this invention may only contain PCM-V or PCM-O. They must be encapsulated or leakproof.

The manufacturer of PCM-S must specify the PCM specific utility value for each product group of PCM-S. In addition, indicate the boundary and operating conditions under which the specific utility of the system is achieved.

The behavior of a PCM-S in case of fire is influenced by the building material class / Eurobrand class of the materials used and the design. The fire behavior of PCM-S is decreasing European standard DIN EN 13501 or the German standards DIN 4102 divided into different classes. The criteria of the tests specified there are the flammability, the flame propagation, the temperature development as well as the smoke gas density and the burning dripping of the materials.

In the brochure Micronal PCM Smartboard of BASF AG, the construction of a fiberglass nonwoven coated gypsum board with latent heat storage material in the gypsum core and a 2-times thickness of 12.5 mm and basis weight of 23.0 Kg / m ² a classification into flame-retardant building materials for special buildings is described. The latent heat capacity (delta H) of the microencapsulated organic PCM, hereinafter referred to as micronal, is quoted in a temperature switching range, not described in more detail, and the mass of the micronal used therein, with 330 kJ / m ² . In the DE 101 39 171 A1 (BASF AG) teaches the use of microcapsules, their production with PCM in plasterboard.

Another brochure from the Saint Gobain (Rigips AG, Switzerland) Alba product family mentions a gypsum plasterboard with a loading of 3 kg of Micronal PCM / m ² and a total thickness of 25.0 mm. This is done by a 2-fold plate thickness of 12.5 mm in each case to achieve a classification in flame-retardant building materials.

For the Knauf Comfortboard 23 plate, a standard plasterboard with a thickness of 12.5 mm filled with 2 kg of organic Micronal PCM / m ² , a classification for fire-resistant building materials is achieved.

The company EMCO uses emcocool Smart Cooling 2 Kg Micro encapsulated organic PCM (Micronal) for their product. The latent heat storage capacity is given as 200 kJ / m ^{2 of} the conventional plasterboard. A classification for flame-retardant building materials is achieved.

Based on the DIN EN 13501 describes a flame-retardant PCM-S product from Metawell, in which the latent heat storage material Micronal is incorporated with a binder material in an aluminum sandwich panel.

Inorganic PCM such. For example, the group of salt hydrates, as known to those skilled in the art, are classified as flame retardant PCM building materials and are available on the market. Furthermore, known in the art flame retardants such as halogenated hydrocarbons, Decabromdiphenyloxid, Octabromdiphenyloxid, antimony oxide, antimony trioxide, etc. in the US 4,797,160 A1 described flame retardants, graphite, nanometallic hydroxides, phosphates esters, magnesium hydroxides and melamine salts are not within the meaning of this invention the subject of further considerations.

task

The object of the present invention is to develop a procedurally simplified and inexpensive producible phase change composite material PCM-V, which has a high PCM degree of filling greater than 5.4 Kg micro-encapsulated organic PCM example Micronal BASF EU. Micronal has as powder a bulk density of 300 to 400 g / m ³ a solids content of> 97% with particle sizes of about 50 to 300 microns. The melting enthalpy of the paraffin active substance is about 96 to 100 kJ / kg.

The PCM-V according to the invention has a latent heat capacity of greater than 540 kJ / m ² , and is classified as flame-retardant.

The following difficulties arise according to the prior art for the previously cited with PCM Micronal filled gypsum or clay slabs in such a way that these plates with a PCM filling degree of greater than 3 Kg / m ² not sufficient strength, combined with a high latent heat capacity at at the same time having low flammability.

Gypsum-lime or clay slabs with a microencapsulated organic PCM content of greater than 5.4 kg / m ² with a plate thickness of 16.0 mm are not known in this form as a flame-retardant PCM building material.

It is an object of the present invention to overcome the described disadvantage of the prior art and to provide a PCM-V, which with a high degree of filling of more than 5.4 Kg / m ² micro-encapsulated organic PCM a latent heat capacity of at least 540 KJ / m ² has. This corresponds to 150 Wh / m ² or 0.150 KWh / m ² with a plate thickness of 1.6 cm. To continue to be connected, the criterion of specified tests with regard to flammability, flame propagation, temperature development, flue gas density and burning dripping of the PCM-V must be met.

The prior art discloses flame-retardant coating compositions based on alkali metal silicate solutions which contain at least 30% by weight of a sodium and / or potassium silicate or lithium silicate solution having a solids content of 28 to 45% by weight.

In addition to quartz flour other ingredients such as gypsum, cement, lime, clay and water glass are known. Advantageously, finely divided crystalline calcium carbonate (CaCO ₃ ) in the form of metamorphic calcite with Teilchengössen be in the range of 1 to more than 500 microns for these coating compositions.

As alkali silicate solutions, potassium water glass or sodium water glass can be used. Here, however, potassium potassium silicate with a solids content of 42% by weight was preferred.

Surprisingly, it has been found that the object of a flame retardant PCM-V can be achieved by preparing a composite of PCC calcium carbonate (CaCO ₃ ), microencapsulated organic PCM, potassium waterglass, urea and natural graphite. In this case, the PCM-V mass may additionally be embedded in the cells of an AL honeycomb.

In the case of the PCM-V product according to the invention, the PCM-V contains the following constituents: BASF Micronal 5040 X; Woellner Betol K 42; Imerys Timrex PP 44; Plascore Al-Honeycomb, cell size 25.4 mm; CaCO _{3, by way of} example, a PCC (Precipicated Calcium Carbonate) from sh minerals Heidenheim, urea from SKW.

In order to control processing properties and product properties overall within wide limits, the product composition according to the invention advantageously comprises the following weight percentages to a total amount of 100% by weight with a volume of 5,200 cm ³ and total mass of 4.95 kg, the following proportions: Micronal 5040; 1.8 kg equals 36.4% by weight; Betol K 42; Corresponds to 1.5 kg 30.4% by weight calculated on dry matter; Timrex PP 44; 0.5 kg corresponds to 10.2% by weight; PCC-CaCO ₃ ; 1.2 kg equals 24.2% by weight. The PCM-V produced in this way has a latent enthalpy of melting of 145 Wh / m ² with a Micronal 5040 mass of 1.8 kg and a volume of 5,200 cm ³ (dimensions: length 57 cm × width 57 cm × height 1.6 cm). With a Micronal 5040 mass of 2.5 kg, introduced into a PCM-V plate with the dimensions: 57 cm × 57 cm × 1.6 cm, volume of 5,200 cm ³ becomes a sensitive and latent enthalpy of fusion of 200 Wh / m ² or 0.200 KWh / m ² achieved. The Al honeycomb mass is 0.045 kg with this plate dimension.

The listed weight percentages may be varied as necessary to meet new product price and material properties requirements.

Surprisingly, it has now been found that with an increase in the microencapsulated organic PCM-V mass to 5.5 Kg / m ² , plate thickness 1.6 cm and a further increase of this mass to 7.7 Kg / m ² at a plate thickness of 1.8 cm, this PCM-V can be classified as flame retardant.

The latent heat storage of PCM-V is known. If you now perform a solid PCM-V heat z. Ex. By a flame, the PCM changes its state of aggregation when it reaches its melting temperature. The phase change material (PCM) absorbs a certain amount of heat, the so-called heat of fusion. Since the temperature of the PCM does not change despite heat input, one also speaks of latent (hidden) heat. In a reverse phase change, from gaseous to liquid and from liquid to solid, the stored latent heat is again at constant temperatures.

The thermal conductivity of microencapsulated organic PCM-V ranges from 0.23 to 0.27 W / mK. The resistors at the thermal interfaces between paraffin polymer shell, polymer shell matrix material in which the spherical microencapsulated PCM is embedded, it is necessary to increase the thermal contact conductivity at the abutting ball contact surfaces, there to the efficiency of heat transfer to the spherical microencapsulated PCM to increase.

The microencapsulated PCM, which serves as the intended temporal temperature storage, only experiences a further increase in temperature when the paraffin of the microencapsulated organic PCM has melted. The temperature rise can only take place after exceeding the heat of fusion. A TIM (Thermal Interface Material) is placed as a heat conduction path to reduce the resistances at the thermal interfaces. TIMs are thermally conductive materials that increase the contact conductivity of interconnected surfaces and increase the efficiency of heat transfer.

At a firing temperature of about 1,100 ° C (propane / butane mixture) cooling mechanisms or Wärmeleitpfade were additionally integrated for cooling in the PCM-V. The efficient heat dissipation through the heat conduction paths is done by mixing natural graphite in the PCM-V and another filling in hexagonal Al-honeycomb cells, which also take over the function of other heat conduction paths.

Thus, a temperature smoothing in the PCM-V is achieved by the latent heat of fusion during the flame duration. As is well known, despite heat input, the internal temperature of the microencapsulated organic paraffin does not increase until it reaches its melting temperature.

A time delay of a rapid increase in temperature at the surrounding area of the heat input by the flame treatment on the PCM-V, is not only due to a thermal isolation effect of the PCM-V, but also on the enthalpy of fusion of the active ingredient of C _n 2H _{n + 2} compounds ( organic PCM) and integration of heat conduction paths for cooling by means of PCMs for trapping heat spikes. The interception of heat peaks by means of organic PCM in the context of this invention is not related only to the group of C _n 2H _{n + 2} paraffins.

The heat conduction paths have a higher thermal conductivity than the organic PCM. The transport of the effective heat flow within the PCM-V can be influenced by the arrangement of the heat conduction paths.

The capsule wall of organic PCM, a highly cross-linked methacrylic acid ester polymer, does not melt on flame. The capsule wall remains as a burnt-out empty shell predominantly in the PCM-V.

At the high load mass of the PCM-V according to the invention with Micronal 5040 of greater than 5.4 Kg / m ² at a plate thickness of 1.6 cm, are also process-related and microencapsulated organic PCM particles on the surface of the PCM-V. If this PCM-V body is exposed to flame, there must also be a self-extinguishing behavior there.

A flame retardant and self-extinguishing behavior of the PCM-V is further enhanced when the PCM-V is mixed in a liquid urea or urea solution and Immersed potassium water glass, and then the applied urea potassium layer is dried at 135 ° C.

It is particularly suitable if, in addition, a liquid urea solution mixed with potassium water glass is introduced into a PCC-CaCO ₃ micronal substrate by mixing.

According to the invention, the Micronal wt.% Proportion, potassium water glass wt.% Proportion, Nat. Graphite wt.% Fraction, PCC-CaCO ₃ wt.% Fraction, liquid urea wt.% Fraction according to the requirements for a flame retardant PCM-V with respect to its wt.% Fractions.

This PCM-V can be made into plates with the known from the plasterboard production process steps and dimensioned. Such process steps are for example from the US 4810569 . US 4195110 . US 4394411 and DE10139171 A1 known.

embodiments

The PCM-V materials according to the invention were produced in the following composition:

Mix (I)

• 1) 1.8 Kg Micronal 5040
• 2) 1.8 Kg potassium waterglass Betol K 42
• 3) 1.2 Kg CaCO ₃ (Precipitated PCC)
• 4) 1.2 Kg potassium waterglass Betol K 42

Mix (II)

• 1) 1.8 Kg Micronal 5040
• 2) 0.9 Kg potassium water glass Betol K42
• 3) 0.9 Kg urea dissolved in water
• 4) 1.2 Kg CaCO ₃ (Precipicated PCC)
• 5) 0.6 Kg potassium waterglass Betol K 426)
• 6) 0.6 Kg urea dissolved in water

Mix (III)

• 1) 1.8 Kg Micronal 5040
• 2) 1.2 Kg potassium waterglass Betol K42
• 3) 0.6 Kg urea dissolved in water
• 4) 1.2 Kg CaCO ₃ (Precipicated PCC)
• 5) 1.2 Kg potassium waterglass Betol K 42
• 6) 0.04 Kg Timrex PP 44 Natural Graphite

Mix (IV)

• 1) 1.8 Kg Micronal 5040
• 2) 0.9 Kg potassium waterglass Betol K 42
• 3) 0.9 Kg urea dissolved in water
• 4) 1.2 kg of earth-moist, fine-grained loam plaster grain size <1 mm

Mix (V)

The PCM filling compound prepared according to Mix (I), Mix (II), Mix (III) and Mix (IV) was dried after drying in a circulating air oven at 200 ° C and 20 min dwell time and removed. Subsequently, the plates are immersed for a further 15 min residence time in a potassium water glass / urea solution and then dried at 135 ° C.

The according to Mix (I); Mix (II) and Mix (III) prepared PCM filling material is sufficient, for example, to a metal cassette with the dimensions 60 cm × 60 cm × 1.6 cm, filling volume 5160 cm ³ , to fill.

The PCM-V materials thus produced can be adapted to further requirements in terms of strength, weight, combustibility and required enthalpy of fusion by varying their weight% of new requirements.

The control samples of the invention prepared according to Mix (I) to Mix (V) were observed for flammability, flame propagation, temperature development, flue gas density, and burning dripping and extinguishing time. They are based on EN 13501 classified as flame retardant.

An insertion of the control sample as a depositor, for example in an open metallic box frame, in which the flame is applied to the metallic surface of the box frame, allows classification as a flame-retardant building material after DIN EN 13501 ,

The insertion of these inserts made according to Mix (I) to Mix (5) in a closed or unilaterally open metallic or non-metallic box frame are preferred variants. The insert is cast as an endless plate material, or preferably as a depositors in a metallic box frame and smoothed. After a solidification time of 15 min at RT, the insert is dried in a circulating air drying cabinet at 200 ° C. for 20 min. An open glass fabric can be applied on both sides for stabilization and a smoother smoothing.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10139171 A1 [0013, 0044]
• US 4797160 A1 [0018]
• US 4810569 [0044]
• US 4195110 [0044]
• US 4394411 [0044]

Cited non-patent literature

• RAL-GZ 896 Edition September 2009 [0002]
• Phase change material, quality assurance, RAL-GZ 896 Edition September 2009, Deutsches Institut für Gütesicherung und Kennzeichnung e. V [0002]
• European standard DIN EN 13501 [0012]
• German standards DIN 4102 [0012]
• DIN EN 13501 [0017]
• EN 13501 [0049]
• DIN EN 13501 [0050]

Claims (8)

Organic phase change material (PCM) for flame retardant PCM composites, PCM objects and PCM systems with microencapsulated organic PCM, characterized in that a flame retardant PCM composite consisting of PCC calcium carbonate, microencapsulated organic PCM, potassium water, urea and Nature Graphite, earth-moist clay, was produced. Flame-retardant PCM composite (PCM-V), characterized in that the PCM-V has a micro-encapsulated organic PCM mass> 5.0 Kg / m ² at a plate thickness of 1.6 cm. Flame-retardant PCM-V, characterized in that the micro-encapsulated organic PCM has an additional thermal contact conductivity at the abutting ball contact surfaces. Flame retardant PCM-V characterized in that the heat flow through a TIM (Thermal Interface Material) serves as a heat conduction path to reduce the thermal resistances at the thermal interfaces. Flame-retardant PCM-V, characterized in that the incorporation of TIM in the PCM-V and integration of heat conduction paths in the composite heat tips are smoothed. Flame retardant PCM-V, characterized in that a self-extinguishing behavior is achieved on the micro-encapsulated organic PCM, if installed in the PCM-V potassium water glass, natural graphite, dissolved urea, PCC-CaCO ₃ or earth-moist clay. The flame retardant PCM-V according to claim 1 to 6 can be further improved in its flame retardancy, when the PCM-V prepared according to claim 1 to 6, immersed in a potassium water glass / urea solution. Residence time in the bath 15 min. followed by drying in a convection oven at 135 ° C. The method of claim 1 to 7 for the production of flame-retardant PCM composite, PCM objects and PCM systems with micro-encapsulated organic PCM characterized in that they are not classified as dripping dripping / falling.