DD205429A1 - METHOD FOR PRODUCING AND PROCESSING A HIGH-TEMPERATURE-RESISTANT THERMAL INSULATION FOAM - Google Patents

Abstract

The aim of the invention is to improve the process - so that this material, without first having to be processed into a semi-finished product, can immediately get its final form. This object is achieved by stirring up an acidic aqueous solution stored in a first storage container and a suspension of a divalent metal carbonate and water stored in a second storage container before processing, then via a respective closure valve and for precisely metering in each case one precision gear pump be promoted to a two-component gun and blown out of this by means of a gaseous pressure medium into the spaces or molds to be filled with the heat-insulating foam. The acidic aqueous solution of the metal phosphate are aggregates such as glass fibers, foam glass granules, perlite granules, kaolin u.ae. added, while the metal oxides and hydroxides, zinc oxide, magnesium oxide and aluminum oxide and the metal carbonate necessary for the preparation of the metal phosphate are calcium carbonate.

Description

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Process for the production and processing of a high temperature resistant thermal insulation foam

International Patent Classification: O 04 B, 43/00 Field of application of the invention: ~

The invention relates to a method for producing and processing a high-temperature, foamable, inorganic heat insulation material, as used by a variety of industries for thermal insulationo So its use for the isolation of • heat cabinets, cooling equipment, refrigerated wagons, buildings u. a · Facilities known ·

-O-

Characteristic of the known technical solutions:

In the UB patent specification 3,148,996 an inorganic, temperature-resistant, foamable material is described, which is prepared from an acid metal phosphate, feinpulvrigem Oalciumsilioat, water as a binder and Oalciumcarbonat as a foaming agent. The product produced after foaming has a density of 290 kg / nr »

«· 2« w

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in 2 -

In US Patent 3,330,675 a foamable material is presented which contains a basic compound in place of the calcium silicate, which neutralizes the free Pg ⁰ S * "bonds" The foamed product has a density of at least 4-10 kg / nr _β in both cases with stoichiometric amounts, d _e h ₀ the Iquivalentverhältnis has worked equal to 1 to achieve a hardening of the phosphate mixture · Due to the relatively long curing time, these foams can not be in place: and place and process in the final form · Bs can thus only semi-finished products such as profiles, cuboid u · a · are made, from which then the desired fittings are to be made.

Another disadvantage is the low thermal insulation due to the high density.

In BRD-AS 2,756,198 a process for the preparation and use of an inorganic foam as warmer; Accordingly, an aqueous acidic solution of a metal phosphate with a variable within certain limits Atma ratio of metals to phosphorus and a likewise variable within certain limits equivalent ratio: with a basic metal carbonate to a foam

3 foamed · The density of this foam is 150 kg / m ·

Due to the mixing condition, the production technology of this foam is cumbersome and impractical The quantities to be processed must be calculated exactly in advance, since an interruption of the processing may not be made · It is equally disadvantageous that this foam can only be cast and processing in horizontal or above inclined position is not possible _e

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Object of the invention:

The aim of the invention is to simplify and improve the production and processing of a high-temperature-resistant heat insulation foam material in such a way that this material can be immediately given its final form without having to be processed into a semifinished product.

Explanation of the essence of the invention:

The invention was based on the task of developing a process for the production and processing of a high temperature, sohaumbaren inorganic thermal insulation foam, which requires no extensive preparatory work, at any time, even in short intervals ^ interruptible and immediately reusable, a processing of the foam in a horizontal position and in a variety of inclinations, and its foam at low density, a high thermal insulation. mung ©

According to the invention, this object has been achieved in that a stored in a first reservoir acidic aqueous metal phosphate solution and stored in a second reservoir suspension of a divalent metal carbonate and water stirred before processing, then via a respective closure valve and for precise metering of a precision gear pump conveyed to a two-component gun and blown out of this by means of a gaseous pressure medium in the spaces or molds to be filled with the thermal insulation foam, wherein the acidic aqueous solution of the metal phosphate additives such as glass fibers, foam glass granules, pearlite granules, kaolin u »ä» added; the mixture of metal phosphate by reaction of 75% ortho

m 4 ««

40 4 6 1 5

m 4 ~

produced by di- and polyvalent metal oxides and hydroxide, the metal oxides zinc oxide and magnesium oxide and the hydroxide are aluminum hydroxide and the metal carbonate is calcium carbonate and for acidification of the metal phosphate small amounts of dilute sulfuric acid, preferably 0.01 part by mass to 0.1 part by mass per 100 parts by mass Metallphosphatlöaung ₀ The foamable mixtures of the metal atoms of aluminum, magnesium and zinc to the phosphorus atoms are in a ratio of 0 »6 to 0.9» while the ratio with addition of calcium by an amount of 0 # 25 to 0.45 becomes largerj the ratio of Is the equivalent of metals to phosphate a value? fQ $ Q _t ty to O «75 and increases by a value of 0.17 to 0.30 when calcium is added»

Three embodiments are intended to explain the invention in more detail.

The consisting essentially of an acidic aqueous solution of a mixture of metal phosphates foam component A and consisting essentially of calcium carbonate and water foam component B are stored in separate storage containers. Both tanks are each provided with a Versohlußventil, in turn, each followed by a Präzisionszahnradpumpe downstream of the pump. "The lines emanating from the pump discharge into a two-component gun, which is connected to a pressure fluid container · For stirring the components A and B, each reservoir is provided with a Eühreinriohtung ,

Essential in the production of both storable individual mixtures and the foamable mixture A + B is the compliance of certain mixing ratios, the following quantitative relationships form the basis:

4 6 Γ 5

"J, Pas ratio of the number of metal atoms to the phosphorus atoms (Me / P ratio).

ll / P » i /« \

| _{= 1} ^a i · ⁿ i ίιΓβ)

r "* ·

p_. »| J -Ll-i (ί; b)

^m i, g - mass of the compound i _f i

ⁿ i, j · »Number of metal (i) or phosphorus (3) atoms in the compound iod

molar mass of the compound i, j

2β The ratio of the valency of the metals to the valence of the phosphorus (equivalent ratio,! -Ratio)

P »r. _w

i, j - valency of the metal (i) or of the phos * phorus (j) in the compound 1 ₉ $

For better identification one differentiates between the following values:

Me / P ^ · * Me / P ratio of component A Me / P ₂ · Me / P << ratio of mixture A + BA \ j · Equivalent ratio of component A Ag μ Equivalent ratio of mixture A + B

m 6 -

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- 6 »·

as well as between

A Me / P »Me / P ₂ - MeZP ₁ ( _3e )

and

AA «A ₂ - I ₁ ^ _{(/ J. #)}

These ratios, as well as their Λ values, must be within a certain range to ensure foaming with parallel hardening of the metal phosphate.

As a favorable range for a Me / P ^ value has been found in the range of 0 * 6 to O ₉ 9 and an A ₁ value of 0.4 to 0.75 · The Λ values run in the opposite direction; A, Me / P from 0.4-5 to 0.25 and A 1 from 0.30 to 0.17V

Of decisive importance for the properties of the foam is the amount of water that is added · Here are two opposite tendencies to consider ·

1 '' As the Me / P.rf value increases, the viscosity of component A increases and hence the tendency for self-curing. For large media, however, small amounts of component B are required for parallel foaming and curing.

2o Low Me / P, j ~ values give a low viscosity and thus a stable aqueous metal phosphate solution. However, a larger amount of B is required for foaming and curing.

Since the ratio of metal carbonate to water is 1 2 for component B (suitable viscosity), too high a water content causes the foam to shrink before final solidification and thus deteriorate such properties as density, thermal conductivity and temperature resistance.

for the Me / P, · «· δΜθ / F- and A \, - δI» · intervals these restrictive conditionso The mass fraction of the water to the mass of the total metal phosphate is thereby in a range of 25 b £ s 45 to 100 · The variation interval including the percentage of water is shown in Figure 1 (Me / P) and Figure 2 (A).

0.7 0.8 OS Aß

Fig. 1 Variation interval for Me / P ^ - and with maximum water content

Me / P values

O ₁ → 0.5 0.6 Q? 0.6 Fig. 2 Variation interval of the JL and λ 1 jffs

Preparation of components A and B

The component A is preferably by reaction of two rad polyvalent metal hydroxides or oxides with 75% strength

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Ortho-phosphoric acid prepared · For acidification, component A dilute sulfuric acid, ca «0.01 to. Q, add 1 part by mass per 100 parts by weight of metal phosphorous. For the preparation of A, add the three components in order, aluminum hydroxide »zinc oxide and magnesium oxide, in a stirred tank of phosphoric acid to a speed of 800 to 1000 minutes complete reaction at normal temperature (about ₀ 3 to 4 h) stirred

The result is a white to transparent viscous suspension having a dynamic viscosity of about 0.1 to 0.5 ^. ¹

In compliance with the o.g. Mixing conditions, this aqueous metal phosphate solution is stable and storable over a longer period of time at normal temperature »After prolonged storage, it is advisable to briefly stir the mixture on.

The component B is prepared by mixing calcium carbonate with water in the ratio 1s2, wherein a white, similar viscous suspension as the component A, is formed. Stored under exclusion of air, component B is also storable. Since there is virtually no chemical transformations taking place in component B, it is only a very supersaturated solution, only a short production time is necessary here (a few minutes). It is also advisable to stir up component B briefly after prolonged storage

Examples and results

The following examples are intended to illustrate the boundary conditions for the production of the foam.

The quantities are in parts by mass · The thermal conductivity was measured using an advanced hot wire method »

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1o example

For the following components, component A is prepared:

100 parts 75% phosphoric acid 28 parts aluminum hydroxide 10 parts zinc oxide 8 parts magnesium oxide

These ingredients are mixed as described and acidified with 0.05 parts by weight dilute sulfuric acid and reacted. The result is a white to transparent viscous liquid with a Me / P ^ value »0.90 and I ^» O, 75 «> Component B is prepared from 20 parts of calcium carbonate and 40 parts of water, after mixing A and B after The process described produces a foam having the following values:

Me / P ₂ * 1.16 ΔMe / P = 0.26 * 0.92 ΔA a 0.17

The physical parameters are: S a 140 kg / m ³

800 ⁰ O (no changes after 6 h)

Compressive strength P _D «59 Average cell size: 1.5 mm Expansion ratio V ₂ / V ^» 16.5

«10

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Examples 2 and 3s

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Components A and B of Examples 2 and 3 are prepared as in Example 1 and processed "The following quantities" ratios and parameters are recorded (a: f.e.he fabele 1)?

{JJabelle 1 Example 2 Example 3 100 100 75% phosphoric acid, 15 12 aluminum hydroxide 12 8th zinc oxide 8th 5 magnesia 0 _s 70 0.62 MeZP ₁ 0.55 0.39 30 35 Oalciumcarbonat 60 70 water 1.09 1.08 Me / P ₂ 0.81 0.80 H 0.39 0.46 AMe / P 0.26 0.31 al

In both examples, the component A was admixed with 0.05 part by weight dilute sulfuric acid.

The foams obtained in Examples 2 and 3 have the following parameters (see Table 2):

Table 2

Parameters. Example 2 Example 3

Density / kg / nr * 95 II5

Thermal conductivity / 3.4 3.7

2 ^1κ1

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Parameter Example 2 Example 3

tasting / KPa 40 £ 4

J) aue: ptemperatur-

besijondigVBit / ^ Q 800

(2h at 100O ⁰ O without change)

average _Λ j, _{Λ 7}

Cell size / mm t, ⁴ + ^Ί >'

Expansion ratio 20 18.5

Claims (5)

240461 5 - Erfindungsanspruchi 12 - It is characterized by the method of manufacturing and processing a high-grade liquid-state oil. that stored in a first reservoir acidic, aqueous I / solution of a Geroisch of metal phosphates and stored in a second reservoir suspension of a divalent ^M etallcarbonat and stirred water before processing, then via each in Ver closure valve and the exact dosage of each a precision gear pump to a two-component gun and from which it is blown into the spaces or molds to be filled with the thermal insulation foam by means of a gaseous pressure medium « 2 »Process according to item 1, characterized in that the acidic aqueous solution of the metal phosphate additives such as glass fibers, foam glass granules, pearlite granules, kaolin u ä ä _{# be} admixed _β 3 «method according to item 1, characterized in that the mixture of metal phosphate by reaction of 75% pure Ortho-phosphoric acid is prepared with di- and polyvalent metal oxides and hydroxide _e 4. The method according to item 1 and 3, characterized in that the metal oxides zinc oxide and magnesium oxide _9, the hydroxide is aluminum oxide and the metal carbonate calcium carbonate. 5 · Method according to item 1 to 4, characterized in that for acidification of the metal phosphate small amounts 2404 dilute sulfuric acid, preferably 0.01 part by mass to 0.1 part by mass of 100 parts by mass of metal phosphate solution are added. Process according to point 1 to 5κ characterized in that the foamable mixtures of the metal atoms of aluminum, magnesium and zinc and the phosphorus streams in a ratio of 0 _f 6 t4s. 0 ^ 9 lie ⁶⁰ and the yerhältnis upon addition of qa ^ O ^ H W a patrag of Oyä5 to 0, ^ - 5 becomes larger, the ratio $ ev eq |; ivälentmässen of the metals to the phosphate has a value of 6 _t 4 to 0 , 75 and when adding the calcium increases by a value of 0.17 to 0.30