Vitreous or vitreous-crystalline, rapidly dissolving material and process for its production.

Field of application of the invention

The invention relates to manufacturing processes of materials which are defined to be rapidly soluble and which do not release any toxic substances with regard to their use. They can be used wherever defined dissolution rates are necessary in a wide range, such as in the application as a bone substitute, bin-Jewegesubstitut, in the connective tissue induction, as a carrier material for inorganic components, such as. B. trace elements, with feed additive or Fertilizers.

Characteristic of the known prior art

Materials with extremely fast solubility are known per se if one considers naturally occurring or synthetically produced salts in the consideration. This applies both to the area of ​​fertilizers and animal feed etc. as well as to the area of ​​application of the bone ice sow. However, the extremely rapid release of all components often creates an unphysiological, even partially toxic concentration (“over-fertilization”) of components that are physiological in themselves. Another disadvantage is that consequently keiru does not have a depot effect. This also applies to the commonly used phosphate, suporphosphate and triplesuperphosphate fertilizers. Such simple salts have also not proven successful in bone or connective tissue substitution. So-called resorbable bone substitute materials based on tricalcium phosphate or hydroxylapatite were introduced in order to remedy this disadvantage in the medical field mentioned, the resorption time of which in many cases is now too long.

Technical solutions for the fertilizer sector, which include a depot effect for this application, are based on materials that have very high phosphate contents and can be classified as metaphosphate glasses (see: Knott, P., Glasses-Agricultural applications, Glastechn. Ber. 62 [1989] 1.29-34; GB-F 2 099 702 A). This also applies to the feed, but especially to materials that can be used implanted subcutaneously in animal production, although in this case the soluble substances preferably serve as carrier materials to compensate for deficiency symptoms, especially magnesium, copper, cobalt and / or Selenium.

Here too - as in the case of fertilizers - the high phosphate content is disadvantageous due to the choice of metaphosphate glasses (see also: Harenz, H., phosphorus use and phosphorus losses in the agricultural, food and household sectors of the GDR from an economic and ecological point of view , From working group Plenum Kl.AdW DDR.- Berlin 14 (1989J3., 25-43). In the field of bioactive bone substitute materials, as already mentioned, resorbable materials are only used in the field of calcium orthophosphates, their originally low solubility being able to be varied within certain limits by various chemical and mechanical processes. (See also: Bauer, G .; Hohenberger, G .: Causes of the different behavior of bioactive calcium phosphate ceramics in the organism, cfi / Ber. DKG 66 [198911 / 2,23-27.)

EP 0 237 043 describes the preparation of calcium phosphate-containing biocompatible laminated bodies, the base body having a layer which enables a higher calcium release than the base body itself. Other solutions expressly refer to the ion-donor effect of both calcium ions and magnesium , Sodium and potassium ions. From this point of view, DE 2 346 739 describes a sintered product made of apatite, glass / Vitrokeram and perrnutite for use as implant material.

The bioactive materials of CaO-P described in DD 248 351 and DE-OS 3 306 648₂O₆-SiO₂-TyP in granular form show a greater release of calcium, sodium, potassium and magnesium ions, but at the same time larger amounts of silicon are released, so that these materials can only be used in compact form. So far, a material with defined rapid solubility has not been developed, which covers precisely the area that has a depot effect on fertilizers and on the above Subcutaneous implantation guaranteed in animal production and on the other hand helps to overcome the (still) insufficient absorption capacity of bone substitute materials. From the point of view of fertilizers as well as bone replacement materials etc., this material should not be appropriate¹ have high phosphorus contents, as is typical of metaphosphate glasses. Nevertheless, the material should be easily meltable and pourable, which represents a further advantage in particular with regard to the processability and the homogeneity of the product.

Aim of the invention

It is the object of the invention to overcome the disadvantages of the prior art.

Essence of the invention

The invention has for its object to provide a material that is quickly soluble in both defined and ex vivo and is easy to melt, pour and produce in granular form.

According to the invention, a material with these features has been developed which also has further advantageous properties which are described in more detail below.

Melt batches of the composition of (figures in parts by mass in%):

22-43 CaO

8-20 na₂O

0-14 K2O, preferably 0.1-14;

0-15 MgO, preferably 0.1-15; 30-55 P.₂O₅

0-15 SiO₂, preferably 0.1-15;

0-40 na₂SO₄ and / or K₂SO₄, preferably 0.1-35

if they are poured in, poured or fried, spontaneously crystallized glass ceramics are obtained, which surprisingly contain a crystalline phase that has not previously been specified in the ASTM file and in the relevant technical literature and is referred to as “X” in this description, or is obtained Mixed crystals of this phase "X".

This phase “X” or mixed crystals of this phase are approximately characterized by the following d-values ​​and intensities by X-ray diffraction:

<table><tgroup cols="12"><tbody><row><entry></entry><entry>2,885 90</entry><entry>2,717 100</entry><entry>2,552 10</entry><entry>2,351 10</entry><entry>2,239 20</entry><entry>2,164 8</entry><entry>1,980 40</entry><entry>1,827 8</entry><entry>1,597 10</entry><entry>-4</entry><entry>- 302 011</entry></row><row><entry>3,199 8</entry><entry>2,851 90</entry><entry>2,679 100</entry><entry>2,529 10</entry><entry>2,321 10</entry><entry>2,209 20</entry><entry>2,141 8</entry><entry>1,953 40</entry><entry>1,808 8</entry><entry>1,578 10</entry><entry>1,569 10</entry><entry>1,517 10</entry></row><row><entry>3.189 δ</entry><entry>2,844 90</entry><entry>2,667 100</entry><entry>2,523 10</entry><entry>2,310 10</entry><entry>2,199 20</entry><entry>2,135 8</entry><entry>1,945 40</entry><entry>1,804 8</entry><entry>1,571 10</entry><entry>1,547 10</entry><entry>1,498 10</entry></row><row><entry>3,15 8</entry><entry>2,835 90</entry><entry>2,663 100</entry><entry>2,514 10</entry><entry>2,303 10</entry><entry>2,195 20</entry><entry>2,131 8</entry><entry>1.941 40</entry><entry>1,800 8</entry><entry>1,569 10</entry><entry>1,539 10</entry><entry>1,495 10</entry></row><row><entry>3,12 8</entry><entry></entry><entry></entry><entry></entry><entry></entry><entry></entry><entry></entry><entry></entry><entry></entry><entry>1,537 8</entry><entry>1,491 8</entry></row><row><entry></entry></row></tbody></tgroup></table>

Example of composition c d value: 3.945 3.650 3.384

Intensities: 20 20 2

Composition¹ is a d value: 3.904 3.618 3.347

Intensities: 20 20 2

Composition example d d value: 3.892 3.611 3.333

Intensities: 15 20 2

Composition example b d value: 3.875 3.600 3.325

Intensities: 20 20 2

This crystalline phase is thus similar to the phase referred to in the literature as phase “A” (cf. in this regard: Ando, ​​J .; Matsuno, S .: Ca₃(PO₄Ij-CaNaPO₄ System, Bulletin, Chem. Soc. Japan 41 [1968) 342-347), from which it differs, however, by considerable line shifts and changes in intensity, and by the lack of a strong diffraction line at the new level (421). Phase "A" was described by Ando as an over-structure of the hexagonal calcium sodium orthophosphate, using both the high and low temperature forms of CaNaPO * as alpha- or beta-rhenanite and the mere formulation rhonanite thus includes both forms. We agree with this use of language or this definition of rhenanite in the present description.

Phase "X" can also be assigned to the structure type of "A", where it seems that up to over half of the sodium can all be replaced by potassium and calcium can also be partially substituted by magnesium in this structure. These substitutions are generally referred to as mixed crystal formation.

The materials containing this phase now also show the desired properties with regard to a defined rapid solubility, in particular with regard to bone substitution. Animal studies have also surprisingly found that a certain proportion of these substances in turn induce connective tissue formation

The new materials are in the cooled state at room temperature as glass or glass-crystalline material, but can in principle be converted into the glass-crystalline state and essentially have physiological constituents. The dissolving speed of the materials is adjusted according to the application within wide limits, as described in detail below, so that no toxic reactions or Overconcentrations of any ingredient are implied.

Widening of the melting range leads beyond phase “X” to further crystalline phases known per se. In addition or individually, phase “A” or its mixed crystals, rhenanite or its mixed crystals can be present in the material produced according to the invention be. These compositional variations are also suitable for application in the genannton areas of application in the sense of the goal, as is the inclusion of the isomorphic relationships of the sulfates of potassium and sodium which are known per se. This expanded composition area therefore extends to the components already mentioned in their mass fractions in%:

20-55 CaO 5-25 Na₂O 0.01-15K₂O 0-15MgO 30-50 P₂O₆ 0-15SiO₂ 0-40 na₂SO₄ and / or K₂SO₄.

However, a further increase in the calcium orthophosphate content leads to increasingly heavier or non-meltable and non-pourable materials, which thus approach known materials both in terms of their production process and in terms of their properties (solubilities) or depart from the objectives of the present document

Particularly advantageous embodiments are therefore in the concentration ranges (mass fractions in%)

21-50 CaO, especially 23-50 5-20 Na₂O, especially 6-20 0.1-14 K.₂O, especially 2-14 0.1-12 MgO, especially 0.5-10

32-48 P.₂O₆, especially 35-48 0.1-15 SiO₂, in particular 1-10 0.1-35 Na₂SO₄ and / or K₂SO₄, especially 0.1-20.

Another preferred embodiment of the material according to the invention consists of

22-55 CaO, 6-12 Na₂0.3-14 K₂0.2-8 MgO, 37-43 P₂O₆, 0.5-10 SiO₂, 0.5-20 Na₂SO₄ and / or K₂SO₄.

The material according to the invention is further characterized in that it is at a temperature in the range of 1200⁰C to 1550³C can be converted into a pourable melt. Another characteristic of the material is that the melt has a cooling rate greater than about 150⁰C per minute in the glassy state at room temperature

can be transferred and that the melt crystallizes spontaneously on cooling under normal cooling rate or under a cooling rate that is slower than about 35 ° C per minute. A fine crystalline structure is formed.

Furthermore, it was found that spontaneously crystallized material of the same chemical composition as the corresponding glos (obtained under extreme cooling conditions) or the crystalline material produced from the glass by tempering each have different solubilities. It was also found that the spontaneously crystallized glass ceramic as the main crystalline constituents of at least one of the phases of rhenanite, mixed crystals of rhenanite, phase “A”, mixed crystals of phase “A”, the new phase “X” mentioned above and / or mixed crystals which contains phase "X". The material can also contain glaserite and / or crystalline potassium sulfate.

If the material contains rhenanite or mixed crystals of rhenanite as the main crystalline constituents, the composition of the material in the batch is as follows (calculated in mass fractions in% and on an oxide basis):

30-40 CaO; 15-20 na₂O; 0-1 K₂O, preferably 0.01-0.1 K₂O; 0-5 MgO, preferably 0.1-5 MgO; 40-55 PjO₆; 0-15 SiO₂, preferably 0.1-8 SiO₂; 0-30 Na₂SO₄ and / or K₂SO₄, preferably 0.1-25 Na₂SO₄ and / or K₂SO₄.

“Crystalline main component” means that the percentage of the component is higher than the percentage of other components present in the material.

If the material contains the phase "A" as the main crystalline constituents, the composition of the material in the batch is as follows (in mass percentages and calculated on an oxide basis):

40-50 CaO; 8-20 na₂O; 0-1 K₂O, preferably 0.1-1 K₂O; 0.5 MgO, preferably 0.1-5 MgO; 40-50 p₂O₆; 3-20 SiO₂; 0-30 Na₂SO₄ and / or K₂SO₄, preferably 0.1-25 Na₂SO₄ and / or K₂SO₄.

If the material contains the phase "X" or mixed crystals of phase "X" as the main crystalline constituents, the composition of the material in the batch is as follows (calculated in mass fractions in% and on an oxide basis):

22-45 CaO; a-20 Na₂O; 0-14 K.₂O, preferably 0.1-14 K₂O; 0-15 MgO, preferably 0.1-15 MgO; 30-55 P.₂O₆; 0-15 SiO₂, preferably 0.1-15 SiO₂; 0-40 na₂SO₄ and / or K₂SO₄, preferably 0.1-35 Na₂SO₄ and / or K₂SO₄.

A particular advantage of the invention is that the material is biocompatible, in some cases even bioactive in the sense of direct bone attachment or with the permanent loosening of new bone tissue. On the other hand, it also promotes connective tissue formation. The material can be used, for example, as granules with a grain size in the range of

The invention further relates to a process for producing a glassy or glassy crystalline material with rapid solubility, which consists in that a mixture consisting of (calculated in mass fractions in% and on an oxide basis):

20-55 CaO; 5-25 na₂O; 0-15 K.₂O; 0-15 MgO; 30-55 P.₂O₆; 0-15 SiO₂; 0-40 na₂SO₄ and / or K₂SO₄

melts for at least 10 minutes at a temperature of about 1200 to 1 580 ° C and the melt cools. The preferred compositions already mentioned above can preferably be used.

As already shown above, cooling can take place at a very high cooling rate of at least 150, but better still 5 * 10^2oC per minute and a glassy material are obtained.

However, the main way of producing rapidly soluble materials according to the invention is by melting with subsequent spontaneous crystallization. Therefore, in the following, all explanations should preferably be based on this method. The melt is at a speed of less than approx. 35⁰C cooled per minute, whereby the spontaneous crystallization occurs. The spontaneously crystallized material is advantageously subjected to a conventional tempering process. This takes place in the temperature range from approx. 600 to 1200⁰C, depending on the chemical composition and the crystal phase to be produced, to increase the crystalline fraction - usually the crystalline main phase. The relationship between chemical composition and crystal phase has already been generally outlined above. The crystal phases of rhenanite, phase “A”, mixed crystals of phase “A”, phase “X”, mixed crystals of phase “X”, glaserite and / or crystalline potassium sulfate appear as a result of the treatment according to the invention.

It is advantageous for the method according to the invention to P₂O₆ use in the form of phosphoric acid.

An advantageous material form is the granulate form, so that the material which has been cooled and optionally tempered from the melt is comminuted and classified using conventional methods.

If the Na₂SO₄ and / or K₂SO₄ is approximately equal to or greater than 3 parts by mass in% in the starting batch, it is advantageous to treat the granules with distilled water over a period of 0.1 to 10 hours at elevated temperature, preferably at about 80 to 100⁰C to suspend. This results in an increase in the inner surface of the material, which is expressed in an increase in solubility, and the proportion of sulfate, if it is not desired, can be reduced. In addition, the sulfate thus recovered can be recycled to the processing process.

As already stated, the neua quickly soluble material can be used as resorbable bone substitute material or for induction of connective tissue.

Here, it is expedient to granulate in the desired grain size into the corresponding body region 6n, e.g. B. to introduce postoperative cavities in the human or animal body, this also being possible in a mixture with other substances,<i>e.g. </i>B. with less quickly soluble biocompatible materials acc. DD 258 713, carrier foils, etc. When used for connective tissue induction, the specific composition chosen first decides on the success of the treatment; However, mixtures with other substances which are known not to lead to bone accumulation can also be used in this case.

The material can also be used to coat implanted moldings for hard tissue replacement, consisting of metals or alloys and / or ceramics, preferably Al₂O₃-Coramics would be used, so that it would contribute to an improved and above all faster healing phase.

It has also been found that the materials according to the invention with rapid solubility in the composition described at the outset, including the advantageous composition ranges, can be used particularly successfully as fertilizers. Compared to conventional fertilizers, they have a reduced phosphate content and, because of their delayed release of phosphate, are particularly advantageous for almost all applications. The problem of “over-fertilization” can hardly occur in the materials according to the invention. Because of the good meltability and pourability, correspondingly easily granulable end products can be produced without great effort. The materials according to the invention can be mixed with conventional auxiliaries and / or carrier substances and with known fertilizers, in particular Nitrogen carriers, are combined and introduced into or into the ground as dust (suspension) or granules using known methods.

The following trace nutrients are suitable as trace elements for fertilizers in the material according to the invention: boron, copper, manganese, zinc, iron, cobalt, molybdenum. The fertilizers according to the invention are particularly suitable for intensively cultivated soils because they lack potassium, phosphorus and magnesium, and occasionally also sulfur.

Since it is customary to use sulfur as a so-called "top fertilizer", the form present in the material according to the invention, the sulfur, the possibility of a rapid release, especially the sulfur-containing potassium component, suits the intended use. (However, when such materials are implanted in living organisms, , preferably use the sodium component).

The application as a fertilizer concentrates on allotments, wine and fruit growing, but it would be just as favorable for field beans and rye, since comparatively much calcium is extracted from the soil and calcium-rich fertilizers can also be derived from the composition field according to the invention.

Although preferably only basic fertilizer is applied before sowing, it is also advisable to use the depot fertilizer according to the invention in this way. The quantities to be applied can be determined on the basis of the respective soil analysis in connection with the tested solubilities of the materials (see also the analysis values ​​of the quick method for determining the solubility below).

Furthermore, it was found that the materials according to the invention with rapid solubility in the composition described at the beginning, including the advantageous composition ranges, can be used successfully as a feed additive. Compared to conventional feed busts based on metaphosphate glasses, the reduced but sufficient phosphate content, which is slowly implemented in the animal body, has beneficial effects.

The shape of the subcutaneous implant body, which additionally contains the trace elements such as copper, cobalt and / or selenium in the desired amount, is particularly favorable, ie the concentration of these constituents in the implant body can include higher values ​​in the percentage range.

The feedstuffs according to the invention can furthermore contain customary auxiliaries and / or carriers as well as known feedstuffs in sensible admixtures. They can be administered as pellets or in suspension in a liquid food; However, they can advantageously be used in the subcutaneous implant body shape already mentioned and thus specifically for the treatment of lean symptoms in tior production. The application amounts can be roughly determined according to the requirements from the solution attempts given below. However, the higher the trace element addition chosen, the more altered (delayed) solution mechanisms occur, which must be taken into account in corresponding estimates.

In order to be able to make a comparison of the in vitro solubility of different substances, two different ways were described, firstly the solubility in a differential circulation cell and secondly a quick method, which should be given here:

The material to be examined is crushed and the grain fraction of 315-400 pm selected for the determination is removed. The sample material is washed with ethanol and then dried at 110 ° C. 10 samples of approx. 2 g each of the test substance are weighed out on the analytical balance. Bidistilled water is reduced to 37⁰C heated and each 200ml in a beaker are mixed with the weighed approx. 2g. This sample remains in the incubator at 37 for 24 hours⁰C, covered with a watch glass, stand. After this time, the samples are transferred quantitatively to previously balanced frits.

Then the filter with the sample substance at 110⁰C dried. After cooling in the desiccator, the weighing is carried out again to determine the weight loss according to: (weight in mg weight in mg) * 1000 / weight in mg = result in mg of punch loss / g weight

The standard deviation is then calculated.

The following values ​​result from this method:

<table><tgroup cols="3"><tbody><row><entry>Material or</entry><entry>Batch 1</entry><entry>mg loss of substance / g weight</entry></row><row><entry>Material code ")</entry><entry>Ch.-qe?</entry><entry></entry></row><row><entry>Approx₃(PO₄I.₂</entry><entry>Batch '</entry><entry>3,1 ± 0,39</entry></row><row><entry></entry><entry>Charge4</entry><entry>3,0 ± 0,63</entry></row><row><entry></entry><entry>Batch 1</entry><entry>2,9 + 0,60</entry></row><row><entry></entry><entry>Batch 1</entry><entry>2,2 ±0,16</entry></row><row><entry>4CaO * P₂O₆</entry><entry>Batch 2</entry><entry>1,8 ±0,72</entry></row><row><entry>a</entry><entry>Batch 3</entry><entry>5,9 ±0,27</entry></row><row><entry></entry><entry></entry><entry>6,6 ±0,55</entry></row><row><entry></entry><entry></entry><entry>6,2 ± 0,28</entry></row><row><entry>b</entry><entry>Batch 1, untreated</entry><entry>5,7 ±0,84</entry></row><row><entry>C.</entry><entry>Batch 2, untreated</entry><entry>14,7 ±0,77</entry></row><row><entry>d</entry><entry>Batch 1 treated</entry><entry>93,6 ±3,57</entry></row><row><entry></entry><entry>untreated</entry><entry>87,6 ±1,22</entry></row><row><entry></entry><entry>drilled</entry><entry>23,1 ±1,23</entry></row><row><entry>e</entry><entry>(glassy, ​​quenched)</entry><entry>36,6 ±1,68</entry></row><row><entry></entry><entry></entry><entry>3,8 ± 0,77</entry></row><row><entry>f</entry><entry>Batch 10, untreated</entry><entry>54,9 ±7,12</entry></row><row><entry>G</entry><entry>Batch 10, untreated</entry><entry>9,8 ±1,98</entry></row><row><entry>O</entry><entry>188.0 ± 0.99 (n = 5)</entry></row><row><entry>P</entry><entry>244.9 ± 0.5 (n = 6y</entry></row><row><entry></entry></row><row><entry></entry></row></tbody></tgroup></table>

') For compositions see Table 1

According to the results of the rapid method Bestimmung jr determination of the solubility, it is evident that the materials can be roughly classified according to the main crystal phases:

Rhenanite or mixed crystals of rhenanite approx. 3 ... 10 mg / g

Phase "A" or mixed crystals of phase "A" approx. 1 ... 4 mg / g phase, X "or mixed crystals of phase" X "approx. 7 ... 15 mg / g.

With the addition of the sulfate components or after carrying out an appropriate treatment (leaching) of materials with high sulfatantoils, this classification is of course no longer valid; these values ​​were then significantly exceeded as requested.

However, it can generally be stated that, in particular, materials which contain the (new) phase “X” or mixed crystals of phase “X” are particularly suitable for the production of the pure and the mixed melts provided with sulfate components and products obtained therefrom. This is expressed, among other things, in the good castability of the melts, the homogeneity of the materials, the leachability in the presence of sulfates, etc.

Embodiments

The preceding statements, which only reveal the full scope of the invention, are explained in more detail below by a few examples. The batches listed in Table 1 were melted and comminuted in accordance with the subsequent application tests. The crystalline phases were determined and the solubility was tested using the rapid method described and in the differential circuit. Some of these results have already been presented in the previous section

The following are examples of some investigations with regard to the application.

Table 1 - List of assembly examples:

Code oxide composition in% by mass

Name CaO MgO Na₂OK₂O

P₂O₆

SiO,

additions

<table><tgroup cols="8"><tbody><row><entry>a</entry><entry>24,0</entry><entry>5,4</entry><entry>8,3</entry><entry>13,3</entry><entry>40,1</entry><entry>8,9</entry><entry>_</entry></row><row><entry>b</entry><entry>25,11</entry><entry>5,52</entry><entry>13,70</entry><entry>6,94</entry><entry>41,48</entry><entry>7,38</entry><entry>-</entry></row><row><entry>C.</entry><entry>31,5</entry><entry>-</entry><entry>8,3</entry><entry>13,3</entry><entry>40,1</entry><entry>8,9</entry><entry>-</entry></row><row><entry>d</entry><entry>24,0</entry><entry>5,4</entry><entry>8,3</entry><entry>13,3</entry><entry>40,1</entry><entry>8,9</entry><entry>10Na₂SO₄</entry></row><row><entry>e</entry><entry>25,11</entry><entry>5,52</entry><entry>13,70</entry><entry>6,94</entry><entry>41,48</entry><entry>7,38</entry><entry>10Na₂SO₄</entry></row><row><entry>f</entry><entry>26,63</entry><entry>6,04</entry><entry>9,27</entry><entry>14,12</entry><entry>34,05</entry><entry>9,05</entry><entry>-</entry></row><row><entry>G</entry><entry>18,68</entry><entry>6,73</entry><entry>10,32</entry><entry>15,64</entry><entry>38,63</entry><entry>10,00</entry><entry></entry></row><row><entry>H</entry><entry>25,76</entry><entry>4,64</entry><entry>11,27</entry><entry>17,48</entry><entry>40,85</entry><entry>-</entry><entry>—</entry></row><row><entry>i</entry><entry>25,76</entry><entry>4,64</entry><entry>11,27</entry><entry>17,48</entry><entry>40,85</entry><entry>-</entry><entry>8Na₂SO₄</entry></row><row><entry>j</entry><entry>32,75</entry><entry>-</entry><entry>13,7</entry><entry>6,94</entry><entry>41,48</entry><entry>7,38</entry><entry>-</entry></row><row><entry>k</entry><entry>32,75</entry><entry>-</entry><entry>13,7</entry><entry>6,94</entry><entry>41,48</entry><entry>7,38</entry><entry>4th N / A₂SO₄</entry></row><row><entry>I.</entry><entry>24,35</entry><entry>5,52</entry><entry>8,84</entry><entry>13,54</entry><entry>40,54</entry><entry>7,21</entry><entry>-</entry></row><row><entry>m</entry><entry>24,35</entry><entry>5,52</entry><entry>8,84</entry><entry>13,54</entry><entry>40,54</entry><entry>7,21</entry><entry>4K₂SO₄</entry></row><row><entry>η</entry><entry>24,35</entry><entry>5,52</entry><entry>8,84</entry><entry>13,54</entry><entry>40,54</entry><entry>7,21</entry><entry>10K₂SO₄</entry></row></tbody></tgroup></table>

Continuation of table I

Code oxide composition in% by mass

Name CaO MgO Na₂OK₂OP₂O₆ SIO₂ additions

<table><tgroup cols="8"><tbody><row><entry>O</entry><entry>24,35</entry><entry>5,52</entry><entry>8,84</entry><entry>13,54</entry><entry>40.Ü4</entry><entry>7,21</entry><entry>30th N / A₂SO₄</entry></row><row><entry>P</entry><entry>24,0</entry><entry>5,4</entry><entry>8,3</entry><entry>13,3</entry><entry>40,1</entry><entry>8,9</entry><entry>20 Well₂SO₄</entry></row><row><entry>q</entry><entry>24,0</entry><entry>5,4</entry><entry>8,3</entry><entry>13,3</entry><entry>40,1</entry><entry>8,9</entry><entry>10th N / A₂SO₄ and 10K₂SO₄</entry></row><row><entry>r</entry><entry>24,35</entry><entry>5,52</entry><entry>8,84</entry><entry>13,54</entry><entry>40,54</entry><entry>7,21</entry><entry>4.5 na₂SO₄ and 4.5K₂SO₄</entry></row><row><entry>S</entry><entry>25,76</entry><entry>4,64</entry><entry>11,27</entry><entry>17,48</entry><entry>40,85</entry><entry>-</entry><entry>3rd N / A₂SO₄ and 18K₂SO₄</entry></row></tbody></tgroup></table>

example 1

A material of composition g was crushed after melting and cooling under normal conditions. A grain fraction of 200 to 500μηι was selected for the subsequent animal experiments.

The material was implanted both subcutaneously and in the bones of rats and rabbits. After 4.8 and 12 weeks of lying time, the material was still detectable in both cases, although the proportion and the grain size had decreased considerably. In the bone tissue, the material was contacted directly by bone tissue, whereas a firm connective tissue separation had been implied in the subcutaneous implantation.

Example 2

A material of composition f was melted, poured into a plate and, after slow cooling, crushed in the oven. The granules of the grain fraction from 200 to SOOpm were implanted analogously to Example 1.

The histological examinations showed that the material, like all implanted materials, healed without inflammation. In this case it was also shown that the material in the bone tissue was completely absorbed after 12 or 20 weeks. On the other hand, residual particles in the connective tissue after subcutaneous implantation could be detected.

Example 3

Analogously to Example 2, material of composition a was produced and implanted. While remains of the implanted granules were still detectable in the bone after 15 weeks, it had already been completely absorbed in the subcutaneous tissue after this time.

Example 4

A material of composition d was melted at 1500 ° C, cast into a plate, which was then crushed after cooling. The granules of the grain fraction of 200-500 μm produced therefrom were pretreated once,

that is, at 90⁰C for 30 min in dist. Boiled water and implanted untreated in test pigs in the bones.

After 20 weeks of lying, both materials were completely absorbed. However, no bone formation was implied at these points, which means that the material is also suitable for filling cavities in which only connective tissue is to be induced.

Example 5

The material production and animal experimental testing was carried out exactly according to Example 4.

In both cases, however, 55% by mass of the material according to the invention was mixed with 45% by mass of a surface-modified tricalcium phosphate (TCP) granulate (corresponding to WP-DD 258 713 A 3) and implanted.

In these cases there was bone formation in the artificially set defects, with remnants of the TCP still being detectable after this period of 20 weeks. However, these implant remnants are comparatively extremely small compared to when the bone defects are filled with pure surface-modified TCP.

This combined application means that the bone is fully functional after an appropriate healing phase.