SU1590468A1 - Thermoplastic binder - Google Patents

Abstract

The invention relates to thermoplastic slips used for the production of structural ceramics from silicon carbide using the hot-cast method. In order to increase the density of the slurry, the thermoplastic binder includes, in wt%: beeswax 1-35

at least one primary or secondary amine with hydrocarbon radicals C 12-C 22 5-15

paraffin rest. To increase the density of the slip, the thermoplastic binder may additionally contain alkenylsuccinimide in the following ratio of components, wt.%: Beeswax 12-35

at least one primary or secondary amine with C 12-c 22 5-15 hydrocarbon radicals

alkenyl succinimide 3-12

paraffin rest. The content of silicon carbide in the slurry, which at 80 ° C has a viscosity of the destroyed structure of * 98N = 1.5 ± 0.1 Pa. C, is 78–84 wt.%, The bending strength of castings is 4.3-6.8. MPa. 1 hp f-ly. 1 tab.

Description

The invention relates to thermoplastic slips used for the production of structural ceramics from silicon carbide using the hot-cast method.

The purpose of the invention is to increase the density of the slip.

As surface-active additives use octadecylamine (ODE) with hydrocarbon radical C ,. and an average mol. mass of 270 g / mol; primary amine, which is a mixture of amines with hydrocarbon radicals (68%) and C, j-C, j (32%) and an average mol. weighing 190 g / mol (CCA); Primary amine constituting

a mixture of amines with hydrocarbon radicals C, -C, (80%) and C2 (rCii (20%) and an average mol. mass of 275 g / mol (GCA); a secondary amine with a hydrocarbon radical of mol. mass of 525 g / mol (VA ) alkenylsuccinimide (SIM) with an average molecular weight of 500 g / mol.

Example. Cooking binder.

Weights of paraffin, beeswax and oleic acid are weighed on a technical scale with an accuracy of 10.1 g, placed in a ceramic beaker and kept in a heat chamber at 80 ° C until the paraffin and wax melt. After that, the mixture is stirred with a spatula. Po-sp

with

about

Uih

One learned binder can be immediately used to prepare the polishing machines or cooled to room temperature and stored in solid form j for use.

To prepare the slurry in a 700 cm ceramic tumbler, weigh 223 g of binder on a technical scale and heat it in a thermo Q cabinet to. 777 g of SiC is weighed in another ceramic cup. A glass with a SiC sample is placed in a vacuum cabinet and subjected to vacuuming at a residual pressure of 2 mm Hg. 15 art. within 30 min. When this occurs, the removal of adsorption water from the surface of the Sic particles. Then (h / 2/5 (500 g)) weighed portions of SiC powder were introduced into a glass with a molten binder, stirred with a spatula, and again vacuumed for 30 minutes while removing air. After this, the slurry is stirred with a propeller stirrer for 30 minutes. The resulting slurry is introduced (180 g) of the remaining Sic Powder, stirred first with a spatula, and then with a propeller stirrer in the same mode. The slip is again evacuated for 30 minutes at 100 ° C, Q is stirred for 30 minutes on a propeller stirrer, the remaining Sic powder is introduced and the jBecb process is repeated (stirring, evacuating, stirring). The rheological properties of the slip are evaluated on a Rheostat 2 instrument for viscosity corresponding to a fully / destroyed structure at 80 ° C.

From the obtained slip in metal forms, castings of straight, straight: coal section with dimensions of 10x1 Ox are prepared.

20

25

35

.

j

Q 15 Q 468

xZO mm, the flexural strength of which is on the tensile testing machine FM-250 by the method of loading the specimen with a reduced medium.

Specific binder compositions and properties of slips obtained on the basis of them are given in the table.

5 Q

0

five

35

Claims (2)

1. A thermoplastic binder for making ceramic products from il, -SiC with a specific surface of 1020, including paraffin and beeswax, characterized in that, in order to increase the density of the slip, it additionally contains at least one primary or secondary amine with hydrocarbon . radicals.-Crg .. with a trace lean ratio of components, wt.%: Beeswax 1-35 At least one primary, or secondary amine with hydrocarbon radicals Cjj-C. 5-20 Paraffin. Rest 2. The binding according to claim 1, which, in order to increase the density of the slip, it additionally contains alkenyl succinimide in the following ratio of components, wt.%:. Beeswax 12-35 At least one primary or secondary amine with carbon radicals yy-crg. Alkenyl Succinimide Paraffin 5-15 3-12 Else  For Sic powder, previously purified with hydrofluoric acid.