SU1618491A1 - Binder for core and mould sands - Google Patents

Abstract

The invention relates to a foundry and can be used as a binder for the preparation of heat-cured core and molding compounds. The purpose of the invention is to increase the strength of the binder, rods and molds after heat drying. The binder contains, in wt.%: Technical alkaline lignosulfonates 10-90, high molecular weight polyethylene polyamine with a molecular weight of 10,000-20000 10-90. At the same time, sulphite liquor or sulphite-alcohol bard or sulphite yeast brch in the amount of 80-90 wt.%, treated with an aqueous solution of caustic soda, with a density of 1.46-1.5 g / cm3 in a quantity of 10-20 wt.%. The introduction of a high molecular weight in l it-ethyl enpoly mama to the composition of the binder promotes the formation of a durable shnnki and an increase in strength in chemical interaction with lignosulfonate. I zp f-ly, 2 tab. F (L

Description

The invention relates to foundry and can be used as a binder for the preparation of core and molding. mixtures, curable by heat drying.

The purpose of the invention is to increase the strength of the binder, rods and molds after heat drying.

The proposed binder contains technical alkaline lignosulfonates and high molecular weight polyethylene polyamine with a molecular weight of 10,000-20000.

As technical alkaline | lignosulphonates use sulphite liquor, or sulphite-yeast brew, or sulphite-alcohol bard, treated with an aqueous solution of caustic soda with a density of 1.46-1.50 g / cm3.

I

High molecular weight polyethylenepolyamine. molecular weight 10,000-20,000 has a binding capacity, behaves in the composition of the binder as a high molecular weight substance, forming a strong film when removing moisture. With alkaline ligno-containing substances enters into chemical interaction with the formation of a strong film

05

So

J

with

forming a complex binder after removing the water after drying.

High molecular weight polyethylene polyamine is used in the form of an aqueous solution of coolant (coolant) for fine diamond grinding of optical parts, made of glass, with a concentration of the polymer substance in an aqueous solution of 25-80%. The studies used a 30% aqueous solution of high molecular weight polyethylene polyamine of various molecular weights.

The binder is prepared by mechanical mixing of a previously prepared alkaline ligno-containing substance and a high molecular weight polyethylenepolyamine molecular weight of 10,000-20000 until a homogeneous state is reached.

In tab. 1 shows the compositions of the proposed binder; in tab. 2 - technical characteristics of these binders.

Binders are tested in compositions of standard molding and core compositions, mixtures with and without clay.

Example 1

Dry quartz

sand 1K016A.

Clay molding

Binder

Water

And p. And mep 2 "Rod mixture without clay, wt.%

Dry quartz

- sand 1K016L

Binder

“In terms of 100%, the mixture with clay is of the following composition, wt.%;

Quartz sand

1K016A

Clay molding

Binder

Water

97.0 3.0 5.0 1.0

100S0 5.0

91, 51 2.83 4.7.2

 0.94

  The composition of the mixture without clay after recalculating the content of components to 100% is as follows, in wt%: Quartz sand 95.24. Binder 4.76. As can be seen from the table. 1 and 25, the strength of the rods and molds in the dry state when using the proposed binder is an order of magnitude higher than when using the known binder. High strength properties in the dry state are achieved when

0

a relatively low drying temperature (180 ° C) for mixtures with clay (Table 2, indications in the numerator), and for mixtures without clay (Table 2, indications in the denominator). Strength for breaking mixtures with the addition of clay - 3-6 times higher, and mixtures without clay — 6-10 times higher for the proposed binders than for the known ones. More

the high strength of the mixtures in the dry state allows to reduce the consumption of St. materials, to obtain castings of higher geometric accuracy,

Claims (2)

1. Binder for core and molding compounds containing a material based on lignin derivatives, characterized in that, with the 5 purpose of increasing the strength of the binder, rods and molds after heat drying, it contains as a material based on lignin derivatives technical alkaline lignosulfonates and, additionally, high molecular weight polyethylene polyamine with a molecular weight of 10,000 to 20,000 with the following ratio of ingredients, may%; Technical alkaline lignosulfonates 10-90 High molecular weight polyethylene polyamine with molecular weight 10000-20000YU-90 2. Binder according to Claim 50 g / cm3 in the following ratio of ingredients, wt.%: Sulphite liquor or sulphite-alcohol 6apfl3j or sulphite yeast. . , mash 80-9.0 Aqueous solution of caustic soda density of 1.40-1.50 g / cm3 10-20 0 five 0 five 0 five Alkaline lignosode, a lubricant. Technical lignosulfonates in combination with alkali in math ratio: 80:20 85: 15 9C: Yu Sulfite yeast brew in combination with alkali in May. ratio 85:15 Sulfite liquor in combination with alkali in the math ratio 80:20 High molecular weight polyethylenepolyamine molecular weight 10,000 12СОО 14,000 16,000 20,000 Technical Ligno Sulfonates ten thirty 70 90 100 Appearance Uniform - Uniform Uniform Uniform Uniform Uniform Uniform Liquid homogeneous liquid liquid liquid liquid liquid bone dark brown brown light brown light brown brown brown brown brown brown korchne- colors of color of color of color of color of color 48.0 44.0 35.4 30.0 0.5 0.4 table 2 37.0 36.0 32.0 31.0 50.0 24.3 15.0 5.9 3.2 13.0 0.3 0.2 0.10 0.5 0.8 Characteristic one The viscosity is conditional on a VZ-1 viscometer with 650 pH of the binder, units 10.5 Density at 20 ° С. g / cm 1.25 The tensile strength in the dry state i. . research institutes, kgf / cm, 13.1 / 16,22,18,2 / 22,124,3 / 26,725,0 / 27,8 26,1 / 29,0 26,0 / 29,0 4,5 / 2,8 Durability on. . . squeezed raw state of kgf / cm1 0.26 / 0.05 0, l 3 / 0.05 0.12 / 0.050.11 / 0.05 0.10 / 0.04 0.12 / 0.05 0.18 / 0.09 Note. - the numerator is the strength of the mixture with clay, the denominator is the strength blends without clay.