SU1208043A2 - Method of producing urea-aldehyde binder - Google Patents

Description

The invention relates to the production of binders for the foundry industry, namely for the production of

rods for iron casting in hot snap, and is an improvement of the known method described in ed. St. No. 876656,

The purpose of the invention is to increase the mechanical strength of the resin, especially in a cold state, after solidification with hot snap, and also the expansion of the raw material base and its production.

Example 1. Preparation of a binder using a furfuryl alcohol and cubic furl furyl distillate (CODF) mixture as a modifying additive.

To 270 ma.ch. neutralized to a pH of 6.8-7.2. 37% formalin is added 100 wt.h. carbamine, sodium formate and carbonate are introduced, the mass is heated and condensation of urea with formaldehyde is carried out at the beginning in neutral and then in weakly acidic medium created with 1% sulfuric acid solution at pH 5.5-5.8 at a temperature of 90-92 C for 90–110 minutes to viscosity using the OZ-4 viscometer no more than 13.5 s. At the end of the condensation in a weakly acidic medium, the mass is neutralized with a solution of 2% sodium hydroxide to pH 6.9-7.3 and dried under vacuum at 60-70 ° until the refractive index of 1.4AO-1.442 is reached. A 2% sodium hydroxide solution and dry sodium tetraborate to pH 7.0-7.5 are added to the dried resin, waste of furfural production - CODF and furfuryl alcohol in a ratio of 1: 1 are introduced, the total amount of CODF and furfuryl spit introduced is 60 % by weight of the urea component.

The test of the resulting binder was carried out in accordance with TU 6-05-1785- 76 (carbamide-furan resins KF-90, KF-40, HB-21 A).

Example 2. Preparation of a bond of chemical compound with the use of a mixture of furfurl alcohol and vat residue of furfuryl alcohol production as a modifier of a powerful mixture.

In the carbamide component, manufactured according to the regime described in Example 1, a bottom is introduced

- five

1208043

the residue of furfuryl alcohol production in the amount of 30% and 30% of furyl alcohol.

The bottom residue of the distillation of furfural has the following composition:

o

0

five

0

five

0

five

64.5 18.5

2.5

1,3

Rest

Furfural

Methylfurfural

1,2-pentadnol

1,5-pentadiol

Products of tarry furfural

The bottoms residue of the production of furfuryl alcohol is a liquid with a specific furfuryl alcohol groin, its composition according to the technological regulations is as follows,%:

Water

furfural

Tetrahydrofurfuryl alcohol

Furfuryl

alcohol

1,2 and 1,5-pentadiols

Me unfurfuryl

alcohol

Oligrmern part

furfuryl

alcohol linear structure)

Impurities

The results of testing the binder are given in Table. one.

Examples of the preparation of a binder using CODF and a bottoms residue of the production of furfuryl alcohol in other ratios beyond the limits of examples 1 and 2 showed that their properties do not exceed or slightly exceed some of the known urinary binder.

The limit of the components of the modifying mixture, providing a positive effect, in ma.ch., is given in table. 2, on the basis that the modifying mixture according to examples 1 and 2 is 120 mas. of the total weight of the urea component.

From the data table. I, it follows that bottom-modified urea-aldehyde bonds have a higher mechanical strength, 5 especially in a cold state, in

compared with the known urea-aldehyde binder.

0,214-0,262 0,188-0,226

0.345-0.474 23.66-34-70 13.84-14.60 0.710-0.914

56.60-44.70 4,443-4,124

Destructive stress during compression of specimens from a sand-resin mixture, hardened at 220 C, kgf / cm:

Cured for 6 minutes

1 minute after removal from the cabinet

5 minutes after being removed from the cabinet

in a cold state

Cured for 8 min

1 min after being removed from the cabinet

5 min after extraction from vspafa

in a cold state

Destructive stress during stretching of samples from sand-resin mixture, kgf / cm

Cured for 7 s at 22 ° C

in hotter condition

in a cold state

Table 1

22

25 27

53

80 76

123

134,140

70 73

150 158 160 198

1.9 8.0

1.9 2.1 9.0 9.0

IndicatorsBinding

Norm TU6-05, Known According to the example -1975-76р Approved for 30 s at 220 ° C

hot not less than 3,5 4,0 5,8 5,4

in a cold state, not less than 18.0 19.0 25.6 22.2

 Table 2

Ko shonenty Ratio of components

ma.ch. by examples

12

. . Furfuryl alcohol 60 .74.2-80.8

(60 + 14.2X60 + 20.8)

Furfural Methylfurfurol

Methylfurfuryl alcohol

Tetrahydrofurfuryl alcohol

1,2 and 1,5-pentadnols

Products of tarry furfural

Furyl alcohol oligomeric products (linear)

Water Impurities

VNISHSh Order 1075 Circulation 471 Subscription

    1 pi

Lshial mm Patent, Zagorod, Proektna St., 4

Continuation of table 1

38.7 11.12

0.113-0.136

0,426-0,548

0.207-0.285

8,304-8,76

33.96-26.83 0.128-0.157 2.622-2.48

Claims (1)

METHOD FOR PRODUCING UREA BINDING BINDER FOR CASTING PRODUCTION by ed. St. No. 876656, characterized in that, in order to increase the mechanical strength and expand the raw material base, the modification of urea-formaldehyde resin is carried out with a mixture of furfuryl alcohol and distillation residue of production of furfuryl alcohol or distillation residue of furfural distillation at a mass ratio of furfuryl alcohol - bottoms of I 1: 1. J 1208043 1 1208043