SU836016A1 - Method of producing elastic porous polyurethan - Google Patents

Description

I

The invention relates to the field of producing flexible polyurethane foam (PUF). The resulting PUF can be used in various industries, in particular, automotive, furniture, etc.

A known method of producing flexible polyurethane foam by reacting a polyether containing at least 10% of primary hydroxyl groups with an isocyanate component in the presence of an amine catalyst for tin octoate, a foam stabilizer and a foaming agent 1.

The polyethers used are polyethers obtained by the condensation of ethylene oxide, propylene, butylene or their mixtures with propylene glycol, glycerin, etc .; Polyol has an equivalent weight of 1003,000 and contains at least 10% of the primary OH groups of the total OH- number. groups. Triethylenediamine, tin octoate and tin oleate are used as catalysts. The density of the produced PPU is 23.5-24.5 kg / m, the tensile strength is 0.91-1.14 kg / cm. The disadvantages of this method are the following:

when used as a catalyst, triethylenediamine the composition has an increased activity, which makes it very accurate to dose the catalysts, especially when pouring large mass (over 2 kg) into the warm form and getting blocks, and this, in turn, creates technological difficulties;

The industrial equipment is not able to provide a very accurate dosage of catalysts, due to which technology becomes unstable and is rejected - PUF with closed pores and shrinkage, PUF with cracks, molded products with edges that are detached when removed from the molds; the need to strictly maintain the temperature of the cell, since its nominal fluctuations lead to ruptures or; closed pores in the foam. Strict adherence to temperature in production is also difficult;

the scarcity and high cost of the amine catalyst DABCO, its introduction into the formulation requires a preliminary dissolution operation in water, since DABCO is a solid substance.

These reasons make it necessary to search for new catalytic systems not only because of technological issues, but also because of economic considerations.

The purpose of the invention is to improve the technology for producing polyurethane foam.

The goal is achieved by the fact that in a known method for producing elastic polyurethane foam by reacting a polyether containing at least 10% of OH groups with an isoctane component in the presence of an amine catalyst — tin octoate of a foaming agent, a foam stabilizer — a dimethyl piperazine is used as an amine catalyst diethylstanolamine in quantities of 0.27-0.39, 09-0.13 weight.h. respectively, for 100 weight.h. polyester ..

The process of obtaining polyurethane foam is carried out according to the one-step method: the components, taken in a certain ratio, are necessary, thoroughly mixed with a hand mixer (or metered and

mix using a special industrial installation, after which the mixture is poured into a mold or onto a moving conveyor, where foaming and curing of the foam occurs.

Copolymers of propylene oxide with ethylene oxide, triols containing 5–18% of ethylene oxide residues, mol. mass 3500-4000, the content of primary HL-groups is 15-30%, for example, Laprol 3503-2N-5, Laprol 4003.

I As aminnik catalysts use a combination of tertiary amines dimethylpiperazine and diethylethanol | amine in the amount of 0.27-0.39 and 0.090, 13 parts by weight respectively, per 100 weight of polyester, as organometallic compounds - tin octaate

(product 230-19, as stabilizers, foamed organic surfactants - block copolymers of polyorganosiloxane and

polyoxyalkylene, for example CEP-1, CEP-2 and others. Toluene diisocyanate-mixture of isomers 2.4 and 2.6 in the ratio 80: 20 is used as the isocyanate component, water and low boiling halohydrocarbons as foaming agents.

Example 1. Elastic PPU is prepared in the laboratory as follows.

Into a cylindrical glass of stainless steel (diameter 70-80 mm, height 120 mm) weigh polyether in the amount of .100.0 g, add the amount of catalyst, dimethyl piperazine and diethyl ethanolamine, CEP-2 stabilizer, octaate catalyst, tin, measured by a syringe, and mix frame mixer with 11 1400 rpm for 20 s. Then add the required amount of 80/20 toluene diisocyanate from the cylinder, mix with the same mixer for 5 seconds, add water, stir for another 5-7 seconds, and stop the mixer, pour the contents of the glass into a 15x 15x15 cm metal box lined with film. The foam sample is kept in a heating cabinet at 100-120 0 for 20-15 minutes, then a day at room temperature, the physicomechanical tests are carried out according to standard methods.

In tab. 1 shows the formulations: in the table. 2 - the results of experiments on the proposed method (3.4, b) and known (1,2,5). B. In the latter case, it was not possible to carry out physical and mechanical tests due to the large number of defects in the PU foam samples (sinks, cracks, closed pores).

Example 2, A pilot production of products from elastic PU foam was carried out using the mold casting method at the Izhevsk plastics plant. A high pressure industrial casting machine from the company Henneke, Germany was used.

Recipe, weight. h:

Laprol 3503-2B-5100.0

Tol ui landii zoci a to t

80/20, 44.0-3

CEP-2A foam stabilizer 1.50-0.2

DimethylPIPERAZIN0.33-0.03

Diethylethanolamine0., 11 -O, OI

Catalyst 230-19

(tin octoate)

0.12-0.03 Water 3.50-0.3

Technological mode fill products.

For work on the foaming machine, two activator mixtures of the following composition were prepared, by weight.h: Water 3.50

CEP-21.70

Dimethyl piperazine 0.33

Diethylethanolamine 0.11

Laprol 3503-2B-524.00

Catalyst 230-191,00

The data of the technological regime for obtaining PPU are given in Table. 3

The results of physico-mechanical tests are shown in table 4.

The data table. 4 shows that polyurethane foam in all respects meets the requirements of the customer and can be used in the automotive industry.

360166

The use of this method of producing elastic PUF provides the following advantages:

the manufacturability and cost-effectiveness of the process are increased due to the reduction in the reject rate (there are no gaps, closed pores, voids, etc.).

process stability is enhanced by extending the temperature fQ range of the catalysts;

allows you to replace the expensive and properly designed Dabco catalyst, not less deficient dimethyl piperazine and diethylethanolamine;

j Provides receipt on existing

industrial equipment molded products that meet the quality requirements of the automotive industry;

allows you to refuse to buy 20 polyester and a catalyst for imports and leads to savings in foreign currency. Table

Seeming density, kg / m

Table 2

- 33.0

26.0

35.0

Destructive stress during stretching, kg / cm

Relative lengthening at discharge,%

Name of parameters

Performance pump

Polyester

TDI 80/20

activator 1

activator P

Filling time, with: front back padding

front padding

stuffing the back of the back M-412. stuffing back pillow M-412

combi back padding

combi back pillow stuffing

Raw material temperature, C: polyester

TDI 80/20 activator 1

activator P Temperature forms before s

0.92

1.24 1.36 190 176 159

Table3

Indicator

installation 1

installation 2

16 000 6520-6820 .828-855 420-564

7.0

10.0-11.0 5.5 6.8

22 22 22

20 23 23

22

23 8-40 38-40

Temperature in the heating channel, С Zone 1

Relative residual deformation under compression,%

Fatigue tests,%: a) relative residual

deformation.

b) relative decrease

stiffness

Stretch Characteristics

836016

10 Continued table. 3

190

180

T a b l and c a 4

5.7

4.6

$ 13.0

0,, 0

18,, 0

Claims (1)

Claim The method of producing elastic foam ^{1 of} polyurethane by reacting a simple subaether containing not less than 10% of primary hydroxyl groups with an isocyanate component in the presence of an amine catalyst of tin octoate, a foam stabilizer and a blowing agent, the fact that in order to improve the Order No. 2823/6 of the circulation of the technology, a combination of dimethylpiperazine and diethylethanopamine is used as an amine catalyst; in the amount of 0.27-0.39 and 0.09-0.13 parts by weight respectively, 100 parts by weight polyester.