SU533318A1 - Composition for producing foam plastic - Google Patents

Abstract

COMPOSITION FOR PREPARING THE FOAM, consisting of phenol-formaldehyde oligomera, acid catalyst, foaming agent and other targeted additives, characterized in that, in order to simplify the process of processing the composition and to obtain a foam with a uniform cellular structure, as a foaming agent contains a mixture of trichlorofluoromethane and carbon tetrachloride, taken in a weight ratio of 4: 6- 6: 4, respectively, with the following ratio of components, wt.h .: Phenol-formahyde oligomer 100 Acid catalyst-5 - 150 Vox vayuschy agent 0.5 - 75.0

Description

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The invention relates to compositions for the preparation of foams based on phenol-formaldehyde resins, which are used as heat insulating materials.

A known composition for the preparation of a foam consisting of a phenol-formaldehyde oligomer, an acid catalyst, a foaming agent and other targeted additives. As a foaming agent, it contains chlorofluoroalkanes, for example, trichlorofluoromethane. Chlorofluoroalkanes are scarce, have a relatively high cost, they are difficult to mix with phenolaldehyde oligomer. In addition, when using freons (chlorofluoroalkanes), the composition has poor flowability, making it difficult to form foams of a complex profile, and the foam obtained on the basis of this composition has an uneven cellular structure (bubbles, shells).

The aim of the invention is to simplify the process of processing the composition and obtaining a foam with a uniform cellular structure.

This goal is achieved in that the composition, consisting of a phenol-formaldehyde oligomer, an acid catalyst, a foaming agent and other targeted additives, contains a mixture of trichlorofluoromethane and carbon tetrachloride as a blowing agent, at a weight ratio of 4: 6-6: 4: 4, with the following ratio of components, ma.ch ,;

Phenol formaldehyde oligomer100

Acid catalyst. 5-150 Foaming agent 0.5 - 75, The amount of foaming agent in the mixture is O ,, 5 - 30% of the total weight of the mixture. The exact proportion of the foaming agent is determined in each specific case, based on the specified volumetric weight of the resulting foam, the activity of the initial phenol-formaldehyde oligomer, the temperature mode of processing. Trichlorofluoromethane and carbon tetrachloride can be used by adding them to the composition either individually or as a zeotropic agent. These compounds are mixed almost instantly, forming an azeotropic

the mixture is stable during storage and transportation, the boiling point of the azeotropic mixture is generally from 35 to 65 ° C. The zeotropic mixture can be added either to the phenol-formaldehyde oligomer, or to the acid catalyst, or to the mixture of oligomer and catalyst. The phenol-formaldehyde oligomer used in the composition according to the invention is phenol-formaldehyde oligomers of the resole type or their mixture with novolac-type oligomers. Acid catalysts commonly used in the preparation of phenol-formaldehyde foams (hydrochloric, sulfuric acid and their mixtures with phosphoric acid, arylsulfonic acid, hydrochloric acid, sulfuric acid, and their mixtures with phosphoric acid, arylsulfonic acid, hydrochloric acid, sulfuric acid, and their mixtures with phosphoric acid, arylsulfonic acid, hydrochloric acid, sulfuric acid and mixtures with phosphoric acid, arylsulfonic acid, hydrochloric acid, sulfuric acid, and mixtures with phosphoric acid, arylsulfonic acid, hydrochloric acid, sulfuric acid and mixtures with phosphoric acid, arylsulfonic acid, hydrochloric acid, sulfuric acid and mixtures with phosphoric acid, arylsulfonic acid, hydrochloric acid, and sulfuric acid are used. their condensation products with aldehydes and, possibly, with urea, sulfonated novolacs, etc.)

In the composition according to the invention, it is also advisable to introduce such target additives as a non-ionic surfactant, urea or other formaldehyde acceptors, fillers, modifying additives that improve certain quality indicators of the final product, for example, compounds of complexing metals (iron, aluminum, cobalt, copper , nickel) to increase the water resistance of the foam,

Target additives are taken in amounts commonly used in lime compositions for the preparation of phenol-aldehyde foams,

The composition is prepared by mixing the components, followed by wiping or spraying the resulting mixture, foaming, curing and molding it without external heating or

when heat is supplied from the outside ,. I

The invention is illustrated by the following examples.

Example 1. C100 May, h, a liquid phenol-formaldehyde oligomer consisting of a liquid phenol-formaldehyde oligomer of the resole type and a liquid phenol-formaldehyde oligomer of the novolac type (ratio 2; 1, respectively) are added 1 wt.h. the product of the addition of ethylene oxide to alkylphenol (product OP - 7), 0.1 mash, aluminum powder and 1 wt.h. urea.

the mixture is then stirred using a stirrer having 980 rpm (for 30 seconds) to obtain component A of the composition, K 100 wt.h. freon-11 (trichlorofluoromethane) is added on 70 May, carbon tetrachloride (carbon tetrachloride), and there is a rapid mixing of both compounds with the formation of a zeotropic mixture boiling (90%) in the temperature range 31 - and having a faint smell of carbon tetrachloride,

5 parts of the resulting zeotropic mixture is added to component A and mixed again. The resulting product is mixed from May 20, h, the condensation product of paraphenol sulfonic acid with formaldehyde and extruded into a form having a trapezoid profile in the section, extended upwards. The resulting foam completely fills the mold. In section, it has a fine homogeneous structure (no caverns and cavities are missing). When using freon as a foaming agent, 11 foam does not completely fill the mold (the upper corners of the mold were not filled) due to the insufficient fluidity of the composition and had in a section a sink and caverns with a total area up to 10%,

PRI mme R 2. A mixture consisting of 100 May, h, liquid resole, 2 May, h, product OP-7, 10 mph, ocher and 8 May, h, a foaming agent comprising 4 weight, h, freon -11 and 4 ve, h, carbon tetrachloride, thoroughly mixed from May 35th, sulphonated novolac resin,

The resulting composition is poured onto the lower tranporter of the continuous plant. After 3 minutes, a foam (in the form of a continuous plate) with a thin and uniform cellular structure is obtained at the exit of the calibration gap of the installation.

When using the composition using the traditional mixture of freon-11 and freon-113 (1,1,2-trichlor, 1,2,2-trifluoroethane) in a weight ratio of 1 and 3, the foam has sinks with a total area of 3%,

Comparative foaming of compositions on the stand installation showed that the time from the beginning of injection to the end of foaming (),

characterizing the fluidity of the compound, in the first case is 4 minutes, and in the second - 2.9 minutes.

Froze 100 ma.ch. a liquid mixture of 98 parts by weight. rezola and 2 May, h. OP-7, mixed in a stream of air with a mixture of 85 wt.h. sulfated novolak, 9 mah. carbon tetrachloride and 6 mah. freon -11.

The composition is sprayed onto a vertically reinforced plywood shield. The composition foams, not the stack, due to the force of its own gravity. You get a foam of a uniform structure (with a cell size of 0.1 - 0.2 mm), not having shells and cavities in the layer adjacent to the surface of the shield. If freon-113 was used in the composition, then the resulting foam had sinks and cavities in the indicated place. When using carbon tetrachloride only, the foam plastic had almost twice the apparent apparent density and uneven structure (across the entire foam section) with a size of 2 to 3 mm. It should be noted that, in contrast to the variant, when only carbon tetrachloride was used as a foaming agent, when using carbon tetrachloride in the combination of freon, 11 practically did not feel the smell of carbon tetrachloride.

PRI me R 4. Mix 100 may, rezol phenol-formaldehyde emoly, 1 may, h ur.viny, 5 May, h calcium hydrocide (pre-coated with methylcellulose film), 5 May, h, copper sulfate (), 45 wt.h. mixtures of carbon tetrachloride and trichlorofluoromethane, taken in a weight ratio of 4: 6, and 40 May, h, product VAG-3 (condensation product of sulfophenyl urea with formaldehyde and orthophooforic acid), the resulting composition is poured into a mold, kept in a heating cabinet at a temperature of 40 + 5 ° C for 1 hour. A foam is obtained with a uniform (without shell) structure and a bulk weight of about 16 kg / m. When using trichlorofluoromethane as a curing agent, a foam is obtained with a bulk weight of about 30 kg / m and a heterogeneous structure (shells and caverns occupy 8% of the section of foam block in the section). Froze To 100 ma.ch. Resol add 3 math. OP-7, May 2.2, tetrachloride methane and trichlorofluoromethane, taken in 1: 1 ratio, and Ju.a.h. water (65% may.% paraphenole sulfokieloty solution. The components are mixed. The resulting composition will heat and cure for 5 minutes. The foam will have a volume weight of about 90 kg / m. When using carbon tetrachloride, as a blowing agent, a foam foam is obtained with a bulk weight of about 150 kg / Thus, the proposed composition has the following properties with a TV: -The resulting foam has a thin and uniform cellular structure. In the section, the foam does not have cavities and cavities. The size of the cells, as a rule, does not exceed 0.3 mm (0.5–3.0 mm in known foams); -the foaming composition has an increased flowability, which makes it possible to shape the foam in the form of elements of a complex configuration. The composition’s flowability is directly dependent on the duration of the system in the transition from gel to three-dimensional (time interval by 15-50%, more than the known); sanitary and hygienic conditions of processing of the foamable mixture are improved; - in the proposed composition a cheaper foaming agent is used than in the known ones, therefore the cost of the foam based on the proposed composition is significantly reduced compared to the cost of the foam based on the known composition. The advantages obtained through the use of a new blowing agent are due to the fact that trichlorofluoromethane, in combination with carbon tetrachloride, forms a zeotropic mixture that boils mainly in the temperature range of 36-65 ° C. Due to the fact that the boiling point of such a mixture is not constant, as with the use of known foaming agents, the composition has an improved flowability and foaming over time occurs smoothly, providing a foam with a uniform and fine cellular structure. The foam obtained on the basis of the composition of the invention is used for heat and heat insulation in construction, mechanical engineering, refrigeration and in a number of other industries.

Claims (1)

COMPOSITION FOR PRODUCING FOAM PLASTIC, consisting of phenol-formaldehyde oligomer, acid catalyst, blowing agent and other target additives, characterized in that, in order to simplify the process of processing the composition and to obtain a foam with a uniform cellular structure, it contains a blowing agent a mixture of trichlorofluoromethane and carbon tetrachloride taken in a weight ratio of 4: 66: 4, respectively, in the following ratio of components, parts by weight: Phenol formaldehyde oligomer 100 Acid Catalysis - the torus •5 - 150 Blowing agent 0.5 - 75.0