CS258209B1 - Inflammatory Modifiers - Google Patents

Abstract

Use of urea-formaldehyde condensates surface-activated powdered water-insoluble inorganic substances, characterized by an ash content of 1.2 to 92.3% by weight, as activators in the production and/or application of blowing agents based on 1,5-methano-3,7-dinitroso-1,3,5,7-tetraazacyclooctane and/or azodicarboxamide in an amount of 5 to 65% by weight based on the weight of the resulting mixture. Particularly suitable for the production and application of rubber blowing agents.

Description

258209 2

The invention relates to the use of urea-formaldehyde condensates of surface-activated water-insoluble inorganic substances as modifiers in the manufacture and / or application of additives based on 1,5-metano-3,7-dinitroso-1,3,5,7-tetraazacycloctane and / or azodicarboxamide.

The blowing agents based on 1,5-metano-3,7-dinitroso-1,3,5,7-tetraazacycloctane (DNPT), depending on the production technology requirements of the rubber and plastic industries, contain! about 40 to 90 wt. active ingredient. Concentrated blowing agent contains a certain amount of mineral oil or other phlegmatizing agent to reduce impact sensitivity. Increased transport and storage safety while improving the porous structure of the bottled products is achieved by controlling the active ingredient with a neutral organic additive such as kaolin, micronised limestone, hydrated borax, sulphonate, micronized zeolite, and the like.

In order to remove the unpleasant odor produced by the thermolysis of DNPT in the process of improving the rubber products in particular, deodorizing agents of the methyl urea / methylenebismurea type, or simultaneously (glycol, glycerin, etc.), alebobiuret, water-insoluble urea derivatives, in particular non-crosslinked water-insoluble urea, are added to the blowing agents. formaldehyde condensates, and others.

In the application of azodicarboxamide-based blowing agents, especially in the rubber industry, or in the ethylene-vinyl acetate copolymer, it is desirable to reduce the temperature of the disintegrating azo compound, i.e. to activate it. This is achieved by the addition of various activators, especially zinc and other metal salts, hexamethylenetetramine, biuret, but also water-soluble urea derivatives or 1,5-methano-3,7-dinitroso-1,3,5,7-tetraazacycloctane (DNPT).

The use of the water-insoluble urea derivatives themselves, in particular urea-formaldehyde condensates, as blowing agent modifiers, has been shown to be less advantageous in terms of increasing the cost of raw materials and energy for their synthesis. partly by the available and fasting micronized minerals (limestone, kaolin, zeolites) is a solution from the point of view of technical safety parameters and nucleation properties of the resulting blowing agents, but in the case of mixtures based on 1,5-metano-3,7-dinitroso-1,3, 5,7-tetraazacyclooctane is negatively reflected in the deodorizing properties of the blowing agent due to the reduction of the total surface area of the deodorant particles with a substitute in that sense.

In addition, with the progressive depletion of deposits of high-quality, light shades of minerals (kaolin, zeolites, limestone), the issue of economic use of less attractive, mostly dark-colored minerals as fillers in rubber, plastics, for example in the paper industry, is at the forefront; there is no need to emphasize that such fillers and modifiers cannot be used in the white and light shades of the articles of the industry to be exchanged, and that this problem cannot be solved only by mechanical blends of micronized mineral darker stains with white pigments such as water-insoluble urea-formaldehyde condensates.

The foregoing and other drawbacks are solved by the process of the present invention, which comprises using urea-formaldehyde condensates of surface-activated water-insoluble inorganic substances, such as kaolin, zeolites, carbonates or sulphates of alkaline earth and the like, characterized by an ash content of 1.2 to 92.3% by weight. as a modifier for the manufacture and / or application of blowing agents based on 1,5-metano-3,7-dinitroso-1,3,5,7-tetraazacycloctane and / or azodicarboxamide in an amount of 5 to 65 wt. to the weight of the resulting mixture. An advantage of the process of the present invention is the ease of availability of surface-activated water insoluble inorganic substances consisting of acid-catalyzed urea-formaldehyde in the presence of a desiccation of the inorganic substance in the reaction mixture. Due to the high capability of the water-insoluble urea formaldehyde condensates, less valuable, dark colored minerals can be utilized, which is a further advantage of the process of the present invention.

By suitable selection of the inorganic water-insoluble substance content of its surface-urea-formaldehyde condensate-activated analogue, it is possible, for example, to prepare deodorant, respectively. activating agent having the same efficacy in this respect as the urea-formaldehyde condensate alone, a further advantage of the present invention, since it is thus possible to realize the reduction of formaldehyde and urea in the modifier synthesis. ,

The use of urea-formaldehyde condensates of surface-activated powdered water-insoluble inorganic substances according to the invention as modifiers has not been previously described in the literature. It is documented by the following examples, but in no way exclude the possible variability of the process of the invention. Example 1 Using the Synthesis Process of Urea Formaldehyde Condensates. No. 227,901, with the addition of a 30% aqueous solution of rubber kaolin to the reaction mixture prior to synthesis, and drying of the resulting activated kaolin spray in the sprayer) dryer with an inlet temperature of 135-140 ° C and an outlet of 98-103 ° C. white kaolin with a content of 2.9 wt. % water, 0.267 wt. methylols and 50.73 wt. ash. Of this kaolin and the technical 1,5-metano-3,7-dinitroso-1,3,5,7-tetraazacycloctane (DNPT), a mixture containing 60 wt. DNPT and 40 wt. activated kaolin. This powder mixture does not change consistency after storage for three months at 20-24 ° C. From the point of view of being used as a rubber blowing agent, this mixture has the same utility properties as the analogous mixture containing only the urea-formaldehyde condensates according to MS. author's certificate No. 227 901 (see Czechoslovak copyright certificate No. 227 904). The thermal stability of the mixture according to this example is presented in Table 1 of Example 5. 'Powder mixture containing 80% by weight of the azodicarboxamide (ACD) and surface-reacted kaolin of Example 1 is prepared. % azodicarboxamide and 20 wt. activated kaolin. From the thermal stability of this mixture (see Table 1 in Example 5), it can be seen that ACD is so activated by the addition of kaolin of Example 1 that it can be used to facilitate rubber-based undercoat materials (at the level of conventional DNTP blowing agents) . Example 3 Using the urea-formaldehyde condensate synthesis process. podlá čs. No. 230,015, with the addition of a 30% slurry of rubber kaolin in water to the reaction mixture prior to synthesis and further processing, as in Example 1, powdered surface-reacted kaolin with a content of 2.96% by weight. water, 0/548 wt%; methylols 49.86 wt. ash (hydrophilized form of activated kaolin). From this kaolin and 1,5-metano-3,7-dinirose-1,3,5,7-tetraazacyclooctane as in Example 1, a mixture containing 40 wt. activated kaolin having similar wear properties to that of Example 1. The thermal stability of this mixture is presented in Table 1 of Example 5.

Example 4 A mixture containing 80% by weight of the azodicarboxamide of Example 2 and the surface-reacted kaolin of Example 3 is prepared. % azodicarboxamide and 20 wt. activated kaolin. 258209 4

As can be seen from the thermal stability overview in Table 1 of Example 5, the azodicarboxaraido is somewhat more activated than in the mixture of Example 2. Example 5

Using a non-isothermal differential thermal analysis (DTA) operating at a temperature rise of 5 ° C / min, a measuring range of 1 mV on a scale scale with a weight of about 50 mg samples is for the mixtures of Examples 1 to 4 as well as 1.5- methano-3,7-dinitroso-1,3,5,7-tetraazacyclooctane (DNPT) and azodicarboxamide (ACD) Specified bases and other thermal decomposition characteristics; the results are presented in Table 1.

The heat explosion method of H. Henkina and R, McGilla (Ind. Eng. Chem. 1952, 44, No. 06, 1391-1395), for the mixtures of Examples 1 to 4 as well as for the initial DNPT and ADC, are the specified induction period induction. ; for DNPT and mixtures containing it in the temperature range of 190 to 210 ° C, for ADC and mixtures containing it in the temperature range of 210 to 250 ° C. From the values thus obtained, the activation energies E of the explosion and the extrapolated induction period Tau are calculated for 150 and 190 ° C. Corresponding results are presented in Table 1. T abu 1 ka No. 1 review of the results of thermostable measurements from Example 5 Sample (mixture) Takes out from DTA Thermal explosion method Exothermic decomposition start (° C) first peak <° C) explosion (° C) E (kJ.mol "Η Tau150 (s) Tau190 (s) DNPT upstream discs 139,1 169,7 185,3 58,94 213,8 50,3 cedes 1,136,4 171,1 183 1 56,88 199,0 49,2 According to Example 3 135,8 167,6 182,2 52,98 174,5 47,5 ADC Discourse According to 161,5 - 193,0 57,68 341.0 82.7 clade 2 159.5 - 195.0 47.91 231.7 71.4 according to example 4 158.7 - 191.5 45.28 186.5 61.3

Notes: Tau ^ g = extrapolated induction periods for 150 ° C;

TaUlgo = averaged for DNPT and its mixtures, extrapolated induction periods at 190 ° C for the ADC and its mixtures; Example Using the Synthesis Process of Urea Formaldehyde Condensers. No. 227,901, and the addition of a 25% aqueous suspension of micronized limestone (natural calcium carbonate) to the reaction mixture prior to synthesis is further treated as in Example 1 to obtain a surface activated limestone containing 2.17% by weight. % water, 0.086 wt. methylols and 92.3 wt. ash. From the activated lime, technical 1,5-methano-3,7-dinitroso-1,3,5,7-tetraaza-cyclooctane (DNPT), a mixed triaryl phosphate based on isopropyl derivatives of triphenyl phosphate, a free-flowing composition is prepared ( % by weight: 30% DNPT, 60% activated limestone and 10% mixed triaryl phosphate.

Claims (1)

OBJECT OF THE INVENTION Use of urea-formaldehyde condensates of surface-activated powdered water-insoluble inorganic substances, such as kaolin, zeolites, carbonates or sulphates of alkaline earth elements, characterized by a content of 1.2 to 92.3% by weight. ash as modifiers in the manufacture and / or application of blowing agents based on 1,5-methano-3,7-dinitroso-1,3,5,7-tetraazacyclooctane and / or azodicarboxamide.