RU2500699C1 - Adhesive additive for bitumen compositions - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: maleinised tall oil-based adhesive additive contains 10-30 wt % bound maleic anhydride. The tall oil used for maleinisation contains resin and fatty acids in weight ratio of 1.0:0.6-5.0, respectively. The adhesive additive is characterised by dynamic viscosity of 0.3-1.0 Pa·s. The additive can be easily batched and has good distribution in the polymer-bitumen composition. Use of the additive does not require premixing thereof with a thermoplastic elastomer, enabling preparation of the polymer-bitumen composition in a single step.

EFFECT: polymer-bitumen composition containing an adhesive additive, characterised by high adhesion to both alkaline and acidic mineral filler.

2 tbl, 12 ex

Description

The invention relates to adhesive additives for bitumen and polymer-bitumen compositions.

Adhesive additives provide the connection of bitumen with mineral filler during the construction of roads, the arrangement of roofing. They significantly increase the adhesion properties of bitumen - improve the adhesion of bitumen to mineral materials. In this case, the physical and mechanical properties of bitumen do not deteriorate.

A number of adhesive additives are known for bitumen-polymer compositions based on nitrogen-containing compounds: quaternary ammonium bases - cationic surfactants, piperazine derivatives, imidazolinol [Sat. "The use of surfactants in road construction", ZAO "TsIVSSM", Astrakhan, 2001]. The dosage of nitrogen-containing additives from 0.5 to 2.0% wt. on the bitumen composition. They retain their properties to a temperature of 160-163 ° C. Significant disadvantages of these additives are unpleasant [amine] odor and high toxicity [these are, as a rule, substances of the 2nd hazard class according to GOST 12.1.007-76].

An adhesive additive is also known, which is the product of the interaction of tall oil and triethanolamine in a mass ratio of 66-68: 32-34, respectively [RU No. 2119513, C08L 95/00, 09/27/1998). It is used in dosages of 0.7-7.0% wt. The additive has the following disadvantages:

- due to the high viscosity of the additive, a stage of preheating it before introducing it into the bitumen composition is necessary;

- unpleasant odor;

- high dosages to ensure the right level of adhesion.

Closest to the claimed technical solution is an adhesive additive to the bitumen composition, which is maleized polybutadiene with a content of bound maleic anhydride 12 ÷ 21 wt.%, Having a dynamic viscosity of 10 ÷ 100 Pa · s at a temperature of 25 ° C [RU No. 2226203, IPC C08L 95/00, 53/02, 15/00, 27.03. 2004).

This additive provides bitumen with a high level of adhesion to mineral fillers when used in low dosages (0.5 ÷ 5.0, for practical purposes, as a rule, 0.5 ÷ 1.0).

The disadvantage of this adhesive additive is its high viscosity: 10 ÷ 100 Pa · s (at 25 ° C). Because of this, technological difficulties arise in introducing an additive into bitumen compositions.

The task of the invention is to improve the technological properties of the additive while maintaining the adhesive properties of the bitumen compositions in which it is used at the same level as in the case of using known adhesive additives.

The technical result is achieved by the fact that as an adhesive additive, an adduct of maleic anhydride with tall oil containing tar and fatty acids in a mass ratio of 1: 0.6 ÷ 5.0 is used, with a mass fraction of bound maleic anhydride in the adduct of 10 ÷ 30% with a dynamic viscosity 0.3-1.0 Pa · s (at 25 ° C).

The inventive adhesive additive is characterized by high technological properties - the value of the dynamic viscosity is lower than for known adhesive additives is 0.3 ÷ 1.0 Pa · s. It is easily dosed and well distributed in the bitumen composition. When its application does not require the operation of preliminary mixing of the adhesive additive with thermoplastic elastomer. Due to this, the preparation of the bitumen composition is carried out in one stage.

The polymer - bitumen composition containing it is characterized by a high level of "adhesion with mineral fillers" to both alkaline and acidic mineral fillers, as is the case with the use of known adhesive additives. The optimal dosage range of the inventive adhesive additives in the composition of the bitumen composition of 0.3-0.8% wt. to the composition.

The adhesive additive can be used as part of a polymer-bitumen composition, as well as in polymer-free bitumen.

The maleic anhydride adduct with tall oil is prepared as follows: a calculated amount of tall oil and maleic anhydride is introduced into a heated reactor equipped with a stirrer [component ratio 70–90: 30–10, respectively), purged with an inert gas [nitrogen or argon), heated to temperatures of 200 and -220 ° C and maintained with stirring for 4-6 hours. A homogeneous mass is obtained with a dynamic viscosity of 0.3 ÷ 1.0 Pa · s and a free maleic anhydride content of not more than 0.3% wt.

In carrying out the invention, the following products are used:

Oil bitumen - according to GOST 22245 Maleic Anhydride - according to GOST 11153 Tall oil - any of the Russian manufacturers with mass ratio 1: 0.6 ÷ 5.0

The parameters of the modified bitumen are evaluated by the following methods:

- grip with marble, sand - GOST 11508; - depth of penetration of the needle - GOST 11501; - softening temperature, according to KISH - GOST 11506; - elasticity at 25 ° C - GOST 11505; - fragility temperature - GOST 11507.

The determination of dynamic viscosity is carried out on a Hepler rheo-viscometer (Rheostat 2.1) at a temperature of 25 ° C.

The content of free (unreacted) maleic anhydride is determined by titration with an alkaline solution of an aqueous extract from an additive.

The content of tar and fatty acids in tall oil is determined by gas-liquid chromatography.

The invention is illustrated by examples of specific performance.

Example 1. In a tank equipped with a stirrer and a circulation pump, load 195 kg of oil bitumen grade BND 60/90, heated to a temperature of 140 ÷ 160 ° C, serves 4 kg of thermoplastic elastomer DST-30R-01 in the form of crumbs and 1 kg of adhesive additives, which is maleized tall oil. The adhesive additive has the following characteristics: dynamic viscosity - 0.60 Pa · s, the content of total maleic anhydride - 24.5% wt., The free maleic anhydride - 0.20% wt., The content of the bound maleic anhydride - 24.3% wt. , the mass ratio of resin and fatty acids is 1: 0.7. Mixing is carried out at a temperature of 150-160 ° C for 60 minutes until the thermoelastoplast is completely dissolved. The adhesive additive is completely dissolved within 5 minutes.

A sample of the bitumen composition is tested by standard methods.

Examples 2-9. All operations are carried out as in example 1. Change the composition of the adhesive additive, its characteristics and dosage in the composition of the bitumen composition, data on the composition, characteristics of the adhesive additives and properties of bitumen compositions are shown in table 1.

Example 10 (prototype). A linear elastomeric thermoplastic elastomer is loaded into the rubber mixer - DST-30R-01 in the form of crumbs in an amount of 2 kg and low molecular weight maleated polybutadiene in an amount of 0.5 kg containing 12% wt. bound maleic anhydride having a dynamic viscosity of 10 Pa · s. Polymers are mixed for 15–20 min at normal temperature. The resulting mixture in the form of granular crumbs in the amount of 2.5 kg is fed into a container equipped with a paddle mixer and a circulation pump, in oil bitumen, heated to a temperature of 140 ÷ 160 ° C, and mixing is carried out at a temperature of 150 ÷ 160 ° C for 60 minutes until the polymer is completely dissolved.

A sample of the bitumen composition is subjected to standard tests. The test results are shown in table 1.

From table 1 it follows that the claimed version of the adhesive additive provides a high level of adhesive properties of road bitumen, no worse than in the case of using the known additives maleinized polybutadiene. At the same time, the technological properties of the inventive additive are much better - its dynamic viscosity is in the range of 0.30 ÷ 1.0 Pa · s, while the well-known [by prototype] additive is 41.5 Pa · s.

Example 11. Oil road bitumen grade BN 90/130 is heated in a tank equipped with a paddle mixer and a circulation pump to a temperature of 150 ÷ 160 ° C. Maleinized tall oil is supplied (the ratio of tar and fatty acids is 1: 0.7, the content of bound maleic anhydride - 24.5% wt., dynamic viscosity - 0.6 Pa · s). Per 100 kg of bitumen serves 0.35 kg of adhesive additives. Stirred for 10 minutes. After cooling, the composition is tested. The test results are presented in table 2 (example 11).

Example 12 (prototype). All operations are carried out as in example 11. Maleicated polybutadiene with the following characteristics is used as an adhesive additive: the content of total maleic anhydride is 20.0% wt., The dynamic viscosity is 41.5 Pa · s. A sample of the bitumen composition is subjected to standard tests. The test results are shown in table 2 (example 12).

For comparison, the characteristics of bitumen without additives are given.

As follows from the data of table 2, the inventive adhesive additive provides high adhesive properties of bitumen, does not impair the basic characteristics of bitumen and at the same time has better technological properties than in the case of the known technical solution.

table 2 Test results of polymer-bitumen compositions with various adhesive additives Properties of polymer-bitumen compositions Example No. The content of additives,% wt. Traction with marble, sand Penetration depth, 0.1 mm at 0 ° C Softening temperature according to KISH, ° С Fragility temperature, ° С Elasticity, mm at 25 ° С eleven 0.35 one 98 44 minus 13 86 12 prototype 0.35 one 97 44 minus 13 87 control, bitumen without additives - four 99 45 minus 11 85

Claims (1)

An adhesive additive for bituminous compositions based on the adduct of maleic acid hydride with an unsaturated organic compound, characterized in that tall oil containing tar and fatty acids in a mass ratio of 1.0: 0.6 ÷ 5.0, respectively, is used as an unsaturated organic compound, the content of bound maleic anhydride in the adduct 10 ÷ 30 wt.%, with a dynamic viscosity of 0.3 ÷ 1.0 Pa · s.