A kind of simplified method for preparing low alkaline naphthalene series concrete water reducing agent
Technical field
The invention belongs to building material technical field, be specifically related to the simplification preparation method of a kind of concrete works with the low alkaline naphthalene series concrete high efficiency water reducing agent.
Background technology
Water reducer in the present China of concrete industry usage quantity maximum is beta-naphthalenesulfonic-acid salt formaldehyde condensation products (hereinafter to be referred as a naphthalene system), and its synthetic production technique is: sulfonation → hydrolysis → condensation.A naphthalene molecule connects a sulfonic group in sulfonation process in theory, but because the organic chemical reactions reaction can not be very thorough, for guaranteeing to reach certain sulfonation degree and required acidity of condensation, often needs to add excessive slightly sulfuric acid.The consumption of its vitriol oil is to be not less than 1.05 times of NAPTHALENE FLAKES. (INDUSTRIAL GRADE weight (being equivalent to mol ratio is: sulfuric acid: naphthalene=1.38: 1), its production method has two kinds: the one, and in sulfonation process, add mol ratio and be about: sulfuric acid: the sulfuric acid of naphthalene=1.38: 1, adding the vitriol oil to the acidity value of reactant after the hydrolysis again is about 30%; The 2nd, directly once add mol ratio and be about: sulfuric acid: naphthalene=1.38~1.44: 1 sulfuric acid.In above 2 kinds of methods because unreacted sulfuric acid is more, in and the time can generate more sodium sulfate (be generally amount of solid about 20%), directly use alkali content too high, alkali easily takes place, aqua can generate mass crystallization, application difficult in the winter time.Reduce sodium sulphate content as need, add milk of lime and take off SO
4 2-, the technology more complicated.
Summary of the invention
The invention provides the simplified method that a kind of low alkaline naphthalene series sulfonate and formaldehyde condenses is produced, the synthetic production technique is: sulfonation → condensation, saved this procedure of hydrolysis, the consumption of the vitriol oil is reduced significantly, the consumption of its vitriol oil is that (being equivalent to mol ratio is: sulfuric acid: naphthalene=1.05~1.17: 1) for 0.8~0.89 times of NAPTHALENE FLAKES. (INDUSTRIAL GRADE weight, sodium sulphate content is about about 6% of amount of solid, only is original 1/3rd, is the low alkaline naphthalene series product.Use winter the aqua (about 32%) can crystallization, reach the dense product level of general height, can save and take off SO
4 2-Complicated procedures of forming, production technique is simplified greatly, improved production efficiency, saved about 30% the vitriol oil simultaneously and neutralization (is taken off SO with caustic soda and lime
4 2-With).Production method and step are: with the NAPTHALENE FLAKES. (INDUSTRIAL GRADE heat fused, warming while stirring then to 140 ℃ of adding 98% vitriol oils, at 160-165 ℃ of reaction 2-2.5h, is carried out sulfonation reaction.Sulfonation cools to reactant about 95 ℃ after finishing, and about 2.5h drips 37% formaldehyde.After adding formaldehyde, carry out condensation reaction 4-5h at 105-110 ℃.After condensation finished, being neutralized to pH value with 30% caustic soda soln was 7-9, was made into certain density aqua or carried out spraying drying and make pulvis.The mol ratio of various starting material consumptions is: naphthalene: sulfuric acid: formaldehyde=1: 1.05~1.17: 0.9~1.The diminishing that experimental results show that the naphthalene water reducer of producing with the inventive method is identical with the product of producing with former method with flowing property.Present method is fit to the production of homologue (as methylnaphthalene etc.) the sulfonate and formaldehyde condenses (comprising tensio-active agent and cement water reducing agent) of naphthalene equally.
Embodiment
Further describe the present invention below by example.
Embodiment one:
In the 2000mL there-necked flask, drop into the 390g NAPTHALENE FLAKES. (INDUSTRIAL GRADE, heat fused.Warming while stirring to 140 ℃ then adds 98% vitriol oil 348g, at 160-165 ℃ of reaction 2.5h, carries out sulfonation reaction.Sulfonation cools to reactant about 95 ℃ after finishing, and about 2.5h drips 37% formaldehyde 234g.After adding formaldehyde, carry out condensation reaction 5h at 105-110 ℃, in the condensation course, if material is feeding-up, the about 15g water of then each adding.After condensation finished, adding 150g cold water also stirred, and being neutralized to pH value with 30% caustic soda soln again is 7-9.
Embodiment two:
In the 2000mL there-necked flask, drop into the 390g NAPTHALENE FLAKES. (INDUSTRIAL GRADE, heat fused.Warming while stirring to 140 ℃ then adds 98% vitriol oil 325g, at 160-165 ℃ of reaction 2h, carries out sulfonation reaction.Sulfonation cools to reactant about 95 ℃ after finishing, and about 2.5h drips 37% formaldehyde 234g.After adding formaldehyde, carry out condensation reaction 4h at 105-110 ℃, in the condensation course, if material is feeding-up, the about 15g water of then each adding.After condensation finished, adding 150g cold water also stirred, and being neutralized to pH value with 30% caustic soda soln again is 7-9.
Embodiment three:
Clean slurry degree of mobilization detects: with 87g water, the above-mentioned finished product of 1.8g (in dry powder), detect by the GB/T8077-2000 standard.Embodiment one and two clean slurry degree of mobilization are respectively 220mm and 236mm, the common process product be 225mm.
Embodiment four:
Glue sand water-reducing rate detects: detect by the GB/T8077-2000 standard.The finished product water-reducing rate of embodiment one preparation is 18.5%, and the finished product water-reducing rate of embodiment two preparations is 18.1%, the common process product be 18.1%.
Embodiment five:
Concrete strength detects: carry out concrete examination collating by the GB8076-1997 standard and survey.Detected result such as following table:
Test item | Standard-required (acceptable end product) | Detected result |
Embodiment one finished product | Embodiment two finished products | The common process product |
Compressive strength rate (%) | 3d | ≥130 | 170 | 173 | 170 |
7d | ≥125 | 165 | 164 | 165 |
28d | ≥120 | 158 | 155 | 155 |