DE3516690A1 - Process for producing a corrosion inhibitor for steel, in particular for steel reinforcements - Google Patents

Abstract

a) A process for producing a corrosion inhibitor for steel, in particular for steel reinforcement. b) The invention is intended to provide corrosion inhibition for steel reinforcements in autoclaved silicate concretes. c) In a one-stage process, a water-, heat- and alkali-resistant corrosion inhibitor is to be produced in a simple manner, whose processing over a long period and whose application to the steel to be protected are made possible by an automated plant. d) According to the invention, a polymer dispersion (styrene/acrylate dispersion, carboxyl-latex dispersion) based on a polymer with a known additive such as water-soluble cellulose derivatives, melamine/formaldehyde condensates, alkylphenyl polyglycol ethers, pigments or inhibitors, an impact-resistant organic high polymer which can be ground at room temperature and has a melting point or melting interval between 40 DEG C and 180 DEG C, and clay are to be ground in a mixing ratio of 1:1.8-3:0.1-0.8 down to a particle size of </= 50 mu m and homogenised with a quantity of water in a ratio of 0.4:1 relative to the total solids content. A cyclohexanone/formaldehyde resin, an alkylcyclohexanone/formaldehyde resin, a highly expanded bitumen, a bituminous coal tar pitch or a polyvinylbutyral can be used as impact-resistant organic high polymers which can be ground at room temperature. The clay is peptised under alkaline conditions. e) Steel reinforcements of aerated concrete finished components, ... at corrosion risk ... Original abstract incomplete.

Description

Title of the invention

Process for the production of an anti-corrosion agent for steel, in particular for steel reinforcement. Field of application of the invention. The invention relates to a method for producing a corrosion protection agent for steel, in particular for steel reinforcement in autoclaved silicate concrete on an aqueous dispersion basis.

Characteristics of the known technical solutions They are corrosion protection systems for steel reinforcement based on karboxyl latex with cement (DD-WP 134 760), based on a dispersion of a copolymer (monomeric building blocks: acrylic acid, Methacrylic acid, esters, styrene, butadiene and / or other vinyl monomers) with cement (DE-OS 3216969) known. A corrosion protection system especially for steel reinforcement in autoclaved silicate concrete contains the DD-WP 69 170. A polyvinyl acetate dispersion, Pitch, butadiene-tyrollatex, casein cold glue are homogenized with one another and with mixed with sulfate-resistant portland cement.

The use of cement in an aqueous corrosion protection system limits the working time due to the setting of the cement.

The addition of setting retarders (DD-WP 156964) also takes time Processing limits.

When using butadiene tyrene latex as a binder is for the stability of the protective colloid casein is indispensable. It could be proven that casein as a peptide easily fungid and bacterial both in aqueous-colloidal Distribution in the liquid corrosion protection system as well as in the dry film destroyed can be. Therefore, the protective performance of the film can be greatly reduced. Calcium ions of the setting cement or the additional th calcium hydroxide chemically react with casein to form insoluble caseinate compounds. That's why larger approaches cannot be controlled rheologically in terms of time. In addition to the disadvantages mentioned The anti-corrosive agent is another factor that applies to all of their manufacturing processes is a two-stage or multi-stage process. So must when using casein this must be unlocked beforehand (DD WP 118 667). In the DD-WP 69170 the bad luck must finely ground with the latex and the dispersion in water and then homogenized added in a third stage to an aqueous slurry of Portland cement will.

The individual process stages require careful control, a large time fund and a high expenditure on machines and units. Conditional Automation is possible due to the time limitation of the processing option of the whole process not given.

OBJECTIVE OF THE INVENTION The aim is to provide a corrosion protection agent in a simple manner for steel, especially for steel reinforcement of autoclaved silicate concrete will. Processing should be possible over a long period of time, which means that the Application to the steel to be protected is made possible by an automated system can be. Protective measures against organic solvents should be omitted.

Explain: and the essence of the invention The invention is the task based on a suitable combination of organic and inorganic polymers Substances a water, heat, and alkali resistant corrosion protection agent in a one-step process.

On the basis of an organic polymer dispersion with the known Additives such as water-soluble cellulose derivatives, melamine formaldehyde condensate, alkylphenyl polyglycol ethers, Pigments or inhibitors, the object is achieved in that an organic Polymer dispersion, a spring-hard organic material that can be milled at room temperature High polymer with a melting point or melting range between 40 "C and 180" C lies, and tone in a mi- ratio from 1: 1.8 to 3 : 0.1 to 0.8 milled with the known additives up to a particle size of s 50 μm and with an amount of water in a ratio of 0.4: 1 to 1.2: 1 to the total solids content be moved.

The polymer dispersion used is a styrene acrylate dispersion based on a copolymer of acrylic ester and styrene or a carboxyl latex dispersion of the mixed polymer of a ° G vinylidene carboxylic acid, styrene and butadiene are used, where the styrene content is> 56%. As hard as a spring, grindable at room temperature Organic high polymers can include a cyclohexanone formaldehyde resin, if appropriate an alkylcyclohexanone-formaldehyde resin with a melting range of 85 - 100 "C, a blown bitumen with a melting range of 110 - 160 "C, coal tar pitch with a melting range of 72-95 "C or polyvinyl butyral with a melting range from 95 - 145 "C. The hydrophobicity of these substances is achieved through their use increased by calcium stearate (melting range 140 - 160 "C). In the primary corrosion protection film The ground resins have the function of a filler; After the autoclave treatment the reinforced silicate concretes, d. H. after melting, they take over the function of the binder, the primary binders acting as plasticizers. The addition of the clay, in addition to improving the rheological properties, the film formation, the adhesive strength an improved anti-corrosion effectiveness of the film.

Radiographically it could be proven that by the autoclave treatment in the alkaline range the clay is partially transformed into zeolitic structures that increase the protective effectiveness of the pigments. The alkaline peptization The clay is ground with the highly alkaline binders.

Depending on the later stressability of the corrosion protection system, known pigments and inhibitors or fillers added are set. The simultaneous grinding of the pigments and inhibitors with the tough organic ones High polymers and the polymer dispersion has proven itself in a one-shot process as proved beneficial.

EXEMPLARY EMBODIMENTS The invention is intended through several exemplary embodiments are explained in more detail.

Example 1 12.84 parts by weight of carboxyl latex dispersion (solid) 30.78 "Coal tar pitch m.p. 85 + 3 ° C. 2.20" calcium stearate 0.09 II carboxymethyl cellulose 0.16 "alkylphenyl polyglycol ether 4.39" clay 0.24 "butyl glycol 0.07" oxethylated Alkylphenol 2.00 "melamine formaldehyde condensate 6.76" zinc tetraoxychromate 0.10 " Caustic soda 40.37 "water All components except the carboxyl latex dispersion are made ground in a ball mill to # 50 pm. The polymer dispersion is then added and everything is briefly homogenized.

The production can take place in porcelain as well as in steel ball mills take place, the crushing effect of the steel ball mills compared to the porcelain mills is several times higher.

Example 2 11.64 parts by weight carboxyl latex dispersion (solid) 29.04 Methylcyclohexanone-formaldehyde resin m.p. 95 + 2 ° C 2.50 parts by mass Melamine formaldehyde condensate 2.93 "calcium stearate 0.10" carboxymethyl cellulose 0.17 "alkylphenyl polyglycol ether 8.91" clay 0.23 "butyl glycol 0.08" oxethylated Alkylphenol 7.01 "lead silica chromate 37.39" water All solid ingredients are Milled to the grain size - 50 μm and with the addition of carboxyl latex dispersion homogenized by further grinding or mixing.

Example 3 12.78 parts by mass of styrene acrylate dispersion (solid) 38.50 "blown bitumen m.p. 125 ° C 1.92" calcium stearate 0.05 "carboxymethyl cellulose 0.06 "polyvinyl alcohol 0.27" alkyl phenyl polyglycol ether 1.93 tons' clay 0.12 "butyl glycol 0.10 "oxethylated alkylphenol 44.27" water The preparation is carried out as under Example 1.

Example 4 12.28 parts by mass carboxyl latex dispersion (solid) 36.85 "Coal tar pitch m.p. 75 + 3 ° C 1.84" calcium stearate 0.07 "carboxymethyl cellulose 0.05 "polyvinyl alcohol 0.18" alkyl phenyl polyglycol ether 1.84 "clay 0.11" butyl glycol 0.10 Parts by weight melamine-formaldehyde condensate 4.30 "lead-II oxide 42.38" water lead-II oxide is also ground with all other components at the same time.

Example 5 14.20 parts by mass of styrene acrylate dispersion (solid) 33.00 "Polyvinyl butyral m.p. 130 + 3 ° C 1.80" Calcium stearate 0.10 "Carboxymethyl cellulose 0.18 "alkyl phenyl polyglycol ether 6.10" clay 0.20 "butyl glycol 7.50" lead II oxide 0.02 "oxethylated alkylphenyl 36.90" water The preparation takes place as under Example 1.

Claims (8)

Claims of the invention 1. A method for producing an anti-corrosion agent for steel, especially for steel reinforcement of autoclaved silicate concrete Polymer dispersion base with known additives, such as water-soluble cellulose derivatives, Melamine-formaldehyde condensates, alkylphenyl polyglycol ethers, pigments or Inhibitors, characterized in that an organic polymer dispersion, a spring-hard organic high polymer that can be milled at room temperature Melting interval or melting point between 40 "C and 180" C, and clay in one Mixing ratio of 1: 1.8-3: 0.1-0.8 to a particle size of 4 50 pm and with an amount of water in the ratio 0.4 - 1.2: 1 to the total solids content be homogenized. 2. The method according to the main point 1, characterized in that as Polymer dispersion a polymeric styrene acrylate dispersion based on a copolymer from an acrylic acid ester and styrene is used. 3. The method according to the main point 1, characterized in that a Carboxyl latex dispersion of the copolymer from a 0- »vinylidene carboxylic acid, Butadiene and styrene are used, the styrene content being> 56%. 4. The method according to items 1 to 3, characterized in that as a spring-hard organic high polymer that can be milled at room temperature, a cyclohexanone-formaldehyde resin, optionally an alkylcyclohexanone-formaldehyde resin with a melting range from 85 - 100 "C is used. 5. The method according to items 1 to 3, characterized in that as a spring-hard organic high polymer that can be milled at room temperature, it is a highly blown one Bitumen with a melting range of 110 ° C to 160 "C is used. 6. The method according to items 1 to 3, characterized in that a hard coal tar pitch as a spring-hard organic high polymer that can be milled at room temperature with a melting range of 72 - 95 "C is used. 7. The method according to items 1 to 3, characterized in that as a spring-hard organic high polymer, polyvinyl butyral, which can be milled at room temperature with a melting range of 95-145 "C is used. 8. The method according to items 1 to 7, characterized in that Clay is peptized during grinding in an alkaline medium.