DE19741912C1 - Production of effective antifoam remaining stable during storage from carrier oil, filler and optionally additives - Google Patents

Abstract

Production of antifoam comprises mixing carrier oil, filler and optionally additives under reduced pressure and simultaneous removal of entrained air and water.

Description

The invention relates to an improved process for the production of anti-foaming agents by Ver mixing of carrier oils, fillers and, if necessary, auxiliary substances and subsequent removal of air and traces of water.

Paints and varnishes are increasingly being produced on an aqueous basis. For inside and outside Paints with pigment concentrations in the range of 50 to 80% by weight have been on the market for years Defoamer based on mineral oil is stabilized because it has a particularly advantageous price / performance ratio relationship. With increasing demands on the biodegradability of all paint com If necessary, the mineral oils can also be replaced by derivatives of native oils. A The problem with the production and use of such preparations is, however, that the Pigment dispersions form foams that impair flow properties and handling and are therefore undesirable. Anti-foaming and anti-foaming agents for aqueous applications such as in other industries such as textile dyeing, paper or sugar industry are used, consisting principally of a water-insoluble carrier oil, one or more fillers and optionally emulsifiers and other auxiliaries (cf. US 3,666,681). The agents are usually obtained by stirring the individual components together provides, however, there is a risk that the ingredients due to their density differences separate. One tries to counter this problem by using the mixtures produces high shear stirrers, which is of course technically complex and therefore too high ferti lead costs. Nevertheless, the disper produced in this way also prove to be ions are only stable in storage for a limited period of time, which is the case, for example, in the sugar industry, that doesn't work continuously, but in campaigns, can lead to problems.  

The object of the present invention was therefore to provide an improved method for To provide the manufacture of anti-foaming agents, with the help of which he stable products are kept, which are preferably also characterized by an improved antifoam effect should.

The invention relates to a process for the production of antifoams, which characterized in that one reduces carrier oils, fillers and optionally additives mixed with each other and at the same time removed stirred-in air and water.

Surprisingly, it was found that known anti-foaming agents in their anti-foaming action for aqueous applications and their long-term storage stability can be significantly improved, if a vacuum is applied after mixing the components at elevated temperature and the Mixtures of stirred-in air and above all residual traces of water are freed.

The components are mixed in the heat, preferably at temperatures above the melting point of the highest melting component, but at most at 140 ° C. Typically, the mixing is carried out at temperatures in the range of 50 to 140 and in particular 90 to 120 ° C carried out. The mixing process can be carried out in any heatable mixing container any agitator, the use of high shear dispersing agitators is possible, but not required. The vacuum should be sufficient to ensure that at the selected mixing temperature Ensure removal of water; a fine vacuum is not required. The right ones The person skilled in the art can set printing conditions on the basis of his general specialist knowledge without to have to be inventive. After the mixing and homogenization described in Ab Depending on the batch size can take 30 minutes to 2 hours, the anti-foaming agents cooled, the vacuum broken and the finished products filled without stirring if possible.

Suitable carrier oils are non-aqueous substances which are liquid at room temperature and in which the fillers are insoluble. Typical examples are Guerbet alcohols based on fatty alcohols with 6 to 18, preferably 8 to 10 carbon atoms, esters of linear C ₆ -C ₂₂ fatty acids with linear C ₆ -C ₂₂ fatty alcohols, esters of branched C ₆ -C ₁₃ carboxylic acids with linear C ₆ -C ₂₂ fatty alcohols, esters of linear C ₆ -C ₂₂ fatty acids with branched alcohols, especially 2-ethylhexanol, esters of linear and / or branched fatty acids with polyhydric alcohols (such as propylene glycol, dimer diol or trimer triol ) and / or Guerbet alcohols, triglycerides based on C ₆ -C ₁₀ fatty acids, liquid mono-di-triglyceride mixtures based on C ₆ -C ₁₈ fatty acids, esters of C ₆ -C ₂₂ fatty alcohols and / or Guerbet alcohols with aromatic carboxylic acids , in particular benzoic acid, vegetable oils, branched primary alcohols, substituted cyclohexanes, linear C ₆ -C ₂₂ fatty alcohol carbonates, Guerbet carbonates, esters of benzoic acid with linear and / or branched C ₆ - C ₂₂ -Alcohols (e.g. B. Finsolv® TN), dialkyl ethers, ring opening products of epoxidized fatty acid esters with polyols and / or aliphatic or naphthenic hydrocarbons, such as mineral oils, white oils or paraffin oils. The carrier oils can be used in amounts of 50 to 95, preferably 70 to 90% by weight, based on the antifoam.

Examples of suitable fillers that do not dissolve in the carrier oil are silica gel, alkaline earth metal or Aluminum salts of fatty acids with 16 to 22 carbon atoms, titanium acid esters, quartz powder, poly siloxanes, polyalkylene amides, polyethylene waxes and microcrystalline waxes. The fillers can be in Amounts of 0.5 to 20, preferably 2 to 8 wt .-% - based on the anti-foaming agents - used will.

Suitable auxiliaries, which may optionally be contained in the antifoam and for adjustment the density or serve as a thickener, surface-active substances are preferred nonionic emulsifiers, and silicone oils. Typical examples of suitable nonionic surfactants are Fatty alcohol polyglycol ether, alkylphenol polyglycol ether, fatty acid polyglycol ester, fatty acid amide poly glycol ether, fatty amine polyglycol ether, alkoxylated triglycerides, mixed ethers or mixed formals, given if necessary, partially oxidized alk (en) yl oligoglycosides or glucuronic acid derivatives, fatty acid N-alkylgluca mide, protein hydrolyzates (especially vegetable products based on wheat), polyol fatty acid esters, Sugar esters, sorbitan esters, polysorbates and amine oxides. If the non-ionic surfactants Polygly contain colether chains, these can be a conventional Ho, but preferably a restricted Ho have molog distribution. Examples of silicone oils are dimethylpolysiloxanes and methylphenyl polysiloxanes, cyclic silicones and amino, fatty acid, alcohol, polyether, epoxy, fluorine, glycoside and / or alkyl-modified silicone compounds that are both liquid at room temperature can also be resinous. The auxiliaries can be used in amounts of 0.2 to 10, preferably 2 to  5 wt .-% - based on the antifoam medium - be obtained. The weight ratio between the Fillers and auxiliaries can be 1:10 to 10: 1.

The antifoam agents obtainable by the process according to the invention are notable for high defoaming effect and are stable in storage for months. They are suitable for for example for defoaming paints and varnishes, detergents, machine dishes detergents and as auxiliaries in the paper, textile and sugar industries.  

Example 1. The carrier oil was placed in a stirred kettle and heated to 100.degree. During the The fillers and auxiliaries were metered in during the heating phase. Then the boiler was eva and the mixture is homogenized for 1 h with stirring. The mixture was then reduced to 30 ° C cools, the vacuum is released and the finished antifoam is filled without stirring.

Comparative Example V1. The carrier oil, the fillers and the auxiliaries were in a stirred tank submitted together, heated to 80 ° C and homogenized for 1 h with stirring. After that the An cooled to 30 ° C and bottled with stirring.

Comparative example V2. Analogous to Comparative Example V1 was a mixture of carrier oil and fillers and auxiliary materials are homogenized in a high-shear agitator of the Ultraturrax type.

5 antifoams were produced using the process according to the invention and the two comparative processes manufactured medium, the composition of which is shown in Table 1 (quantities as weight %)

Table 1

Antifoam compositions

Defoamer test 1: acrylic dispersion (paint / varnish). 100 ml Mowilith DM 760 (Hoechst AG) who weighed in 1 liter beaker and washed with 100 ml dist. Diluted water; the fill level is marked. 2nd min with a propeller agitator with a diameter of 70 mm at a speed stirred by 200 rpm. The upper foam limit is also marked. With a pipette dropwise 0.2 ml silicone-containing defoamers (A3, A4) or 0.5 ml silicone-free defoamers (A1, A2, A5) dripped onto the non-stirred foam at various points. Then slowly with 800 Keep stirring until the foam has completely disintegrated. The time for decay on the output height is measured. The results are summarized in Table 2; the foam is specified height in ml.

Table 2

Anti-foam effect

Defoamer test 2: surfactant solution / whipped foam test (textile). 13.6 g dimethyl coconut alkyl betaine (Dehyton AB30) are dissolved in 400 ml hard water (20 ° d). 8.8 g of this solution and 0.1 g of ent Foamers are made up to 1 l with water. 200 ml of this solution are placed in a 1 liter measuring cylinder (Diameter 6 cm, height 36 cm) filled. Then a perforated stamp (diameter 5.5 cm, 40 holes of 4 mm in a 4 mm thick plexiglass plate) 30 times every second generated according to DIN 53901 foam and the foaming height in ml after 10 s. The results nisse are summarized in Table 3; the foam height is given in ml.

Table 3

Anti-foam effect

Storage trials. The anti-foaming agents produced by the three methods were subjected to a storage test subjected to 6 months at 30 ° C and checked optically for homogeneity. The results are in Table 4 summarized.

Table 4

Storage trials

Claims (10)

1. A process for the preparation of anti-foaming agents, characterized in that carrier oils, fillers and optionally additives are mixed with one another under reduced pressure and, at the same time, air and water which have been stirred in are removed. 2. The method according to claim 1, characterized in that the carrier oils, fillers and optionally additives at temperatures above the melting point of the highest melting component, but at most mixed at 140 ° C. 3. Process according to claims 1 and 2, characterized in that carrier oils are used which are selected from the group formed by Guerbet alcohols based on fatty alcohols having 6 to 18 carbon atoms, esters of linear C ₆ -C ₂₀ fatty acids with linear C ₆ -C ₂₀ fatty alcohols, esters of branched C ₆ -C ₁₃ carboxylic acids with linear C ₆ -C ₂₀ fatty alcohols, esters of linear C ₆ -C ₁₈ fatty acids with branched alcohols, esters of linear and / or branched fatty acids with polyhydric alcohols and / or Guerbet alcohols, triglycerides based on C ₆ -C ₁₀ fatty acids, esters of C ₆ -C ₂₂ fatty alcohols and / or Guerbet alcohols with aromatic carboxylic acids, vegetable oils, branched primary alcohols, substituted cyclohexanes, Guerbet carbonates, dialkyl ethene, ring opening products of epoxidized fatty acid esters with polyols and / or aliphatic or naphthenic hydrocarbons. 4. Process according to claims 1 to 3, characterized in that the carrier oils in Amounts of 50 to 95 wt .-% - based on the anti-foaming agents - used. 5. Process according to claims 1 to 4, characterized in that fillers are used, which are selected from the group consisting of silica gels, alkaline earth metal or aluminum salts of fatty acids with 16 to 22 carbon atoms, titanium acid esters, quartz powder, polysi loxanes, polyalkylene amides, polyethylene waxes and microcrystalline waxes. 6. Process according to claims 1 to 5, characterized in that the fillers in Amounts of 0.5 to 20 wt .-% - based on the anti-foaming agents - used. 7. Process according to claims 1 to 6, characterized in that auxiliary substances are used, which are selected from the group consisting of surface-active substances and Silicone oils.   8. The method according to claim 7, characterized in that surface-active substances uses, which are selected from the group consisting of fatty alcohol polyglycol ethers, Alkylphenol polyglycol ethers, fatty acid polyglycol esters, fatty acid amide polyglycol ethers, fatty amine polyglycol ethers, alkoxylated triglycerides, mixed ethers or mixed formals, if appropriate partially oxidized alk (en) yl oligoglycosides or glucoronic acid derivatives, fatty acid N-alkylgluca miden, protein hydrolyzates, polyol fatty acid esters, sugar esters, sorbitan esters, polysorbates and amine oxides. 9. The method according to claim 7, characterized in that one uses silicone oils made of are selected from the group formed by dimethylpolysiloxanes, methylphenylpoly siloxanes, cyclic silicones and amino, fatty acid, alcohol, polyether, epoxy, fluorine, glyko sid- and / or alkyl-modified silicone compounds. 10. The method according to claims 1 to 9, characterized in that the auxiliary substances in Quantities of 0.2 to 10 wt .-% - based on the anti-foaming agents - used.