Patent Application
20240141185
The present invention relates to a defoamer composition based on vegetable oil.
In the coating and ink industry, foaming issues are ubiquitous in the water-borne coating and ink systems, since the water-borne systems normally have surfactants, dispersants, wetting agents, emulsifiers and the like in their formulations, which lower the surface tension, readily leading to foam formation. More recently, classes of defoamers have been introduced to the market that can prevent or eliminate the foam which occurs during the coating and ink production, ink printing and coating application process.
For example, mineral oil or silicone oil-based emulsion type defoamer was largely used in the printing ink industry. However, mineral oil has potential negative effects on human health. Thus, it is harmful when the mineral oil is used in the waterborne ink formulation for food contact. Silicone oil-based defoamer could tend to create defects in the printing ink layer when they are added in the printing process without enough shear force to disperse this kind of defoamer into ink systems.
Known polyether-modified siloxane based defoamers with good defoaming ability give a better performance regarding compatibility in the waterborne coating and ink systems than silicone oil, but still the compatibility is not good enough when the application only is under low shear force to disperse into ink systems.
While health-friendly vegetable oil based defoamer is easy to disperse but do not have enough power to knockdown foam created during printing.
It would therefore be desirable to provide a defoamer composition which is in particular advantageous for food contact waterborne coating and ink systems by the combination of polyether-modified polysiloxane and vegetable oil. However, polyether-modified polysiloxane and vegetable oil cannot dissolve with each other, especially when the polyether-modified polysiloxane is used in relative high amount to enhance the defoaming ability of the vegetable oil.
It is an object of the present invention to overcome at least part of the defects of the prior art, and to provide defoamer composition with good defoaming ability, good compatibility and easy dispersion under low shear force, e.g. when added into ink formulation during the printing process.
This objective is accomplished by the discovery of a new defoamer composition comprising
wherein the amount of the water phase is 20-90 wt. %, preferably 60-85 wt. % based on the total weight of the composition, characterized in that the oil phase is an oil-in-oil emulsion comprising
The invention also includes the following embodiments:
R1O-A-[B-A-]tR1 (I)
The terms “siloxanes” and “polysiloxanes” are used as synonyms in the present invention.
The terms “defoamer composition” and “oil-in-water emulsion” are used as synonyms in the present invention.
In the context of the present invention the terms “oil phase” and “oil-in-oil emulsion are to be understood as being synonymous.
The term “defoamer” in the present case encompasses both products and formulations that prevent foam and also those that destroy foam and enable deaeration. In practice, the transitions between these product properties are blurred, so that here the common collective term defoamer is used.
It has surprisingly been found that the inventive oil-in-oil emulsion is stable which could be used as the oil phase for the inventive defoamer composition.
Without being bound to a theory, the inventors believe that the polyether ester has the function as a compatibilizer or as a stabilizer in the oil-in-oil emulsion comprising the polyether-modified polysiloxane as the dispersed phase and the vegetable oil as the continuous phase.
Vegetable Oil as Component A
The vegetable oils may be selected from those conventionally used in the art. The vegetable oil useful in the present invention is typically liquid in room temperature. The most kinds of vegetable oil are triglycerides of saturated and/or unsaturated fatty acid.
Preferably, component A is selected from the group consisting of soybean oil, rape seed oil, canola oil, sunflower oil, corn oil, peanut oil and palm oil or a mixture thereof.
Polyether Ester as Component B
Preferably, component B is selected from the group consisting of polyoxyalkylene ester and polyoxyalkylene (poly)glyceryl ether ester.
It is particularly preferable that the polyoxyalkylene ester is derived from PEG, PPG, polyethylene-propylene glycol and fatty acids.
Preferably, the carbon chain length of fatty acid is from C2 to C22, more preferably the carbon chain length is from C10 to C18.
It is preferable when the PO unit of polypropylene glycol can be from 10 to 100 mole, more preferably from 14 to 55 mole.
The EO unit of polyethylene glycol can be preferably from 5 to 50 mole, more preferably from 8 to 10.
The total mole of EO-PO unit of polyethylene-propylene glycol can be preferably 5 to 100 mole, more preferably from 10 to 80 mole.
The polyoxyalkylene ester corresponds to the average general formula (III):
R7-(EO)a(PO)b—R8 (III)
If R7 and R8, which may be identical or different, represent R6C(O)O—, wherein R6 is a monovalent aliphatic saturated or unsaturated hydrocarbon radical having 2 to 22 and preferably from 10 to 18 carbon atoms, such a polyoxyalkylene ester is a di-ester.
If either one of R7 and R8 represents a hydroxyl group, the polyoxyalkylene ester is a monoester.
The polyoxyalkylene ester can be a mixture of different monoesters or a mixture of different di-esters or a mixture of monoester and di-ester to disperse the polyether siloxane in the vegetable oil.
Examples of polyoxyalkylene esters are PEG 400 oleic oil diester or PPG 2000 tall oil diester.
Besides the polyoxyalkylene esters, one could also additionally or alternatively use polyoxyalkylene (poly)glyceryl ether esters to obtain the desired properties.
For the polyoxyalkylene (poly)glyceryl ether and its ester, the structure of formula (IV) is for example as follows:
Or either one or two of R3, R4 and R5 represent a hydroxyl group, the rest of them, identical or different, represent R6C(O)O—, wherein R6 is a monovalent aliphatic saturated or unsaturated hydrocarbon radical having 2 to 22 and preferably from 10 to 18 carbon atoms.
The polyoxyalkylene (poly)glyceryl ether esters as defined above can be used singly or as mixture of two or more kinds.
Particularly, polyoxyalkylene (poly)glyceryl ether, in which all of R3, R4 and R5 represent a hydroxyl group, may be used together with the polyoxyalkylene ester as define above to disperse the polyether siloxane in the vegetable oil.
Particularly, polyoxyalkylene (poly)glyceryl ether, in which R3, R4 and R5 represent a hydroxyl group, may be used together with the polyoxyalkylene (poly)glyceryl ether ester to disperse the polyether siloxane in the vegetable oil.
Suitable polyoxyalkylene (poly)glyceryl ether includes PPG 4000 glyceryl ether. Suitable polyoxyalkylene (poly)glyceryl ether ester includes PPG 4000 glyceryl oleic oil triester.
Polyether-Modified Polysiloxane as Component C
Preferably, component C conforms to general formula (I)
R1O-A-[B-A-]fR1 (I)
Component C according to formula (I) are known in principle. Further production processes are disclosed in EP 0 331 952 B1.
Component C according to formula (II) are known in principle. Further production processes are disclosed in WO 2009/138205.
It is likewise conceivable that further solids, for example silica, waxes and solids may be added to further increase the defoaming activity. Such additives are known to those skilled in the art.
It is preferably when the hydrophobic particles are selected from hydrophobic fumed silica and hydrophobic wax.
Preferably, the hydrophobic particles can be hydrophobically modified silica particles and/or wax like ethylene bis-stearamide (EBS wax) or polyethylene wax (PE wax).
Preferably, the composition having an oil-in-oil emulsion consisting of
It is preferable, from the viewpoint of the cost effectiveness and the defoaming performance, that the oil-in-oil emulsion contains 20 and 50 wt. % of the polyether-modified polysiloxane based on the total weight of the oil-in-oil emulsion.
The oil-in-oil emulsion preferably does not comprise mineral oil.
Preferably, the inventive defoamer composition comprises a thickener and/or a pH modifier.
The emulsifiers can be selected based on the calculations of HLB according to the Davis methods. It is preferably when the O/W emulsifier has a HLB from 8-20, more preferably from 10-18.
It is preferably when the W/O emulsifier as co-emulsifier has a HLB from 2-8, more preferably from 2-5.
The total amount of emulsifiers is preferably 2-10 wt. %, more preferably 3-8 wt. %, based on the total weight of the defoamer composition.
The thickener is preferably an alkali swellable emulsion thickener, which is used to stabilize the oil phase in the water. The amount of alkali swellable emulsion thickener is preferably from 1-5 wt. %, more preferably 2-4 wt. % based on the total weight of the defoamer composition.
The pH modifier may be NaOH solution, which is used to adjust the pH value to 7-9 to swell the alkali swellable emulsion thickener to adjust viscosity to stabilize the emulsion.
It is preferably when the O/W emulsifier and the W/O emulsifier as co-emulsifier may be dissolved in the water phase.
The inventive defoamer composition not only has good compatibility to waterborne formulations such as painting and ink formulations, but also has good defoaming ability.
According to another aspect of the present invention, it provides an oil-in-oil emulsion comprising
Preferably, the oil-in-oil emulsion consisting of
The invention further provides for the use of the oil-in-oil emulsion for producing a defoamer composition.
A further aspect of the invention is the use of the defoamer composition for producing dispersions, millbases, paints, coatings or printing inks, inkjet, grind resins, pigment concentrates, colour preparations, pigment preparations, filler preparations or coating compositions.
The examples which follow are provided merely to elucidate this invention to those skilled in the art and do not constitute any limitation of the described subject matter or of the described process whatsoever.
The invention is now described in detail by the following examples. The scope of the invention should not be limited to the embodiments of the examples.
1. Production of the Inventive Defoamer Composition and Comparative Composition
5 g EBS wax was melt at 160° C. and dispersed into 45 g rape seed oil under 3000 rpm by a high-speed disperser. Then 10 g PEG 400 oleic oil diester and 10 g PPG 2000 tall oil diester were added into the mixture under 500 rpm. Then 30 g mixture of a polyether-modified polysiloxane produced according to example of EP 0 331 952 B1 and a polyether-modified polysiloxane produced according to comparative Example 6 of WO 2009/138305 was added into the mixture and the mixture was blended at 500 rpm for 30 mins to form an oil phase. Then the oil phase was left at least overnight to obtain an oil-in-oil emulsion.
71 g water was placed into reactor and then 2.5 g Tego Tagat R 200 (HLB=18, as W/O emulsifier, from Evonik) and 1.5 g Tego Arknol S2 (HLB=5, as co-emulsifier, from Evonik) were added into the water at 300 rpm and 80° C. under vacuum. Then 4 g Rheovis® AS 1125 (alkali swellable emulsion thickener, from BASF) was added under 300 rpm for 10 mins. 20 g oil phase mixture prepared above was added and the obtained mixture was mixed for 30 mins. Then 0.25 g NaOH water solution (50%) and 0.75 g biocide was added and mixed for additional 10 mins. Then the obtained mixture was homogenized to obtain an inventive defoamer composition.
The same preparation procedure as the one in Example 1 was used to prepare the oil-in-water emulsion of Example 2, except that in Example 2, EBS wax was substituted with PE wax and rape seed oil was substituted with soybean oil.
Example 3 was prepared with the same method as the one in Example 1 except that 10 g PEG 400 oleic oil diester and 10 g PPG 2000 tall oil diester was replaced with 20 g PPG 2000 tall oil diester.
The oil-in-water emulsion for this example was prepared with the same method as the one in Example 1 except that 3 g EBS wax, 27 g rape seed oil, 20 g PPG 2000 tall oil diester and 50 g polyether siloxane mixture were used to replace 5 g EBS wax, 45 g rape seed oil, 10 g PEG 400 oleic oil diester and 10 g PPG 2000 tall oil diester, and 30 g polyether siloxane mixture.
Example 5 was prepared with the same method as the one in Example 1 except that 59 g water was placed into reactor and then 3.75 g Tego Tagat R 200 (HLB=18, as W/O emulsifier) and 2.25 g Tego Arknol S2 (HLB=5, as co-emulsifier), and 30 g oil phase mixture were added.
The oil-in-water emulsion for Example 6 was prepared with the same method as the one in Example 1 except that 3 g PE wax, 27 g soybean oil and 50 g polyether siloxane mixture were used to replace 5 g EBS wax, 45 g rape seed oil and 30 g polyether siloxane mixture.
Example 7 was again prepared with the same method as the one in Example 1 except that 10 g PEG 400 oleic oil diester and 10 g PPG 4000 glyceryl ether were used instead of 10 g PEG 400 oleic oil diester and 10 g PPG 2000 tall oil diester.
Example 8 was prepared with the same method as the one in Example 1 except that 10 g PEG 400 oleic oil diester and 10 g PPG 4000 glyceryl oleic oil triester were used instead of 10 g PEG 400 oleic oil diester and 10 g PPG 2000 tall oil diester.
Comparative Examples 1-4 were prepared with the same method as the one in Example 1 but without the hydrophobic particles and the polyether ester.
2. Production of Ink Formulations for Performance Test
To compare the inventive defoamer with other prior art defoamer technology like silicone oil defoamer, polyether siloxane defoamer, mineral oil defoamer and vegetable oil defoamer, the following two ink formulations were tested.
3. Stability Testing of Oil Phase
The stability of the oil phase with or without polyether ester was compared to check the stability of polyether siloxane in the vegetable oil. The prepared oil phase samples were stored at room temperature to see whether the phase separation will happen. The results of the stability test are reported in Table 4. All weight percentages are relative to the total weight of the respective oil phase.
4. Compatibility Test
Defoamer composition was mainly added during the printing process. So only low shear force is available to disperse the defoamer into ink systems. To simulate the process, the defoamer is added into ink formulation and mixed by hand then draw down on the Laneta chart at 7-micron wet film thickness and then check the compatibility after the film is dried.
The compatibility is ranked by scoring:
D-foam RC-920, a silicone oil defoamer supplied by Clariant, with 100% active content was post added at 0.1% based on the ink formulation. The emulsion type defoamer according to the present invention (Example 1 and Example 4) and Tego® Foamex 1488 as well as Tego® Foamex 825 (The latter two defoamers are both polyether siloxane emulsion defoamers supplied by Evonik) were all 20% oil in the emulsions and post added at 0.3% based on the ink formulations. Each of the two vegetable oil-based defoamers, Tego® Foamex 833 supplied by Evonik and Tego® Foamex 18 supplied by Evonik, is 100% active content and was added at 0.3% in the ink formulations. Each of the two mineral oil type defoamers, Foamstar ST2410 AC supplied by BASF and Tego® Foamex 9 supplied by Evonik, with 100% active content was added at 0.3% in the ink formulation respectively for compatibility reference. The above percentages are all percentages by weight.
The test results in both ink formulations are reported in Table 5 and Table 6.
Comparing to silicone oil and polyether siloxane emulsion defoamer, the inventive defoamer composition Example 1 and 4 showed a significant improvement on the compatibility in the ink formulation that does not cause too many defects even under low shear force. Such compatibility is even comparable to that of vegetable oil defoamers.
5. Defoaming Test
Defoaming ability is compared by using a bubbling test method wherein a stainless-steel bubble stone is used to put into 200 g ink with different kinds of defoamers respectively by pumping air to create foam at 2.0 L/min air flow. The different kinds of the defoamers are post added into the ink formulations respectively and mixed simply by hand. After that, the foam height is recorded along with time up to 30 mins. The lower the foam height, the better the defoaming ability.
0.3 wt. % of the inventive defoamer composition (Examples 1 and 4) was added into both ink systems respectively. The amount of mineral oil (Foamstar ST2410 AC), vegetable oil based defoamers (Tego® Foamex 833 and Tego® Foamex 18) and polyether siloxane emulsion defoamers (Tego® Foamex 1488) were added into both ink systems was also 0.3 wt. %. The amount of silicone oil defoamer (D-foam RC-920) with 100 wt. % active content were added into both ink systems was 0.1 wt. %.
The test results in both ink formulations are reported in Table 7 and Table 8.
As the results show, both ink formulations according to the present invention showed a significant improvement in the defoaming ability compared to that of vegetable oil defoamers. The performance is even comparable to that of polyether siloxane emulsion defoamers. Comparing to mineral oil defoamer, even with a lower active content which is 27 wt. %, the defoaming ability is better than mineral oil with 100 wt. % active which is typical used in the ink formulation (when mineral oil was allowed to be added according to applicable governmental regulations).
The above description is presented to enable a person skilled in the art to make and use the invention and is provided in the context of a particular application and its requirements. Various modifications to the preferred embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Thus, this invention is not intended to be limited to the embodiments shown but is to be accorded the widest scope consistent with the principles and features disclosed herein. In this regard, certain embodiments within the invention may not show every benefit of the invention, considered broadly.
| Number | Date | Country | Kind |
|---|---|---|---|
| PCT/CN2022/123790 | Oct 2022 | WO | international |
This application claims priority to International Application No. PCT/CN2022/123790, filed on Oct. 8, 2022, the content of which is hereby incorporated by reference in its entirety.
