JP2013000649A - Defoamer composition, method for production thereof, and method for applying the defoamer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a defoamer composition being good in product stability and being capable of exhibiting sufficient performance of breaking and preventing foam especially in a foamable aqueous system carrying much suspended matter; to provide a method for the production thereof; and to provide a method for applying the defoamer composition.SOLUTION: There are provided: a defoamer composition comprising a hydrofined petroleum fraction, hydrophobic silica, and a hydrocarbon-type wax and characterized in that the hydrophobic silica particles coated with the hydrocarbon-type wax are dispersed in the hydrofined petroleum fraction; a method for the production thereof; and a method for applying the defoamer composition.

Description

  The present invention relates to an antifoaming composition applied to foaming aqueous water having good product stability and a large amount of suspended solids, a production method thereof, and an application method of the antifoaming composition. .

  In general, the performance of antifoaming agents is classified into foam suppressing performance that suppresses foaming and foam breaking performance that quickly eliminates generated foam. However, kraft pulp manufacturing process water and deinked pulp manufacturing process in paper pulp manufacturing plants. In water-based water with many suspended solids such as water, metal coating process circulating water, plastic coating process circulating water, and wastewater treatment process water, bubbles are likely to be generated, and once generated bubbles are often difficult to disappear, The operation of the process becomes unstable, leading to a decrease in productivity and product quality.

  Therefore, various antifoaming agents such as mineral oil defoaming agents, silicone defoaming agents and polyether defoaming agents have been used for the purpose of defoaming or suppressing foaming of aqueous water in these processes. In addition to the hydrocarbon oil, amide compound, hydrophobic silica, fatty acid ester, vegetable oil, silicone oil, and the like as active ingredients of the mineral oil-based antifoaming agent, Patent Document 1 discloses a polyoxyalkylene compound. . In addition, vinyl acetate-fatty acid ester copolymer, vinyl acetate-olefin copolymer, silicone surfactant (Patent Document 2) for the purpose of enhancing the effectiveness of fatty acid amide as an auxiliary agent for enhancing the defoaming effect. ) And partially esterified products of α-olefin-maleic anhydride copolymer are applied at the time of preparation of the fatty acid amide solution (Patent Document 3), and fatty acid glycerides for the purpose of preventing aggregation of various active ingredients and imparting an expansibility effect The addition of a fluorosurfactant to an antifoaming agent (Patent Document 4) has been proposed. However, these conventional antifoaming agents have not been fully satisfactory in terms of operational stability and product quality in the above process.

  The cause is that defoaming components such as hydrocarbon oils, amide compounds, hydrophobic silica, and fatty acid esters are hydrophobic compounds, so they are easily adsorbed on suspended matter, and the defoaming components are present in the foamed water system in an effective form. It is thought that it is because it is not obtained. In particular, this phenomenon is remarkable in hydrophobic silica having a high effect as an antifoaming component, and there is a problem that the antifoaming performance is low although the foam breaking performance is high. Further, the hydrophobic silica particles are easily self-aggregated, and therefore there are problems such as product stability due to aggregation in the composition.

JP-A-11-276806 JP 55-70308 A Japanese Patent Laid-Open No. 10-216407 Japanese Patent Laid-Open No. 51-80692

  The present invention has been made in view of the above-described conventional circumstances, and prevents self-aggregation of hydrophobic silica in the composition. When applied, the present invention is particularly hydrophobic in foaming aqueous water in which a large amount of suspended substances are present. To find an antifoaming agent composition capable of causing the active silica to exist in an effective form and exhibit both sufficient foam breaking performance and foam suppressing performance, a method for producing the same, and a method for applying the antifoaming composition. It is an issue.

  In order to solve the above problems, the present inventors have focused on the alkylpolysiloxane film formed on the outside of the hydrophobic silica, and the polar alkylpolysiloxane film has agglomeration and adsorption to suspended substances. I thought that it might be promoting. Therefore, an attempt was made to coat hydrophobic silica with a non-polar hydrocarbon wax to prevent self-aggregation and adsorption to suspended substances.

  As a method, hydrorefined petroleum fraction is used as a solvent. Hydrophobic silica and nonpolar hydrocarbon wax are mixed, dissolved by heating, cooled and then crystallized, and coated with hydrocarbon wax. When a composition in which the hydrophobic silica particles are dispersed in a hydrorefined petroleum fraction is prepared, the composition has increased stability as a product, and there are many suspended substances. It has been found that the foam is likely to be generated and the foam once generated has a sufficient effect not only in the foam breaking performance but also in the foam suppression performance against the aqueous water which is difficult to disappear, and the present invention has been completed.

  That is, the invention according to claim 1 is a defoamer composition comprising a hydrorefined petroleum fraction, hydrophobic silica, and a hydrocarbon wax, wherein the hydrophobic foam is coated with the hydrocarbon wax. An antifoaming composition applied to an aqueous system in which suspended substances are present, characterized in that silica particles are dispersed in a hydrorefined petroleum fraction.

  The invention according to claim 2 is the defoamer composition according to claim 1, wherein the hydrorefined petroleum fraction is naphthenic oil and / or paraffin oil.

  Invention of Claim 3 is an antifoamer composition of Claim 1 or Claim 2 whose ratio of the said hydrorefined petroleum fraction is 25-100 weight% in all the solvents.

  According to a fourth aspect of the present invention, the hydrocarbon wax is one or more selected from paraffin wax, microstalline wax, Fischer-Tropsch wax, and polyethylene wax. It is an antifoamer composition as described in an item.

  The invention according to claim 5 is the antifoaming composition according to any one of claims 1 to 4, wherein the hydrocarbon wax has a melting point of 45 to 120 ° C.

  The invention according to claim 6 is characterized in that the hydrocarbon wax is contained in an amount of 0.5 to 15% by weight with respect to the total amount of the antifoaming agent composition, according to any one of claims 1 to 5. It is a foam composition.

  According to a seventh aspect of the present invention, in the production of the antifoam composition, the hydrorefined petroleum fraction, the hydrophobic silica, and the hydrocarbon wax are mixed, heated, dissolved, and cooled at the stage of cooling. The method for producing an antifoaming agent composition according to any one of claims 1 to 6, wherein silica is precipitated, and then a hydrocarbon wax is precipitated in the antifoaming agent composition. .

  The invention according to claim 8 applies the antifoaming composition according to any one of claims 1 to 6 to aqueous water having a suspended solid content of 100 mg / L or more. It is an application method of a foaming agent composition.

  The invention according to claim 9 is the activated sludge in the pulp and paper manufacturing process water system, the metal coating process circulating water system, the plastic coating process circulating water system, and the wastewater treatment process. It is an application method of the antifoamer composition of Claim 8 which is 1 type chosen from aqueous system.

  By using the antifoam composition according to the present invention, it is possible to expect improvement in operational stability and product quality in various production processes using aqueous water containing a large amount of suspended substances as process water.

It is a schematic diagram of the apparatus which evaluates the antifoaming effect of the antifoamer composition of this invention.

  The present invention relates to a defoamer composition containing a hydrorefined petroleum fraction, hydrophobic silica, and a hydrocarbon wax, and the method for producing the defoamer composition is characterized by hydrorefining. In the obtained petroleum fraction, the hydrophobic silica and the hydrocarbon wax are mixed and dissolved by heating, and then the periphery of the hydrophobic silica is coated with a nonpolar hydrocarbon wax when crystallizing by cooling. Suppresses agglomeration of hydrophobic silica in the product to increase product stability, and prevents hydrophobic silica from adsorbing to suspended solids when added to a foamed water system that contains a lot of suspended solids It is possible to form particles in a form that can be formed. The antifoam composition produced in this way is a surprising breakthrough that cannot be predicted from the prior art, particularly when used for foaming aqueous water having a suspended solid content of 100 mg / L or more. A foam effect and a foam suppression effect can be obtained.

  The hydrorefined petroleum fraction used in the antifoam composition of the present invention acts as a solvent for dissolving the hydrophobic silica blended at the same time, for example, a fraction having an aromatic content of 1% or less. Examples include hydrorefined naphthenic oil and liquid paraffin.

  This hydrorefined petroleum fraction may be used alone, but for the purpose of controlling the precipitation temperature of hydrophobic silica and petroleum wax, two or more types of hydrogenated petroleum fractions may be used at any ratio. It is possible to mix the components and a paraffinic lubricant base material having a low hydrorefining degree. However, when a paraffinic lubricating oil base material having a low hydrorefining degree is mixed, the solubility of hydrophobic silica is lowered. Therefore, the hydrolyzed petroleum fraction is preferably 25% or more of the total solvent weight. . Here, the total solvent weight refers to the total weight of the hydrorefined petroleum fraction and the paraffinic lubricating oil base material having a low hydrorefining degree.

  The hydrophobic silica used in the antifoam composition of the present invention is silicon oxide fine particles obtained by treating hydrophilic silica with a hydrophobizing agent.

  The above-mentioned hydrophilic silica is silicon oxide fine particles that have not been hydrophobized, and can be obtained by any method such as wet method (for example, precipitation method, gel method) silica, dry method (for example, combustion method, arc method) silica, etc. It may be manufactured.

  Examples of hydrophobizing agents include polysiloxane and dimethyldichlorosilane. Examples of polysiloxane include straight silicone oils such as dimethyl silicone oil, methyl hydrogen silicone oil, and methylphenyl silicone oil, side chains of dimethyl silicone oil, Examples thereof include modified silicone oil in which an organic group (for example, carbinol group, hydroxyl group, polyether group, etc.) is introduced at the terminal.

  Hydrophobic method for treating hydrophilic silica with a hydrophobizing agent can be achieved by a known method (for example, Japanese Patent Publication No. 42-26179). A hydrophobizing agent is added to a hydrophilic silica suspension and dried. Either wet treatment or dry treatment in which a hydrophobizing agent is added to dry hydrophilic silica and heated may be used.

  The requirement that the hydrophobic silica used in the antifoam composition of the present invention should satisfy is that the hydrophobic silica should be in the liquid when the liquid temperature is lower than 40 ° C. It crystallizes and precipitates. This precipitation temperature depends on the solubility of the hydrophobic silica in the hydrorefined petroleum fraction that is the solvent, and can be set to an arbitrary temperature of 40 ° C. or higher depending on the type and combination of the petroleum fraction. It is necessary to set it higher than the melting point of the hydrocarbon wax to be produced.

  Thus, the content of the hydrophobic silica in the antifoam composition of the present invention depends on the solubility in the solvent to be blended at the same time. The content of hydrophobic silica in the defoamer composition is generally 1 to 20% by weight because it is inconvenient and the effect per unit volume is low when the content is small. It is preferable.

  The hydrocarbon wax used in the defoamer composition of the present invention is a substance that is solid at room temperature, which is mainly composed of saturated hydrocarbons, and may be either a natural wax or a synthetic wax. In the case of wax, microstalline wax, and synthetic wax, Fischer-Tropsch wax and polyethylene wax may be used.

  The melting point of the hydrocarbon wax used in the antifoaming composition of the present invention needs to be lower than the precipitation temperature of the hydrophobic silica blended at the same time. On the other hand, it is preferable that the melting point is higher than the temperature of foaming aqueous water to which the antifoam composition of the present invention is applied. By setting the melting point of the hydrocarbon wax within this range, the hydrocarbon wax is solid in the applied aqueous water, and therefore the hydrophobic silica coated with the hydrocarbon wax is applied to the foamable aqueous system to be applied. Since it is not adsorbed by suspended substances existing in water, a sufficient defoaming effect is exhibited. However, taking into consideration the heat source during the production of the antifoam composition, a wax having a very high melting point is disadvantageous from the viewpoint of production efficiency, and a wax having a melting point of 40 to 300 ° C is preferable, and a wax having a melting point of 45 to 120 ° C is more preferable.

  Further, the blending ratio of the hydrocarbon wax to the hydrophobic silica can be arbitrarily set according to the effect on the target aqueous water, but when the blending amount of the hydrocarbon wax increases, Since there exists a tendency for the viscosity of the antifoamer composition of an invention to rise, it is preferable that it is 0.5 to 15 weight% of content with respect to the antifoamer composition whole quantity obtained by this invention.

  The method for producing the defoaming agent composition of the present invention can be selected from a plurality of methods, and a procedure for mixing hydrophobic silica and hydrocarbon wax in a hydrorefined petroleum fraction, heating and dissolving, and then cooling. Are common. According to this procedure, dissolved hydrophobic silica and hydrocarbon wax are gradually precipitated, and the hydrophobic silica deposited first is covered with the hydrocarbon wax deposited later, so that self-aggregation is difficult, and Particularly, it is possible to form particles having an excellent bubble-breaking effect and foam-reducing effect with respect to aqueous water in which a large amount of suspended substances are present.

  As an example of the method for producing the antifoaming composition of the present invention, hydrophobic silica and hydrocarbon wax are introduced into a hydrorefined petroleum fraction, and the hydrophobic silica and hydrocarbon wax are stirred and stirred. There is a method in which the temperature is raised to a melting temperature and the respective components are sufficiently mixed and then gradually cooled. In addition, after hydrophobizing hydrophilic silica with a hydrophobizing agent (wet treatment) in a hydrorefined petroleum fraction used in the present invention, a hydrocarbon wax is added and the same operation as described above is performed. An antifoam composition can also be prepared. Furthermore, after preparing a liquid mixture of hydrolyzed petroleum fraction, hydrocarbon wax, hydrophilic silica, and hydrophobizing agent, hydrophilic silica is hydrophobized (wet treatment), and then the same operation as described above. It is also possible to prepare an antifoaming agent composition.

  In the method for producing the antifoaming composition of the present invention, as a device for uniformly mixing each component charged, there is no limitation as long as it is a device capable of uniform mixing, a propeller type stirrer, a line mixer, a homomixer, a kneader, An ultrasonic disperser or the like can be used, and these devices can be arbitrarily combined. Further, in order to control the particle size of the hydrophobic silica coated with the hydrocarbon wax, it is more preferable that the coating is mechanically refined using a homomixer or the like after coating.

  When the particle size of the hydrophobic silica coated with the hydrocarbon wax obtained in the production of the antifoam composition of the present invention is too large, the coated hydrophobic silica particles are produced because the sedimentation rate is high. In the antifoaming agent composition, phase separation occurs. On the contrary, if it is too small, the energy cost is increased, and the long-term stability of the antifoaming agent composition is also deteriorated. For this reason, it is preferable that the particle size of the refined particles is 1 to 100 μm.

  The antifoaming composition of the present invention includes a hydrocarbon oil, an amide compound, hydrophobic silica, hydrophilic silica, fatty acid ester, vegetable oil, silicone oil, polyoxy as necessary, as long as the effects of the present invention are not reduced. Known defoaming components such as alkylene compounds and fluorine-based surfactants, and other auxiliary components can be added.

  The antifoaming composition of the present invention can be applied to any foamable aqueous water in which a suspended substance is present, and in particular, an aqueous water in which a suspended substance content of 100 mg / L or more is present in a large amount. As a result, it is possible to obtain a surprising bubble-breaking effect and a foam-suppressing effect that cannot be expected from the prior art. Such water-based water is present in many water systems such as kraft pulp manufacturing process water systems, deinked pulp manufacturing process water systems, metal coating process circulating water systems, plastic coating process circulating water systems, and wastewater treatment process water systems in paper pulp manufacturing plants.

  The suspended substance in the present invention refers to a solid substance having a particle size of 2 mm or less or colloidal particles dispersed in the target aqueous water, and a liquid organic substance insoluble in water exists as fine particles. Including those that are.

  The antifoaming agent composition in the present invention can be applied to any foamable aqueous water in which a suspended substance is present, and in particular, an aqueous water in which a suspended substance content of 100 mg / L or more exists in a large amount. When applied, a clear and large effect difference is shown with respect to the prior art. On the other hand, when there is no suspended substance, or when it is applied to aqueous water with a suspended substance content of less than 1 mg / L, there is no or very little substance that adsorbs hydrophobic silica. The effect difference of the antifoam composition of the invention is slight.

  The addition method and amount of the antifoam composition of the present invention may be appropriately selected according to the type of foamable aqueous water, the process conditions, and the state of foam generation. There are a method of adding to process water, a method of adding to process water before foaming, a method of adding to shower water for defoaming, and the like.

  Moreover, any of continuous addition, intermittent addition, or the addition linked with the bubble measuring device may be sufficient, and any of single point addition or multipoint addition may be sufficient. At the time of addition, it may be diluted with a suitable solvent or water, and can be used in combination with other types of antifoaming agents. When diluting, a solvent or water may be added to the concentrated solution, or a concentrated solution may be added to the solvent or water.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited only to a following example. In addition, various modifications may be included in the present invention as long as those skilled in the art can easily conceive without departing from the scope of the claims.

(Examples 1-5)
In a stainless steel container equipped with a propeller-type stirrer, 15 parts of naphthenic oil (trade name: Exol D-80 manufactured by ExxonMobil), 85 parts of liquid paraffin (trade name: liquid paraffin 350, manufactured by JX Nippon Oil & Energy Corporation), hydrophobic 10 parts of functional silica (trade name: Nippon Sil-10, manufactured by Tosoh Silica) and 5 parts of paraffin wax (trade name: Paraffin Wax-140, manufactured by Nippon Seiki Co., Ltd., melting point: 61 ° C.) The temperature was raised to 150 ° C., and the hydrophobic silica and paraffin wax were dissolved, and the same temperature was maintained for 15 minutes. Thereafter, cooling was started at a rate of 2 ° C./min. After cooling to 40 ° C., the same temperature was maintained for 15 minutes. Next, the sample solution after cooling was treated at 40 ° C. and 6,000 rpm for 5 minutes using a homogenizer (manufactured by TK Homomixer Primes) to obtain antifoaming agent 1 as Example 1.

  By the same method, the antifoamers 2-5 of the composition shown in Table 1 were prepared as Examples 2-5, respectively.

In Table 1, the following commercially available products were used as the solvent.
Naphthenic oil (trade name: Exol D-80, manufactured by ExxonMobil)
Paraffin oil A (trade name: Moresco White P-40, manufactured by MORESCO)
Paraffin oil B (trade name: liquid paraffin 350, manufactured by JX Nippon Oil & Energy Corporation)
Lubricant base material (trade name: Daphne Oil KP-68, manufactured by Idemitsu Kosan Co., Ltd.) (paraffinic lubricant base material with low hydrorefining degree)

(Examples 6 to 10)
In a stainless steel container equipped with a propeller-type stirrer, 50 parts of naphthenic oil (trade name: Exol D-80, manufactured by ExxonMobil), a paraffinic lubricant base material (trade name: Diana Process Oil NR) with low hydrorefining degree -68, manufactured by Idemitsu Kosan Co., Ltd.) 50 parts, hydrophilic silica (trade name: Nipgel AY-200, manufactured by Tosoh Silica) 8 parts, dimethyl silicone oil as a hydrophobizing agent (trade name: KF-96, Shin-Etsu Silicone) 5 parts, paraffin wax (trade name: Paraffin Wax-115, Nippon Seiki Co., Ltd., melting point 48 ° C.) 20 parts, and then heated to 200 ° C. with stirring and maintained at that temperature for 3 hours did. Thereafter, cooling was started at a rate of 2 ° C./min. After cooling to 40 ° C., the same temperature was maintained for 15 minutes. Next, the sample solution after cooling was treated at 40 ° C. and 6,000 rpm for 5 minutes using a homogenizer (manufactured by TK Homomixer Primes) to obtain antifoaming agent 6 as Example 6.

  By the same method, the antifoamers 7-10 of the composition shown in Table 2 were prepared as Examples 7-10, respectively.

In Table 2, the following commercially available products were used as the wax.
Paraffin wax (melting point 48 ° C.) (Brand name: Paraffin Wax-115, manufactured by Nippon Seiki Co., Ltd.)
Paraffin wax (melting point 61 ° C.) (trade name: Paraffin Wax-140, manufactured by Nippon Seiki Co., Ltd.)
・ Microstalline wax (melting point: 88 ° C.) (trade name: Hi-Mic-1090, manufactured by Nippon Seiki Co., Ltd.)
Polyethylene wax (melting point 106 ° C.) (trade name: A-C6, manufactured by Honeywell)
・ Fischer Tropus wax (melting point 113 ° C.) (trade name: FNP-0115, manufactured by Nippon Seiki Co., Ltd.)

(Examples 11 to 15)
In a stainless steel vessel equipped with a propeller-type stirrer, 50 parts of naphthenic oil (trade name: Exol D-110, manufactured by ExxonMobil), a paraffinic lubricant base material having a low hydrorefining degree (trade name: Daphne Oil KP-) 68, manufactured by Idemitsu Kosan Co., Ltd.) 50 parts, hydrophilic silica (trade name: Nipsil SS-10, manufactured by Tosoh Silica Co., Ltd.), dimethyl silicone oil as a hydrophobizing agent (SH200-50CS manufactured by Toray Dow Corning) After adding 3 parts, the temperature was raised to 200 ° C. with stirring, and the temperature was maintained for 3 hours to prepare a hydrophobic silica dispersion. To 108 parts of this hydrophobic silica dispersion, 5 parts of polyethylene wax (trade name: A-C6, Honeywell, melting point 106 ° C.) is added, and the temperature is raised to 150 ° C. with stirring. Hydrophobic silica and paraffin wax are added. After dissolution, the same temperature was maintained for 15 minutes. Thereafter, cooling was started at a rate of 2 ° C./min. After cooling to 60 ° C., the same temperature was maintained for 15 minutes. Next, the sample solution after cooling was treated for 5 minutes at 60 ° C. and 6,000 rpm using a homogenizer (manufactured by TK Homomixer Primes).

  By the same method, the antifoamers 12-15 of the composition shown in Table 3 were prepared as Examples 12-15, respectively.

In Table 3, the following commercially available products were used as hydrophobizing agents.
・ Dimethyl silicone (trade name: KF-96, manufactured by Shin-Etsu Silicone)
・ Methyl hydrogen silicone (trade name: KF-99, manufactured by Shin-Etsu Silicone) ・ Carbinol-modified dimethyl silicone (trade name: KF-6002, manufactured by Shin-Etsu Silicone)
・ Hydroxyl-modified dimethyl silicone (trade name: KF-9701, manufactured by Shin-Etsu Silicone)
・ Epoxy-modified dimethyl silicone (trade name: X-22-9002, manufactured by Shin-Etsu Silicone)

(Comparative Examples 1-5)
In a stainless steel vessel equipped with a propeller-type stirrer, 100 parts of a paraffinic lubricant base material (trade name: Daphne Oil KP-68, manufactured by Idemitsu Kosan Co., Ltd.) with low hydrorefining degree, hydrophobic silica (trade name: Nippon Sil SS) -10, manufactured by Tosoh Silica Co., Ltd.), 10 parts of paraffin wax (trade name: Paraffin Wax-140, manufactured by Nippon Seiki Co., Ltd., melting point: 61 ° C), and then heated to 150 ° C under stirring. The same temperature was maintained for 15 minutes. Thereafter, cooling was started at a rate of 2 ° C./min. After cooling to 40 ° C., the same temperature was maintained for 15 minutes. Next, the sample solution after cooling was treated at 40 ° C. and 6,000 rpm for 5 minutes using a homogenizer (manufactured by TK Homomixer Primes) to obtain antifoaming agent 16 as Comparative Example 1.

  By the same method, the antifoamers 17-20 of the composition shown in Table 4 were prepared as Comparative Examples 2-5, respectively.

In Table 4, the following commercial products were used for each component.
・ Naphthenic oil (trade name: Exol D-80, manufactured by ExxonMobil)
・ Lubricant base material (trade name: Daphne Oil KP-68, manufactured by Idemitsu Kosan Co., Ltd.) (paraffinic base material with low hydrorefining degree)
・ Hydrophobic silica (trade name: Nipsil SS-10, manufactured by Tosoh Silica)
・ Wax (trade name: Paraffin Wax-140, manufactured by Nippon Seiki Co., Ltd.)

(Stability test)
(1) Test method 400 ml of each sample of Example 2 (antifoaming agent 2) and Comparative Example 3 (antifoaming agent 18) having the same defoaming agent composition except for the presence or absence of wax was prepared in a 500 ml glass bottle. The bottle was sealed, sealed and allowed to stand at room temperature. The oil layer separation state of the sample was visually confirmed after 1 week of standing, 2 weeks, and 3 weeks. As self-aggregation of the blended hydrophobic silica proceeds, a transparent oil layer appears in the upper layer of the sample. The separation status confirmation results are shown in Table 5.

Evaluation criteria ○: Separation is not recognized.
Δ: Slight separation is observed.
X: Clear separation is recognized.

(2) Results In the sample of Comparative Example 3 in which the hydrophobic silica particles were not coated with wax, the transparent oil layer was separated into the sample upper layer after 3 weeks of standing, but the hydrophobic silica particles were coated with wax. In the sample of Example 2, which is the antifoam composition of the present invention, no separation was observed even after 3 weeks of standing, and in the antifoam composition of the present invention, the blended hydrophobic silica particles It was shown that the progress of self-aggregation was suppressed.

(Defoaming effect test)
(1) Test solution The test solution used for the defoaming effect test is 500 mg / L of an anionic surfactant (polyoxyethylene lauryl ether sodium sulfate, trade name: Burelite NA-25S, manufactured by Sanyo Chemical Industries) in tap water. Light calcium carbonate granular powder (special grade reagent average particle diameter 10-20 μm manufactured by Kishida Chemical Co., Ltd.) and kerosene were mixed in the blending amounts shown in Table 6 to prepare test solutions 1-5. Here, the test solution 1 is a system in which no suspended substance exists.

Also, process water from various factories is collected, passed through a 2 mm sieve, filtered using a 0.22 μm Millipore filter, and the concentration of solid suspended solids is measured. The concentration was adjusted and test solutions 6 to 8 were prepared. The collection location and properties of each test solution are as follows.
Test solution 6 Black liquor after pulp cooking in the pulp and paper mill kraft pulp manufacturing process (solid suspended solid 500 mg / L)
Test solution 7 Paint process circulating water in plastic coating factory (solid suspended solids 3,000mg / L)
Test solution 8 Activated sludge water in food factory wastewater treatment process (solid suspended solids 30,000mg / L)

(2) Evaluation method The defoaming effect with respect to each test solution was evaluated using the evaluation apparatus shown in FIG. In FIG. 1, 1 is a cylinder (inner diameter 16.5 cm), 2 is a test solution (1,400 ml), 3 is a bubble generated by foaming of the test solution, 4 is a circulation pump, 5 is a flow meter, and 6 is a stop valve. is there. The test solution was put in the cylinder 1, and the test solution 2 was circulated at a rate of 10 L / min from the bottom of the cylinder via the flow meter 5 with a circulation pump 4 and dropped from a position 30 cm above the liquid level on the cylinder top. Foaming occurs when this circulating fluid drops onto the liquid level in the cylinder and is mixed. After starting to circulate and foaming for 15 seconds, 2 ppm of antifoaming agent was added to the test solution in terms of hydrophobic silica, and after 30 seconds, 150 seconds, and 300 seconds after addition, the height of the foam was measured, The defoaming effect was compared.

(3) Results Table 7 shows the comparison results of the defoaming effect. In Table 7, the amount of foaming immediately before the addition of the antifoaming agent is indicated by the bubble height at an elapsed time of 0 seconds, but the foaming height immediately after the addition of the antifoaming agent is due to the defoaming effect of the added antifoaming agent. It greatly decreases from the bubble height at time 0 seconds. Therefore, the difference between the bubble height after the elapsed time of 0 seconds and the addition of 30 seconds indicates the foam breaking performance of the added antifoaming agent. The foam height after 150 seconds after addition and after 300 seconds after addition mainly indicates the suppression of foaming by the added antifoaming agent, that is, the foam suppression effect, and the foam height is kept low. It shows that the foam suppression performance is high.

  From the results of Table 7, in Test Solution 1 in which no suspended solids exist, no significant difference is observed in the foam height between the example and the comparative example, but solid particles such as calcium carbonate, or kerosene In the test solutions 2 to 4 in which 100 mg / L of liquid organic insoluble fine particles suspended in water is present as a suspended substance, both the foam breaking performance and the foam suppression performance are superior to the comparative examples. The excellent antifoaming effect of the antifoam composition was clearly shown. Furthermore, the test solution 5 contains 10 times the suspended substance of the test solution 3 and has high foaming properties, but there is no significant difference in the defoaming effect of the examples in the test solution 5 and the test solution 3, It has been clarified that the antifoaming agent composition of the present invention exhibits a stable defoaming effect regardless of the content of the suspended substance of foamable aqueous water. This indicates that the antifoaming component of the antifoaming composition of the present invention is difficult to be adsorbed by the suspended material in the aqueous water, and therefore the defoaming effect is hardly affected by the amount of the suspended material. In addition, the results of the examples in the test solutions 6 to 8 clearly show that the antifoaming agent composition of the present invention exhibits a stable defoaming effect even with process water of various water quality existing in various processes. I made it.

  From the above results, it is clear that the antifoaming composition of the present invention has an excellent defoaming effect that cannot be obtained by the prior art with respect to foaming aqueous water in which suspended substances exist. .

  The antifoaming agent of the present invention can be applied to all water systems in which a large amount of suspended substances are present and foaming can occur. Specific examples include a kraft pulp manufacturing process water system, a deinked pulp manufacturing process water system, a metal painting process circulating water system, a plastic coating process circulating water system, and a wastewater treatment process water system in a paper pulp manufacturing factory.

1: Cylinder 2: Test solution 3: Foam 4: Circulation pump 5: Flow meter 6: Stop valve

Claims (9)

  An antifoam composition comprising a hydrorefined petroleum fraction, a hydrophobic silica, and a hydrocarbon wax, wherein the hydrophobic silica particles coated with the hydrocarbon wax are hydrorefined. An antifoaming composition applied to an aqueous system in which a suspended substance is present, characterized by being dispersed in minutes.   The antifoam composition according to claim 1, wherein the hydrorefined petroleum fraction is naphthenic oil and / or paraffin oil.   The defoamer composition according to claim 1 or 2, wherein a ratio of the hydrorefined petroleum fraction is 25 to 100% by weight in the total solvent.   The defoaming according to any one of claims 1 to 3, wherein the hydrocarbon wax is at least one selected from paraffin wax, microstalline wax, Fischer-Tropsch wax, and polyethylene wax. Agent composition.   The defoamer composition according to any one of claims 1 to 4, wherein the hydrocarbon wax has a melting point of 45 to 120 ° C.   The defoamer composition according to any one of claims 1 to 5, wherein the hydrocarbon wax is contained in an amount of 0.5 to 15% by weight based on the total amount of the defoamer composition.   In the production of the defoamer composition, the hydrorefined petroleum fraction, the hydrophobic silica, and the hydrocarbon wax are mixed and dissolved in a solution, and then the hydrophobic silica is precipitated in the cooling step, followed by the hydrocarbon. The method for producing an antifoaming composition according to any one of claims 1 to 6, wherein the system wax is precipitated in the antifoaming composition.   The application method of an antifoamer composition which applies the antifoamer composition of any one of Claims 1 thru | or 6 to the aqueous water whose content of a suspended solid is 100 mg / L or more. The water system in which the content of the suspended substance is 100 mg / L or more is one selected from the paper pulp manufacturing process water system, the metal coating process circulating water system, the plastic coating process circulating water system, and the activated sludge water system in the wastewater treatment process. A method for applying the antifoam composition according to claim 8.

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