JPS5936509A - Composition for defoaming and its production - Google Patents

Abstract

PURPOSE:To provide a compsn. for defoaming having specified defoaming performance by using liquid hydrocarbon oil and ethylene-bis-stearylamide consisting of >=80% beta type. CONSTITUTION:>=80% portion of ethylene-bis-stearylamide used in a titled compsn. has a beta type crystalline form. Either arom. or aliphat. liquid hydrocarbon oil is usable and the oil having 10-40cps (100 deg.F) viscosity is preferred in terms of stability. Paraffin oil is most preferable. The ethylene-bis-stearylamide is suspended in such hydrocarbon oil, and the suspension thereof is heat-treated at about 45-90 deg.C to convert and adjust predominant alpha-type portion of the ethylene-bis-stearylamide in such a way that >=80wt% thereof has a beta type. The compsn. for defoaming is thus obtd. It is preferred to contain 1-10pts.wt. ethylene-bis-stearylamide and 99-90pts.wt. liquid hydrocarbon.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to antifoaming compositions. More specifically, the present invention relates to an antifoaming composition having an excellent antifoaming effect and a method for producing the same.

Various antifoaming compositions containing fatty acid amide and mineral oil as main components have been proposed in the past.In particular, antifoaming agents containing ethylene bisstearylamide and mineral oil as main components are used in the pulp industry, paper manufacturing industry, Widely used for defoaming purposes in various industrial wastewater, etc. These antifoaming agents are usually obtained by uniformly suspending yoriethylenebisstearylamide or a mixed fatty acid amide based on it in mineral oil by heat treatment or mechanical stirring, and optionally adding auxiliary ingredients. ing.

However, these antifoaming agents have a problem in that their antifoaming performance is not necessarily constant even though the active ingredients are kept at a constant ratio.

This invention was made to solve this problem. The inventors of the present invention first focused on the crystalline form of suspended ethylene bisstearylamide and conducted extensive research.

For example, ethylene bisstearylamide is disclosed in Japanese Patent Application Laid-Open No. 51-6
It is produced by the method disclosed in Publication No. 8487, that is, by reacting 2 moles of stearic acid per mole of ethylenediamine, and industrially it is produced by reacting not with stearic acid alone but with a mixed fatty acid mainly composed of stearic acid. The latter, ie, mixed fatty acid amide mainly composed of ethylene bisstearylamide, is used for general antifoaming purposes. In any case, the crystal form u of ethylene bisstearylamide obtained in this way consists of the α type and the β type, with the α type being particularly predominant (US Pat. No. 4,248
(See the specification of No. 792, etc.). The α-type and β-type can be fully distinguished because they have different infrared absorption characteristics at the following wavenumbers. Type Yes None Yes None The inventors of this invention raised a new problem: whether such differences in crystal morphology and their composition ratios have some influence on defoaming performance. As a result of repeated research, research, and consideration, we found that there was a surprising difference in antifoaming performance between the main crystal forms of ethylene bisstearylamide, the α type and the β type, with the β type having better antifoaming properties. It was discovered that the ratio of α type and β type in ethylene bisstearylamide changes due to temperature changes during the production of antifoaming compositions, and this causes fluctuations in antifoaming performance. Reached.

Thus, according to the present invention, in an antifoaming composition containing ethylene bis stearylamide and liquid hydrocarbon oil as main components, 80% of the ethylene bis stearyl amide
There is provided an antifoaming composition characterized in that the above is composed of β-type ethylene bisstearylamide.

The antifoaming composition of the present invention contains ethylene bisstearylamide (hereinafter referred to as EBS) in which 80% or more has a β-type crystal form, and the antifoaming composition of the present invention has a similar structure to the conventional antifoaming composition. It has significantly better defoaming performance than other products. In particular, it is preferable that the β-type EBS be 95% or more in terms of antifoaming performance.
It is more preferable that it be of a type.

The liquid hydrocarbon oil used as a component of the antifoam composition of this invention may be either aromatic or aliphatic.

Specifically, hexane, heptane, octane, benzene,
xylene, toluene, paraffin oil, mineral oil, kerosene,
Examples include naphtha and petroleum. These may be a mixture of two or more. Usually, from the viewpoint of stability, the viscosity is 10~
40 cps (100'F) is preferred. The most preferred example is paraffin oil.

The defoaming composition of the present invention is made by suspending the above-mentioned specific EBS in liquid hydrocarbon oil. Such a composition is usually made by suspending commercially available EB8 in liquid hydrocarbon oil and heat-treating this suspension at about 45 to 90°C, preferably about 70°C, to obtain alpha-predominant EB- It can be obtained by converting and adjusting 8 so that 80% by weight or more of it becomes β type. Specifically, for example, around the melting point of EBS (approximately 120 to 160
℃) and add the desired amount of FiB to it.
After adding S little by little and dissolving BB8 under stirring, 5- cool to obtain a composition in which EBS is uniformly suspended, and heat-treat this at a temperature of about 45 to 90°C, preferably about 70°C. It can be obtained by In addition, EBS is ground into fine particles using a ball mill, etc., and then added to liquid hydrocarbon oil, and the mixture is sufficiently mixed at a temperature of about 45 to 90°C, preferably about 70°C, to form EBS. obtained by suspending. Usually, the former method, in which EBS is dissolved in liquid hydrocarbon oil and then heat-treated, is preferred because it is simple and can be carried out in a short time.
Most of the BS becomes α-type, but 80% of it can be reduced by heat treatment at 70°C for 45 minutes to several hours after cooling.
The above can be converted into β-type EB8 in a short time.

However, without being limited to such a production method, for example, the method disclosed in US Pat. No. 4,248,792 may be applied. At least 80% or more of the 3BS contained in β
It is only necessary to adjust it so that it becomes a type FiBS.

The appropriate blending ratio of EBS and liquid hydrocarbon oil to be suspended is usually ~10 parts by weight of EBSI and 99-90 parts by weight of liquid hydrocarbon. EBS is 1
If it exceeds 0 parts by weight, the viscosity of the resulting composition will be inconvenient in terms of dispersibility and handling when used, and it will not lead to an improvement in the defoaming effect and will be uneconomical. Also, EBS is 1%
Below this, the antifoaming effect will be significantly inferior and unsuitable. In addition, if a commercially available industrial product is used as the EBS to be removed, as mentioned above, other fatty acid amides (
012 to 22 fatty acid amides), and substantially multi-component fatty acid amides are contained, but it is preferable that at least EBS is mainly composed of mixed fatty acid amides, especially pure EBS.
There is no need to use The content ratio when such EBS is used is also the same as above.

In this way, the antifoaming composition of the present invention containing EBS containing 80% or more of β-type EBS and liquid hydrocarbon oil as main components is obtained. The composition of the present invention may be composed only of these two components, or may further contain other known auxiliary components and additives (such as those for further increasing stability and antifoaming performance). Good too. Such auxiliary components and additives include, for example, hydrophobic silica (made by spraying silicone oil on the surface of inorganic powdered silica and sintering it).
, silicone oil (polysiloxane oil such as dimethylpolysiloxane), polyalkylene glycol (molecular weight 1750
to about 8,000), Pluronic type antifoaming agents, and various dispersants (for example, polyether nonionic surfactants, etc.). In particular, the defoaming composition of the present invention in which silicone oil is used in combination is one of the preferred compositions because the foam-breaking effect is further improved, and furthermore, when a small amount of a dispersant is included, the storage stability is more uniformly improved. At this time, the content of the silicone oil is suitably about 1 part by weight per 100 parts by weight of the EBS+liquid hydrocarbon oil, and the content of the dispersant is similarly suitably about 1 to 10 parts by weight. As the dispersant, it is preferable to use a Pluronic type surfactant which itself has antifoaming properties.

The antifoam compositions of this invention are suitable for use in aqueous liquids or aqueous suspensions that are handled in many industrial processes, such as latex,
It can be effectively applied to foaming liquids for manufacturing glue, starch, paper pulp, etc.

The concentration of the antifoam composition of this invention is generally from 0.01 to
20,000 ppm, and 1 to 15 ppm is usually used for black liquor, especially in the production of kraft pulp.

Hereinafter, this invention will be explained in more detail with reference to comparative examples and examples, but the invention is not limited thereby.

In the examples, the ratio between the α-type crystal form and the β-type crystal form of ethylene bisstearylamide is determined by the absorption intensity of the absorption at wave number 955an-1 and the absorption at wave number 94QCIR-' in the infrared absorption spectrum. Quantification was performed. A reference example regarding the quantitative method is shown below.

Reference examples Figures 1 to 5 show 6g of ethylene bisstearylamide.
The infrared radiation of ethylene 9-bis stearylamide was measured using a sample prepared by mixing the mixture with Nujol 941 and then processing the mixture in a ball mill for 1 hour to pulverize the ethylene bis stearylamide powder therein. The absorption spectrum (measurement device used was Hitachi Model 215). What is shown in FIG. 1 is an IR absorption spectrum of 100% β-type crystal form. Figure 2 shows 95% β-type crystal form, α
5% type crystal form (mixture of 95% by weight of 100% β-type crystal form and 5% by weight of 100% β-type crystal form)
This is the IR absorption spectrum of Figure 8 shows the IR of a mixture of 80% β-type crystal and 20% α-type crystal.
The absorption spectrum shown in Figure 4 is β type crystal form 5.
0%, α-form crystal form 50% (mixture).

What is shown in FIG. 5 is an IR absorption spectrum of 100% α-type crystal form. Focusing on the absorption at wave number 955 cll-' and the absorption at wave number 94 Q (Im-'), for example, the infrared absorption spectrum of an ethylene bis stearylamide sample whose content of β-type crystals is unknown is shown in Figure 2. Alternatively, by comparing with FIG. 3, it can be determined whether the content of β-type crystals in the sample is 80% or more (or 95% or more). ■Absorption spectrum = 94 wave number for absorbance of wave number 955z-' at 10-le
If the ratio of absorbance at 0 cm-1 is larger than that in Figure 3, the β-type crystal content of this sample is greater than 80%, and if the ratio is larger than that in Figure 2, the β-type crystal content of this sample is greater than that in Figure 2.
It can be determined that the type crystal content is greater than 95%. It is also possible to quantify the α-type crystal content based on the absorption intensity of absorption at a wave number of 678 m-1.

Example sample n 1 (Sample for Comparative Example 1): 12 volts of ethylene bisstearylamide (Alflo I (508; manufactured by NOF ■ - same as F) and 30 volts of liquid paraffin, with a hot wire coil wrapped around the outer periphery. Pour into an 800 tl separatory funnel,
The contents were heated to a temperature of 140-145°C to dissolve the ethylene bisstearylamide in the liquid halafin.

Separately, a flask containing 158 g of liquid paraffin was cooled to -10°C in an ice-cold water bath to which common salt had been added, and the heated ethylene bisstearylamide solution was gradually dropped into the flask. While the solution was being added dropwise, the dropping rate was adjusted so that the temperature of the contents of the flask was maintained below 5°C. After completion of the dropwise addition, the contents of the flask were stirred for 1 hour at a temperature of 5° C. or lower, and the contents were further taken out of the flask and treated in a ball mill for 1 hour to obtain an antifoaming composition in which ethylene bisstearyl atF was uniformly dispersed. I got something. This composition consisted of 6% by weight of ethylenebisstearylamide and 94% by weight of fluid halafin, and 100% of the ethylenebisstearylamide was in the α-type crystal form.

Sample 2 (sample for Comparative Example 2): 12 jl of ethylene bisstearylamide and 30 g of liquid paraffin were placed in a separatory funnel with a capacity of 800 sgl and a hot wire coil was wound around the outer periphery.
The contents were heated to a temperature of 140-145°C to dissolve the ethylene bisstearylamide into the liquid halafin. Separately, a flask containing 158 g of liquid paraffin was heated to 40° C. in a water bath, and the heated ethylene bisstearylamide solution was gradually dropped into the flask.

While the solution was being added dropwise, the temperature of the contents of the flask was 70°C.
The dropping rate was adjusted to maintain the temperature below ℃. After the addition was completed, the contents of the flask were stirred at a temperature of 70°C ± 2°C for 80 minutes, then allowed to cool to 25°C while stirring, and the contents were taken out of the flask and processed in a ball mill for 1 hour. An antifoaming composition in which ethylene bisstearylamide was uniformly dispersed was obtained. This composition consisted of 6% by weight of ethylene bis-stearylamide and 94% by weight of liquid paraffin, and the ethylene bis-stearylamide was a mixture of 45% by weight of α-type crystal form and 55% by weight of β-type crystal form.

Sample 8 (sample for Example 1): 12F of ethylene bisstearylamide and 30F of liquid paraffin were placed in a separatory funnel with a capacity of 800s+7 with a hot wire coil wound around the outer periphery, and the contents were brought to a temperature of 140 to 145°C. The ethylene bisstearylamide was dissolved in the liquid paraffin by heating. Separately, a flask containing 158 g of liquid paraffin was heated to 40°C in a water bath, and the heated ethylene bisstearylamide solution was gradually dropped into the flask.

18- While the solution is being added dropwise, the temperature of the contents of the flask is 70°C.
The dropping rate was adjusted to maintain the temperature below ℃. After the addition was completed, the contents of the flask were stirred at a temperature of 70°C ± 2°C for 45 minutes, then allowed to cool to 25°C while stirring, and the contents were taken out of the flask and processed in a ball mill for 1 hour. 7. An antifoaming composition in which ethylene bisstearylamide was uniformly dispersed was obtained. This composition consists of 6% by weight of ethylene bisstearylamide and 94% by weight of liquid paraffin.
It was a mixture of 88% by weight of β type crystal form.

Sample 4 (sample for Example 2): Ethylene bisstearylamide 12F and 30 g of liquid paraffin were placed in an 800 ml separating funnel with a hot wire coil wrapped around the outer periphery, and the contents were brought to a temperature of 140 to 145°C. The ethylene bisstearylamide was dissolved in the liquid paraffin by heating to . Separately, a flask containing liquid paraffin 158f was heated to 40° C. in a water bath, and the heated ethylene bis-stay 14=allylamide solution was gradually dropped into the flask.

While the solution was being added dropwise, the temperature of the contents of the flask was 70°C.
The dropping rate was adjusted to remain below °C. After completion of the addition, the contents of the flask were stirred for 90 minutes at a temperature of 70°C ± 2°C, then allowed to cool to 25°C without stirring,
Further, the contents were taken out from the flask and treated in a ball mill for 1 hour to obtain an antifoaming composition in which ethylene bisstearylamide was uniformly dispersed. This composition consists of 6% by weight of ethylene bisstearylamide and 94% by weight of liquid paraffin.
It was a mixture containing 95% by weight or less of the β-type crystal form.

Sample 5 (sample for Example 3): 12y of ethylene bisstearylamide and 30g of liquid paraffin were placed in a separatory funnel with a capacity of 800m/volume wrapped around a hot wire coil, and the contents were heated to a temperature of 140 to 145°C. The ethylene bisstearylamide was dissolved in the liquid paraffin by heating to . Separately, a flask containing 158f of liquid paraffin was heated to 40°C in a water bath, and the heated ethylene bisstearylamide solution was gradually dropped into the flask.

While the solution was being added dropwise, the temperature of the contents of the flask was 70°C.
The dropping rate was adjusted to remain below °C. After the addition was completed, the contents of the flask were stirred for 5 hours at a temperature of 70"C ± 2°C, then allowed to cool to 25°C without stirring, and the contents were taken out of the flask and milled in a ball mill for 1 hour. A defoaming composition in which ethylene bis stearylamide was uniformly dispersed was obtained by time treatment. This composition consisted of 6% by weight of ethylene bis stearylamide and 94% by weight of liquid paraffin. Shape accounted for 100%.

[Defoaming performance test]

A liquid obtained by diluting the black liquor (pH 1, 2, 8, solids content 25.7% by weight) produced at the base pulp mill with pure water to a solids content of 10% by weight. −,
The solution was placed in a cylindrical container (for example, shaped like a graduated cylinder) with an inner diameter of 6.31 mm and maintained at a temperature of 75° C., and 9 ppm (by weight) of an antifoaming composition was added to the solution. Air is bubbled through the liquid from the bottom of the container at a rate of 1120°C per minute, and the time required from the start of ventilation until the volume of the bubbles reaches 100 g, 800 m/min, or 500 g/min. was measured, and those with a long time were judged to have excellent defoaming performance.

The results obtained are shown in Table 1.

From the results in Table 1 and above, β in ethylene bisstearylamide
When the content of β-type crystals is 80% or more, the defoaming performance is significantly improved, and when the content of β-type crystals is 95% or more by weight, β-type crystals become 100%.
It can be seen that the antifoaming performance is so excellent that there is virtually no discernible difference between the two.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an infrared absorption spectrum of ethylene bisstearylamide in which the β-type crystal form accounts for 100%. FIG. 2 is a diagram showing an extravascular absorption spectrum of ethylene bisstearylamide containing 5% by weight of α type crystal form and 95% by weight of β type crystal form. FIG. 8 is a diagram showing an infrared absorption spectrum of ethylene bisstearylamide containing 20% by weight of α type crystal and 80% by weight of β type crystal. Figure 4 shows α-type crystal form 5.
FIG. 2 is a diagram showing an infrared absorption spectrum of ethylene bisstearylamide with 0% by weight and 50% β-type crystal form. Fifth
The figure shows an infrared absorption spectrum of ethylene bis stearylamide in which the α-type crystal form accounts for 100%. 18-

Claims (1)

[Claims] 1. An antifoaming composition containing ethylene bis stearylamide and liquid hydrocarbon oil as main components, characterized in that 80% or more of the ethylene bis stearyl amide is composed of β-type ethylene bis stearyl amide. A defoaming composition. 2. By suspending ethylene bis stearylamide in liquid hydrocarbon oil and heating this suspension at about 45 to 90°C, the content of β-type ethylene his stearylamide in ethylene bis stearylamide is reduced to 80% or more. 1. A method for producing an antifoaming composition, which is characterized by adjusting the father exchange rate.