JP5779782B2 - Manufacturing method and reuse agent of regenerated cleaning liquid. - Google Patents

Description

  The present invention relates to the production of a regenerated cleaning solution that uses a reuse agent for phase-separating a cleaning solution containing an oil component that has been used for cleaning (also referred to herein as an “aging cleaning solution”) into an aqueous phase and an oily phase. The present invention relates to a method and its reuse agent.

  Conventionally, a nonionic surfactant is contained in the cleaning liquid, heated to a cloud point or higher of the nonionic surfactant in the state of becoming an aging cleaning liquid, and the micelle composed of the surfactant and the oil is removed as the main solvent of the cleaning liquid. A method for separating oil from water and facilitating oil recovery has been performed (for example, Patent Documents 1 and 2).

JP 2001-131582 A JP 2007-39724 A

  However, in the method as described above, the nonionic surfactant has a function for recovering the oil contained in the liquid when it becomes an aging cleaning liquid while taking part of the cleaning function in the cleaning liquid. Also need to have. For this reason, it is difficult to increase the degree of freedom in designing the composition of the cleaning liquid, and it has not always been easy to apply it as a cleaning agent for cleaning machined parts and the like having a high degree of dirt. Further, in order to recover the oil contained in the aging cleaning liquid, it has been necessary to dilute the aging cleaning liquid or heat it to a particularly high temperature.

  Furthermore, in the above cleaning liquid, oil components that interact with the nonionic surfactant to form micelles are mainly recovered, and the aging cleaning liquid contains oil components that have little interaction with the nonionic surfactant. In such a case, there is a problem that such oil cannot be sufficiently recovered.

  For this reason, with the above cleaning liquid, when cleaning an object to be cleaned that has a high degree of oil contamination, such as cleaning of machined parts, particularly parts obtained by secondary processing such as cutting, an aging cleaning liquid The cleaning liquid after recovering the oil content still contains a large amount of oil, which is not satisfactory from the viewpoint of regeneration of the cleaning liquid.

  The present invention improves the present situation, and provides a method for producing a regenerated washing liquid having excellent washing ability, a reuse agent for use in the production method, and a method for removing oil from an aging washing liquid using the reuse agent. Objective.

  As a basic idea for solving the above problems, the inventors of the present invention do not impart a function of oil recovery to a cleaning liquid, but a composition for phase-separating an aging cleaning liquid into an aqueous phase and an oily phase. A certain reuse agent was used. By using such a reuse agent, it becomes unnecessary to provide the cleaning liquid with a special oil content recovery function, so that the degree of freedom in designing the components of the cleaning liquid is increased. Moreover, a cleaning liquid that does not have such an oil content recovery function can be used as a raw material for a regenerated cleaning liquid by adding a reuse agent.

  Further, by using the reuse agent independently of the cleaning agent, the nonionic surfactant contained in the reuse agent can be a component particularly suitable for phase separation. From the standpoint of increasing the degree of phase separation, it is preferable to use a substance having high lipophilicity, that is, a low HLB value as a component of the reuse agent. However, if such a highly lipophilic substance is used as a component of the reuse agent, it becomes clear that the component cannot be sufficiently diffused into the aging cleaning liquid as it is, and phase separation may not be performed properly. It was. As a result of further investigation, by coexisting an ionic surfactant as a component of the reuse agent, a highly lipophilic nonionic surfactant can be easily diffused into the aging cleaning liquid, and phase separation of the aging cleaning liquid I got the knowledge that the degree of increase.

The present invention completed based on this finding is as follows.
(1) A reuse agent containing a polyether type nonionic surfactant (A) and an ionic surfactant (B) having an HLB value based on the Davis method of 3.72 or more and 4.23 or less, and washing Mixing step of mixing with an aging cleaning liquid that is an oil-containing cleaning liquid and heating the mixture to a cloud point or higher of the nonionic surfactant (A) to obtain the mixture. A phase separation step of phase-separating into an oily phase and an aqueous phase, a recovery step of collecting the aqueous phase to obtain an aqueous composition, and a regeneration step of obtaining a regenerated cleaning liquid using at least one of the aqueous composition as a raw material The nonionic surfactant (A) is a compound represented by the following general formula (i), and the ionic surfactant (B) is composed of a cationic surfactant. A method for producing a regenerated cleaning solution.
R-O-[(PO) m / (EO) n] -H (i)
(In the formula, R is a linear or branched alkyl group or alkenyl group having 20 or less carbon atoms, PO is an oxypropylene group, EO is an oxyethylene group, m is an average addition mole number of PO, and n is an average addition of EO. Represents the number of moles, and m and n are non-negative integers satisfying m + n ≦ 8.)

(2) The production method according to (1), wherein the content of the ionic surfactant (B) in the regenerated cleaning liquid is 0.003 molar equivalent / L or less.

(3) The production method according to (2) , wherein the nonionic surfactant (A) has an average added mole number m of PO of 4 or less and an average added mole number n of EO of 6 or less.

(4) A reuse agent used for carrying out the production method described in any one of (1) to (3) above , wherein the nonionic surfactant (A) and the ionic interface A reuse agent comprising an active agent (B) and a polar solvent having solubility thereto.

(5) From the mixing step to the recovery step described in (1) above, using the reuse agent used for carrying out the production method described in any one of (1) to (3) above. A method for removing oil from an aging cleaning liquid, which is a cleaning liquid that is subjected to cleaning and contains oil.

  According to the present invention, it is possible to obtain a regenerated cleaning liquid that efficiently removes oil from an aging cleaning liquid and has excellent cleaning power.

1. Reuse Agent A reuse agent according to an embodiment of the present invention is a polyether type nonionic resin having an HLB value based on the Davis method (hereinafter abbreviated as “HLB value”) of 3.72 to 4.64 . A surfactant (A) and an ionic surfactant (B) are contained.

(1) Nonionic surfactant (A)
The nonionic surfactant (A) according to this embodiment has a polyether type structure. When a molecule having such a structure is heated to a cloud point or higher, the degree of interaction with water molecules decreases, the hydrophilicity in the molecules decreases, and the solubility in a liquid composed of an aqueous solvent decreases. . The reuse agent which concerns on this embodiment isolate | separates an aging washing | cleaning liquid into an oil-based phase and an aqueous phase using this characteristic. Hereinafter, the function of performing phase separation based on the nonionic surfactant (A) in the reuse agent is referred to as “phase separation function”.

  Therefore, the lower the HLB value of the nonionic surfactant (A), the lower the cloud point and the higher the ability to phase separate the aging cleaning liquid. However, when the HLB value of the nonionic surfactant (A) is excessively low, the hydrophilicity in the nonionic surfactant (A) becomes excessively low, and the polar solvent is a solvent for the aging cleaning liquid. Typically, the interaction with water (hereinafter, this solvent is referred to as “cleaning liquid solvent”) is reduced, and as a result, it cannot be appropriately diffused into the cleaning agent. Therefore, there is a lower limit for the HLB value of the nonionic surfactant (A).

  Since the reuse agent according to this embodiment has an ionic surfactant (B) as described in detail later, the nonionic surfactant (A) in the reuse agent is an ion contained in the reuse agent. It is in the state which interacted with the surface active agent (B). Although the details of this interaction are unknown, the affinity of the nonionic surfactant (A) for the solvent of the aging cleaning solution is improved by interacting with the ionic surfactant (B).

  Hereinafter, as an example of the interaction, an ionic surfactant (B) forms micelles, and the case where the nonionic surfactant (A) is included in the micelles, The nonionic surfactant (A) will be described. Note that the nonionic surfactant (A) in a state of interacting with the ionic surfactant (B) is referred to as a soluble nonionic surfactant (A ′).

  The soluble nonionic surfactant (A ′) in the aging cleaning liquid has a high affinity for water in the aging cleaning liquid because the ionic surfactant (B) forms micelles, and thus the aging It can be easily diffused into the cleaning liquid.

  Here, the general aging cleaning liquid often contains an ionic oil based on the saponification of the oil by an alkali component, an ionic surfactant, or the like. For this reason, the ionic surfactant (B) in the state of interacting with the nonionic surfactant (A) also interacts with such ionic substances in the aging cleaning solution. As a result, the degree of interaction between the nonionic surfactant (A) and the ionic surfactant (B) in the soluble nonionic surfactant (A ′) is reduced, and the nonionic surfactant is reduced. (A) can interact directly with the oil in the aging cleaning solution.

  When the aging cleaning liquid is heated to a cloud point or higher of the nonionic surfactant (A) in this state, the nonionic surfactant (A) has high lipophilicity as a whole molecule, and the nonionic surfactant ( An oily layer is formed together with the oil component interacting with A) and other lipophilic substances. As a result, phase separation between the aqueous phase and the oily phase occurs.

From the viewpoint of stably implementing the method for producing a regenerated cleaning liquid including the above phase separation step, the HLB value of the nonionic surfactant (A) according to this embodiment is set to 3.72 or more and 4.64 or less .

  The specific structure of the nonionic surfactant (A) is not particularly limited as long as it has a polyether structure and is in the above HLB value range as a molecule. From the viewpoint of easily satisfying the above HLB value, preferred specific examples of the nonionic surfactant (A) include compounds represented by the following general formula (i).

R-O-[(PO) _m / (EO) _n ] -H (i)
In the above formula (i), R is a linear or branched alkyl group or alkenyl group having 20 or less carbon atoms, PO is an oxypropylene group, EO is an oxyethylene group, m is the average added mole number of PO, and n is EO. In which m and n are non-negative integers and satisfy m + n ≦ 8. The average added mole number m of PO is preferably 4 or less, and more preferably 2 or less. On the other hand, the average added mole number n of EO is preferably 6 or less, and more preferably 4 or less.

  The content of the nonionic surfactant (A) in the reuse agent is not particularly limited. The content of the nonionic surfactant (A) may be high from the viewpoints of reducing the footprint when storing as a reuse agent and reducing the amount of the reuse agent as an reuse agent in the aging cleaning liquid. However, if it is excessively high, the stability during storage and the handleability during addition may be reduced, so it is preferable to set it to about 500 g / L or more and 1000 g / L or less.

(2) Ionic surfactant (B)
The ionic surfactant (B) contained in the reuse agent according to the present embodiment interacts with the nonionic surfactant (A) at the lipophilic group portion, and at the hydrophilic group portion. The specific structure is not particularly limited as long as it can interact with the cleaning solution solvent. The hydrophilic group may be a cationic group or an anionic group.

  However, in many cases, the aging cleaning liquid contains a surfactant, and since the type thereof is generally anionic, when the ionic surfactant (B) is cationic, the micelles in the aging cleaning liquid are used. Can function as a breaker. Moreover, when the oil component in an aging washing | cleaning liquid is contained in the state (emulsification) of a fatty acid ion, such an emulsified oil component can also be efficiently contained in an oily layer. For this reason, the separation performance of the reuse agent is improved, and the cleanliness of the liquid contained in the aqueous phase is increased. This contributes to improving the cleaning power of the regenerated cleaning liquid.

  The specific structure when the ionic surfactant (B) is cationic, that is, when it is a cationic surfactant, is not particularly limited. Specific examples of the cationic surfactant include di-long-chain alkyldimethyl quaternary ammonium ions, long-chain alkyldimethyl quaternary ammonium ions, alkylammonium ions, and quaternary ammonium ions. These are usually blended in the form of hydrochloride. The ionic surfactant (B) may be composed of one kind or a plurality of kinds.

  Among these, long-chain alkyldimethyl quaternary ammonium ions are preferable because of excellent supply stability and a good balance between quality and cost.

  The content of the ionic surfactant (B) is not limited as long as the phase separation function of the reuse agent is within an appropriate range. When the content of the ionic surfactant (B) is excessively large or excessively small, there is a concern that the phase separation function of the reuse agent tends to decrease. Usually, the content of the ionic surfactant (B) is preferably 0.001 molar equivalent / L or more, more preferably 0.002 molar equivalent / L or more, and 0.003 molar equivalent / L. More preferably, the above is used.

  When the ionic surfactant (B) is cationic and the regenerated cleaning liquid contains an anionic surfactant, the content of the ionic surfactant (B) contained in the regenerated cleaning liquid is as follows. If it is about 0.003 molar equivalent / L or more, there is a concern that the function of the anionic surfactant in the regenerated cleaning liquid may be impaired, so it is preferable to pay attention to this point. Specifically, the content of the cationic ionic surfactant (B) in the reuse agent is preferably 0.02 molar equivalent / L or less, and 0.015 molar equivalent / L or less. Is more preferable, and it is still more preferable that it is 0.01 molar equivalent / L or less.

(3) Solvent The solvent of the reuse agent according to this embodiment is not particularly limited, but it is a polar solvent having solubility in the nonionic surfactant (A) and the ionic surfactant (B). It is preferable from the viewpoint of appropriately interacting in the reuse agent, and more preferably a protic polar solvent. A typical example of such a solvent is water, and other alcohols are exemplified. However, since a solvent having an organic group such as alcohol may lower the phase separation function of the reuse agent, the solvent of the reuse agent according to this embodiment is preferably water.

(4) Other components The reuse agent which concerns on this embodiment may contain components other than said nonionic surfactant (A) and ionic surfactant (B). Examples of such components include neutral inorganic salts such as sodium sulfate, organic sequestering agents such as chelating agents, sequestering agents such as zeolite, antifoaming agents such as silicone oil, and corrosion inhibitors such as benzotriazole. Illustrated. These contents are not limited. It is optional as long as the functions of the nonionic surfactant (A) and the ionic surfactant (B) are not inhibited.

(5) Preparation method of reuse agent The preparation method of the reuse agent which concerns on this embodiment is not specifically limited. Of the components contained in the reuse agent, at least the nonionic surfactant (A) and the ionic surfactant (B) may be dissolved in the solvent. The technique for doing so is arbitrary, and the solvent may be heated to increase the solubility of these components. When the reuse agent includes other components and the other components contained include components having low solubility or insoluble components, these components may be dispersed in the reuse agent in a solid state.

  When the reuse agent contains other components, it is preferable that the nonionic surfactant (A) and the ionic surfactant (B) interact in the reuse agent as described above. It is preferable to prepare a composition containing only the components separately and mix it with other components. When adjusting in a single tank, the nonionic surfactant (A) and the ionic surfactant (B) should be added first so that these interactions take place preferentially. Is preferred.

2. Manufacturing method of regenerated cleaning liquid The manufacturing method of the regenerating cleaning liquid according to the present embodiment includes a mixing step of mixing a reuse agent and an aging cleaning liquid to obtain a mixture, and the mixture is more than the cloud point of the nonionic surfactant (A) A phase separation step in which the mixture is phase-separated into an oily phase and an aqueous phase, a recovery step in which the aqueous phase is recovered to obtain an aqueous composition, A regeneration step to obtain.

  The details of the mixing step are not limited. As described above, the reuse agent also contains the ionic surfactant (B) so that the contained nonionic surfactant (A) can be sufficiently diffused into the aging cleaning liquid. There is no particular need for the work of vigorously stirring or diluting. The reuse agent may be appropriately stirred so that diffusion into the aging cleaning solution is appropriate. If necessary, slight heating may be performed up to about 40 ° C. in order to promote the interaction between the oil in the aging cleaning liquid and the components in the reuse agent.

  Details of the phase separation step are as described above. In addition, when heating more than the cloud point of a nonionic surfactant (A), the specific temperature of a cloud point is each of a nonionic surfactant (A) and an ionic surfactant (B). Since it varies depending on the type and content, and also the type and content of other components, it is not deterministic. When the ionic surfactant (B) is cationic, the cloud point may tend to decrease. Moreover, although the time for completing a phase-separation process is arbitrary, it is preferable to leave the heated mixture in that state for about several hours from a viewpoint of stabilizing phase-separation.

  The method for recovering the aqueous phase in the recovery step is arbitrary. Usually, operations such as extracting the aqueous phase from the bottom of the container and pouring out the oily phase at the top of the container are performed.

  The aqueous composition comprising the recovered aqueous phase becomes at least one of the raw materials for the regenerated cleaning liquid. The aqueous composition may be used as it is as a regenerated cleaning solution, or an alkali component or a surfactant may be added as necessary. The addition amount of these additive components should be set as appropriate.

  The regenerated cleaning liquid thus obtained has a small residual amount of oil contained in the aging cleaning liquid, and thus can be used as a cleaning agent for cleaning a cleaning object such as a machined part having a high degree of contamination. . Specific examples of such objects to be cleaned include primary processed products such as plates, rods and wires made of metal materials, and secondary processed products such as screws and bolts.

3. Oil Removal Method An oil removal method including the mixing step to the recovery step in the above method for producing a regenerated cleaning liquid may be carried out.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further more concretely, the scope of the present invention is not limited to these Examples etc.

Example 1
(1) Preparation of simulated aging cleaning solution Sodium hydroxide 8 g / L, sodium silicate pentahydrate 3 g / L, and lauryl alcohol ether EO adduct (manufactured by Sanyo Chemical Industries, Ltd., Emalmine NL-80) 3 g / L 495 ml of a washing solution containing water as a solvent was prepared in a 1 L beaker.

  In a state where the temperature of the cleaning liquid was maintained at 50 ° C., 10 ml / L of mineral oil (Hechel Vitoria Oil 100 manufactured by Showa Shell Co., Ltd.) was added, and the cleaning liquid after the addition was stirred with a stirrer for 2 hours. 500 ml of the liquid thus obtained was used as a simulated aging cleaning solution imitating an aging cleaning solution.

(2) Evaluation of separation function Nonionic surfactant (A) shown in Table 1 (compound represented by the above formula (i), wherein R, m and n are shown in Table 1. )) And a cationic surfactant as the ionic surfactant (B) were mixed to prepare a reuse agent .
5 ml of each prepared reuse agent was added to 500 ml of the above simulated aging cleaning solution. In addition, Test No. In 1, no reuse agent was added. As a result, the contents of the nonionic surfactant (A) and the ionic surfactant (B) in the obtained liquid were as shown in Table 1.
The simulated aging cleaning liquid to which the reuse agent was added (test No. 1 is only the simulated aging cleaning liquid) was stirred with a glass rod for 30 seconds, heated to 60 ° C., and left in that state for 2 hours. The liquid after standing was phase-separated into an oily phase and an aqueous phase. The oily phase in this liquid was removed by suction using a syringe, and an oil mat was placed on the liquid after suction removal, and the oily phase remaining in the liquid was removed by adsorption.
In this way, 230 ml of the liquid consisting only of the aqueous phase with the oily phase removed was placed in a turbidity measuring graduated cylinder having a capacity of 250 ml (having a cross pattern on the bottom and draining on the bottom). After confirming that the flow of the liquid in the graduated cylinder has subsided, while observing the liquid from the upper part of the graduated cylinder, the liquid was drained from the drain of the graduated cylinder to reduce the amount of liquid in the graduated cylinder. . When the cross pattern provided on the bottom of the graduated cylinder could be visually confirmed through the liquid, the drainage was stopped, and the height of the liquid level at that time in the graduated cylinder was measured.

The separation performance was evaluated according to the following criteria based on the measured liquid level.
Good (excellent in separation function, “◎” in Table 1): 7 cm or more Possible (having separation function necessary as a reuse agent, “◯” in Table 1): When not less than 5 cm and less than 7 cm Impossible: ( Does not have the separation function required as a reuse agent, “×” in Table 1): less than 5 cm

(3) Evaluation of the cleaning function of the regenerated cleaning liquid The entire amount of the liquid consisting of the above aqueous phase was extracted from the graduated cylinder, and lauryl alcohol ether EO adduct (Sanyo Chemical Industries, Emalmin NL-80) ) Content was 3 g / L to obtain a regenerated cleaning solution. When the content of the ionic surfactant (B) in the regenerated cleaning solution was measured, it was below the detection limit (1.0 × 10 ⁻⁶ molar equivalent / L).
The above-mentioned mineral oil was applied to both main surfaces (main surface shape: 10 cm × 5 cm) of the SPCC-SD steel plate at 0.5 ml / cm ² and left in that state for 12 hours.

The steel plate after standing for 12 hours was immersed in the regenerated cleaning liquid whose liquid temperature was maintained at 50 ° C. for 10 seconds. Thereafter, the steel sheet was taken out from the regenerated cleaning solution, washed thoroughly with water, and the water wetted part after water washing was regarded as the part where the mineral oil was washed, and the water wetted area on the main surface of the steel sheet was measured. The ratio of the wetted area to the area of the main surface was determined as the wetted area ratio, and the cleaning function of the regenerated cleaning liquid was evaluated according to the following criteria using the wetted area ratio.
Good (Excellent cleaning function, “、” in Table 1): 90% or more Possible (having cleaning function, “◯” in Table 1): 80% or more and less than 90% Not possible: (Not having cleaning function, "X" in Table 1): less than 80%

  The evaluation results are shown in Table 1.

Claims (5)

A reuse agent containing a polyether type nonionic surfactant (A) and an ionic surfactant (B) having an HLB value of 3.72 or more and 4.23 or less based on the Davis method, and used for washing A mixing step of obtaining a mixture by mixing with an aging cleaning liquid which is a cleaning liquid containing oil,
A phase separation step in which the mixture is heated above the cloud point of the nonionic surfactant (A) to phase-separate the mixture into an oily phase and an aqueous phase;
A recovery step of recovering the aqueous phase to obtain an aqueous composition, and a regeneration step of obtaining a regenerated cleaning liquid using at least one of the aqueous composition as a raw material ,
The nonionic surfactant (A) is a compound represented by the following general formula (i):
A method for producing a regenerated cleaning liquid, wherein the ionic surfactant (B) comprises a cationic surfactant .
R-O-[(PO) m / (EO) n] -H (i)
(In the formula, R is a linear or branched alkyl group or alkenyl group having 20 or less carbon atoms, PO is an oxypropylene group, EO is an oxyethylene group, m is an average addition mole number of PO, and n is an average addition of EO. Represents the number of moles, and m and n are non-negative integers satisfying m + n ≦ 8.) The process according to claim 1 content is 0.003 molar equivalents / L of the ionic surfactant of the reproduction in the cleaning solution (B). The said nonionic surfactant (A) is a manufacturing method of Claim 2 whose average added mole number m of PO is 4 or less, and whose average added mole number n of EO is 6 or less. It is a reuse agent used in order to implement the manufacturing method as described in any one of Claim 1 to 3 , Comprising: The said nonionic surfactant (A) and the said ionic surfactant (B), And a reuse agent characterized by containing a polar solvent having solubility in these. It carries out from the mixing process described in Claim 1 to the collection | recovery process using the reuse agent used in order to implement the manufacturing method described in any one of Claim 1 to 3. A method of removing oil from an aging cleaning liquid that is a cleaning liquid that is subjected to cleaning and contains oil.