A suspension agent composition containing microcapsules, a preparation method thereof, and applications thereof

Abstract

The present invention relates to the daily chemical field, and discloses a suspending agent composition containing microcapsules, a preparation method thereof, and an application. The suspending agent composition comprises the following raw materials: hydrogenated castor oil 0.1-20%, polyether-type anionic surfactant 10-40%, microcapsule functional auxiliary 0.1-10%, and water. By selecting a polyether-type anionic surfactant as the emulsifier for hydrogenated castor oil and adopting a special two-step water addition process to prepare the suspending agent composition, the present invention can finally obtain a suspending agent composition in which the microcapsule functional auxiliary is uniformly dispersed in the system in advance. In the process of preparing the suspending agent, the microcapsule functional auxiliary is added, so that the scheme of copolymerizing with the HCO structuring agent in the later stage to form a new suspension system has more performance advantages in application.

Description

Technical Field

[0001] The present invention relates to the field of daily chemicals, and in particular to a suspension composition containing microcapsules, a preparation method and an application thereof. Background Art

[0002] As is well known, adding microcapsule fragrances to liquid detergents to achieve long-lasting fragrance is one of the most common technical means in the detergent field. However, existing microcapsule fragrances are generally made by encapsulating essential oils through an emulsion polymerization process, that is, the formed O / W emulsion droplets are finally polymerized into a microcapsule structure. Therefore, microcapsule fragrances can only be dispersed in an aqueous phase system. At the same time, during the application process, microcapsule fragrances have problems such as easy aggregation, easy sedimentation, and easy stratification. In order to ensure the application stability of microcapsule fragrances in daily chemical products, the existing technology is to add a certain amount of suspending agent to the formula. At present, common suspending agents mainly include the following three categories: microcrystalline cellulose, hydrogenated castor oil, and polymers. Among them, hydrogenated castor oil suspending agents have the lowest cost and the highest cost performance.

[0003] Hydrogenated castor oil (HCO), whose main component is 12-hydroxyoctadecanoic acid triglyceride, has been used in the cosmetics industry for many years as a rheology modifier and external structurant. Emulsifying hydrogenated castor oil with a surfactant and then crystallizing it under controlled conditions and processes to form an external structurant is a relatively mature technology, disclosed in numerous publications and patents. For example, CN104685043A discloses an external structuring system comprising crystallized triglycerides (hydrogenated castor oil), common surfactants and organic alcohols without amino functional groups, and the non-ionic surfactant accounts for a relatively high proportion in the emulsification system. A suspending agent is pre-generated under certain process conditions and then added to the liquid detergent; another example is CN109880700A discloses an external structuring system composition comprising an alkyl aryl sulfonic acid solubilizer, which is then added and applied to a detergent product, and the suspending agent emulsification system contains common LAS and / or common non-ionic surfactants; another example is CN113773916A discloses a preparation method for a structured liquid detergent that relies on the detergent's own surfactant components to generate a structuring system in situ, and the emulsification system is the surfactant system itself, and also contains anionic surfactants and non-ionic surfactants.

[0004] It can be seen that in the existing technologies, the process technical principles are generally unified. They all seek to emulsify HCO with a certain surfactant at high temperature, and then rapidly cool it at a certain rate to promote the crystallization and demulsification of HCO, and form a structurant at a certain crystallization temperature. Obviously, different types of surfactants used for emulsification have different emulsifying abilities for HCO at high temperature. At the same time, the stability of the emulsion formed at high temperature is not only related to the type of emulsifying surfactant, but also has a certain correlation with a series of process conditions such as temperature, homogenization degree (emulsion particle size), and cooling rate. Therefore, theoretically, there are differences in the crystallization temperatures of different HCO suspending agents prepared using different emulsification systems or different production processes.

[0005] In the actual production process, the differences in the crystallization temperatures of the suspending agents will significantly affect the convenience and production efficiency of actual production. For example, in the actual preparation process of the suspending agent, during the process of the system changing from an emulsion to a structurant, there is also a significant change in the rheological properties of the system, usually manifested as a sharp increase in the system viscosity and becoming paste-like, which will further affect the subsequent heat transfer efficiency during cooling and the stirring efficiency. In the publicly available patents, the process of CN109880700A performs heat preservation between 55 and 80 °C to make HCO form paste; another example is that the process disclosed in CN113773916A requires heat preservation for 0.5 to 3.5 h at the crystallization temperature, and it is clearly stated in the examples that crystallization can be carried out at 70 °C.

[0006] In summary, it can be seen that during the preparation of hydrogenated castor oil suspending agent, the emulsification system and production process control are very important. Although in the publicly available patents, the vast majority of surfactants can emulsify HCO and thus prepare specific related suspending agents. However, it is obvious that how to optimize the production process of the suspending agent, improve the application structural stability and production convenience of the suspending agent still has more practical application value, and it is also the difficulty in the development of suspending agents at present. Summary of the Invention

[0007] In order to solve the above technical problems, the present invention provides a suspending agent composition containing microcapsules, its preparation method and application. The present invention selects a polyether-type anionic surfactant as the hydrogenated castor oil emulsifier, and at the same time adopts a special two-step water addition process to prepare the suspending agent composition, and finally a suspending agent composition in which the microcapsule functional auxiliary is uniformly dispersed in the system can be obtained. The present invention adds the microcapsule functional auxiliary during the preparation process of the suspending agent, and the scheme of copolymerizing it with the HCO structurant to form a new suspension system in the later stage has more performance advantages in application.

[0008] The specific technical solution of the present invention is as follows:

[0009] In a first aspect, the present invention provides a suspension agent composition containing microcapsules, comprising raw materials in the following mass percentages: hydrogenated castor oil (HCO) 0.1 - 20%, polyether-type anionic surfactant 10 - 40%, microcapsule functional aid 0.1 - 10%, and water.

[0010] The suspension agent composition containing microcapsules of the present invention is formed by an emulsification-room temperature crystallization process, that is, hydrogenated castor oil first forms a stable O / W emulsion with a polyether-type anionic surfactant and water at a high temperature, and water is added and the temperature is lowered while maintaining the emulsion in an unbroken state. During this period, the emulsion always remains in a low-viscosity state, and the microcapsule functional aid can be uniformly dispersed in this state. Since HCO itself has a high melting point and is insoluble in water, it will slowly demulsify and crystallize during the cooling process. During this demulsification and crystallization process, hydrogenated castor oil can form a linear network structure, and the microcapsule functional aid can be uniformly dispersed in this network structure, thereby forming the final suspension agent composition.

[0011] As described in the background art part of this application, in the prior art, when preparing liquid detergents, the microcapsule functional aid and the suspension agent can usually only be added to the liquid detergent system in a separately added form, and it is difficult to pre-disperse the microcapsule functional aid in the suspension agent and then add it to the liquid detergent system. The reason is that in the preparation process of the existing suspension agent, when the emulsion demulsifies and crystallizes during cooling to transform into a suspension agent, it is accompanied by a significant change in the rheological properties of the system, usually manifested as a sharp increase in the system viscosity to become a paste-like state, which in turn affects the subsequent heat transfer efficiency and stirring efficiency during cooling, and makes it difficult for the microcapsule functional aid to be fully dispersed after being added.

[0012] Therefore, the present invention first starts from the raw material aspect to solve the above technical difficulties. The present invention discovers through research that a polyether-type anionic surfactant with a specific structure can better emulsify hydrogenated castor oil, and the emulsion has better high-temperature stability, enabling the system to remain in a low-viscosity emulsion state before adding the microcapsule functional aid under certain process conditions; after adding the microcapsule functional aid, it slowly demulsifies to form a suspension agent. Research shows that anionic surfactants have relatively stronger emulsifying ability for vegetable oils, while non-ionic surfactants have a relatively larger solubilization space and stronger solubilization ability because the proportion of EO head groups in their molecules is larger and there is a fence layer in the self-assembled structure. The polyether-type anionic surfactant used in the present invention has a part of the polyether component embedded in its molecular structure compared with conventional anionic surfactants such as LAS, SDS, fatty acid soaps, etc., which enables it to retain the advantages of anions as a whole while also having some non-ionic capabilities to a certain extent, which is beneficial to improving the emulsion stability during the emulsification process of the present invention.

[0013] In summary, the present invention can obtain a suspending agent composition in which microcapsule functional auxiliaries are uniformly dispersed in the system. When applying existing similar suspending agent products to make liquid detergents, the conventional batching process is to first add the HCO suspending agent to the liquid detergent, and after the added suspending agent is mechanically stirred for a long time until it is completely dispersed, the microcapsule functional auxiliaries are added by post-blending. The overly long mechanical stirring during this period is likely to cause a decline in the suspending ability of the suspending agent. However, in the present invention, through the optimization of the emulsifier, the system remains a low-viscosity O / W emulsion during the process, thus making it possible to compound the microcapsule functional auxiliaries and the suspending agent. If ordinary surfactants such as sulfonic acid and AEO are used as emulsifiers, although they can also emulsify HCO to form a structuring agent subsequently, the cream formation temperature of the relevant system emulsion is relatively high (about 70 - 80 °C). It is difficult to add the microcapsule functional auxiliaries at this temperature, which is likely to cause unnecessary volatilization loss of the functional auxiliaries (such as fragrances). In addition, due to the sharp increase in viscosity after the system creams, it is also difficult to directly post-blend the microcapsule functional auxiliaries to achieve effective uniform dispersion.

[0014] In subsequent tests of the present invention, it was found that adding microcapsule functional auxiliaries during the preparation of the suspending agent and copolymerizing them with the HCO structuring agent to form a new suspension system in the later stage has more performance advantages in application. This is mainly because the microsphere structure of the microcapsule functional auxiliaries also participates in the formation of the network structure in the suspending agent system, so it has better compatibility with the suspension system, relatively stronger mechanical shear resistance, and relatively better application stability.

[0015] Preferably, the suspending agent composition comprises the following raw materials in mass percentages: hydrogenated castor oil 3 - 15%, polyether-type anionic surfactant 15 - 30%, microcapsule functional auxiliaries 5 - 10%, water.

[0016] Preferably, the microcapsule functional auxiliaries refer to nano- or micro-microcapsules with a core-shell structure and water dispersibility formed by encapsulating a core material with a wall material. The wall material can be a water-soluble polymer material, including but not limited to one or more of sodium alginate, modified chitosan, modified cellulose, gelatin, cyclodextrin, gum arabic, modified starch, polyurethane, polyurea, melamine resin, and urea-formaldehyde resin. The core material can be an oil-soluble raw material, including but not limited to one or more of fragrances, plant essential oils, vitamins, colorants, anti-UV agents, emollient oils, and fats.

[0017] More preferably, the microcapsule functional auxiliaries are microcapsule fragrances.

[0018] Preferably, the polyether-type anionic surfactant is a carboxylate or sulfate surfactant containing a small amount of EO (ethylene oxide) and / or PO (propylene oxide) and / or BO (butylene oxide) in the molecule.

[0019] The polyether-type anionic surfactant used in the present invention incorporates a portion of polyether components in its molecular structure compared to conventional anionic surfactants such as LAS, SDS, fatty acid soaps, etc. This enables it to retain the advantages of anions while also possessing some non-ionic capabilities to a certain extent, which is beneficial for enhancing the emulsion stability during the emulsification process of the present invention.

[0020] Further preferably, the polyether-type anionic surfactant includes but is not limited to one or more of sodium lauryl polyether sulfate (AES), sodium lauryl polyether carboxylate (AEC), sodium sulfonated modified oil ethoxylate (SNS-80), and Extended surfactant of alcohol ether sulfate; among which, sodium lauryl polyether sulfate (AES) is most preferred.

[0021] In a second aspect, the present invention provides a method for preparing the above-mentioned suspending agent composition, comprising the following steps: S1: Dissolve the polyether-type anionic surfactant in water to form a 20 - 50 wt% solution, and stir well to make it evenly mixed. The concentration of the surfactant in the S1 solution has a certain influence on the suspending ability of the final suspending agent. Generally, the higher the surfactant concentration, the relatively more stable the formed emulsion, manifested as an increasing trend in the yield stress of the sample. However, when the surfactant concentration is too high, it is likely to cause a significant increase in the system viscosity, thus affecting the homogenization efficiency. On the contrary, if the surfactant concentration is low, the yield stress of the prepared suspending agent is small.

[0022] S2: Add hydrogenated castor oil and heat it above its melting point (about 85°C). After the hydrogenated castor oil is completely melted, perform homogenization to form an O / W emulsion.

[0023] S3: Rapidly cool down by adding water to the system, and maintain homogenization during this period to avoid emulsion demulsification, that is, the system will remain in an emulsion state.

[0024] S4: Continue to cool down to 45 - 55°C, stop homogenization, add the microcapsule functional additive, and slowly stir until the microcapsule functional additive is evenly dispersed.

[0025] S5: Continue to cool down to 30 - 40°C, make up for the evaporated water volume, and discharge the material. At this time, the appearance of the feed liquid is still a low-viscosity emulsion.

[0026] S6: At room temperature, the emulsion will slowly demulsify and crystallize to form a viscous suspending agent composition containing microcapsules.

[0027] In order to uniformly disperse the microcapsule functional auxiliary agent in the suspending agent in advance, in addition to optimizing the raw materials, the present invention also improves from the preparation process. The present invention adopts an innovative two-step water addition process. Among them: in the first step, relatively less water is added to increase the surfactant concentration in the emulsion system, so as to form an O / W emulsion at a relatively higher surfactant concentration, making the particle size of the emulsion droplets smaller and the high-temperature stability better; in the second step, a part of cold water is added. On the one hand, it can achieve rapid cooling of the system, and on the other hand, it can also dilute the formed emulsion droplets, increase the distance between the emulsion droplets, so that they can avoid rapid aggregation and demulsification to form a structuring agent under subsequent cooling and homogenization conditions, and to a certain extent, it also assists in the decrease of the crystallization temperature in the process.

[0028] Preferably, in S1, the pH of the solution is adjusted to 6-10.

[0029] Since the emulsification process is carried out in an aqueous solution at a high temperature, too acidic or too alkaline conditions may cause hydrolysis of the emulsifier or castor oil.

[0030] Preferably, in S2, the heating temperature is 88-95 °C.

[0031] Preferably, in S2, the homogenization time can be specifically determined according to the specific emulsification equipment and the particle size of the emulsion droplets. At the end of homogenization, the particle size of the emulsion droplets formed by HCO and the surfactant should be roughly uniform. The particle size of the emulsion droplets in the O / W emulsion is 10-100 μm, and more preferably 10-50 μm.

[0032] If the particle size of the emulsion droplets is too large or the particle sizes are not uniform, it indicates that the formed emulsion is not very stable, which may cause HCO to form a structuring agent in advance.

[0033] Preferably, in S3, the mass of the added water accounts for 5-70% of the total water amount, and the temperature of the added water is 20-50 °C; the temperature of the system after adding water is 60-80 °C.

[0034] If the temperature after adding water is too low, it will cause too rapid cooling, which may lead to too rapid crystallization rate of HCO, resulting in its premature demulsification to form a structuring agent; conversely, if the temperature after adding water is too high, resulting in too high water temperature, subsequent long-term cooling is still required, and the production efficiency is low.

[0035] Preferably, in S4 and S5, the cooling rate is 0.3-2.0 °C / min.

[0036] If the cooling is too fast, it may lead to too rapid crystallization rate of HCO, resulting in its premature demulsification to form a structuring agent.

[0037] Thirdly, the present invention provides the application of the above-mentioned suspending agent composition in liquid detergents.

[0038] Preferably, the suspending agent composition is added to the liquid detergent by post - blending method.

[0039] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0040] (1) In the molecular structure of the polyether - type anionic surfactant of the present invention, there are some polyether components in the block, which enables it to retain the advantages of anions as a whole while also having some non - ionic capabilities. The polyether - type anionic surfactant of the present invention is used to emulsify hydrogenated castor oil, which can ensure that the emulsification system remains a low - viscosity emulsion before adding the micro - capsule functional additive; after adding the micro - capsule functional additive, it slowly demulsifies to form a suspending agent.

[0041] (2) The present invention adopts a two - step water - adding process in the preparation of the suspending agent composition: First, less water is added in the first step to obtain a surfactant with a sufficiently high concentration, which can form a sufficiently stable O / W emulsion with HCO at high temperature; when subsequent water is added, the system quickly cools down. Due to the good stability of the emulsion, during the water - adding process, the emulsion droplets only show an increase in spacing and particle size microscopically, without changing the emulsion state, so that the system remains a low - viscosity emulsion, which makes it possible to directly add the micro - capsule functional additive to the subsequent system. As the temperature drops, the crystallized HCO microscopically causes the system to slowly demulsify, thus forming a linear network structure, and the micro - capsule functional additive can be evenly dispersed in this network structure to jointly form the final suspending agent composition.

[0042] (3) The present invention adds the micro - capsule functional additive during the preparation of the suspending agent, making the scheme of copolymerizing with the HCO structuring agent to form a new suspension system more performance - advantageous in application. The reason is that the micro - sphere structure of the micro - capsule functional additive also participates in the formation of the network structure in the suspending agent system, so it has better compatibility with the suspension system, relatively stronger mechanical shear resistance and relatively better application stability. Description of the Drawings

[0043] Figure 1 It is the tracking of the microscopic structure of the sample during the preparation of Example 1.

[0044] Figure 2 It is the change of the microscopic structure of the sample in Example 1 under a polarized light microscope (the left figure is the polarized light photo when it is slightly thickened at room temperature (slightly structured); the right figure is the polarized light photo after 12 h at room temperature (fully formed structure)).

[0045] Figure 3 It is the comparison chart of the anti - shear stability of the samples applied to the laundry detergent in Test Example 2, Comparative Examples 3 and 4, and Example 1. Detailed Embodiments

[0046] The following examples further describe the present invention, but the protection scope of the present invention is not limited thereto.

[0047] The professional terms and technical means used in the present invention have the same meaning as commonly understood by those skilled in the art. Without special instructions, various reagents, raw materials, equipment, etc. in the invention are common reagents, raw materials, and equipment understood by those skilled in the art and can be commercially obtained.

[0048] General Example

[0049] First, the present invention provides a suspension agent composition containing microcapsules, comprising the following raw materials in mass percentages: hydrogenated castor oil (HCO) 0.1 - 20%, polyether-type anionic surfactant 10 - 40%, microcapsule functional aid 0.1 - 10%, and water.

[0050] Preferably, the suspension agent composition comprises the following raw materials in mass percentages: hydrogenated castor oil 3 - 15%, polyether-type anionic surfactant 15 - 30%, microcapsule functional aid 5 - 10%, and water.

[0051] Preferably, the microcapsule functional aid refers to nano- or micron-sized microcapsules with a core-shell structure and water dispersibility formed by encapsulating a core material with a wall material. The wall material can be a water-soluble polymer material, including but not limited to one or more of sodium alginate, modified chitosan, modified cellulose, gelatin, cyclodextrin, gum arabic, modified starch, polyurethane, polyurea, melamine resin, and urea formaldehyde resin. The core material can be an oil-soluble raw material, including but not limited to one or more of essence, plant essential oil, vitamin, colorant, anti-UV agent, emollient oil, and grease.

[0052] More preferably, the microcapsule functional aid is microcapsule essence.

[0053] Preferably, the polyether-type anionic surfactant is a carboxylate or sulfate surfactant containing a small amount of EO (ethylene oxide) and / or PO (propylene oxide) and / or BO (butylene oxide) in the molecule; more preferably, the polyether-type anionic surfactant includes but is not limited to one or more of sodium lauryl polyether sulfate (AES), sodium lauryl polyether carboxylate (AEC), sodium sulfonated modified oil ethoxylate (SNS-80), and alcohol ether sulfate Extended surfactant. Most preferably, it is sodium lauryl polyether sulfate (AES).

[0054] Secondly, the present invention provides a preparation method of the above suspension agent composition, specifically comprising the following steps: S1: Dissolve the polyether-type anionic surfactant in water to form a 20 - 50 wt% solution, and stir well to make it evenly mixed.

[0055] Preferably, in S1, the pH of the solution is adjusted to 6 - 10.

[0056] S2: Add hydrogenated castor oil and heat it above its melting point (about 85 °C). After the hydrogenated castor oil is completely melted, homogenize it to form an O / W emulsion.

[0057] Preferably, in S2, the heating temperature is 88 - 95 °C.

[0058] Preferably, in S2, the homogenization time can be specifically determined according to the specific emulsification equipment and the particle size of the emulsion droplets. At the end of homogenization, the particle size of the emulsion droplets formed by HCO and the surfactant should be roughly uniform. The particle size of the emulsion droplets in the O / W emulsion is 10 - 100 μm, more preferably 10 - 50 μm.

[0059] S3: Add water to the system and quickly cool it down. During this process, maintain homogenization to avoid emulsion demulsification, that is, the system will remain in an emulsion state.

[0060] Preferably, in S3, the mass of the added water accounts for 5 - 70% of the water content, and the temperature of the added water is 20 - 50 °C; after adding water, the system temperature is 60 - 80 °C;

[0061] S4: Continue to cool down to 45 - 55 °C, stop homogenization, add microcapsule functional additives, and slowly stir until the microcapsule functional additives are evenly dispersed. S5: Continue to cool down to 30 - 40 °C, make up for the evaporated water volume, and discharge the material. At this time, the appearance of the material liquid is still a low-viscosity emulsion.

[0062] Preferably, in S4 and S5, external circulating water is used for cooling.

[0063] Preferably, in S4 and S5, the cooling rate is 0.3 - 2.0 °C / min.

[0064] S6: At room temperature, the emulsion will slowly demulsify and crystallize to form a viscous suspension agent composition containing microcapsules.

[0065] Finally, the present invention provides a liquid detergent containing the above suspension agent composition.

[0066] Preferably, the suspension agent composition is added to the liquid detergent by post-formulation.

[0067] Preferably, the content of the suspension agent composition in the liquid detergent is 0.1 - 10 wt%.

[0068] Specific examples and comparative examples

[0069] The present invention will be further described below in conjunction with specific cases. Unless otherwise specified, percentages are by weight (wt%) and temperatures are in °C. "Alkyl" is a substituted or unsubstituted saturated hydrocarbon group having from one to twenty-two carbon atoms arranged in a straight or branched chain. Unless otherwise specified, the alkyl group is unsubstituted.

[0070] Unless otherwise specified, the surfactant raw materials in the following examples and comparative examples of the present invention are in terms of pure form, and the information of the microcapsule auxiliaries used is as follows:

[0071] Flower and fruit fragrance microcapsule 1, with a content of 30%, and the wall material is melamine resin, which can be commercially purchased from Givaudan;

[0072] Rose essential oil microcapsule 2, with a content of 99%, and the wall material is modified starch, which can be commercially purchased from IFF;

[0073] UV-resistant agent microcapsule 3, with a content of 30%, and the wall material is polyurea, which can be commercially purchased from BASF.

[0074] Test Examples 1-3

[0075] Table 1: Laundry detergent base

[0076]

[0077]

[0078] The preparation method of the laundry detergent base in Table 1 above is as follows:

[0079] 1) Add the solvent (water), liquid alkali and surfactants (coconut oil fatty acid, LAS, AEO-9 and AES) in sequence, and stir until completely dissolved;

[0080] 2) Add a pH regulator (citric acid) to adjust the pH to 8;

[0081] 3) Add the small ingredients HP20, NaCl, and sodium citrate, and stir until the appearance is uniform.

[0082] Table 2: Test Examples 1, 2, 3

[0083]

[0084] The specific preparation methods of the detergents in the above Test Examples 1-3 are as follows:

[0085] Add 20 parts of LAS or AES or AEO-9 and 45 parts of deionized water to the reaction kettle, stir evenly to prepare a surfactant solution, and adjust the pH of the system to about 8.

[0086] Add 5 parts of solid HCO, start heating up, and heat to 92 °C to fully melt the HCO.

[0087] Start homogenization with a homogenization rate of 5000 rpm and a homogenization time of 10 min.

[0088] Maintain homogenization, add 30 parts of deionized water at 30 °C to the system. After adding water, the temperature of the system drops rapidly. Observe the state of the liquid material in the reaction kettle.

[0089] Start cooling with circulating water. The average cooling rate is about 0.8 °C / min. Observe the state of the emulsion in the reaction kettle. When the viscosity of the system surges, turn off homogenization and start stirring. Maintain cooling with circulating water until 40 °C to obtain the suspending agent.

[0090] Mix 5 parts of the suspending agent, 0.5 part of liquid essence, 0.25 part of microcapsules and 94.25 parts of laundry detergent base evenly to obtain the detergent.

[0091] The sample tests are as follows:

[0092] Yield stress test: Test with a Brookfield RST rheometer at a temperature of 25 °C and a shear rate scanning range of 0.01 - 100 s -1 , with data from 0.1 - 100 s -1 fitted with the Herschel - Bulkley model. The stability index R 2 should be greater than 0.999.

[0093] Stability test: Place the relevant samples under corresponding conditions and observe whether there are unstable phenomena such as stratification in the samples.

[0094] Table 3: Test process records and sample performance tests of suspending agents in Test Examples 1 - 3

[0095]

[0096] The tests show that suspending agents with yield stress were successfully prepared in Test Examples 1, 2, and 3 in a similar two - step water - adding process. However, from the results of the yield stress tests, there are significant differences in the performance and appearance of suspending agents in different emulsification systems. In addition, although the types of emulsifiers are different, emulsions can be formed through homogenization at a high - temperature range of 92 °C, which is also the key to successfully preparing the suspending agent. Surprisingly, there are significant differences in the actual performance during the cooling process for different emulsifiers. For example, in Test Example 1 and Test Example 3, using LAS and AEO - 9 as emulsifiers respectively, structurants were quickly formed by demulsification at about 72 °C and 65 °C after adding water. In the case of using AES as the emulsifier, the liquid material remained as a low - viscosity emulsion when cooled to 40 °C. Therefore, AES as an emulsifier provides the possibility for the uniform dispersion of microcapsule essence.

[0097] It was also found during the test that bubbles were inevitably generated during the homogenization of the samples, which affected the particle size statistics of the emulsion to a certain extent. Therefore, in order to more accurately understand the changes in the microstructure during this process, a small amount of Sudan III (oil-soluble dye) was added in Example 1 below, which would make the emulsion core show red to distinguish bubbles from the emulsion. Considering that when AES is used as an emulsifier, the liquid is of low viscosity throughout the cooling process, this makes it possible to add microcapsule essence in a compound manner.

[0098] Example 1

[0099] Table 4: Example 1

[0100]

[0101] The specific preparation method of the detergent in Example 1 above is as follows:

[0102] Add 20 parts of AES and 45 parts of deionized water to the reaction kettle, stir evenly to prepare a surfactant solution, and adjust the pH of the system to about 8.

[0103] Add 5 parts of solid HCO and the coloring Sudan III dye, and start heating up to 92 °C to fully melt the HCO.

[0104] Start homogenization, with a homogenization rate of 5000 rpm and a homogenization time of 10 min.

[0105] Maintain homogenization, add 25 parts of 40 °C deionized water to the system. After adding water, the temperature of the system drops rapidly, from 92 °C to about 78 °C.

[0106] Start cooling with circulating water, with an average cooling rate of about 0.8 °C / min. When the temperature drops to about 50 °C, add 5 parts of microcapsules, observe the state of the emulsion in the reaction kettle. When the viscosity of the system surges, turn off homogenization and start stirring. Maintain cooling with circulating water until 40 °C, make up for the volatilized water and stir well. The emulsion breaks and crystallizes at room temperature to obtain the final suspending agent.

[0107] Stir 5 parts of the suspending agent, 0.5 part of liquid essence and 94.5 parts of laundry detergent base evenly to obtain the detergent.

[0108] Comparing the sample stability test results of Example 1 and Test Example 2, it can be found that when the addition amounts of HCO and microcapsule essence are basically the same, the yield stress and freeze-thaw recovery stability of the samples in Example 1 are better than those in Test Example 2. This shows that when the microcapsules are added during the preparation stage of the suspending agent, the microsphere structure of the microcapsules may also participate in the formation of the suspension structure during the same period, thus bringing higher suspension force and stability under the same addition amount.

[0109] In addition, from Figure 1The results show that in Example 1, the process temperature decreased from 92°C to 70°C and then to 40°C, and the liquid material was in the form of an emulsion throughout. Only the particle size of the emulsion tended to increase, and the spacing between the emulsions increased to a certain extent after water addition, indicating that the emulsion in this system tended to develop towards instability. Since the HCO suspending agent structure could not be seen under a microscope after formation, its liquid crystal structure could be seen under a polarizing microscope. Figure 2 The left is a polarizing photo of the suspending agent sample liquid in Example 1 when it slightly changed from thin to thick. The small dot-like bright lights in the figure are liquid crystal structures. Figure 2 The right is a polarizing photo of the same sample at 12 hours at room temperature. The typical "cross flower" liquid crystal structure of the HCO suspending agent can be seen.

[0110] Examples 2 - 5

[0111] Table 5: Examples 2 - 5

[0112]

[0113] The specific preparation methods of the detergents in the above Examples 2 - 5 are as follows:

[0114] Dissolve the polyether-type anionic surfactant in a part of deionized water to prepare a surfactant solution with a relatively high concentration, stir well to make it evenly mixed, and adjust the pH of the system to the range of 6 - 10.

[0115] Heat the system to a temperature above the melting point of HCO (about 85°C), about 88°C, and add HCO; after HCO is completely melted, start homogenization. After homogenization, an O / W emulsion with a certain particle size distribution is formed in the system.

[0116] Add a certain proportion of cold water at 20°C to the system to rapidly cool the system. During this period, homogenization needs to be maintained all the time to avoid demulsification of the system, that is, the system will maintain an emulsion state. The water temperature after water addition is about 70°C.

[0117] After water addition, start to cool the system with circulating water at a rate of 0.3 - 2.0°C / min.

[0118] When the system temperature drops to about 50°C, turn off homogenization, then add microcapsules, and start stirring to make the microcapsules evenly dispersed in the emulsion system.

[0119] Continue to cool. After the temperature drops to 35°C, make up the evaporated water volume, and then the product can be discharged. At this time, the appearance of the liquid material is still a low-viscosity emulsion.

[0120] After discharging, at room temperature, the emulsion will slowly demulsify and finally crystallize into a viscous suspending agent containing microcapsules.

[0121] The types of emulsified anionic surfactants were expanded in Table 5. The results showed that similar polyether-type anionic surfactants such as sodium fatty alcohol polyether carboxylate (AEC), sodium modified oil ethoxylate sulfonate (SNS-80), and a small-scale trial alcohol ether sulfate extended surfactant provided by Lianhong were similar to common AES. Under the two-step water addition process conditions, the emulsions prepared had relatively good high-temperature stability, ensuring that the emulsions were homogeneous throughout the process of preparation.

[0122] Comparative Example 1, Examples 6-9 and Comparative Example 2

[0123] Table 6: Comparative Example 1 and Examples 6-9

[0124]

[0125] The preparation methods of the detergents in the above examples and comparative examples were generally the same as those in Examples 2-5.

[0126] From the test results in Table 6, it can be seen that the concentration of the surfactant in the first step in the present invention has a certain influence on the suspension ability of the final suspending agent. Generally, the higher the surfactant concentration, the relatively more stable the formed emulsion, which is reflected in an increasing trend of the yield stress of the sample. However, when the surfactant concentration is too high, it is easy to cause a significant increase in the system viscosity, thus affecting the homogenization efficiency. In Comparative Example 1, the surfactant concentration during the first-step emulsification was 15.5%, which was relatively low, so the yield stress of the prepared suspending agent was small; while in Comparative Example 2, the surfactant concentration during the first-step emulsification was 58.3%, which was too high, so the emulsion viscosity was too high during homogenization with HCO, resulting in a significant change in the viscosity of the feed liquid at 55°C. Overall, it can be seen that the concentration of the surfactant in the first step has a great influence on the emulsification process, and the preferred concentration of the surfactant can be in the range of 20-50%.

[0127] Furthermore, obviously, the water temperature for water replenishment in the water replenishment process of the present invention directly affects the temperature of the system after water replenishment. To prevent the system from cooling too quickly during water replenishment, resulting in rapid demulsification of the emulsion, the temperature of the system after water replenishment is preferably in the range of 60-80°C. During actual operation, the temperature of water replenishment can be adjusted according to the amount of water replenished and the target temperature after water replenishment. Generally, deionized water at 20-50°C is preferred.

[0128] Comparative Examples 3-4

[0129] The preparation scheme of Comparative Example 3: Prepare a suspending agent according to the ratio of Test Example 2. After the structure is formed, add 5% of the floral microcapsule fragrance 1 and disperse it into a suspending agent under mechanical stirring. Add it to the liquid laundry base material at an addition amount of 5% as the final sample. Among them, the actual addition amount of the floral microcapsule fragrance 1 was also about 0.25%.

[0130] Preparation scheme of Comparative Example 4: The commercially available suspending agent CHE-100 (Hecuang Company) was applied and added to the laundry detergent base material in a post-mixing manner, and then 0.25% of the floral and fruity microcapsule fragrance 1 was added to form the final sample.

[0131] Figure 3 For the comparative chart of the anti-shear stability of the samples of Test Example 2, Comparative Example 3, 4 and Example 1 applied to laundry detergent, it examines the shear resistance of the laundry detergent samples finally formed by adding microcapsule fragrances in different ways. The test shows that under high-speed shearing, the structures of the structuring agents in the laundry detergent are all damaged to a certain extent, manifested as a decrease in the yield stress. However, after homogenization at 5000 rpm or 10000 rpm for the laundry detergent samples of Test Example 2, Comparative Example 3 and Comparative Example 4, the yield stress of the samples decreased significantly, while for Example 1, although the yield stress decreased after shearing at 5000 rpm or 10000 rpm, the degree of decrease was significantly better than other schemes.

[0132] Meanwhile, Figure 3 also gives the microscopic photos of the microcapsule dispersion of the initial laundry detergent sample. The results show that the method of adding microcapsules (Comparative Example 3) to the structuring agent is likely to cause microcapsule aggregation and uneven dispersion; while for the methods of post-mixing microcapsule fragrance and suspending agent and the scheme of the present invention (Test Example 2, Comparative Example 4, Example 1), the microcapsules ( Figure 3 the microsphere structures therein) can be evenly dispersed.

[0133] Unless otherwise specified, the raw materials and equipment used in the present invention are all common raw materials and equipment in the art; unless otherwise specified, the methods used in the present invention are all conventional methods in the art.

[0134] The above are only the preferred embodiments of the present invention, and do not impose any limitations on the present invention. Any simple modifications, changes and equivalent transformations made to the above embodiments according to the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A suspending agent composition containing microcapsules, characterized in that Raw materials comprising the following mass percentages: Hydrogenated castor oil 0.1 - 20%, Polyether anionic surfactant 10 - 40%, Microcapsule functional aid 0.1 - 10%, Water; The hydrogenated castor oil forms an O / W emulsion with a polyether anionic surfactant concentration of 20 - 50 wt% with the polyether anionic surfactant and water at a temperature above its melting point; the microcapsule functional aid is added and uniformly dispersed during the process of replenishing water and cooling while maintaining the O / W emulsion in an unbroken state.

2. The suspending agent composition according to claim 1, characterized in that Raw materials comprising the following mass percentages: Hydrogenated castor oil 3 - 15%, Polyether anionic surfactant 15 - 30%, Microcapsule functional aid 5 - 10%, Water.

3. The suspending agent composition according to claim 1 or 2, characterized in that: The wall material of the microcapsule functional aid is a water-soluble polymer material, and the core material is an oil-soluble functional raw material.

4. The suspending agent composition according to claim 1 or 2, characterized in that: The polyether anionic surfactant is a carboxylate or sulfate surfactant containing EO and / or PO and / or BO in the molecule.

5. The suspending agent composition according to claim 4, characterized in that: The polyether anionic surfactant includes one or more of sodium lauryl polyether sulfate, sodium lauryl polyether carboxylate, sodium modified oil ethoxylate sulfonate, and Extended alcohol ether sulfate surfactant.

6. A method for preparing the suspending agent composition according to any one of claims 1-5, characterized in that Comprising the following steps: S1: Dissolve the polyether anionic surfactant in water to form a solution with a concentration of 20 - 50 wt%; S2: Add hydrogenated castor oil and heat to a temperature above its melting point, melt and homogenize to form an O / W emulsion; S3: Add water to the system to cool down, and maintain homogenization during this period to avoid emulsion breaking; S4: Continue to cool down to 45 - 55 °C, stop homogenization, and add the microcapsule functional aid to disperse evenly; S5: Continue to cool down to 30 - 40 °C, and make up for the evaporated water volume; S6: At room temperature, the emulsion breaks and crystallizes to form a suspending agent composition containing microcapsules.

7. The preparation method according to claim 6, characterized in that: In S1, adjust the pH of the solution to 6 - 10.

8. The preparation method according to claim 6, characterized in that: In S2, the heating temperature is 88 - 95 °C.

9. The preparation method according to claim 6, characterized in that: In S2, the emulsion droplet diameter in the O / W emulsion is 10 - 100 μm.

10. The preparation method according to claim 6, characterized in that: In S3, the mass of the added water accounts for 5 - 70% of the water volume, and the temperature of the added water is 20 - 50 °C.

11. The preparation method according to claim 10, characterized in that: In S3, the temperature of the system after adding water is 60 - 80 °C.

12. The preparation method according to claim 6, characterized in that: In S4 and S5, the cooling rate is 0.3 - 2.0 °C / min.

13. Use of the suspending agent composition according to any one of claims 1 - 5 or the suspending agent composition obtained by the preparation method according to any one of claims 6 - 12 in a liquid detergent.

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