Microcapsule-containing suspending agent composition as well as preparation method and application thereof

Abstract

The invention relates to the field of daily chemicals, and discloses a microcapsule-containing suspending agent composition as well as a preparation method and application thereof. The suspending agent composition is prepared from the following raw materials: 0.1 to 20 percent of hydrogenated castor oil, 10 to 40 percent of polyether type anionic surfactant, 0.1 to 10 percent of microcapsule functional additive and water. According to the invention, a polyether type anionic surfactant is selected as a hydrogenated castor oil emulsifier, and meanwhile, a special two-step water adding process is adopted to prepare the suspending agent composition, so that the suspending agent composition in which a microcapsule functional additive is uniformly dispersed in a system in advance can be finally obtained. In the preparation process of the suspending agent, the microcapsule functional additive is added, so that the scheme that the microcapsule functional additive is copolymerized with the HCO structuring agent in the later stage to form a new suspension system has better performance advantages in application.

Description

Technical Field

[0001] The 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 we all know, adding microcapsule flavors to achieve long-lasting fragrance in liquid detergents is one of the most common technical means in the detergent field. However, existing microcapsule flavors 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, so the microcapsule flavors can only be dispersed in an aqueous phase system. At the same time, during the application process, the microcapsule flavors have problems such as easy aggregation, easy sedimentation, and easy stratification. In order to ensure the application stability of microcapsule flavors 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] The main component of hydrogenated castor oil (HCO) is 12-hydroxy-octadecanoic acid triglyceride, which has been used as a rheological property modifier and external structurant in the field of daily chemicals for many years. In the existing technology, emulsifying hydrogenated castor oil with a surfactant and then controlling certain conditions and processes to make it crystallize to form an external structurant is a relatively mature technical solution, and many documents or patents have been disclosed. 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 proportion of non-ionic surfactants in the emulsification system is relatively high. The suspending agent is pre-generated under certain process conditions and then added to the liquid detergent; for another example, CN109880700A discloses an external structuring system composition comprising an alkyl aryl sulfonic acid solubilizer, which is then added and applied in a detergent product, and the suspending agent emulsification system contains common LAS and / or common non-ionic surfactants; for another example, CN113773916A discloses a method for preparing 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 contains both anionic surfactants and non-ionic surfactants.

[0004] It can be seen that in the existing technology, the process technology principles are roughly unified, all of which seek to emulsify HCO at high temperature with a certain surfactant, and then quickly cool down at a certain rate to promote HCO crystallization and demulsification, and form a structurant at a certain crystallization temperature. Obviously, the types of surfactants used for emulsification are different, and the emulsification ability of HCO at high temperature is also different. At the same time, the stability of the emulsion formed at high temperature is not only related to the type of emulsified surfactant, but also has a certain correlation with a series of process conditions such as temperature, homogeneity (emulsion particle size), cooling rate, etc. Therefore, in theory, different HCO suspensions prepared by different emulsification systems or different production processes have different crystallization temperatures.

[0005] In the actual production process, the different crystallization temperatures of the suspension will significantly affect the convenience and efficiency of the actual production. For example, in the actual preparation process of the suspension, the system is transformed from an emulsion to a structuring agent, which is accompanied by a significant change in the rheological properties of the system, usually manifested as a surge in the viscosity of the system into a paste, which will affect the subsequent cooling, heat transfer efficiency and stirring efficiency. In the existing published patents, the process of CN109880700A is kept warm between 55 and 80°C to allow HCO to form a paste; for example, the process disclosed in CN113773916A needs to be kept warm at the crystallization temperature for 0.5 to 3.5 hours, while the examples clearly state that crystallization can be at 70°C.

[0006] In summary, in the process of preparing hydrogenated castor oil suspension, the emulsification system and production process control are very important. Although in the existing patents, most surfactants can emulsify HCO and then prepare specific related suspensions. However, it is obvious that how to optimize the production process of suspensions and improve the application structure stability and production convenience of suspensions is still more practical and is also the difficulty in the current development of suspensions. Summary of the invention

[0007] In order to solve the above technical problems, the present invention provides a suspension composition containing microcapsules, a preparation method and application thereof. The present invention selects a polyether type anionic surfactant as a hydrogenated castor oil emulsifier and adopts a special two-step water-adding process to prepare the suspension composition, and finally obtains a suspension composition in which a microcapsule functional auxiliary agent is pre-uniformly dispersed in the system. The present invention adds the microcapsule functional auxiliary agent during the preparation of the suspension, and the solution of copolymerizing the microcapsule functional auxiliary agent with the HCO structural agent to form a new suspension system in the later stage has more performance advantages in application.

[0008] The specific technical scheme of the present invention is: In a first aspect, the present invention provides a microcapsule-containing suspension composition, comprising the following raw materials in percentage by mass: 0.1-20% hydrogenated castor oil (HCO), 10-40% polyether anionic surfactant, 0.1-10% microcapsule functional additive, and water.

[0009] The above-mentioned microcapsule-containing suspension composition 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 high temperature, and replenishes water and cools down the emulsion under a non-demulsified state. During this period, the emulsion remains in a low-viscosity state, and the microcapsule functional additive is added in this state to achieve uniform dispersion. Since HCO itself has a high melting point and is insoluble in water, it can slowly demulsify and crystallize during the cooling process. In this demulsification and crystallization process, hydrogenated castor oil can form a linear network structure, and the microcapsule functional additive can be evenly dispersed in the network structure, thereby forming a final suspension composition.

[0010] As described in the background technology section of this application, in the prior art, when preparing liquid detergents, microcapsule functional aids and suspending agents can usually only be added to the liquid detergent system in the form of separate additions, and it is difficult to pre-disperse the microcapsule functional aids in the suspending agent and then add them to the liquid detergent system. The reason is that in the existing suspension preparation process, the cooling demulsification crystallization from the emulsion to the suspension is accompanied by a significant change in the rheological properties of the system, which is usually manifested as a surge in the viscosity of the system to a paste state, which in turn affects the subsequent cooling heat transfer efficiency and stirring efficiency, and makes it difficult to fully disperse the microcapsule functional aid after addition.

[0011] To this end, the present invention first solves the above technical difficulties from the perspective of raw materials. The present invention has found through research that the polyether anionic surfactant of a specific structure can better emulsify hydrogenated castor oil, and the emulsion has better high temperature stability, so that it can ensure that the system remains as a low-viscosity emulsion before adding the microcapsule functional additive under certain process conditions; after adding the microcapsule functional additive, it slowly breaks the emulsion to form a suspension. Studies have shown that anionic surfactants have relatively stronger emulsification ability for vegetable oils and fats, while non-ionic surfactants have a larger solubilization space and relatively stronger solubilization ability due to the larger proportion of EO head groups in their molecules and the presence of a fence layer in the self-assembly structure. The polyether anionic surfactant used in the present invention has a portion of the polyether component blocked in the molecular structure relative to conventional anionic surfactants such as LAS, SDS, fatty acid soaps, etc., which allows it to retain the overall anionic advantage while also having some non-ionic capabilities, which is beneficial to a certain extent to improve the emulsion stability in the emulsification process of the present invention.

[0012] In summary, the present invention can obtain a suspension composition in which microcapsule functional aids are uniformly dispersed in the system. When the existing similar suspension products are used to make liquid detergents, the conventional batching process is to first add HCO suspension agent to the liquid detergent, and then add the microcapsule functional aid after the suspension agent to be added is completely dispersed by mechanical stirring for a long time. During this period, excessive mechanical stirring can easily cause the suspension ability of the suspension agent to decrease. However, the present invention optimizes the emulsifier to keep the system as a low-viscosity O / W emulsion in the process, thereby making it possible to compound the microcapsule functional aid and the suspension agent. If ordinary surfactants such as sulfonic acid and AEO are used as emulsifiers, although HCO can also be emulsified to form a structuring agent later, the emulsion of the relevant system has a high paste temperature (about 70 to 80°C), and it is difficult to add microcapsule functional aids at this temperature, which easily causes unnecessary volatilization losses of functional aids (such as flavors). In addition, due to the sharp increase in the viscosity of the system after the paste, it is also difficult to achieve effective and uniform dispersion of the microcapsule functional aid directly after the paste.

[0013] The present invention has found in subsequent tests that the solution of adding microcapsule functional additives during the preparation of the suspension agent and copolymerizing them with the HCO structural agent to form a new suspension system has better performance advantages in application. This is mainly because the microsphere structure of the microcapsule functional additive also participates in the formation of the network structure in the suspension agent system, so it has better compatibility with the suspension system, relatively stronger mechanical shear resistance, and relatively better application stability.

[0014] Preferably, the suspension composition comprises the following raw materials in percentage by mass: 3-15% hydrogenated castor oil, 15-30% polyether anionic surfactant, 5-10% microcapsule functional additive, and water.

[0015] Preferably, the microcapsule functional additive refers to a water-dispersible nano- or micron-microcapsule with a core-shell structure formed by wrapping a core material with a wall material. The wall material may be a water-soluble polymer material, including but not limited to sodium alginate, modified chitosan, modified cellulose, gelatin, cyclodextrin, gum arabic, modified starch, polyurethane, polyurea, melamine resin, urea-formaldehyde resin, and one or more thereof. The core material may be an oil-soluble raw material, including but not limited to one or more of essences, plant essential oils, vitamins, colorants, UV inhibitors, moisturizing oils, and greases.

[0016] More preferably, the microcapsule functional additive is a microcapsule flavor.

[0017] Preferably, the polyether 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.

[0018] Compared with conventional anionic surfactants such as LAS, SDS, fatty acid soaps, etc., the polyether anionic surfactants used in the present invention have a portion of polyether components blocked in the molecular structure, which allows it to retain the overall anionic advantages while also having some non-ionic capabilities, which is beneficial to improving the emulsion stability in the emulsification process of the present invention to a certain extent.

[0019] Further preferably, the polyether anionic surfactant includes but is not limited to one or more of fatty alcohol polyether sulfate (AES), fatty alcohol polyether carboxylate (AEC), modified oil ethoxylate sodium sulfonate (SNS-80), and alcohol ether sulfate ester Extended surfactant; among which fatty alcohol polyether sulfate (AES) is most preferred.

[0020] In a second aspect, the present invention provides a method for preparing the above-mentioned suspension composition, comprising the following steps: S1: dissolving a polyether anionic surfactant in water to form a 20-50wt% solution, and stirring it thoroughly to mix it evenly. The concentration of the surfactant in the S1 solution has a certain influence on the suspension ability of the final suspension, which is generally manifested as the higher the surfactant concentration, the more stable the emulsion formed, which is reflected in the tendency of the yield stress of the sample to increase. However, when the concentration of the surfactant is too high, it is easy to cause a significant increase in the viscosity of the system, thereby affecting the homogenization efficiency. On the contrary, if the surfactant concentration is low, the yield stress of the prepared suspension is smaller.

[0021] S2: Add hydrogenated castor oil and heat to above its melting point (about 85° C.), and then homogenize after the hydrogenated castor oil is completely melted to form an O / W emulsion.

[0022] S3: Add water to the system and cool it down quickly, while maintaining homogeneity to avoid emulsion demulsification, that is, the system will remain in an emulsion state.

[0023] S4: Continue to cool down to 45-55°C, stop homogenizing, add microcapsule functional additives, and stir slowly until the microcapsule functional additives are evenly dispersed.

[0024] S5: Continue to cool down to 30-40°C, replenish the volatile water, and discharge the material. At this time, the appearance of the material liquid is still a low-viscosity emulsion.

[0025] S6: At room temperature, the emulsion will slowly break and crystallize to form a viscous suspension composition containing microcapsules.

[0026] In order to make the microcapsule functional additives uniformly dispersed in the suspending agent in advance, in addition to the optimization of the raw materials, the present invention also improves the preparation process. The present invention adopts an innovative two-step water addition process. Among them: the first step requires relatively less water to increase the concentration of the surfactant in the emulsification system, so as to form an O / W emulsion at a relatively higher surfactant concentration, so that the particle size of the emulsion droplets is smaller and the high-temperature stability is better; the second step is to add some cold water, which can achieve rapid cooling of the system on the one hand, and on the other hand, it can also dilute the formed emulsion droplets and increase the spacing between the emulsion droplets, so that it can avoid rapid aggregation and demulsification to form a structuring agent under subsequent cooling and homogenization conditions, and at the same time, it also assists in the reduction of the crystallization temperature in the process to a certain extent.

[0027] Preferably, in S1, the pH of the solution is adjusted to 6-10.

[0028] Since the emulsification process is carried out in aqueous solution at high temperature, excessive acidity or alkali may cause hydrolysis of the emulsifier or castor oil.

[0029] Preferably, in S2, the heating temperature is 88-95°C.

[0030] 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 to 100 μm, and more preferably 10 to 50 μm.

[0031] If the particle size of the emulsion droplets is too large or the particle size is uneven, it means that the formed emulsion is not very stable and may cause HCO to form a structuring agent prematurely.

[0032] Preferably, in S3, the mass of the replenished water accounts for 5-70% of the water volume, and the temperature of the replenished water is 20-50°C; and the system temperature after the replenished water is 60-80°C.

[0033] If the temperature is too low after water replenishment, the temperature will drop too quickly, which may cause HCO to crystallize too quickly, causing it to break the emulsion prematurely and form a structuring agent; on the contrary, if the temperature is too high after water replenishment, the water temperature will be too high, and a long time of cooling will be required afterwards, resulting in low production efficiency.

[0034] Preferably, in S4 and S5, the cooling rate is 0.3-2.0°C / min.

[0035] If the temperature drops too quickly, HCO may crystallize too quickly, causing it to break the emulsion prematurely and form a structuring agent.

[0036] In a third aspect, the present invention provides use of the above suspending agent composition in liquid detergents.

[0037] Preferably, the suspending agent composition is added to the liquid detergent by post-mixing.

[0038] Compared with the prior art, the beneficial effects of the present invention are: (1) The polyether type anionic surfactant of the present invention has a partial polyether component in the molecular structure, which makes it retain the anionic advantage as a whole while also having a partial nonionic ability. The present invention uses the polyether type anionic surfactant to emulsify hydrogenated castor oil, which can ensure that the emulsified system remains a low-viscosity emulsion before adding the microcapsule functional additive; after adding the microcapsule functional additive, the emulsion is slowly broken to form a suspension.

[0039] (2) The present invention adopts a two-step water addition process in the preparation process of the suspension composition: first, a small amount of water needs to be added in the first step to obtain a sufficiently high concentration of surfactant, which can form an O / W emulsion that is sufficiently stable at high temperature with HCO; when water is added later, the system is cooled quickly. Due to the good stability of the emulsion, during the water addition process, the emulsion droplets only show a larger spacing and larger particle size, and the emulsion state does not change, so that the system remains a low-viscosity emulsion, which makes it possible to directly add microcapsule functional additives to the subsequent system. As the temperature drops, the microscopically crystallized HCO causes the system to slowly demulsify, thereby forming a linear network structure, and the microcapsule functional additives can be evenly dispersed in the network structure to form the final suspension composition.

[0040] (3) The present invention adds microcapsule functional additives during the preparation of the suspension, and then copolymerizes them with the HCO structural agent to form a new suspension system, which has better performance advantages in application. The reason is that the microsphere structure of the microcapsule functional additive also participates in the formation of the network structure in the suspension system, so it has better compatibility with the suspension system, relatively stronger mechanical shear resistance, and relatively better application stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is the sample microstructure tracking during the preparation process of Example 1.

[0042] Figure 2 The microstructural changes of the sample in Example 1 under a polarizing microscope (the left picture is a polarized photo of the sample when it is slightly thickened at room temperature (slightly with structure); the right picture is a polarized photo of the sample at room temperature after 12 hours (with fully grown structure)).

[0043] Figure 3 This is a comparison chart of the shear stability of samples applied to laundry detergent in Test Example 2, Comparative Examples 3, 4 and Example 1. DETAILED DESCRIPTION

[0044] The present invention is further described in the following examples, but the protection scope of the present invention is not limited thereto.

[0045] The professional terms and technical means used in the present invention have the same meanings as those generally understood by those skilled in the art. Unless otherwise specified, the various reagents, raw materials, equipment, etc. in the present invention are commonly used reagents, raw materials, equipment understood by those skilled in the art and are all commercially available.

[0046] Overall embodiment Firstly, the invention provides a microcapsule-containing suspension composition, which comprises the following raw materials in percentage by mass: 0.1-20% hydrogenated castor oil (HCO), 10-40% polyether anionic surfactant, 0.1-10% microcapsule functional additive and water.

[0047] Preferably, the suspension composition comprises the following raw materials in percentage by mass: 3-15% hydrogenated castor oil, 15-30% polyether anionic surfactant, 5-10% microcapsule functional additive, and water.

[0048] Preferably, the microcapsule functional additive refers to a water-dispersible nano- or micron-microcapsule with a core-shell structure formed by wrapping a core material with a wall material. The wall material may be a water-soluble polymer material, including but not limited to sodium alginate, modified chitosan, modified cellulose, gelatin, cyclodextrin, gum arabic, modified starch, polyurethane, polyurea, melamine resin, urea-formaldehyde resin, and one or more thereof. The core material may be an oil-soluble raw material, including but not limited to one or more of essences, plant essential oils, vitamins, colorants, UV inhibitors, moisturizing oils, and greases.

[0049] More preferably, the microcapsule functional additive is a microcapsule flavor.

[0050] Preferably, the polyether 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; further preferably, the polyether anionic surfactant includes but is not limited to one or more of fatty alcohol polyether sulfate (AES), fatty alcohol polyether carboxylate (AEC), modified oil ethoxylate sodium sulfonate (SNS-80), and alcohol ether sulfate ester salt Extended surfactant. Most preferably, fatty alcohol polyether sulfate (AES) is used.

[0051] Secondly, the present invention provides a method for preparing the above suspension composition, which specifically comprises the following steps: S1: dissolving a polyether anionic surfactant in water to prepare a 20-50wt% solution, and stirring the solution sufficiently to mix the solution evenly.

[0052] Preferably, in S1, the pH of the solution is adjusted to 6-10.

[0053] S2: Add hydrogenated castor oil and heat to above its melting point (about 85° C.), and then homogenize after the hydrogenated castor oil is completely melted to form an O / W emulsion.

[0054] Preferably, in S2, the heating temperature is 88-95°C.

[0055] 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 to 100 μm, and more preferably 10 to 50 μm.

[0056] S3: Add water to the system and cool it down quickly, while maintaining homogeneity to avoid emulsion demulsification, that is, the system will remain in an emulsion state.

[0057] Preferably, in S3, the mass of the water replenishment accounts for 5-70% of the water volume, and the temperature of the water replenishment is 20-50°C; the system temperature after the water replenishment is 60-80°C; S4: Continue to cool down to 45-55°C, stop homogenizing, add microcapsule functional additives, and stir slowly until the microcapsule functional additives are evenly dispersed. S5: Continue to cool down to 30-40°C, replenish the amount of volatile water, and discharge the material. At this time, the appearance of the material liquid is still a low-viscosity emulsion.

[0058] Preferably, in S4 and S5, external circulating water is used for cooling.

[0059] Preferably, in S4 and S5, the cooling rate is 0.3-2.0°C / min.

[0060] S6: At room temperature, the emulsion will slowly break and crystallize to form a viscous suspension composition containing microcapsules.

[0061] Finally, the present invention provides a liquid detergent containing the above suspending agent composition.

[0062] Preferably, the suspending agent composition is added to the liquid detergent by post-mixing.

[0063] Preferably, the content of the suspending agent composition in the liquid detergent is 0.1-10 wt %.

[0064] Specific Examples and Comparative Examples The present invention is further described below with reference to specific examples. Unless otherwise specified, percentages are weight percentages (wt%) and temperatures are in ° C. "Alkyl" is a substituted or unsubstituted saturated hydrocarbon group having one to twenty-two carbon atoms in a straight or branched arrangement. Unless otherwise specified, an alkyl group is unsubstituted.

[0065] Unless otherwise specified, the surfactant raw materials in the following examples and comparative examples of the present invention are all pure, and the information of the microcapsule additives used is as follows: Floral and fruity microcapsules 1, with a content of 30%, and a wall material of melamine resin, which can be purchased from Givaudan; Rose essential oil microcapsules 2, with a content of 99%, and a wall material of modified starch, which can be purchased from IFF; Anti-UV agent microcapsule 3, with a content of 30%, and a wall material of polyurea, which can be purchased from BASF.

[0066] Test Example 1-3 Table 1: Laundry detergent bases The preparation method of the laundry detergent base in Table 1 above is as follows: 1) Add solvent (water), liquid alkali and surfactant (coconut oil fatty acid, LAS, AEO-9 and AES) in sequence and stir until completely dissolved; 2) adding a pH adjuster (citric acid) to adjust the pH to 8; 3) Add small ingredients HP20, NaCl and sodium citrate and stir until the appearance is uniform.

[0067] Table 2: Test cases 1, 2, and 3 The specific preparation methods of the detergents in the above test examples 1-3 are as follows: Add 20 parts of LAS or AES or AEO-9 and 45 parts of deionized water into a reaction kettle, stir evenly to form a surfactant solution, and adjust the pH of the system to about 8.

[0068] Add 5 parts of solid HCO and turn on the temperature to 92°C to fully melt the HCO.

[0069] Start homogenization, the homogenization speed is 5000rpm, and the homogenization time is 10min.

[0070] While maintaining homogeneity, 30 parts of 30°C deionized water were added to the system. After the water was added, the temperature of the system dropped rapidly, and the state of the feed liquid in the reactor was observed.

[0071] Turn on the circulating water to cool down, the average cooling rate is about 0.8℃ / min, observe the state of the emulsion in the reactor, when the viscosity of the system surges, turn off the homogenizer and turn on the stirring. Keep the circulating water cooling down until 40℃, which is the suspension.

[0072] The detergent is obtained by uniformly mixing 5 parts of suspending agent, 0.5 parts of liquid essence, 0.25 parts of microcapsules and 94.25 parts of laundry detergent base.

[0073] The sample tests are as follows: Yield stress test: tested with Brookfield RST rheometer, temperature 25°C, shear rate scanning range 0.01~100s -1 , 0.1~100s -1 The data were fitted with the Herschel-Bulkley model, and the stability index R 2 Must be greater than 0.999.

[0074] Stability test: Place relevant samples under corresponding conditions and observe whether the samples have any unstable phenomena such as stratification. Table 3: Test process records of suspension concentrate test examples 1-3 and sample performance tests The test shows that test examples 1, 2, and 3 all successfully prepared suspensions with yield stress in a similar two-step water replenishment process. However, judging from the yield stress test results, there are significant differences in the performance and appearance of suspensions of different emulsification systems. In addition, despite the different types of emulsifiers, they can all form emulsions after homogenization in the high temperature range of 92°C, which is also the key to their successful preparation of suspensions. But surprisingly, different emulsifiers have significant differences in actual performance during the cooling process. For example, in test examples 1 and 3, LAS and AEO-9 were used as emulsifiers, respectively. After water replenishment, the emulsions were quickly demulsified at high temperatures of about 72°C and 65°C to form a structurant. When AES was used as an emulsifier, the liquid remained a low-viscosity emulsion when the temperature was cooled to 40°C. Therefore, AES as an emulsifier provides the possibility of uniformly dispersing microcapsule flavors.

[0075] It was also found in the test that bubbles will inevitably be generated during the homogenization process of the sample, which affects the particle size statistics of the emulsion to a certain extent. Therefore, in order to more accurately understand the changes in the microstructure during the process, a small amount of Sudan III (oil-soluble dye) was added in the subsequent Example 1, which will make the emulsion core appear red. In order to distinguish between bubbles and emulsion. Considering that the cooling process is a low-viscosity liquid when AES is used as an emulsifier, it makes it possible to compound and add microcapsule flavors.

[0076] Example 1 Table 4: Example 1 The specific preparation method of the detergent of Example 1 above is as follows: Add 20 parts of AES and 45 parts of deionized water into a reaction kettle, stir evenly to prepare a surfactant solution, and adjust the pH of the system to about 8.

[0077] Add 5 parts of solid HCO and Sudan III dye, and turn on the temperature to 92°C to fully melt the HCO.

[0078] Start homogenization, the homogenization speed is 5000rpm, and the homogenization time is 10min.

[0079] While maintaining homogeneity, 25 parts of 40°C deionized water were added to the system. After the water was added, the temperature of the system dropped rapidly from 92°C to about 78°C.

[0080] Start circulating water cooling, the average cooling rate is about 0.8℃ / min, when it drops to about 50℃, add 5 microcapsules, observe the state of the emulsion in the reactor, when the viscosity of the system surges, turn off the homogenizer and start stirring. Keep the circulating water cooling down to 40℃, add volatile water and stir thoroughly, the emulsion breaks at room temperature, and the final suspension is obtained after crystallization.

[0081] The detergent is obtained by uniformly mixing 5 parts of suspending agent, 0.5 parts of liquid essence and 94.5 parts of laundry detergent base.

[0082] Comparing the sample stability test results of Example 1 and Test Example 2, it can be found that when the amount of HCO added and the amount of microcapsule essence added are basically the same, the yield stress and freeze-thaw recovery stability of the sample of Example 1 are better than those of Test Example 2. This shows that the microcapsules are added in the preparation stage of the suspension, and the microsphere structure of the microcapsules may also participate in the formation of the suspension structure at the same time, thus bringing higher suspension force and stability at the same addition amount.

[0083] In addition, by Figure 1 The results show that in Example 1, the entire process is from 92°C to 70°C and then to 40°C, and the feed liquid is an emulsion, but the particle size of the emulsion tends to increase, and the spacing of the emulsion increases to a certain extent after water replenishment, which shows that the emulsion of this system tends to develop towards instability. After the HCO suspension structure is formed, it cannot be seen under a microscope, but its liquid crystal structure can be seen under a polarizing microscope. Figure 2 The left is a polarized photo of the suspension sample solution of Example 1 when it slightly changes from thin to thick. The tiny dots of light in the photo are liquid crystal structures. Figure 2 On the right is a polarized photo of the same sample at room temperature for 12 hours, showing the typical "cross flower" liquid crystal structure of the HCO suspension.

[0084] Embodiment 2-5 Table 5: Examples 2-5 The specific preparation methods of the detergents of Examples 2-5 above are as follows: The polyether anionic surfactant is dissolved in a portion of deionized water to prepare a surfactant solution with a relatively high concentration, and the solution is stirred thoroughly to mix the solution evenly, and the pH of the system is adjusted to a range of 6-10.

[0085] Heat the system to above the melting point of HCO (about 85°C), about 88°C, add HCO; after HCO is completely melted, start homogenization. After homogenization, the system forms an O / W emulsion with a certain particle size distribution.

[0086] Add a certain proportion of cold water at a temperature of 20°C into the system to quickly cool the system. During this period, it is necessary to maintain homogeneity to avoid demulsification of the system, that is, the system will be maintained in an emulsion state. After replenishing water, the water temperature is about 70°C.

[0087] After replenishing water, start circulating water to cool down at a rate of 0.3-2.0℃ / min.

[0088] When the system temperature drops to about 50°C, turn off the homogenizer, then add the microcapsules and start stirring to evenly disperse the microcapsules in the emulsion system.

[0089] Continue to cool down, and when the temperature drops to 35°C, replenish the volatile water and then discharge the material. At this time, the appearance of the material liquid is still a low-viscosity emulsion.

[0090] After discharging, at room temperature, the emulsion will slowly break up and finally crystallize into a viscous suspension containing microcapsules.

[0091] The types of anionic surfactants for emulsification are expanded in Table 5. The results show that similar polyether anionic surfactants such as sodium fatty alcohol polyether carboxylate (AEC), modified oil ethoxylate sulfonate (SNS-80) and a small-scale sodium alcohol ether sulfate extended surfactant provided by Lianhong are similar to common AES. Under the two-step water addition process conditions, the emulsions prepared have relatively good high-temperature stability, which can ensure that the emulsions in the process preparation are all emulsions.

[0092] Comparative Example 1, Examples 6-9 and Comparative Example 2 Table 6: Comparative Example 1 and Examples 6-9 The preparation methods of the detergents in the above embodiments and comparative examples are roughly the same as those in embodiments 2-5.

[0093] It can be seen from the test results in Table 6 that the concentration of the first step surfactant in the present invention has a certain influence on the suspension ability of the final suspension agent, which is generally manifested as the higher the surfactant concentration, the more stable the emulsion formed, which is reflected in the increasing trend of the yield stress of the sample. However, when the concentration of the surfactant is too high, it is easy to cause a significant increase in the viscosity of the system, thereby affecting the homogenization efficiency. In Comparative Example 1, the surfactant concentration in the first step of emulsification is 15.5%, which is relatively low, so the yield stress of the prepared suspension agent is relatively small; while in Comparative Example 2, the surfactant concentration in the first step of emulsification is 58.3%, which is too high, so the viscosity of the emulsion is too high when homogenized with HCO, resulting in a significant change in the viscosity of the feed liquid at 55°C. It can be seen that the concentration of the surfactant in the first step has a greater impact on the emulsification process, and the concentration of the surfactant is preferably in the range of 20 to 50%.

[0094] Furthermore, it is obvious that the water temperature of the water replenishment process of the present invention directly affects the temperature of the system after water replenishment. In order to prevent the temperature from dropping too fast during the water replenishment process, which leads to rapid emulsion demulsification, the temperature of the system after water replenishment is preferably in the range of 60 to 80°C. In actual operation, the water replenishment temperature can be adjusted according to the water replenishment amount and the target temperature after water replenishment, and deionized water at 20 to 50°C is generally preferred.

[0095] Comparative Examples 3-4 Preparation scheme of comparative example 3: prepare the suspension agent according to the ratio of test example 2, add 5% of flower and fruit microcapsule essence 1 after the structure is formed, and disperse it under mechanical stirring to form a suspension agent. Add it to the laundry detergent base material at an addition amount of 5% to obtain the final sample. Among them, the actual addition amount of flower and fruit microcapsule essence 1 is also about 0.25%.

[0096] Preparation scheme of comparative example 4: commercially available suspending agent CHE-100 (Hechuang Company) was added to the laundry detergent base in a post-mixing manner, and then 0.25% of floral and fruity microcapsule essence 1 was added to form the final sample.

[0097] Figure 3 This is a comparison chart of the shear stability of the samples applied to laundry detergent in Test Example 2, Comparative Examples 3, 4 and Example 1, which examines the shear resistance of the laundry detergent samples formed by adding microcapsule fragrances in different ways. The test shows that under high-speed shear conditions, the structure of the structuring agent in the laundry detergent is destroyed to a certain extent, which is manifested as a decrease in yield stress. However, after the laundry detergent samples of Test Example 2, Comparative Example 3 and Comparative Example 4 were homogenized at 5000rpm or 10000rpm, the yield stress of the samples decreased significantly, while the yield stress of Example 1 decreased after shearing at 5000rpm or 10000rpm, but the degree of decrease was significantly better than other solutions.

[0098] at the same time, Figure 3The microscopic photos of the dispersion of microcapsules in the initial laundry detergent sample are also given. The results show that the method of adding microcapsules to the structuring agent (Comparative Example 3) easily causes microcapsules to aggregate and disperse unevenly; while the method of adding microcapsule essence and suspending agent and the scheme of the present invention (Test Example 2, Comparative Example 4, Example 1), microcapsules ( Figure 3 The microsphere structure in the solution can be evenly dispersed.

[0099] The raw materials and equipment used in the present invention, unless otherwise specified, are all commonly used raw materials and equipment in the art; the methods used in the present invention, unless otherwise specified, are all conventional methods in the art.

[0100] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent transformation made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A suspension composition containing microcapsules, characterized in that The following raw materials are included in the following mass percentages: Hydrogenated castor oil 0.1~20%, Polyether anionic surfactant 10~40%, Microcapsule functional additives 0.1~10%, water.

2. The suspension composition according to claim 1, characterized in that The following raw materials are included in the following mass percentages: Hydrogenated castor oil 3~15%, Polyether anionic surfactant 15~30%, Microcapsule functional additives 5~10%, water.

3. The suspension concentrate composition according to claim 1 or 2, characterized in that: The wall material of the microcapsule functional additive is a water-soluble polymer material, and the core material is an oil-soluble functional raw material; The polyether anionic surfactant is a carboxylate or sulfate surfactant containing EO and / or PO and / or BO in the molecule.

4. The suspension composition according to claim 3, characterized in that: The polyether type anionic surfactant includes one or more of fatty alcohol polyether sodium sulfate, fatty alcohol polyether sodium carboxylate, modified oil ethoxylate sodium sulfonate and alcohol ether sulfate ester salt Extended surfactant.

5. A method for preparing a suspension concentrate composition according to any one of claims 1 to 4, characterized in that The following steps are involved: S1: dissolving a polyether anionic surfactant in water to prepare a 20-50 wt% solution; S2: adding hydrogenated castor oil and heating it to above its melting point, melting and homogenizing to form an O / W emulsion; S3: Add water to the system to cool it down, and maintain homogeneity during this period to avoid emulsion demulsification; S4: Continue to cool down to 45~55℃, stop homogenizing, add microcapsule functional additives and disperse evenly; S5: Continue to cool down to 30~40℃ to replenish the volatile water; S6: The emulsion breaks and crystallizes at room temperature to form a suspension composition containing microcapsules.

6. The preparation method according to claim 5, characterized in that: In S1, the pH of the solution is adjusted to 6-10.

7. The preparation method according to claim 5, characterized in that: In S2, The heating temperature is 88-95°C; The particle size of the emulsion droplets in the O / W emulsion is 10-100 μm.

8. The preparation method according to claim 5, characterized in that: In S3, The quality of the replenished water accounts for 5-70% of the water volume, and the temperature of the replenished water is 20-50°C; After replenishing water, the system temperature is 60~80℃.

9. The preparation method according to claim 5, characterized in that: In S4 and S5, the cooling rate is 0.3-2.0°C / min.

10. Use of the suspension concentrate composition according to any one of claims 1 to 4 or the suspension concentrate composition obtained by the preparation method according to any one of claims 5 to 9 in liquid detergents.

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