Microcapsule for encapsulating core material and preparation method thereof

Abstract

The invention discloses a microcapsule for encapsulating a core material, and relates to the technical field of daily chemical products. The microcapsule for encapsulating the core material comprises the core material, a wall material for encapsulating the core material, a pH adjusting aid and water, the components of the wall material comprise a polymer A, a polymer B and a cationic polymer, the polymer A is selected from one or a mixture of two of 1a) and 1b), and the polymer B is selected from one or a mixture of two of compounds shown as a formula I and a formula IV. The wall material of the microcapsule is not easy to have residual isocyanate groups, and when the microcapsule encapsulating the core material is used in a detergent, the wrapping stability of the microcapsule in a matrix can be improved, and the inner core material can be released through friction.

Description

Technical Field

[0001] The invention belongs to the technical field of daily chemical products, and relates to a microcapsule encapsulating a core material, and specifically relates to an application of the microcapsule encapsulating a core material in enhancing the fragrance retention performance of a detergent. Background Art

[0002] At present, the wall material of the fragrance microcapsules used in detergents on the market is mainly composed of melamine resin, which is often a highly branched and difficult to biodegrade material. In order to avoid the "microplastic" pollution caused by the use of microcapsules, materials commonly used to replace melamine resin wall materials include polyurea, polyurethane, β-amino ester, etc. If you want to ensure that the microcapsules in the detergent maintain stable packaging of the fragrance core material at room temperature within a shelf life of 2 years, the microcapsules need to be stored in a detergent at 45°C for 28 days and still have the friction fragrance release performance. However, polyurea or polyurethane wall materials are often not dense enough, and the internal fragrance core material of the formed microcapsules is more likely to leak when used in detergents. Patent CN116786044A uses polymer stabilizers and polyurea and polyurethane as wall materials to wrap the fragrance microcapsules. The friction fragrance release performance of this microcapsule is only maintained for 14 days in a detergent at a temperature of 45°C.

[0003] In addition, polyurea and polyurethane wall materials are usually obtained by reacting isocyanate compounds with amine polymers, or isocyanate compounds with hydroxyl-containing polymers. Due to the steric effect of the polymer, there is a risk of residual isocyanate groups after the reaction. When microcapsules containing residual isocyanate groups come into contact with the human body, it can cause skin tingling, itching or allergies at the mildest, and damage liver function and hematopoietic function at the worst, making this type of microcapsules unsuitable for use in daily necessities. Summary of the invention

[0004] One of the purposes of the present invention is to provide a microcapsule for encapsulating a core material, wherein the microcapsule comprises a core material and a wall material composed of polyurea / polyurethane; a second purpose of the present invention is to reduce the residual isocyanate groups in the polyurea / polyurethane type microcapsule; a third purpose of the present invention is to solve the problem of unstable encapsulation of the fragrance core material by the polyurea / polyurethane type microcapsule used in detergents within a two-year shelf life.

[0005] The objectives of the present invention are achieved through the following technical solutions.

[0006] A microcapsule for encapsulating a core material, comprising a core material, a wall material for encapsulating the core material, a pH adjusting aid and water;

[0007] The components of the wall material include:

[0008] 1) Polymer A: wherein polymer A is selected from one or a mixture of two of the following 1a) and 1b);

[0009] 1a) polyvinyl alcohol;

[0010] 1b) Polyvinylpyrrolidone;

[0011] 2) polymer B, wherein polymer B is selected from one or a mixture of two of the following compounds of formula II and formula IV;

[0012]

[0013] Wherein, n is an integer between 2 and 800;

[0014] The repeating unit L1 is a residue composed of a group connected to two nitrogen atoms on an isocyanate compound; the isocyanate compound is selected from at least one of anion-modified hexamethylene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, and isophorone diisocyanate;

[0015] The repeating unit L2 is derived from a residue consisting of a group connected to the nitrogen atoms on two primary amines in polyethyleneimine;

[0016] The repeating unit L3 is derived from the residue of the aminosiloxane consisting of groups other than the amino group, and its general formula is

[0017] [R 1 S i 2 x (OR 3 ) 4-x ] y Formula V; wherein R 1 represents a straight or branched alkyl group having 1 to 6 carbon atoms; R 2 represents a straight or branched alkyl group having 1 to 4 carbon atoms; R 3 represents a straight or branched alkyl group having 1 to 4 carbon atoms; x=0, 1, 2; y=1, 2;

[0018] In the raw materials used to prepare the polymer B, the mass content of aminosiloxane is 2-16%;

[0019] 3) Cationic polymer, wherein the cationic polymer is selected from one or a mixture of polyquaternium-10, polyquaternium-22, and polyquaternium-47.

[0020] In some other embodiments, the polymer B further comprises a compound of the following formula I and / or formula III;

[0021]

[0022] The components of the wall material include, by weight percentage:

[0023] Polymer A 12-34%,

[0024] Polymer B 45-70%,

[0025] Cationic polymer 3-10%.

[0026] The pH adjusting auxiliary agent is one or more of NaOH, ammonia water, citric acid and sodium citrate.

[0027] In some other embodiments, the wall material further comprises 0-22% polysiloxane.

[0028] Based on the total weight of the microcapsules, the core material accounts for 21-38% of the total weight, the wall material accounts for 5-12% of the total weight, the pH adjusting agent accounts for 0.02-0.06% of the total weight, and the remainder is water.

[0029] In one embodiment, the raw materials corresponding to the repeating unit L1 are anion-modified hexamethylene diisocyanate and dicyclohexylmethane-4,4'-diisocyanate, and the repeating unit L1 is a residue consisting of a group connected to two nitrogen atoms on the anion-modified hexamethylene diisocyanate (Formula VI) and a residue consisting of a group connected to two nitrogen atoms on dicyclohexylmethane-4,4'-diisocyanate (Formula VII).

[0030]

[0031] In one embodiment, the raw material corresponding to the repeating unit L2 is polyethyleneimine, and the repeating unit L2 is a residue consisting of a group connecting the nitrogen atoms on two primary amines in polyethyleneimine (Formula VIII).

[0032]

[0033] In one embodiment, the resulting polymer B has a structure as shown in Formula IX.

[0034]

[0035] In one embodiment, the obtained polymer B has a structure as shown in Formula X.

[0036]

[0037] In some specific embodiments, the wall material further comprises 0-11% polysiloxane, wherein the polysiloxane is formed by polycondensation of epoxysiloxane.

[0038] The microcapsule encapsulating the core material is characterized by being prepared by the following steps:

[0039] 1) Add polymer A and pH adjusting agent into water and stir until completely dissolved;

[0040] 2) preparing the core material in another container;

[0041] 3) mixing the products obtained in 1) and 2), stirring at 60° C. to 80° C. for 0.5 h to 1.5 h, and cooling to room temperature;

[0042] 4) adding the raw material isocyanate compound corresponding to the repeating units L1, L2, and L3 in polymer B, polyethyleneimine, pH adjusting agent, aminosiloxane, and cationic polymer in sequence, heating to 80° C. to 100° C., and stirring for 1 to 5 hours;

[0043] 5) Cooling to room temperature, discharging to obtain microcapsules encapsulating the core material.

[0044] In some other embodiments, step 2) of the preparation process further includes adding polysiloxane, specifically, stirring the core material and the polysiloxane until they are uniformly mixed.

[0045] The core material of the present invention contains at least one flavor and / or one cosmetic ingredient.

[0046] Preferably, the fragrance is selected from 2-tert-butyl-1-cyclohexyl acetate, benzyl benzoate, benzyl acetate, 3-oxo-2-pentylcyclopentyl acetate methyl ester, 4-tert-butyl cyclohexyl acetate, 2-methyl-2-phenoxyethyl propionate, 2-propenyl heptanoate, (3-methylbutoxy)-acetic acid-2-propenyl ester, linalyl acetate, citronellyl acetate, hexyl salicylate, 2-(benzylidene)octanol, 2,6-dimethyl-7-octen-2-ol, 3,7-dimethyl-3-octanol, Terpineol, 3,7-dimethyl-6-octen-1-ol, phenylethyl alcohol, (E)-3,7-dimethyl-2,6-octadien-1-ol, (Z)-3,7-dimethyl-2,6-octadien-1-ol, 4-(1,1-dimethylethyl)-α-methyl-phenylpropanal, dodecanal, β-(3,4-methylenedioxy)phenyl-α-methylpropanal, 10-undecenal, α-methyl-4-(1-methylethyl)phenylpropanal, 1-(1,2,3,4,5,6, 7,8a-octahydro-2,3,8,8-tetramethyl-2-naphthyl)ethanone, (R-)1-methyl-4-(1-methylvinyl)cyclohexene, diphenyl ether, (E)-3,7-dimethyl-2,6-octadiene-1-ol acetate, benzyl benzoate, neroli acetate, 2,6-dimethyl-7-octen-2-ol, (E)-3,7-dimethyl-2,6-octadiene-1-ol, 3,7,11,15-tetramethyl-1-hexadecene-3-ol, 1-methyl 1-[(1,2,2-trimethylbicyclo[3,1,0]hexan-3-yl)methyl]cyclopropylmethanol, β-(3,4-methylenedioxy)phenyl-α-methylpropanal, α-methyl-4-(1-methylethyl)phenylpropanal, 6-pentyl-2H-tetrahydropyran-2-one, 1-[4-(1,1-dimethylethyl)-2,6-dimethyl-3,5-dinitrophenyl]ethanone, 4-methylanisole, 6,6-dimethyl-2-methylene-bicyclo[3.1.1]-heptane, 1-methyl-4-(1-methylethyl)-1,4-cyclohexadiene, α-pinene, 3a,4,5,6,7,7a-hexahydro-4,7-methylene-1H-inden-6-ol propionate, 3a,4,5,6,7,7a-hexahydro-4,7-methylene-1H-inden-5-ol propionate, 2-hydroxy-pentyl benzoate, benzyl acetate, 2-hydroxybenzoic acid hexyl ester, α-(trichloromethyl)benzyl acetate, butyric acid-1,1-dimethyl-2-phenylethyl ester, 2,4-dihydroxy-3,6-dimethylbenzoic acid methyl ester, 2-propenyl hexanoate, 3,7-dimethyl-1,6-octadien-3-ol, 1,8-terpenoid, terpineol, 3,7-dimethyl -3-octanol, 3-phenyl-2-propene-1-ol, 4-(1,1-dimethylethyl)-a-methyl-phenylpropanal, 3-phenyl-2-propenal, 10-undecenal, 3,4-methylenedioxybenzaldehyde, 1,3-benzodioxole-5-carboxaldehyde, undecane, dodecanal, 2-(phenylmethylene)octanal, 2H-1-benzopyran-2-one, 1-[4-(1,1-dimethylethyl)-2,6-dimethyl-3,5-dinitrophenyl]ethanone, 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethyl-cyclopenta[g]-2-benzopyran, 1,3,3-trimethyl-2-oxabicyclo[2.2.2]octane. .

[0047] The cosmetic ingredient has a calculated octanol / water partition coefficient (Cl ogP) of 1.5 or greater, more preferably 3 or greater. Alternatively, preferably the cosmetic ingredient has a ClogP of 2 to 7.

[0048] The cosmetic ingredients may be chosen from emollients, smoothing actives, hydrating actives, smoothing and soothing actives, decorative actives, anti-aging actives, drainage actives, remodeling actives, skin-smoothing actives, preservatives, antioxidant actives, antimicrobial or antimicrobial actives, cleansing actives, lubricating actives, structuring actives, hair conditioning actives, whitening actives, texturizing actives, softening actives, anti-dandruff actives and exfoliating actives.

[0049] Particularly useful cosmetic ingredients include, but are not limited to, hydrophobic polymers such as alkyl dimethicone, polymethyl silsesquioxane, polyethylene, polyisobutylene, styrene-ethylene-styrene and styrene-butylene-styrene block copolymers, mineral oils such as hydrogenated isoparaffins, silicones, vegetable oils such as argan oil, jojoba oil, aloe oil, fatty acids and fatty alcohols and their esters, glycolipids, phospholipids, sphingolipids such as ceramides, sterols and steroids, terpenes, sesquiterpenes, triterpenes and their derivatives, essential oils such as arnica oil, caraway oil, bark oil, birch leaf oil, calendula oil, cassia oil, echinacea oil, eucalyptus oil, ginseng oil, jujube oil, sunflower oil, jasmine oil, lavender oil, lotus seed oil, perilla oil, rosemary oil, sandalwood oil, tea tree oil, thyme oil, valerian oil, wormwood oil, ylang ylang oil, yucca oil.

[0050] The microcapsules encapsulating the core material of the present invention can be applied and added to consumer products, including fabric care detergents and conditioners, hair care conditioners, shampoos, heavy-duty liquid detergents, hard surface cleaners, laundry detergents, soaps, shower gels and skin care products.

[0051] The beneficial effects of the present invention are:

[0052] 1. The present invention provides a new polyurea / polyurethane type microcapsule wall material, in which isocyanate groups are unlikely to remain.

[0053] 2. The microcapsules encapsulating the core material of the present invention are used in detergents, which can improve the encapsulation stability of the microcapsules on the core material such as fragrance in the matrix; after washing with the detergent containing the microcapsules, the internal core material can be released by friction. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0055] Figure 1 This is the infrared test result of the microcapsule of Example 1 of the present invention.

[0056] Figure 2 This is the infrared test result of the microcapsule of Example 2 of the present invention.

[0057] Figure 3 This is the infrared test result of the microcapsule of Example 8 of the present invention.

[0058] Figure 4 This is the infrared test result of the microcapsule of Comparative Example 1 of the present invention.

[0059] Figure 5 This is the infrared test result of the microcapsule of Comparative Example 2 of the present invention. DETAILED DESCRIPTION

[0060] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0061] It should be understood that when used in this specification and the appended claims, the terms "comprises" and "comprising" indicate the presence of the described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or their collections. In the present invention, the term water is not distinguished from pure water.

[0062] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0063] The microcapsules of the present invention are obtained by forming an encapsulation wall around oil droplets dispersed in an aqueous phase in the form of an oil-in-water emulsion. The size of the microcapsules affects the deposition effect and release properties of the microcapsules on substrates such as fabrics, hair, and skin.

[0064] In the context of the present invention, the term "aminosiloxane" refers to a siloxane comprising at least one amine group and at least one alkoxysilyl group.

[0065] The size and size distribution of the microcapsules can be determined using methods known in the art. In the present invention, a specific method for measuring the size of the microcapsules is light scattering. The light scattering measurement can be performed using a Malvern Mastersizer 2000S instrument and Mie scattering theory. By experiment, a few drops of slurry are added to a degassed circulating water stream connected to a scattering cell. Under this dilution condition, the angular distribution of the scattering intensity is measured and analyzed by Malvern copyrighted software attached to the equipment to provide the average size and size distribution of the droplets present in the sample. In the case of a unimodal (monodisperse) droplet distribution, the percentiles Dv(10), Dv(50) and Dv(90) are used as characterizations of the droplet size distribution, while Dv(50) corresponds to the median of the distribution and is taken as a measure of the volume average size of the microcapsules. In the present invention, according to the experience of those skilled in the art, when Dv(50)>50μm, the microcapsule size is considered to be too large, and when Dv(50)<10μm, the microcapsule size is considered to be too small.

[0066] The microcapsule sample was dried with filter paper, and 0.2 g of the dried microcapsule sample was weighed and tested by infrared spectrum using Perkin Elmer spectrum 100 instrument. The infrared spectrum of the microcapsule sample was observed at 2240-2280 cm -1 Whether there is an infrared characteristic absorption peak of isocyanate group at the microcapsule. If it exists, it is considered that isocyanate group is likely to remain in the microcapsule; if it does not exist, it is considered that isocyanate group is unlikely to remain in the microcapsule.

[0067] When the core material of the microcapsule is a flavor, the release performance of the microcapsule can be determined by testing the friction release performance of the microcapsule. The friction release performance of the microcapsule is evaluated by comparing the fragrance intensity of the sample before and after friction after using the consumer product. The fragrance intensity is evaluated by a panel of 4 experts, with a score range of 1 to 10. The difference in fragrance intensity before and after friction is greater than or equal to 3, which is considered to be a good friction release performance; the fragrance intensity after friction is greater than 2 and less than 3, which is considered to be a fair friction release performance; the fragrance intensity after friction is less than 2, which is considered to be a poor friction release performance.

[0068] Table 1 Fragrance evaluation standards

[0069] Points Fragrance level 0 No fragrance 1 A faint scent 2 Relatively light fragrance 3 The right amount of fragrance 4 Stronger scent 5 Very strong fragrance

[0070] The packaging stability of the microcapsules can be evaluated by comparing the release performance of the microcapsules after being stored at room temperature and 45°C for 28 days. The fragrance retention rate is the ratio of the fragrance level of the microcapsules after being stored at 45°C for 28 days to the fragrance level after being stored at room temperature for 28 days. If the fragrance retention rate is greater than or equal to 50%, the packaging stability of the microcapsules is considered to be good; if the fragrance retention rate is less than 50%, the packaging stability of the microcapsules is considered to be poor.

[0071] The stability of microcapsules refers to the changes in the appearance of consumer products, such as shower gel and laundry detergent, and the retention of the release performance of the microcapsules after storage in consumer products. If the appearance of the consumer product does not change, that is, the color of the consumer product does not change, there is no precipitation in the consumer product, and the release performance of the microcapsules in the consumer product still maintains good friction fragrance release performance, then the stability of the microcapsules is considered to be high.

[0072] In the following examples and comparative examples, the abbreviations of the compound names and the terminology are shown in Table 2.

[0073] Table 2 Comparison table of compound name abbreviations and terms

[0074]

[0075]

[0076] In the following examples and comparative examples, the composition of the flavors used is:

[0077] Table 3 Composition of flavors

[0078] Element Content wt% 3,7-Dimethyl-1,6-octadien-3-ol 20 3,4-Methylenedioxybenzaldehyde 20 Citronellyl acetate 10 Phenylethyl alcohol 10 1,8-terpene 10 Hexyl Salicylate 15 2-tert-Butyl-1-cyclohexyl acetate 15

[0079] According to the raw material dosage shown in Table 4 and Table 5, Examples 1-8 and Comparative Examples 1-4 were prepared. The preparation method is as follows:

[0080] 1) Add polyvinyl alcohol or polyvinyl pyrrolidone and alkali (NaOH) into pure water and stir until completely dissolved;

[0081] 2) Add flavor and (3-glycidylpropoxy)trimethoxysilane to another container and stir until well mixed;

[0082] 3) The products obtained in 1) and 2) were mixed and stirred at 70°C (fluctuation range ±10°C) for 1 h;

[0083] 4) Cool to room temperature, add 4,4'-dicyclohexylmethane diisocyanate and anion-modified diisocyanate compound, polyethyleneimine, acid (citric acid), aminosiloxane, and polyquaternium-22 in sequence, heat to 90°C (fluctuation range ±10°C), and stir for 3h;

[0084] 5) Cool to room temperature and discharge.

[0085] Table 4 Raw material dosage of Examples 1-8

[0086]

[0087] The difference between Example 2 and Example 3 and Example 1 is that the amount of TMSPA added is different.

[0088] The difference between Example 4 and Example 5 and Example 1 is that the type and amount of aminosiloxane added are different.

[0089] The difference between Example 6 and Example 7 and Example 1 is that, except for the amount of TMSPA, the amounts of other raw materials of the microcapsule wall material are different.

[0090] The difference between Example 8 and Example 1 is that the type and amount of polymer A used are different, and GTPS is not added.

[0091] Table 5 Raw material dosage of comparative examples 1-4

[0092]

[0093] The contents of the raw materials in the wall materials of the microcapsules of Examples 1-8 and Comparative Examples 1-4 are shown in Tables 6-7 below; wherein the content of polymer B is the content of components HMD I, HD I -, the total content of PE I, TMSPA and BTSA.

[0094] Table 6 Content of each raw material in the microcapsule wall material of Examples 1-8 and content of aminosiloxane in polymer B

[0095]

[0096]

[0097] Table 7 Content of each raw material in microcapsule wall material of Comparative Examples 1-4 and content of aminosiloxane in polymer B

[0098]

[0099] Particle size analysis test:

[0100] The microcapsules of Examples 1-8 and Comparative Examples 1-4 were subjected to particle size analysis tests, and the results are shown in Tables 8-9.

[0101] Table 8 Size distribution results of Examples 1-8, Comparative Examples 1 and 2

[0102]

[0103]

[0104] The size distribution results of Examples 1-8 and Comparative Examples 1 and 2 in Table 8 show that the D50 of the microcapsules after adding an appropriate amount of aminosilicone and the microcapsules without adding aminosilicone are between 10μm and 50μm, both achieving the technical effect of the present invention.

[0105] Table 9 Size distribution results of comparative examples 3-4

[0106] sample D50 / μm D90 / μm Comparative Example 3 9 35 Comparative Example 4 8 35

[0107] Combined with the results of Table 5 and Table 9, Comparative Examples 3 and 4 added excessive aminosilicone, resulting in an increase in small-sized microcapsules, causing D50 to decrease to 9 μm and 8 μm, respectively, which did not meet the technical requirements of the present invention.

[0108] Infrared spectrum test:

[0109] The microcapsules of Examples 1-8 and Comparative Examples 1-4 were subjected to infrared spectrum test after reacting at 80° C. for 3 hours. The test results of the microcapsules are shown in Table 10.

[0110] Table 10 Infrared test results of Examples 1-8 and Comparative Examples 1-4

[0111]

[0112]

[0113] The infrared test results of the microcapsules in Example 1 are as follows Figure 1 As shown; the infrared test results of the microcapsules of Example 2 are as shown Figure 2 As shown; the infrared test results of the microcapsules of Example 8 are as shown Figure 3 As shown; the infrared test results of the microcapsules of Comparative Example 1 are as follows Figure 4 As shown; the infrared test results of the microcapsules of Comparative Example 2 are as follows Figure 5 shown.

[0114] The infrared spectra (Table 10) test results of Examples 1-8 and Comparative Examples 1-4 show that after the addition of aminosiloxane, the reaction of the isocyanate group can be completed within 3 hours, and the isocyanate group is not likely to remain in the microcapsules finally obtained. However, the microcapsules in Comparative Example 1 do not add aminosiloxane, and the infrared absorption peak of the isocyanate group is still observed after the reaction for 3 hours. The results of Comparative Example 2 and Comparative Example 1 show that even if a large amount of amine polymer polyethyleneimine is added, the infrared absorption peak of the isocyanate group is still observed in the microcapsules of Comparative Example 2 after the reaction for 3 hours, indicating that residual isocyanate groups are likely to exist in Comparative Examples 1 and 2.

[0115] Release performance test of microcapsules:

[0116] The microcapsule samples of Examples 1 to 8 and Comparative Examples 1 to 4 were added to the same laundry detergent base liquid to prepare the laundry detergents of Examples 1 to 8 and Comparative Examples 1 to 4 with a microcapsule weight content of 0.3%.

[0117] Test method: dissolve 1g of laundry detergent in 1L of water, add the towel and soak it for 15 minutes, rub and wash 10 times, wring it out, rinse it twice with 1L of water, and dry it naturally (4h). Then evaluate the fragrance of the towel before and after friction to obtain the release performance results of the microcapsule (at room temperature).

[0118] The release performance test results of the microcapsules (at room temperature) in the laundry detergents of Examples 1 to 8 and Comparative Examples 1 to 4 are shown in Table 11.

[0119] Table 11 Test results of release performance of microcapsules in laundry detergents (at room temperature) of Examples 1 to 8 and Comparative Examples 1 to 4

[0120]

[0121]

[0122] It can be seen from the test results in Table 11 that Examples 1 to 8 and Comparative Examples 1 to 2 all have good release performance. Comparative Examples 3 and 4 have average friction release performance due to the small size of the microcapsules, which do not meet the technical effect of the technical solution of the present invention.

[0123] Microcapsule packaging stability test:

[0124] The microcapsule samples of Examples 1 to 8 and Comparative Examples 1 to 4 were respectively added into the same laundry detergent base liquid to prepare the laundry detergents of Examples 1 to 8 and Comparative Examples 1 to 4 with a microcapsule weight content of 0.3%.

[0125] Test method: Place the laundry detergent sample of the above microcapsule sample at 45°C for 28 days. After taking out, the appearance of all laundry detergents containing microcapsules did not change significantly. Test the release performance of microcapsules: dissolve 1g of laundry detergent in 1L of water, add the towel and soak it for 15 minutes, rub and wash 10 times, wring it out, rinse it twice with 2L of water, and dry it naturally (4h). Then evaluate the fragrance intensity of the towel before and after friction, and obtain the release performance of the microcapsules after storage at 45°C for 28 days. Compare the release performance of the microcapsules at room temperature (see Table 11) with the release performance after storage at 45°C for 28 days.

[0126] The specific test results are shown in Table 12 below:

[0127] Table 12 Release performance test and fragrance retention rate of microcapsules in laundry detergents of Examples 1 to 8 and Comparative Examples 1 to 4 after 28 days at 45°C

[0128] sample Before friction After friction Fragrance retention rate Example 1 0 2.5 67％ Example 2 0 2 55％ Example 3 0 2.7 70％ Example 4 0 2.4 69％ Example 5 0 2.5 72％ Example 6 0 2 52％ Example 7 0 2.3 67％ Example 8 0 2 51％ Comparative Example 1 0 0.5 15％ Comparative Example 2 0 0.5 14％ Comparative Example 3 0 1 50％ Comparative Example 4 0 1.4 54％

[0129] It can be seen from the test results in Table 12 that the fragrance retention of Examples 1 to 8 and Comparative Examples 3 to 4 is all above 50%, indicating that the addition of aminosiloxane can effectively enhance the encapsulation stability of the microcapsules.

[0130] Combined with Table 5, Table 11 and Table 12, although Comparative Examples 1 and Comparative Examples 2 have good friction fragrance release performance, due to the fact that the microcapsule wall material is not dense enough, the fragrance retention after being placed at 45°C for 28 days is only 15% and 14%, which does not meet the technical effect of the technical solution of the present invention.

[0131] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A microcapsule encapsulating a core material, characterized in that: It includes a core material, a wall material encapsulating the core material, a pH adjusting agent and water; The components of the wall material include: 1) polymer A; the polymer A is selected from one or a mixture of two of the following 1a) and 1b); 1a) polyvinyl alcohol; 1b) Polyvinylpyrrolidone; 2) polymer B; the polymer B is selected from one or a mixture of two of the following compounds of formula II and formula IV; Wherein, n is an integer between 2 and 800; The repeating unit L1 is a residue composed of a group connected to two nitrogen atoms on an isocyanate compound; the isocyanate compound is selected from at least one of anion-modified hexamethylene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, and isophorone diisocyanate; The repeating unit L2 is derived from a residue consisting of a group connected to the nitrogen atoms on two primary amines in polyethyleneimine; Repeating unit L3 is derived from the residue of groups other than the amino group in aminosiloxane, and its general formula is [R 1 S i 2 x (OR 3 ) 4-x ] y Formula V; wherein R 1 represents a straight or branched alkyl group having 1 to 6 carbon atoms; R 2 represents a straight or branched alkyl group having 1 to 4 carbon atoms; R 3 represents a straight or branched alkyl group having 1 to 4 carbon atoms; x=0, 1, 2; y=1, 2; In the raw materials used to prepare the polymer B, the mass content of aminosiloxane is 2-16%; 3) Cationic polymer; the cationic polymer is selected from one or a mixture of polyquaternium-10, polyquaternium-22, and polyquaternium-47.

2. The microcapsule encapsulating the core material according to claim 1, characterized in that: The polymer B also includes compounds of the following formula I and / or formula III; 3. The microcapsule encapsulating the core material according to claim 1 or 2, characterized in that: The components of the wall material include, by weight percentage: Polymer A12-34%, Polymer B 45-70%, Cationic polymer 3-10%.

4. The microcapsule encapsulating the core material according to claim 3, characterized in that: The wall material also contains 0-22% polysiloxane.

5. The microcapsule encapsulating the core material according to claim 1, characterized in that: The pH adjusting auxiliary agent is one or more of NaOH, ammonia water, citric acid and sodium citrate.

6. The microcapsule encapsulating the core material according to any one of claims 1 to 5, characterized in that: Based on the total weight of the microcapsules, the core material accounts for 21-38% of the total weight, the wall material accounts for 5-12% of the total weight, the pH adjusting agent accounts for 0.02-0.06% of the total weight, and the remainder is water.

7. The method for preparing a microcapsule encapsulating a core material according to claim 1, characterized in that: Prepared by the following steps: 1) Add polymer A and pH adjusting agent into water and stir until completely dissolved; 2) preparing the core material in another container; 3) mixing the products obtained in 1) and 2), stirring at 60° C. to 80° C. for 0.5 h to 1.5 h, and cooling to room temperature; 4) adding the raw materials corresponding to the repeating units L1, L2, and L3 in polymer B, namely, isocyanate compounds, polyethyleneimine, aminosiloxane, and cationic polymers, heating to 80° C. to 100° C., and stirring for 1 to 5 hours; 5) Cooling to room temperature, discharging to obtain microcapsules encapsulating the core material.

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