High-glossiness silicone oil and preparation method thereof

Abstract

The invention provides high-glossiness silicone oil and a preparation method thereof, and relates to the technical field of silicone oil synthesis. According to the high-glossiness silicone oil disclosed by the invention, a biphenyl structure is grafted on the side chain of a polysiloxane main chain, so that the refractive index and glossiness of the silicone oil are obviously improved.

Description

Technical Field

[0001] The invention belongs to the technical field of silicone oil synthesis and relates to high-gloss silicone oil and a preparation method thereof. Background Art

[0002] Silicone oil is widely used in personal care products. Conventional dimethyl silicone oil generally has a refractive index (25°C) of around 1.39-1.42. High-gloss silicone oil is a special type of silicone oil with a higher refractive index, typically 1.45 or higher at 25°C. Adding silicone oil with a higher refractive index (refractive index 1.45-1.53) to personal care products can make the skin smoother and softer when applied to the skin. Currently, high-gloss silicone oils are generally phenyl silicone oils. This is achieved by introducing phenyl groups into the side chains of polysiloxane to increase the refractive index. The higher the phenyl content, the higher the refractive index. For example, at a phenyl content of 30 mol%, the refractive index of phenyl silicone oil can reach around 1.50, and at a phenyl content of 40-50 mol%, the refractive index of phenyl silicone oil can reach around 1.53-1.55. Existing phenyl silicone oils are generally obtained through the ring-opening reaction of octamethylcyclotetrasiloxane and methylphenylcyclotetrasiloxane. The ring-opening reaction rates of these two raw materials differ significantly, resulting in poor reaction efficiency. Alternatively, chlorosilanes can be hydrolyzed and condensed, as disclosed in Chinese patent CN103408759A, using dimethyldichlorosilane, methylphenyldichlorosilane, and diphenyldichlorosilane for hydrolysis and condensation. This method produces a large amount of acidic wastewater, and the resulting phenyl silicone oil is likely to contain residual HCl.

[0003] In addition, in some special applications, silicone oil is required to have a higher refractive index, such as above 1.60 or even higher.

[0004] Therefore, there is a need to develop silicone oils with higher refractive index. Summary of the Invention

[0005] One approach to developing silicone oils with higher refractive indices is to introduce more phenyl groups into the side chains of the polysiloxane backbone of phenyl silicone oils. However, excessive phenyl content increases production difficulties. Furthermore, the refractive index of phenyl silicone oils has an upper limit, making further improvement difficult. To address these technical issues, the present invention provides a high-gloss silicone oil and a method for its preparation.

[0006] The technical solutions of the present invention are as follows:

[0007] A high gloss silicone oil having a structure as shown in the following formula (1):

[0008]

[0009] wherein R1, R2, R3, R4, R5, R6, R7, R8 and R9 are independently selected from C1-C4 alkyl groups, R 10 is absent, C1-C6 alkylene or C1-C8 substituted alkylene, R 11 is absent, C1-C4 alkyl, C1-C4 substituted alkyl or halogen, a>0, b>0, 0.05≤b / (a+b)≤0.4.

[0010] Preferably, R1, R2, R3, R4, R5, R6, R7, R8 and R9 are independently selected from methyl groups.

[0011] Preferably, the R 10 Containing -NHCONH-, -NHCON(R 14 )-, -NHCOO-, secondary amino group, tertiary amino group, ether bond or thioether bond C1-C8 divalent organic group, wherein R 14 It is a C1-C4 alkyl group.

[0012] Preferably, the values of a and b satisfy: 0.1≤b / (a+b)≤0.3.

[0013] Preferably, the values of a and b satisfy: a+b≤200.

[0014] A method for preparing the high-gloss silicone oil according to any of the above embodiments, comprising reacting a polysiloxane having a structure represented by the following formula (2) with a biphenyl compound represented by the following formula (3),

[0015]

[0016] Among them, R 12 and R 13 The reaction forms R 10 .

[0017] Preferably, the R 12 is selected from C1-C5 alkyl groups containing -NH2, -NH- and / or -OH, wherein R 13 Selected from C1-C6 alkyl groups containing -NCO groups and / or epoxy groups.

[0018] Preferably, the R 12 Selected from H or C2-C6 alkyl containing sulfhydryl, said R 13 Selected from C2-C6 alkyl groups containing a terminal vinyl group.

[0019] Preferably, the R 12 Selected from chlorine-containing C1-C6 alkyl, said R 13 Selected from C2-C5 alkyl groups containing a primary amino group.

[0020] Preferably, the biphenyl compound is selected from one or a combination of two or more of 2-biphenyl isocyanate, 2-(4-biphenyl)ethyl isocyanate, 4-biphenyl isocyanate, 4-vinylbiphenyl, 4-cyano-4'-(2-propenyloxy)biphenyl, 3-aminobiphenyl, 2-aminobiphenyl, 4-aminobiphenyl, 4-aminoethylbiphenyl, 4'-ethylbiphenyl-4-amine, 2-amino-4,4-di-tert-butylbiphenyl and 4'-tert-butylbiphenyl-4-amine.

[0021] The beneficial effects of the present invention are:

[0022] (1) The present invention grafts a biphenyl structure on the side chain of the polysiloxane segment. The biphenyl structure has a large refractive index and can significantly increase the refractive index of the silicone oil at a low grafting rate. Therefore, the obtained silicone oil also has a high refractive index and gloss, and the refractive index can be regulated according to the content of the biphenyl group.

[0023] (2) The preparation method of the high gloss silicone oil of the present invention is relatively simple and controllable. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further illustrated and described below through specific implementation methods.

[0025] In order to obtain a silicone oil having a higher refractive index (the refractive index in the present invention is the refractive index of 25° C.) and glossiness, on the one hand, the present invention proposes a high-gloss silicone oil having a structure shown in the following formula (1):

[0026]

[0027] wherein R1, R2, R3, R4, R5, R6, R7, R8 and R9 are independently selected from C1-C4 alkyl groups, R 10 is absent, C1-C6 alkylene or C1-C8 substituted alkylene, R 11 is absent, C1-C4 alkyl, C1-C4 substituted alkyl or halogen, a>0, b>0, 0.05≤b / (a+b)≤0.4.

[0028] In the present invention, the biphenyl structure grafted on the side chain of the polysiloxane has the following characteristics: (1) the biphenyl structure has a higher refractive index than the phenyl group, (2) the biphenyl structure has a higher polarizability than the phenyl group, and (3) the volume of the biphenyl structure is larger than that of the phenyl group, which can improve the rigidity of the silicone oil molecular structure and reduce the free volume. Therefore, compared with methylphenyl silicone oil, when the grafting ratio (the molar ratio of phenyl and biphenyl structures, equivalent to the value of b / (a+b) in the above formula (1)) is the same or similar, the high-gloss silicone oil of the present invention has a higher refractive index. For example, the refractive index of methylphenyl silicone oil with a phenyl content of 5 mol% (i.e., the grafting ratio of phenyl is 5 mol%) at 25°C is 1.425-1.440. When b / (a+b) = 5% (i.e., the grafting ratio of biphenyl structure is 5 mol%) in the above-mentioned high-gloss silicone oil of the present invention, the refractive index is 1.480-1.500, which is significantly higher than the refractive index of methylphenyl silicone oil.

[0029] In the high-gloss silicone oil represented by the structure of formula (1), there is no particular limitation on the value of b / (a+b). For example, it can be any value among 0.05, 0.08, 0.1, 0.12, 0.15, 0.17, 0.18, 0.2, 0.22, 0.25, 0.27, 0.3, 0.33, 0.35, 0.38, 0.4, etc. Generally, the larger the value of b / (a+b), the higher the refractive index of the high-gloss silicone oil of the present invention. For example, when b / (a+b) = 0.05, the refractive index of the high-gloss silicone oil can reach about 1.483, and when b / (a+b) = 0.4, the refractive index of the high-gloss silicone oil can reach about 1.625.

[0030] In some embodiments, R1, R2, R3, R4, R5, R6, R7, R8 and R9 are independently selected from methyl groups. In this case, the raw materials used to prepare the above-mentioned high-gloss silicone oil are relatively common and can be directly obtained from the market. The raw materials include hexamethyldisiloxane (or low-viscosity dimethyl silicone oil, with a viscosity of 3-10 mPa.s at 25°C), octamethylcyclotetrasiloxane, etc., which are more conducive to industrial production.

[0031] In some embodiments, R 10 The connecting structure of the biphenyl structure of the side chain and the polysiloxane main chain may be -NHCONH-, -NHCON(R 14 )-, -NHCOO-, secondary amino group, tertiary amino group, ether bond or thioether bond C1-C8 divalent organic group, wherein R 14 is a C1-C4 alkyl group. 10 When the above groups or structures are used, the biphenyl structure can be well connected to the side chain of polysiloxane, which has good stability. 10The high polarity of the structure is also beneficial to maintaining or improving the refractive index of the high gloss silicone oil of the present invention. For example, the C1-C8 divalent organic group containing -NHCONH- can be -CH2NHCONH-, -NHCONHCH2-, -CH2NHCONHCH2-, -CH2CH2NHCONHCH2-, -CH2CH2CH2NHCONH-, etc.; for the C1-C8 divalent organic group containing -NHCONH-, -NHCONHCH2-, -CH2NHCONHCH2-, -CH2CH2NHCONHCH2-, -CH2CH2CH2NHCONH-, etc. 14 For example, -CH2NHCON(CH3)-, -CH2CH2CH2NHCON(CH3)-, etc.; for C1-C8 divalent organic groups containing -NHCOO-, for example, -CH2NHCOO-, -CH2CH2NHCOO-, -CH2CH2NHCOOCH2-, -CH2CH2CH2NHCOO-, -CH2CH2CH2NHCOOCH2-, etc.; for C1-C8 divalent organic groups containing secondary amino groups, for example, -CH2CH2NH-, -CH2CH2CH2NH-, -CH2CH2 CH2NHCH2-, etc.; for the C1-C8 divalent organic group containing a tertiary amino group, examples include -CH2CH2N(CH3)-, -CH2CH2CH2N(CH3)-, -CH2CH2N(CH2CH3)-, etc.; for the C1-C8 divalent organic group containing an ether bond, examples include -CH2CH2OCH2-, -CH2CH2OCH2CH2-, etc.; for the C1-C8 divalent organic group containing an ether-sulfide bond, examples include -CH2CH2S-, -CH2CH2CH2S-, -CH2CH2CH2SCH2-, -CH2CH2CH2SCH2-, etc.

[0032] In some embodiments, the values of a and b satisfy the following: 0.1 ≤ b / (a+b) ≤ 0.3. That is, when the grafting ratio of the biphenyl structure is 10-30 mol%, the refractive index of the high-gloss silicone oil of the present invention can be approximately 1.500-1.580. For example, the value of b / (a+b) can be any of 0.1, 0.12, 0.14, 0.15, 0.16, 0.17, 0.18, 0.2, 0.22, 0.24, 0.25, 0.27, 0.3, etc., without particular limitation.

[0033] In some embodiments, the values of a and b satisfy: a+b≤200. Since the biphenyl structure of the side chain is relatively bulky and increases the rigidity of the silicone oil molecular structure, if the degree of polymerization a+b is too large, the viscosity of the high-gloss silicone oil of the present invention will be too high, which is not conducive to application. Specifically, the value of a+b can be any value of 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, etc.

[0034] On the other hand, the present invention also provides a method for preparing the high-gloss silicone oil described in any of the above embodiments, which is obtained by reacting a polysiloxane having a structure represented by the following formula (2) with a biphenyl compound represented by the following formula (3):

[0035]

[0036]

[0037] Among them, R 12 and R 13 The reaction forms R 10 .

[0038] In the present invention, R 13 R in the polysiloxane represented by formula (2) 12 The reaction can smoothly chemically graft the biphenyl structure onto the side chain of the polysiloxane, thereby obtaining the high-gloss silicone oil of the present invention. The preparation method of the polysiloxane represented by formula (2) is well known to those skilled in the art. For example, it can be prepared by a ring-opening reaction of an end-capping agent (hexamethyldisiloxane, decamethyltetrasiloxane, dimethyl silicone oil with a viscosity of 3-10 mPa.s at 25°C, etc.), octamethylcyclotetrasiloxane and other siloxane ring bodies (such as tetramethylcyclotetrasiloxane) or a dialkoxysilane (such as 3-aminopropylmethyldimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, etc.) in the presence of an acidic catalyst or a basic catalyst, and then removing the catalyst and removing the low-boiling substances to obtain the polysiloxane.

[0039] In some embodiments, R 12 is selected from C1-C5 alkyl groups containing -NH2, -NH- and / or -OH, R 13 The polysiloxane side chain of formula (2) contains reactive groups such as -NH2, -NH-, and / or -OH, and the biphenyl compound of formula (3) contains -NCO and / or epoxy groups, which can smoothly undergo reactions such as addition reactions between -NCO groups and -NH2, -NH-, or -OH.

[0040] In some embodiments, R 12 is selected from H or a C2-C6 alkyl group containing a thiol group, R 13 The polysiloxane compound is selected from C2-C6 alkyl groups containing terminal vinyl groups. That is, the polysiloxane side chain shown in formula (2) contains active groups such as -Si-H and -SH, and the biphenyl compound shown in formula (3) contains terminal alkenyl groups, which can smoothly undergo reactions such as hydrosilylation reaction and thiol-ene click chemistry reaction.

[0041] In some embodiments, R 12 Selected from chlorine-containing C1-C6 alkyl, R 13 The polysiloxane of formula (2) contains a -Cl side chain, and the biphenyl compound of formula (3) contains a primary amino group. This allows for smooth reactions, such as the removal of HCl by reacting -CH2CH2CH2Cl with -NH2 in the presence of a basic catalyst (or an acid-binding agent).

[0042] In some embodiments, the biphenyl compound is selected from one or a combination of two or more of 2-biphenyl isocyanate, 2-(4-biphenyl)ethyl isocyanate, 4-biphenyl isocyanate, 4-vinylbiphenyl, 4-cyano-4'-(2-propenyloxy)biphenyl, 3-aminobiphenyl, 2-aminobiphenyl, 4-aminobiphenyl, 4-aminoethylbiphenyl, 4'-ethylbiphenyl-4-amine, 2-amino-4,4-di-tert-butylbiphenyl and 4'-tert-butylbiphenyl-4-amine.

[0043] The high-gloss silicone oil of the present invention can be used not only in heat-insulating care products, but also in optical instruments, lighting industries, and the like.

[0044] The technical solution of the present invention is further described and illustrated below based on various preparation examples and embodiments.

[0045] Preparation Example 1-3 Preparation of polysiloxane

[0046] Preparation Example 1

[0047] 0.6 mol of decamethyltetrasiloxane, 10 mol of octamethylcyclotetrasiloxane, and 2.2 mol of 3-aminopropylmethyldimethoxysilane were heated to 80° C. and dehydrated under reduced pressure for 20 minutes. Then, tetramethylammonium siloxane (0.012 wt % based on tetramethylammonium hydroxide) was added. The mixture was heated under nitrogen protection and reacted at 110-120° C. for 2 hours. The pressure was reduced to -(0.08±0.005) MPa, and the temperature was raised to 135-140° C. to decompose the catalyst for 30 minutes. The pressure was reduced to below -0.099 MPa, and the temperature was raised to 150-155° C. to remove low-boiling substances to obtain primary aminopolysiloxane.

[0048] Preparation Example 2

[0049] The difference between this preparation example and Preparation Example 1 is that in Preparation Example 1, the amount of decamethyltetrasiloxane was adjusted from 0.6 mol to 0.3 mol, and the amount of 2.2 mol of 3-aminopropylmethyldimethoxysilane was adjusted to 17.2 mol of N-methylaminopropylmethyldimethoxysilane. The remaining steps remained unchanged to obtain a secondary aminopolysiloxane.

[0050] Preparation Example 3

[0051] 0.8 mol of decamethyltetrasiloxane, 10 mol of octamethylcyclotetrasiloxane and 1.1 mol of tetramethylcyclotetrasiloxane were mixed, concentrated sulfuric acid accounting for 2% of the total weight of the raw materials was added, the temperature was raised to 80-85° C. and the reaction was carried out for 6 hours. Excess sodium bicarbonate was added to neutralize the concentrated sulfuric acid, and the concentrated sulfuric acid was filtered after dehydration. The filtrate was heated to 140-150° C. and the pressure was reduced to below -0.099 MPa to remove low-boiling substances to obtain hydrogen-containing polysiloxane.

[0052] Example 1

[0053] The primary amino polysiloxane (containing 0.01 mol of primary amino group) of Preparation Example 1 was added to 2000 ml of anhydrous butyl acetate, and the mixture was placed in an ice-water bath. A mixed solution containing 0.01 mol of 2-(4-biphenyl)ethyl isocyanate and 20 ml of anhydrous butyl acetate was added dropwise. After the addition was complete, the mixture was stirred and reacted in an ice-water bath for 5 h. The mixture was transferred to room temperature (23° C.) and stirred and reacted for 2 h. The temperature was then raised to 60° C. and reacted for 4 h. The butyl acetate was removed to obtain a transparent oily liquid, which was a high-gloss silicone oil. The refractive index at 25° C. was measured to be 1.486, and the viscosity at 25° C. was 1030 mPa.s (tested using an NDJ-5S rotational viscometer).

[0054] Example 2

[0055] At room temperature, the secondary aminopolysiloxane of Preparation Example 2 (containing 0.01 mol of secondary amino groups) was added to 4000 ml of anhydrous butyl acetate, and a mixed solution containing 0.01 mol of 2-(4-biphenyl)ethyl isocyanate and 20 ml of anhydrous butyl acetate was added dropwise. After the addition, the mixture was stirred and reacted at room temperature for 6 h. The temperature was raised to 80° C. and the reaction was continued for 5 h. The butyl acetate was removed to obtain a transparent, viscous, nearly colloidal silicone oil with a refractive index of 1.607 at 25° C.

[0056] Example 3

[0057] At room temperature, the hydrogenated polysiloxane (containing 0.01 mol of Si—H) from Preparation Example 3, 0.01 mol of 4-cyano-4′-(2-propenyloxy)biphenyl, and 200 ml of mesitylene were mixed and heated to 80° C. Karstedst catalyst (25 ppm, calculated as Pt) was added. The mixture was reacted at 135-140° C. under nitrogen for 6 h. The mesitylene was removed to obtain a transparent oily liquid, i.e., a high-gloss silicone oil. The refractive index at 25° C. was measured to be 1.524, and the viscosity at 25° C. was 2260 mPa.s (measured using an NDJ-5S rotational viscometer).

[0058] Comparative Example 1

[0059] The hydrogenated polysiloxane (containing 0.01 mol of Si—H) prepared in Preparation Example 3, 0.01 mol of 4-cyano-4'-(2-propenyloxy)biphenyl, and 200 ml of mesitylene were mixed and dissolved by stirring at room temperature. After removing the mesitylene, solids precipitated in the liquid, which may be due to the poor compatibility of 4-cyano-4'-(2-propenyloxy)biphenyl with the hydrogenated polysiloxane.

[0060] As described above, the basic principles, main features, and advantages of the present invention are shown and described. Those skilled in the art should understand that the present invention is not limited to the above-described embodiments. The above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. In other words, equivalent changes and modifications made within the scope of the present invention and the contents of the specification should still fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A high gloss silicone oil, characterized in that, It has the structure shown in the following formula (1), wherein R1, R2, R3, R4, R5, R6, R7, R8 and R9 are independently selected from C1-C4 alkyl groups, R 10 is absent, C1-C6 alkylene or C1-C8 substituted alkylene, R 11 is absent, C1-C4 alkyl, C1-C4 substituted alkyl or halogen, a>0, b>0, 0.05≤b / (a+b)≤0.

4.

2. The high gloss silicone oil according to claim 1, characterized in that The R1, R2, R3, R4, R5, R6, R7, R8 and R9 are independently selected from methyl groups.

3. The high gloss silicone oil according to claim 1, characterized in that The R 10 Containing -NHCONH-, -NHCON(R 14 )-, -NHCOO-, secondary amino group, tertiary amino group, ether bond or thioether bond C1-C8 divalent organic group, wherein R 14 It is a C1-C4 alkyl group.

4. The high gloss silicone oil according to claim 1, characterized in that The values of a and b satisfy: 0.1≤b / (a+b)≤0.

3.

5. The high gloss silicone oil according to claim 1, characterized in that The values of a and b satisfy: a+b≤200.

6. A method for preparing the high-gloss silicone oil according to any one of claims 1 to 5, characterized in that: Obtained by reacting a polysiloxane having a structure represented by the following formula (2) with a biphenyl compound represented by the following formula (3), Among them, R 12 and R 13 The reaction forms R 10 .

7. The method for preparing high gloss silicone oil according to claim 6, wherein The R 12 is selected from C1-C5 alkyl groups containing -NH2, -NH- and / or -OH, wherein R 13 Selected from C1-C6 alkyl groups containing -NCO groups and / or epoxy groups.

8. The method for preparing high gloss silicone oil according to claim 6, wherein The R 12 Selected from H or C2-C6 alkyl containing sulfhydryl, said R 13 Selected from C2-C6 alkyl groups containing a terminal vinyl group.

9. The method for preparing high gloss silicone oil according to claim 6, wherein The R 12 Selected from chlorine-containing C1-C6 alkyl, said R 13 Selected from C2-C5 alkyl groups containing a primary amino group.

10. The method for preparing high gloss silicone oil according to claim 6, characterized in that: The biphenyl compound is selected from one or a combination of two or more of 2-biphenyl isocyanate, 2-(4-biphenyl)ethyl isocyanate, 4-biphenyl isocyanate, 4-vinylbiphenyl, 4-cyano-4'-(2-propenyloxy)biphenyl, 3-aminobiphenyl, 2-aminobiphenyl, 4-aminobiphenyl, 4-aminoethylbiphenyl, 4'-ethylbiphenyl-4-amine, 2-amino-4,4-di-tert-butylbiphenyl and 4'-tert-butylbiphenyl-4-amine.

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