A soft and durable foamed silicone rubber material, its preparation method and use

Abstract

The present application relates to the technical field of room temperature curing foamed silicone rubber, and specifically discloses a soft and durable foamed silicone rubber material, a preparation method and application thereof. The foamed silicone rubber material comprises component A and component B. The component A comprises 20-30 parts of 107 silicone rubber, 2-6 parts of hydroxyl silicone oil, 1-2 parts of anti-aging filler and 0.05-0.1 parts of catalyst. The component B comprises 30-50 parts of vinyl silicone oil, 40-45 parts of hydrogen-containing silicone oil and 2-3 parts of anti-aging filler. The anti-aging filler is modified titanium dioxide. The foamed silicone rubber material disclosed by the present application is soft and comfortable, and has excellent application prospect in the fields of underwear breast pads, sofa mattress and the like.

Description

Technical Field

[0001] The invention relates to the technical field of room temperature curing foamed silicone rubber, and specifically discloses a soft and durable foamed silicone rubber material, a preparation method and application thereof. Background Art

[0002] Silicone rubber possesses exceptional physical properties unmatched by other synthetic and natural polymer materials, including resistance to high and low temperatures, weathering, UV radiation, arcing, ablation, and high dielectric strength. Foamed silicone rubber is a porous polymer composite material formed by foaming typical silicone rubber materials. Silicone rubber foaming mechanisms can be categorized into physical and chemical foaming. Physical foaming primarily involves introducing a phase-changing gas or liquid, or thermally expandable microspheres, into the silicone rubber matrix. The volume change caused by the phase change of the gas or liquid under temperature or pressure changes is exploited to construct a network of bubbles within the silicone rubber matrix. Chemical foaming involves generating gas through a chemical reaction within the silicone rubber matrix, which is then used to form bubbles. Through bubble coalescence and internal gas release, an open-pore silicone rubber structure is formed. When the pore formation rate is close to the crosslinking and curing rate of the silicone rubber, the resulting bubble size is stabilized. Controlling the bubble formation rate and the crosslinking and curing rate of the silicone rubber during chemical foaming is key to producing silicone rubber foam materials with uniform structure, high expansion ratio, or low density. Compared with solid silicone rubber, foam silicone rubber material not only continues the inherent high and low temperature resistance, flame retardancy and physiological inertness of solid silicone rubber material, but also has technical characteristics such as light weight, cushioning and shock absorption, damping and sound insulation and low thermal conductivity. Therefore, foam silicone rubber material combines the advantages of ordinary silicone rubber and foaming materials, and has broad application prospects in the field of silicone padding, such as bra padding.

[0003] Patent CN105394826A discloses a traditional Chinese medicine health-care silicone breast pad. The pad comprises a multilayer film bag comprised of at least three layers of TPU film stacked and joined together along its perimeter. The multilayer film bag comprises, from the inside out, an inner film bag and at least one outer film bag. The outer film bag is filled with silicone gel, which, after thermal curing, is bonded to the TPU film forming the outer film bag. The inner film bag is filled with traditional Chinese medicine powder. While this traditional Chinese medicine health-care silicone breast pad offers health and therapeutic benefits and combines the tactile feel and shaping properties of silicone breast pads, it fails to address the issues of deformation and cracking after use and washing, resulting in poor durability. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention discloses a soft and durable foamed silicone rubber material, its preparation method, and its application. The foamed silicone rubber material disclosed in the present invention is soft, skin-friendly, comfortable, and durable, and has excellent application prospects in areas such as underwear bra pads and sofa mattresses.

[0005] To achieve the above object, the technical scheme adopted by the present application is as follows:

[0006] The present application provides a kind of soft and durable foamed silicone rubber material, the foamed silicone rubber material includes A component and B component, by weight parts, the A component includes 107 silicone rubber 20-30 parts, hydroxyl silicone oil 2-6 parts, anti-aging filler 1-2 parts, catalyst 0.05-0.1 part;The B component includes vinyl silicone oil 30-50 parts, hydrogen-containing silicone oil 40-45 parts and anti-aging filler 2-3 parts;The anti-aging filler is modified titanium dioxide.

[0007] In some embodiments of the present application, the preparation steps of the modified titanium dioxide are as follows:

[0008] Tetrabutyl titanate, ethanol and formic acid are stirred and mixed, and after standing to gel, amino-containing silane coupling agent is added, and stirring is carried out at 45-50 DEG C for 2-4 h, then starch nanocrystals and deionized water are added, and ultrasonic dispersion is carried out for 10-30 min, and the modified titanium dioxide is obtained after drying.

[0009] In some embodiments of the present application, the mass ratio of tetrabutyl titanate, amino-containing silane coupling agent and starch nanocrystals is 1:(0.2-0.4):(0.4-0.6).

[0010] Preferably, the mass ratio of tetrabutyl titanate, amino-containing silane coupling agent and starch nanocrystals is 1:0.3:0.5.

[0011] In some embodiments of the present application, the amino-containing silane coupling agent is gamma-aminopropyl triethoxysilane.

[0012] In some embodiments of the present application, the particle size of the starch nanocrystals is 10-20 nm.

[0013] Preferably, the particle size of the starch nanocrystals is 15 nm.

[0014] The present application uses 107 silicone rubber and vinyl silicone oil as base stock, hydrogen-containing silicone oil as crosslinking agent, hydroxyl silicone oil as foaming aid, and modified titanium dioxide as anti-aging filler, to prepare a kind of soft and durable foamed silicone rubber material under the action of catalyst.

[0015] In the application, the titanium dioxide is modified by adding starch nanocrystals, and then added into the silicone rubber material system as an anti-aging filler. The starch nanocrystals are combined with the silicon hydroxyl groups on the surface of the titanium dioxide through dehydration condensation to form Si-O-Si bonds, and then a three-dimensional network dispersion structure is constructed, which further ensures the stability and durability of the system. At the same time, the titanium dioxide dispersed in the system can effectively absorb ultraviolet light and reduce the aging reaction of the material surface under ultraviolet light, further improving the anti-aging property of the silicone material. On the other hand, with the application of the silicone rubber material, the active oxygen atoms on the surface of the titanium dioxide can be further activated by the active centers of the titanium dioxide to generate hydroxyl radicals and active oxygen center ions, which endow the silicone rubber material with certain oxidation-reduction ability and improve the anti-aging stability of the silicone rubber material. At the same time, the modified titanium dioxide can also be combined with the base glue in the system through physical action, and the introduction of the amino group further improves the firmness, reduces the functional weakening phenomenon caused by the falling off with the increase of the use time, and increases the durability of the system.

[0016] In some embodiments of the application, the viscosity of the 107 silicone rubber in the A component is 800-1500 mPa·s at 25°C.

[0017] Preferably, the viscosity of the 107 silicone rubber in the A component is 1000 mPa·s at 25°C.

[0018] In some embodiments of the application, the vinyl silicone oil in the B component is a double-end vinyl terminated polydimethylsiloxane, and the viscosity is 8000-13000 mPa·s at 25°C.

[0019] Preferably, the vinyl silicone oil in the B component is a double-end vinyl terminated polydimethylsiloxane, and the viscosity is 10000 mPa·s at 25°C.

[0020] In some embodiments of the application, the hydroxyl content of the hydroxyl silicone oil is 1.5-1.8%.

[0021] Preferably, the hydroxyl content of the hydroxyl silicone oil is 1.6%.

[0022] In some embodiments of the application, the catalyst is a platinum-gold catalyst.

[0023] In some embodiments of the application, the hydrogen content of the hydrogen-containing silicone oil is 1-2%.

[0024] Preferably, the hydrogen content of the hydrogen-containing silicone oil is 1.5%.

[0025] Another aspect of the present invention provides a method for preparing a soft and durable foamed silicone rubber material, comprising the following steps:

[0026] S1: Mix 107 silicone rubber, hydroxy silicone oil, modified titanium dioxide, and catalyst and stir at room temperature for 1 to 2 hours to obtain component A;

[0027] S2: Mix vinyl silicone oil, hydrogenated silicone oil and modified titanium dioxide and stir at room temperature for 1 to 2 hours to obtain component B;

[0028] S3: When in use, component A of step S1 and component B of step S2 are mixed, stirred at room temperature for 0.5 to 1 hour, transferred to a mold, and vulcanized to obtain a foamed silicone rubber material.

[0029] Preferably, in step (3), component A and component B are mixed in a weight ratio of 1:(0.9-1.1).

[0030] Further preferably, in step (3), component A and component B are mixed in a weight ratio of 1:1 to obtain a foamed silicone rubber material for an underwear bra pad.

[0031] Further preferably, in the step (3), component A and component B are mixed in a weight ratio of 1:1.1, so that the foamed silicone rubber material is a sofa mattress.

[0032] In another aspect, the present invention further provides an application of the foamed silicone rubber material or the foamed silicone rubber material obtained by the preparation method in the field of underwear bra pads or sofa mattresses.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] (1) The present invention uses 107 silicone rubber and vinyl silicone oil as base rubber, hydrogenated silicone oil as cross-linking agent, hydroxy silicone oil as foaming aid, and modified titanium dioxide as aging-resistant filler to prepare a foamed silicone rubber material under the action of a catalyst. The material is soft, skin-friendly, comfortable and durable, and has excellent application prospects in the fields of underwear bra pads and sofa mattresses.

[0035] (2) The present invention modifies titanium dioxide by adding starch nanocrystals and then adds it to the silicone rubber material system as an aging-resistant filler. The starch nanocrystals combine with the silanol groups introduced by the pretreatment of the titanium dioxide surface through a large number of active hydroxyl groups on their surfaces through dehydration condensation to form Si-O-Si bonds, thereby constructing a three-dimensional network dispersed structure, further ensuring the stability and durability of the system.

[0036] (3) The active oxygen atoms on the silane coupling agent introduced on the surface of titanium dioxide in the present invention can further generate hydroxyl radicals and active oxygen central ions under the activation effect of the active center of titanium dioxide absorbing environmental energy, which gives the silicone rubber material a certain redox ability and synergistically improves the aging resistance and stability of the silicone rubber material. DETAILED DESCRIPTION

[0037] The present invention will be described below in conjunction with specific embodiments. It should be noted that the following examples are examples of the present invention and are only used to illustrate the present invention, but are not intended to limit the present invention. At the same time, all professional terms mentioned below have the same meaning as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention. Other combinations and various improvements within the scope of the present invention can be made without departing from the gist or scope of the present invention.

[0038] Unless otherwise specified, the reagents used below can be easily obtained from commercial companies. The viscosity of the 107 silicone rubber used below is 1000 mPa·s at 25°C; the vinyl silicone oil used is double-end vinyl-terminated polydimethylsiloxane with a viscosity of 10000 mPa·s at 25°C; the hydroxyl content of the hydroxyl silicone oil used is 1.6%; the catalyst used is a platinum catalyst; and the hydrogen content of the hydrogen-containing silicone oil used is 1.5%.

[0039] Unless otherwise specified, the post-processing steps such as "ultrasound", "drying" and "stirring" used below are routine operations of those skilled in the art and can be selected according to actual operations.

[0040] Preparation Example 1

[0041] The preparation steps of starch nanocrystals are as follows:

[0042] 1 g of waxy corn starch was mixed with 10 mL of 3.16 mol / L sulfuric acid solution to obtain a suspension, which was heated at 70 °C and stirred for 3.5 days. Starch nanocrystals were obtained by centrifugation, washing, and freeze-drying.

[0043] Preparation Example 2

[0044] The preparation steps of modified titanium dioxide are as follows:

[0045] 10 g of tetrabutyl titanate, 40 mL of ethanol and 10 g of formic acid were stirred and mixed, and allowed to stand until a gel formed. Then, 3 g of γ-aminopropyltriethoxysilane was added and stirred at 48 ° C for 3 h. Then, 5 g of starch nanocrystals and 50 mL of deionized water were added, and the mixture was ultrasonically dispersed for 20 min and dried to obtain modified titanium dioxide.

[0046] The starch nanocrystals used were obtained from Preparation Example 1.

[0047] Preparation Example 3

[0048] The preparation steps of modified titanium dioxide are the same as those in Preparation Example 2, except that the amount of γ-aminopropyltriethoxysilane added is 4.5 g.

[0049] Preparation Example 4

[0050] The preparation steps of modified titanium dioxide are the same as those in Preparation Example 2, except that the amount of starch nanocrystals added is 6.5 g.

[0051] Example 1

[0052] A soft and durable foamed silicone rubber material comprises a component A and a component B. Component A comprises 25 parts by weight of 107 silicone rubber, 4 parts by weight of hydroxy silicone oil, 1.5 parts by weight of modified titanium dioxide, and 0.07 parts by weight of a catalyst; and component B comprises 40 parts by weight of vinyl silicone oil, 42 parts by weight of hydrogenated silicone oil, and 2.5 parts by weight of modified titanium dioxide.

[0053] The method for preparing the soft and durable foamed silicone rubber material comprises the following steps:

[0054] S1: Mix 107 silicone rubber, hydroxy silicone oil, modified titanium dioxide, and catalyst, and stir at 25°C for 1.5 hours to obtain component A;

[0055] S2: Vinyl silicone oil, hydrogenated silicone oil and modified titanium dioxide were mixed and stirred at 25°C for 1.5 hours to obtain component B;

[0056] S3: When in use, component A of step S1 and component B of step S2 are mixed in a weight ratio of 1:1, stirred at 25°C for 8 minutes, transferred to a breast pad mold, and reacted and formed at 25°C and a relative humidity of 45% to obtain a foamed silicone rubber material, i.e., an underwear breast pad.

[0057] The modified titanium dioxide used in this example was obtained from Preparation Example 2.

[0058] Example 2

[0059] A soft and durable foamed silicone rubber material comprises a component A and a component B. Component A comprises 20 parts by weight of 107 silicone rubber, 2 parts by weight of hydroxy silicone oil, 1 part by weight of modified titanium dioxide, and 0.05 parts by weight of a catalyst; and component B comprises 30 parts by weight of vinyl silicone oil, 40 parts by weight of hydrogenated silicone oil, and 2 parts by weight of modified titanium dioxide.

[0060] The method for preparing the soft and durable foamed silicone rubber material comprises the following steps:

[0061] S1: Mix 107 silicone rubber, hydroxy silicone oil, modified titanium dioxide, and catalyst, and stir at 25°C for 1 hour to obtain component A;

[0062] S2: mixing the vinyl silicone oil, hydrogen-containing silicone oil and modified titanium dioxide, and stirring at 25°C for 1 h to obtain component B;

[0063] S3: in use, mixing component A of step S1 and component B of step S2 in a weight ratio of 1:1, stirring at 25°C for 5 min, transferring to a breast pad mold, and reaction molding at 25°C and a relative humidity of 40% to obtain a foamed silicone rubber material, i.e. a breast pad for underwear.

[0064] The modified titanium dioxide used in this example is obtained from Preparation Example 2.

[0065] Example 3

[0066] A soft and durable foamed silicone rubber material, which comprises component A and component B, wherein the component A comprises, by weight parts, 107 silicone rubber 30 parts, hydroxyl silicone oil 6 parts, modified titanium dioxide 2 parts, and catalyst 0.1 part; and the component B comprises vinyl silicone oil 50 parts, hydrogen-containing silicone oil 45 parts, and modified titanium dioxide 3 parts.

[0067] A method for preparing a soft and durable foamed silicone rubber material, which comprises the following steps:

[0068] S1: mixing 107 silicone rubber, hydroxyl silicone oil, modified titanium dioxide, and catalyst, and stirring at 25°C for 2 h to obtain component A;

[0069] S2: mixing the vinyl silicone oil, hydrogen-containing silicone oil and modified titanium dioxide, and stirring at 25°C for 2 h to obtain component B;

[0070] S3: in use, mixing component A of step S1 and component B of step S2 in a weight ratio of 1:1, stirring at 25°C for 10 min, transferring to a breast pad mold, and reaction molding at 25°C and a relative humidity of 60% to obtain a foamed silicone rubber material, i.e. a breast pad for underwear.

[0071] The modified titanium dioxide used in this example is obtained from Preparation Example 2.

[0072] Example 4

[0073] A soft and durable foamed silicone rubber material and a method for preparing the same, the specific implementation manner of which is the same as that of Example 1, except that the modified titanium dioxide used is obtained from Preparation Example 3.

[0074] Example 5

[0075] A soft and durable foamed silicone rubber material and a method for preparing the same, the specific implementation manner of which is the same as that of Example 1, except that the modified titanium dioxide used is obtained from Preparation Example 4.

[0076] Comparative Example 1

[0077] A soft and durable foamed silicone rubber material and a preparation method thereof. The specific implementation method is the same as that of Example 1, except that an equal amount of titanium dioxide is used to replace modified titanium dioxide as an aging-resistant filler.

[0078] Performance Testing

[0079] (1) Mechanical property test: The tear strength of each foamed silicone rubber material prepared in Examples 1-5 and Comparative Example 1 was tested with reference to the standard GB / T 528-2009.

[0080] (2) Foaming density test: The foaming density of each foamed silicone rubber material prepared in Examples 1 to 5 and Comparative Example 1 was tested with reference to the standard GB / T 6343-2009.

[0081] (3) Durability test: The foamed silicone rubber materials prepared in Examples 1-5 and Comparative Example 1 were placed in a standard washing test machine and washed 10 times according to the 5A washing test standard. The 5A washing test standard is washing at 60°C for 1 hour. Five consecutive washes are counted as one wash. After each wash and drying, observe whether the foamed silicone rubber material has cracking or falling debris after 10 washes.

[0082] Table 1

[0083] Group Tear strength (N / mm) <![CDATA[发泡密度(g / cm 3 )]]> Durability Example 1 29.7 0.18 none Example 2 29.3 0.19 none Example 3 29.6 0.21 none Example 4 27.6 0.25 none Example 5 28 0.23 There is cracking, no slag Comparative Example 1 27.0 0.26 There are cracks and chipping

[0084] As can be seen from Table 1, the foamed silicone rubber materials provided by Examples 1 to 3 of the present invention have high tear strength, low foaming density and good durability. As can be seen from Example 4 compared with Example 1, when the amount of γ-aminopropyltriethoxysilane added to prepare the modified titanium dioxide is changed, the silicon hydroxyl groups introduced by the surface pretreatment of the titanium dioxide are insufficient, which will affect the dispersibility of the system and the construction of the network structure, thereby causing the tear strength of the foamed silicone rubber material to decrease to varying degrees and the foaming density to increase. As can be seen from Example 5 and compared with Example 1, when the amount of starch nanocrystals added when preparing the modified titanium dioxide is changed, the stability of the three-dimensional network dispersion structure of the foamed silicone rubber material is affected, resulting in a decrease in durability. As can be seen from Comparative Example 1 compared with Example 1, when titanium dioxide is directly used in an equal amount to replace the modified titanium dioxide as the aging-resistant filler of this system, the uniformity of the three-dimensional network structure of the system will decrease, thereby causing the tear strength and durability of the foamed silicone rubber material to decrease.

[0085] The above merely describes preferred embodiments of the present application, and is not intended to limit the present application in any form. Although the present application has been disclosed with the preferred embodiments as above, it is not intended to limit the present application. Any person skilled in the art, without departing from the technical solution of the present application, can make some changes or modifications to the above disclosed technical content to obtain equivalent embodiments with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application, without departing from the technical solution of the present application, shall still fall within the scope of the technical solution of the present application.

Claims

1. A soft and durable foamed silicone rubber material, characterized in that: The foamed silicone rubber material comprises component A and component B. Component A comprises 20 to 30 parts of 107 silicone rubber, 2 to 6 parts of hydroxy silicone oil, 1 to 2 parts of aging-resistant filler, and 0.05 to 0.1 parts of catalyst, and component B comprises 30 to 50 parts of vinyl silicone oil, 40 to 45 parts of hydrogenated silicone oil, and 2 to 3 parts of aging-resistant filler. The aging-resistant filler is modified titanium dioxide. The preparation steps of the modified titanium dioxide are as follows: Tetrabutyl titanate, ethanol and formic acid are stirred and mixed, and after standing until a gel is formed, an amino-containing silane coupling agent is added, and the mixture is stirred and reacted at 45-50° C. for 2-4 hours, and starch nanocrystals and deionized water are added, and the mixture is ultrasonically dispersed for 10-30 minutes and dried to obtain the modified titanium dioxide. The mass ratio of tetrabutyl titanate, amino-containing silane coupling agent and starch nanocrystals is 1:(0.2-0.4):(0.4-0.6); The amino-containing silane coupling agent is γ-aminopropyltriethoxysilane.

2. The soft and durable foamed silicone rubber material according to claim 1, characterized in that: The particle size of the starch nanocrystal is 10 to 20 nm.

3. The soft and durable foamed silicone rubber material according to claim 1, characterized in that: The vinyl silicone oil in the B component is a double-end vinyl-terminated polydimethylsiloxane with a viscosity of 8000 to 13000 mPa·s at 25°C.

4. The soft and durable foamed silicone rubber material according to claim 1, characterized in that: The hydroxyl content of the hydroxy silicone oil in component A is 1.5-1.8%.

5. The soft and durable foamed silicone rubber material according to claim 1, characterized in that: The hydrogen content of the hydrogen-containing silicone oil in the B component is 0.1-0.2%.

6. A method for preparing the soft and durable foamed silicone rubber material according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1: Mix 107 silicone rubber, hydroxy silicone oil, modified titanium dioxide, and catalyst and stir at room temperature for 1 to 2 hours to obtain component A; S2: Mix vinyl silicone oil, hydrogenated silicone oil and modified titanium dioxide and stir at room temperature for 1 to 2 hours to obtain component B; S3: When in use, component A of step S1 and component B of step S2 are mixed, stirred at room temperature for 5 to 10 minutes, transferred to a mold, and vulcanized to obtain a foamed silicone rubber material.

7. Use of the foamed silicone rubber material according to any one of claims 1 to 5 or the foamed silicone rubber material obtained by the preparation method according to claim 6 in the field of underwear bra pads or sofa mattresses.