A kind of organic silicon-based plastic caulking sealing material and its preparation method and application

Abstract

The present invention relates to a silicone-based plastic caulking sealing material, a preparation method, and an application thereof. The material comprises the following components in parts by weight: 100 to 340 parts of hydroxyl-terminated polydimethylsiloxane, 300 to 600 parts of filler, 140 to 520 parts of plasticizer, 5 to 20 parts of resin, 0.5 to 5 parts of thickener, 5 to 20 parts of pigment, 0.5 to 3 parts of mildew inhibitor, and 0.5-50 parts of thixotropic agent; the weight of the thixotropic agent accounts for 0.1% to 6% of the total weight of the hydroxyl-terminated polydimethylsiloxane and the plasticizer. The silicone-based plastic caulking sealing material of the present invention has no chemical cross-linking reaction and is a non-cross-linking system. When applied to concrete panel dams of hydraulic structures, it meets the use requirements of an environment of 40°C to 70°C, has the characteristics of not hardening at low temperatures, not flowing at high temperatures, and excellent plastic deformation ability.

Description

Technical Field

[0001] The invention relates to the technical field of waterproofing and anti-seepage of expansion joints of hydraulic structures, and in particular to an organosilicon-based plastic caulking sealing material and a preparation method and application thereof. Background Art

[0002] Concrete face rockfill dams (FRMs), a hydraulic structure, have been widely adopted in the hydropower industry both domestically and internationally, playing a critical role in the construction of hydropower stations. Joint waterstopping is a crucial component of the concrete face dam's anti-seepage system. The Gouhou Reservoir concrete face dam in Gonghe County, Qinghai Province, has a maximum height of 71 meters and a normal water level of 3278.00 meters. In 1993, when the reservoir water level reached 3227.35 meters, the joint waterstop between the wave-breaking wall base and the top of the face dam failed, allowing reservoir water to flow in from the upper part of the dam body and escape from the upper part, eroding the dam slope and causing the dam to fail. Therefore, the quality of the joint waterstop structure directly affects the safe operation of a hydropower station.

[0003] Plastic caulking sealing material for face dam is the key material in joint anti-seepage and water-stopping structure. Figure 1 The joint water-stopping structure includes a cover plate 1, a caulking sealing material 2, a panel 3, a panel joint 4, and a rubber rod 5. Its working principle is that under the protection of the rubber sealing cover plate and other materials on the top, under the action of uniform water pressure and various temperature conditions, the plastic caulking sealing material gradually flows into the deformed seam cavity, and with the support of the water stop in the middle of the peripheral seam or the copper water stop cushion material at the bottom, it eventually blocks the peripheral seam, forming a stable and reliable water-stopping structure. The cohesive strength of an ideal plastic caulking sealing material is almost zero, and it can flow into and fill the open joint cavity under the action of pressurized water. During the flow process, it may not be penetrated by the pressurized water, or once penetrated by the pressurized water, it has the ability to self-heal the penetrated holes or cracks, that is, the so-called flow water-stopping ability, and cannot flow out from the bottom of the joint. Currently, there are two main types of commonly used plastic caulking sealing materials: one is modified asphalt-based plastic caulking sealing material (SR), and the other is chlorobutyl rubber-based plastic caulking sealing material (GB). Engineering practice has proven that SR and GB caulking sealing materials are more suitable for use in hydraulic structures with ambient temperatures above -30°C. For high-altitude cold areas (below -30°C), SR and GB materials harden at low temperatures and lose their ability to plastically deform. Especially when the ambient temperature is below -40°C, as the temperature drops, the dam surface concrete slab gradually shrinks, and SR and GB materials cannot deform with the panel, resulting in a "seam separation" phenomenon and a loss of water-stopping function.

[0004] Currently, the relevant technical standards (DL / T 949-2005, DL / T5115-2016) for plastic caulking and sealing materials for hydraulic structures have detailed descriptions. However, in specific engineering practices, for example, the plastic caulking and sealing materials used in the Qingyuan Pumped Storage Power Station in Fushun City, Liaoning Province, harden at low temperatures (-40°C), failing to exert their anti-seepage and water-stopping properties; the material itself cannot achieve reliable bonding with the concrete interface; and the material itself has a pungent odor.

[0005] Patent CN1687289A describes a nano-SR plastic waterstop material for caulking and preventing seepage in deformed concrete joints. The technical problem addressed by this invention patent is to provide a material that maintains the excellent impermeability, high plasticity, and ease of construction characteristics of the original SR plastic waterstop material while also offering excellent heat resistance and a high cost-effectiveness. The plastic waterstop material is composed of the following raw materials (by weight percentage): rubber: 20-50%; rubber antioxidant: 1-5%; modified resin: 20-40%; plasticizer: 10-30%; nano-modifier: 5-10%; and reinforcing agent: 10-30%.

[0006] Patent CN101602931B discloses a plastic water-stopping material for concrete joints. The technical problem to be solved by this invention patent is to provide a plastic water-stopping material for concrete joints, in order to improve the material's own impermeability, thermal stability, and the firmness of its bonding with concrete, and to adapt to large deformations of the joints without causing damage. The plastic water-stopping material for concrete joints is composed of 5 to 20 parts by weight of rubber, 1 to 5 parts by weight of a rubber antioxidant, 20 to 40 parts by weight of a modified resin, 10 to 30 parts by weight of a plasticizer, 30 to 50 parts by weight of a filler, and 0.2 to 1 part by weight of a surfactant. This invention patent is suitable for waterproofing concrete joints and cracks in water conservancy, hydropower, industrial, and civil construction projects.

[0007] Patent CN103131162A discloses a reinforced polyurethane sealing and water-stopping material specially designed for dams and its production method. The material is composed of two materials, A and B, which are stirred and embedded on site during use until the product is formed. The polyether polyol is heated and dehydrated to form anhydrous polyether polyol, and then MDI is added. The toughening agent is then added while the temperature is maintained constant, and the A component material is generated after the temperature is lowered. The liquid filler, powdered filler and toughening agent are mixed, a chain extender is added to the mixture, and the mixture is heated, stirred and dehydrated. Anti-aging agents and other additives are added, and the mixture is ground to generate the B component material. The material is cold-worked at room temperature, easy to operate and fast to construct. The material has excellent bonding strength, good bonding with concrete, high plasticity and excellent resilience. The material has excellent low-temperature flexibility, high-temperature stability, mechanical properties and durability, and is suitable for sealing and water-stopping of expansion joints in panel dams or other high-grade hydraulic structures.

[0008] With the rapid development of the hydropower industry, the height of concrete dams is constantly increasing. This poses greater challenges to the durability of joint water-stopping materials, especially in extremely cold regions (below -30°C), where low-temperature performance requirements are becoming increasingly stringent. Plastic caulking sealants based on chlorobutyl rubber (GB) have poor low-temperature performance (below -30°C). They tend to harden at low temperatures, resulting in reduced fluidity and difficulty in embedding into cracks under water pressure to provide a water-stopping effect. Furthermore, existing GB and SR plastic caulking sealants exhibit poor adhesion to the concrete interface and are prone to detachment, allowing water to easily enter cracks and corrode concrete dams. Furthermore, GB and SR plastic caulking sealants require a primer, making the application process cumbersome. Existing GB and SR plastic caulking sealants have a strong and irritating odor, and small molecules are continuously volatilized from the materials, making them less environmentally friendly. Polyurethane sealants are two-component and require on-site mixing, resulting in a complex application process that impacts construction schedules. Furthermore, polyurethane sealants have poor weather resistance and a short service life.

[0009] In summary, how to obtain a caulking sealing material with excellent performance to overcome the above-mentioned defects is a technical problem that needs to be solved urgently. Summary of the Invention

[0010] The present invention provides an organosilicon-based plastic caulking sealing material and its preparation method and application, with the purpose of improving the sealing, corrosion resistance, weather resistance and other properties of the caulking sealing material under severe cold conditions (below -30°C).

[0011] In a first aspect, the present invention relates to an organosilicon-based plastic caulking sealing material, which comprises the following components in parts by weight:

[0012]

[0013] The weight of the thixotropic agent accounts for 0.1% to 6% of the total weight of the hydroxyl-terminated polydimethylsiloxane and the plasticizer, preferably 0.2% to 5.3%; the molecular weight of the hydroxyl-terminated polydimethylsiloxane is 500,000 to 2,000,000.

[0014] Optionally, the filler is selected from hydrophobic fillers; the hydrophobic filler is selected from one or a combination of silicon micropowder, nano calcium carbonate and talc.

[0015] Optionally, the plasticizer is selected from one or a combination of dimethyl silicone oil, methylphenyl silicone oil and phenyl silicone oil; and / or the viscosity of the plasticizer is 100 to 350 cst.

[0016] Optionally, the resin is terpene resin and / or petroleum resin.

[0017] Optionally, the thickener is selected from amide compounds.

[0018] Optionally, the pigment is selected from a combination of one or more of titanium dioxide, carbon black, white paste and black paste.

[0019] Optionally, the mildew inhibitor is selected from heterocyclic ketone compounds.

[0020] Optionally, the thixotropic agent is selected from one or a combination of fumed silica, organic bentonite and polyamide wax.

[0021] In a second aspect, the present invention relates to a method for preparing the silicone-based plastic caulking sealing material described in the first aspect, the preparation method comprising the following steps: (1) adding hydroxyl-terminated polydimethylsiloxane, filler and plasticizer to a kneader in batches, and kneading for 30 to 60 minutes at a kneading temperature of 130 to 170°C; then adding resin, thickener, pigment, mildew inhibitor and thixotropic agent in batches, maintaining the kneading temperature, and continuing to knead for 2 to 3 hours to obtain a mixture; (2) extruding the mixture into a long strip shape through an extruder, cutting, and packaging to obtain the silicone-based plastic caulking sealing material.

[0022] In a third aspect, the present invention relates to the use of the organosilicon-based plastic caulking sealing material described in the first aspect, or the organosilicon-based plastic caulking sealing material prepared by the preparation method described in the second aspect, in concrete panel dams of hydraulic structures.

[0023] Beneficial effects:

[0024] This invention, for the first time, utilizes a silicone-based plastic caulking sealant for use in hydraulic concrete panel dams. The material can be used in environments between -40°C and 70°C, does not harden at low temperatures, and does not flow at high temperatures. It exhibits exceptional plastic deformation capabilities, excellent sealing properties, and strong resistance to water pressure breakdown and impermeability. It also exhibits excellent corrosion resistance (acids, alkalis, and salts), weather resistance, and durability. It can reliably bond to dry or wet concrete interfaces without the need for a primer, and has no pungent odor. This solves the problem with SR and GB plastic caulking sealants (made of asphalt and chlorobutyl rubber), which harden at low temperatures (≤-30°C) and lose their plastic deformation capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the joint water-stop structure;

[0026] Description of Reference Numerals

[0027] 1 Cover plate 2 Caulking sealing material 3 Panel

[0028] 4 panel seams with 5 rubber bars. DETAILED DESCRIPTION

[0029] The present application will be further described in detail below through the accompanying drawings and examples, through which the features and advantages of the present application will become more clear and distinct.

[0030] The word "exemplary" is used exclusively herein to mean "serving as an example, example, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise indicated.

[0031] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0032] In a first aspect, the present invention relates to an organosilicon-based plastic caulking sealing material, which comprises the following components in parts by weight:

[0033]

[0034] The weight of the thixotropic agent accounts for 0.1% to 6% of the total weight of the hydroxyl-terminated polydimethylsiloxane and the plasticizer, preferably 0.2% to 5.3%; the molecular weight of the hydroxyl-terminated polydimethylsiloxane is 500,000 to 2,000,000.

[0035] It should be noted that the weight of the thixotropic agent in the total weight of the hydroxyl-terminated polydimethylsiloxane and the plasticizer is preferably 0.2% to 5.3%, and specifically can be 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4% and 5%, etc., so that the silicone-based plastic caulking sealing material can show very good performance in both flow water-stop length and flow value (droop), and other properties are excellent, and the overall performance is better.

[0036] It should be noted that the silicone-based plastic caulking sealing material of the present application can be used for waterproofing of joints in hydraulic structures, or for caulking and sealing in various situations such as other concrete buildings. The material has excellent corrosion resistance (acid, alkali and salt resistance), weather resistance and durability; it has strong plastic deformation ability and can be embedded in cracks under water pressure to block water erosion of concrete; it can achieve reliable bonding with dry or wet concrete interfaces without the use of primer; it does not harden at low temperatures and does not flow at high temperatures, and can be used in environments of -40℃ to 200℃, and has high cold resistance (-40℃) plastic deformation ability; it has strong anti-penetration and anti-permeability capabilities.

[0037] It should be noted that hydroxyl-terminated polydimethylsiloxane (i.e. 107 silicone rubber) is an important organosilicon compound widely used in the fields of synthesizing organosilicon polymers, preparing silicone rubber, silicone rubber molds, etc., or it can also be used directly as raw rubber. Its molecular structure is a linear polymer connected by silicon-oxygen bonds Si-O, with hydroxyl groups at the end of the molecular chain. The structural formula can be expressed as:

[0038]

[0039] Hydroxyl-terminated polydimethylsiloxane has the advantages of excellent thermal stability, low-temperature elasticity and chemical stability. It also has a certain polarity and can be well compatible with other organic compounds.

[0040] The backbone of hydroxyl-terminated polydimethylsiloxane is a -Si-O- bond, whose bond energy (370 kJ / mol) is much higher than the C-C bond energy (240 kJ / mol). Silicone rubber (organosiloxane or silicone rubber) with a similar structure also has a -Si-O- bond backbone, resulting in a flexible molecular chain and excellent high and low temperature resistance, with an operating temperature range of -70 to 300°C. It is also odorless, non-toxic, and exhibits excellent aging resistance.

[0041] This application uses hydroxyl-terminated polydimethylsiloxane as a base adhesive to prepare a plastic caulking and sealing material that exhibits good plasticity at low temperatures (-40°C), no flow at high temperatures (70°C), excellent water resistance and impermeability, and excellent adhesion to dry or wet concrete interfaces. In particular, by controlling the weight of the thixotropic agent relative to the total weight of the hydroxyl-terminated polydimethylsiloxane and the plasticizer, the silicone-based plastic caulking and sealing material exhibits excellent tensile bonding properties. More importantly, the silicone-based plastic caulking and sealing material can simultaneously meet the index requirements in terms of both flow waterstop length and flow value (sag), while also exhibiting excellent performance.

[0042] It should be noted that the present application innovatively uses high molecular weight hydroxyl-terminated polydimethylsiloxane, which is compounded with other components of the silicone-based plastic caulking sealing material of the present application. The high molecular weight hydroxyl-terminated polydimethylsiloxane can provide plastic deformation well and give the material a higher elongation. The components in the system synergize with each other, so that the caulking sealing material of the present application has no chemical cross-linking reaction and does not construct a cross-linking system, forming a plastic caulking sealing material, which can be better applied to concrete panel dams of hydraulic structures, and can show excellent performance in both flow water stop length and flow value (sag), and has excellent comprehensive performance.

[0043] According to another specific embodiment of the organosilicon-based plastic caulking sealing material according to the first aspect of the present invention, the filler is selected from hydrophobic fillers; the hydrophobic filler is selected from one or a combination of silicon micropowder, nano-calcium carbonate and talc.

[0044] It should be noted that the addition of fillers can increase the specific gravity of the silicone-based plastic caulking sealing material, and in actual use, prevent the sealing material from floating on the water surface. Hydrophilic fillers can be used as fillers in existing caulking materials. During the research and development process, the inventors of this application innovatively discovered that based on the silicone-based plastic caulking sealing material system of this application, the use of the hydrophobic filler can, firstly, further significantly improve the stability of the silicone-based plastic caulking sealing material to better exert its efficacy; secondly, the hydroxyl-terminated polydimethylsiloxane molecular chains are entangled with each other, and the intermolecular force is relatively large. The addition of the hydrophobic filler can better block the entanglement between the molecular chains and reduce the intermolecular force, so as to further improve the stability and applicable temperature range of the caulking sealing material.

[0045] According to a specific embodiment of the organosilicon-based plastic caulking sealing material according to the first aspect of the present invention, the plasticizer is selected from one or a combination of dimethyl silicone oil, methylphenyl silicone oil and phenyl silicone oil;

[0046] and / or,

[0047] The viscosity of the plasticizer is 100 to 350 cst.

[0048] It should be noted that the plasticizer acts as a lubricant, which can further reduce the intermolecular forces of hydroxyl-terminated polydimethylsiloxane, and at the same time reduce the forces between the hydroxyl-terminated polydimethylsiloxane molecular chains and the fillers, and the forces between the fillers, thereby increasing the plastic deformation capacity of the silicone-based plastic caulking sealing material. There are many types of plasticizers that can be used for caulking materials in the prior art. After long-term research and development experiments, the inventors of this application found that the above-mentioned plasticizers are selected and compounded with other components in the silicone-based plastic caulking sealing material of this application. The above-mentioned plasticizers obtain a wider temperature range, remain non-volatile, and have better compatibility with other components in the system. They can be well compounded and synergistically enhanced with other components at lower low temperatures and higher high temperatures, so that the silicone-based plastic caulking sealing material of this application can obtain better stability at lower or higher temperatures.

[0049] According to another specific embodiment of the organosilicon-based plastic caulking sealing material according to the first aspect of the present invention, the resin is terpene resin and / or petroleum resin.

[0050] It should be noted that the use of terpene resin and / or petroleum resin can be better compounded with other components to better increase the compatibility of the system and enhance the uniformity of the system.

[0051] According to a specific embodiment of the organosilicon-based plastic caulking sealing material according to the first aspect of the present invention, the thickener is selected from amide compounds.

[0052] It should be noted that the viscosity of the sealing material can be adjusted by the thickener, and the use of amide compounds as thickeners can be well compounded with other components to obtain a sealing material with excellent performance.

[0053] According to a specific embodiment of the organosilicon-based plastic caulking sealing material according to the first aspect of the present invention, the pigment is selected from a combination of one or more of titanium dioxide, carbon black, white paste and black paste.

[0054] It should be noted that the main component of titanium dioxide is titanium dioxide. Among the commonly used white pigments, titanium dioxide has the smallest relative density. Among white pigments of equal mass, titanium dioxide has the largest surface area and the highest pigment volume. Carbon black is a pigment carbon black, which is used as a pigment to change the color of the material. White slurry is a mixture of titanium dioxide and resin, which is obtained by mixing and grinding. Black slurry is a pigmented concentrated slurry, which is processed by adding carbon black. Its main component is carbon black, and resin and other materials are added thereto. The present invention uses a combination of one or more of titanium dioxide, carbon black, white slurry and black slurry as pigment, which not only can play the role of pigment well, but also can be compounded with other components according to the above-mentioned weight proportions, which is beneficial to further improve the performance of silicone-based plastic caulking sealing materials.

[0055] According to a specific embodiment of the organosilicon-based plastic caulking sealing material according to the first aspect of the present invention, the mildew inhibitor is selected from heterocyclic ketone compounds.

[0056] It should be noted that heterocyclic ketone compounds are ketone compounds composed of a carbonyl group or a thiol group attached to a heterocyclic compound. They are organic compounds containing a heterocyclic structure in their molecules, generally five-membered heterocyclic rings or six-membered heterocyclic rings. In addition to carbon atoms, the atoms constituting the heterocyclic ring also contain at least one heteroatom, generally composed of atoms such as N, O, and S. Alternatively, the mildew inhibitor can be selected from organic nanopolymer mildew inhibitors. Mildew inhibitors can prevent mold in silicone-based plastic caulking and sealing materials, increase the material's service life, and can be well compounded with other components to provide silicone-based plastic caulking and sealing materials with better overall performance.

[0057] According to a specific embodiment of the organosilicon-based plastic caulking sealing material according to the first aspect of the present invention, the thixotropic agent is selected from one or a combination of fumed silica, organic bentonite and polyamide wax.

[0058] It should be noted that thixotropic agents can enhance the thixotropy of plastic caulking sealing materials. Thixotropic agents refer to substances that are added to resins to make the resin glue have a higher viscosity when static, and turn into a low-viscosity fluid under the action of external forces. Thixotropic agents are also called anti-flow agents. They are substances with a large specific surface area that can form hydrogen bonds or some other structures with polymers. They become thinner when subjected to force and thicker when left static. After adding thixotropic agents to silicone-based plastic caulking sealing materials, when subjected to water pressure and shear, the viscosity of the material decreases and the fluidity increases, allowing it to be embedded in cracks to play a sealing and water-stopping role; when the water pressure disappears, it thickens again and does not flow, and is mostly used for construction on vertical surfaces. If a thixotropic agent is not added, the flow value of the plastic caulking sealing material is difficult to control. At high temperatures, the plastic caulking sealing material is prone to flow, affecting the sealing effect.

[0059] More importantly, there are many types of thixotropic agents available. After years of research and development experiments, the inventors of the present application have found that the silicone-based plastic caulking sealing material based on the present application, using one or more of fumed silica, organic bentonite and polyamide wax as thixotropic agents and compounded with other components of the present application, can significantly exert a synergistic effect with other components, especially when the weight of the above-mentioned thixotropic agent accounts for 0.1% to 6% of the total weight of the hydroxyl-terminated polydimethylsiloxane and the plasticizer, preferably 0.2% to 5.3%, the silicone-based plastic caulking sealing material can exhibit very excellent performance in both flow waterstop length and flow value (sag), and other properties are excellent, and the overall performance is very good.

[0060] Furthermore, in the organosilicon-based plastic caulking sealing material system of the present application, the thixotropic effect of the thixotropic agent may show a decreasing trend from fumed silica, organic bentonite to polyamide wax.

[0061] In a second aspect, the present invention relates to a method for preparing the organosilicon-based plastic caulking sealing material according to the first aspect, the preparation method comprising the following steps:

[0062] (1) Adding hydroxyl-terminated polydimethylsiloxane, filler and plasticizer to a kneader in batches, kneading at a kneading temperature of 130-170° C. for 30-60 minutes; then adding resin, thickener, pigment, mildew inhibitor and thixotropic agent in batches, maintaining the kneading temperature, and continuing to knead for 2-3 hours to obtain a mixture; (2) extruding the mixture into a long strip shape through an extruder, cutting and packaging to obtain the silicone-based plastic caulking sealing material.

[0063] It should be noted that, preferably, the kneading temperature is 150° C. The preparation method of the present invention is ingenious, simple, and easy to implement. The prepared organosilicon-based plastic caulking sealing material has the advantages of good plasticity at low temperatures (-40° C.), no flow at high temperatures (70° C.), good water resistance and impermeability, good adhesion to dry or wet concrete interfaces, and long service life.

[0064] In a third aspect, the present invention relates to the use of the organosilicon-based plastic caulking sealing material described in the first aspect, or the organosilicon-based plastic caulking sealing material prepared by the preparation method described in the second aspect, in concrete panel dams of hydraulic structures.

[0065] It should be noted that, in the first aspect of the present invention, the raw materials and weight ratios are optimized, and in the second aspect, the processing technology is improved. The prepared silicone-based plastic caulking sealing material can be used in an environment of -40°C to 70°C when applied to concrete panel dams of hydraulic structures. It does not harden at low temperatures and does not flow at high temperatures. It has very excellent plastic deformation ability; good sealing performance, strong resistance to water pressure breakdown and impermeability; excellent corrosion resistance (acid, alkali, salt), weather resistance and durability; can achieve reliable bonding with dry or wet concrete interfaces without the use of primer; and has no pungent odor.

[0066] In summary, the organosilicon-based plastic caulking sealing material of the present invention has excellent performance and meets the indicators shown in Table 1 below:

[0067] Table 1

[0068]

[0069] The present invention is further described in detail below by way of examples, but the present invention is not limited thereto. Unless otherwise specified, the reagents used in the following examples may be commercially available finished reagents.

[0070] The 107 silicone rubber used in the following examples is 107 room temperature vulcanized silicone rubber (hydroxyl-terminated polysiloxane content ≥99.9%) purchased from Shenzhen Jipeng Silicone Fluorine Materials Co., Ltd.; silicon micropowder GSF-2S was purchased from Anhui Ge Rui New Materials Technology Co., Ltd.; dimethyl silicone oil was purchased from Dow Corning Corporation with the brand PMX-200; methylphenyl silicone oil was purchased from Dow Corning Corporation with the brand DC-550; phenyl silicone oil was purchased from Dow Corning Corporation with the brand DC-556; terpene resin is a refined terpene resin purchased from Guangxi Sanfeng Group Forest Chemical Resin Factory; thickener Tech-9605 was purchased from Shanghai Tiger Polymer Technology Co., Ltd.; mildew inhibitor M-1099 was purchased from Guangzhou Leisman New Materials Technology Co., Ltd.; thixotropic agent Wacker N20 was purchased from Wacker Chemical Fumed Silica (Zhangjiagang) Co., Ltd.; organic bentonite was purchased from Lingshou County Yousheng Mineral Products Processing Plant; polyamide wax was purchased from Nanjing Tianshi New Materials Technology Co., Ltd. with the brand NEW-0401C.

[0071] Example 1:

[0072] In parts by weight, 100 parts of 107 silicone rubber (molecular weight of 1 million), 600 parts of silicon powder (filler, brand GSF-2S) and 150 parts of dimethyl silicone oil (plasticizer, viscosity of 100 cst) were added to a kneader in batches, and the kneading temperature was set to 150°C. After kneading for 30 minutes, 5 parts of terpene resin (resin), 1 part of thickener (brand Tech-9605), 10 parts of titanium dioxide (pigment), 2 parts of mildewproof agent (brand M-1099) and 0.5 parts of fumed silica (thixotropic agent, brand Wacker N20) were slowly added, and the kneading temperature was maintained at 150°C. The kneading was continued for 2 hours to obtain a mixture.

[0073] The mixture is added into an extruder, and the extruder is started to perform extrusion molding to obtain an organosilicon-based plastic caulking sealing material.

[0074] Example 2:

[0075] In parts by weight, 100 parts of 107 silicone rubber (molecular weight of 1 million), 595 parts of silicon powder (filler, brand GSF-2S) and 150 parts of methylphenyl silicone oil (plasticizer, viscosity of 350cst) were added to a kneader in batches, and the kneading temperature was set to 150°C. After kneading for 30 minutes, 16 parts of terpene resin (resin), 1 part of thickener (brand Tech-9605), 10 parts of titanium dioxide (pigment), 1 part of mildewproofing agent (brand M-1099) and 5 parts of polyamide wax (thixotropic agent) were slowly added, and the kneading temperature was maintained at 150°C. The kneading was continued for 2 hours to obtain a mixture.

[0076] The mixture is added into an extruder, and the extruder is started to perform extrusion molding to obtain an organosilicon-based plastic caulking sealing material.

[0077] Example 3:

[0078] In parts by weight, 340 parts of 107 silicone rubber (molecular weight of 1 million), 410 parts of silicon powder (filler, brand GSF-2S) and 515 parts of dimethyl silicone oil (plasticizer, viscosity of 350 cst) were added to a kneader in batches, and the kneading temperature was set to 150°C. After kneading for 30 minutes, 11 parts of terpene resin (resin), 5 parts of thickener (brand Tech-9605), 7 parts of titanium dioxide (pigment), 2.5 parts of mildewproof agent (brand M-1099) and 45 parts of fumed silica (thixotropic agent, brand Wacker N20) were slowly added, and the kneading temperature was maintained at 150°C. The kneading was continued for 2 hours to obtain a mixture.

[0079] The mixture is added into an extruder, and the extruder is started to perform extrusion molding to obtain an organosilicon-based plastic caulking sealing material.

[0080] Example 4:

[0081] By weight, 100 parts of 107 silicone rubber (molecular weight of 500,000), 551.5 parts of silicon powder (filler, brand GSF-2S), 30 parts of nano calcium carbonate (filler) and 155 parts of dimethyl silicone oil (plasticizer, viscosity of 350cst) were added to a kneader in batches, and the kneading temperature was set to 150°C. After kneading for 30 minutes, 10 parts of terpene resin (resin), 2 parts of thickener (brand Tech-9605), 5 parts of titanium dioxide (pigment), 2 parts of mildewproof agent (brand M-1099) and 7 parts of organic bentonite (thixotropic agent) were slowly added, and the kneading temperature was maintained at 150°C. The kneading was continued for 2 hours to obtain a mixture.

[0082] The mixture is added into an extruder, and the extruder is started to perform extrusion molding to obtain an organosilicon-based plastic caulking sealing material.

[0083] Example 5

[0084] In parts by weight, 340 parts of 107 silicone rubber (molecular weight of 1 million), 415 parts of silicon powder (filler, brand GSF-2S), 10 parts of talc (filler) and 145 parts of phenyl silicone oil (plasticizer, viscosity of 350cst) were added to a kneader in batches, and the kneading temperature was set to 150°C. After kneading for 30 minutes, 20 parts of terpene resin (resin), 5 parts of thickener (brand Tech-9605), 18 parts of titanium dioxide (pigment), 3 parts of mildewproof agent (brand M-1099) and 10 parts of fumed silica (thixotropic agent) were slowly added, and the kneading temperature was maintained at 150°C. The kneading was continued for 2 hours to obtain a mixture.

[0085] The mixture is added into an extruder, and the extruder is started to perform extrusion molding to obtain an organosilicon-based plastic caulking sealing material.

[0086] Comparative Example 1:

[0087] In parts by weight, 340 parts of 107 silicone rubber (molecular weight of 1 million), 415 parts of silicon powder (filler, brand GSF-2S), 10 parts of talc (filler) and 145 parts of phenyl silicone oil (plasticizer, viscosity of 350cst) were added to a kneader in batches, and the kneading temperature was set to 150°C. After kneading for 30 minutes, 20 parts of terpene resin (resin), 5 parts of thickener (brand Tech-9605), 18 parts of titanium dioxide (pigment), 3 parts of mildewproof agent (brand M-1099) and 50 parts of fumed silica (thixotropic agent) were slowly added, and the kneading temperature was maintained at 150°C. The kneading was continued for 2 hours to obtain a mixture.

[0088] The mixture is added into an extruder, and the extruder is started to perform extrusion molding to obtain an organosilicon-based plastic caulking sealing material.

[0089] Comparative Example 2

[0090] The sealing material was prepared by the same method as in Example 1, except that the 107 silicone rubber with a molecular weight of 1 million in Example 1 was replaced by an equal weight portion of hydroxyl-terminated polydimethylsiloxane with a degree of polymerization of 4 to 11, Ruiyuan hydroxy silicone oil purchased from Jinan Ruiyuan Chemical Co., Ltd.

[0091] Test Example 1

[0092] The properties of the sealing materials prepared in the above examples and comparative examples were tested, and the test results are shown in the following table.

[0093] The immersion mass loss rate is tested at room temperature for 3600 hours according to the technical standard DL / T949-2005 for plastic caulking and sealing materials for hydraulic structures;

[0094] The tensile bonding performance is tested according to the test method for building sealing materials GB / T 13477.8-2017;

[0095] The flow waterstop length is tested according to the technical standard DL / T 949-2005 for plastic caulking and sealing materials for hydraulic structures;

[0096] The flow value (sag) is tested according to the test method for building sealing materials GB / T 13477.6-2002;

[0097] The workability (needle penetration) is tested according to the asphalt penetration test method GB / T 4509-2010;

[0098] Density is tested according to the test method for density and relative density of plastics GB 1033-86.

[0099] Table 2

[0100]

[0101]

[0102] Table 3

[0103]

[0104]

[0105] It should be noted that the only difference between Example 5 and Comparative Example 1 is that the proportion of the thixotropic agent in the total weight of the hydroxyl-terminated polydimethylsiloxane and the plasticizer is different. In Comparative Example 1, the thixotropic agent accounts for 10.3% of the total weight of the hydroxyl-terminated polydimethylsiloxane and the plasticizer, while that in Example 5 is 2.1%. It can be seen from the data in the above table that the flow value (droop) of the sealing material in Comparative Example 1 can meet the requirements, but the flow water-stop length is too small to meet the performance requirements. The sealing material in Example 5 can meet the requirements well in terms of both the flow water-stop length and the flow value (droop).

[0106] The molecular weight of the hydroxyl-terminated polydimethylsiloxane with a degree of polymerization of 4 to 11 used in Comparative Example 2 is approximately 330 to 848, and the degree of polymerization of the hydroxyl-terminated polydimethylsiloxane with a molecular weight of 500,000 is approximately 6760; compared with Example 1, Comparative Example 2 uses a hydroxyl-terminated polydimethylsiloxane with a molecular weight much lower than that of Example 1, and as a result, the flow value (droop) is too large, which cannot meet the performance indicators and has poor tensile bonding properties.

[0107] The inventors of this application innovatively discovered during the research and development process that when plastic caulking sealing materials are used in concrete panel dams of hydraulic structures, if the plastic caulking sealing materials meet the requirements of good bonding performance and elongation at break, and the flow waterstop length and sag can also meet the index requirements, then the plastic caulking sealing materials can play a very good caulking role.

[0108] More importantly, the inventors of the present application have innovatively found that the relationship between the amount of thixotropic agent and the total amount of hydroxyl-terminated polydimethylsiloxane and plasticizer is closely related to whether the index of flow waterstop length and sag can be met simultaneously. If the weight of the thixotropic agent in the total weight of hydroxyl-terminated polydimethylsiloxane and plasticizer is too large, as in Comparative Example 1, the flow value (sag) can be improved, but the flow waterstop length is too small and can not meet the requirement that the flow waterstop length is greater than 130mm, and the thixotropic agent is too much and can reduce the elongation of the material. On the contrary, when the thixotropic agent is too little, that is, the weight of the thixotropic agent in the total weight of hydroxyl-terminated polydimethylsiloxane and plasticizer is too small, the flow waterstop length can meet the requirements, but the flow value (sag) may be too large to meet the requirements, and the tensile bonding performance is poor.

[0109] In the description of this application, it should be noted that the terms "upper", "lower", "inside", "outside", "front", "back", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships in the working state of this application. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on this application.

[0110] In the description of this application, it should be noted that, unless otherwise specified or limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0111] The present application has been described above in conjunction with preferred embodiments, but these embodiments are merely exemplary and serve only as an illustrative example. On this basis, various replacements and improvements can be made to the present application, all of which fall within the scope of protection of the present application.

Claims

1. A silicone-based plastic caulking sealing material, wherein: The organosilicon-based plastic caulking sealing material comprises the following components in parts by weight: The weight of the thixotropic agent accounts for 0.1% to 6% of the total weight of the hydroxyl-terminated polydimethylsiloxane and the plasticizer; and the molecular weight of the hydroxyl-terminated polydimethylsiloxane is 500,000 to 2,000,000.

2. The organosilicon-based plastic caulking sealing material according to claim 1, wherein: The weight of the thixotropic agent accounts for 0.2% to 5.3% of the total weight of the hydroxyl-terminated polydimethylsiloxane and the plasticizer.

3. The organosilicon-based plastic caulking sealing material according to claim 1, wherein: The filler is selected from hydrophobic fillers; The hydrophobic filler is selected from one or a combination of silicon micropowder, nano calcium carbonate and talc.

4. The organosilicon-based plastic caulking sealing material according to claim 1, wherein: The plasticizer is selected from one or a combination of dimethyl silicone oil, methylphenyl silicone oil and phenyl silicone oil; and / or, The viscosity of the plasticizer is 100 to 350 cst.

5. The organosilicon-based plastic caulking sealing material according to claim 1, wherein: The resin is terpene resin and / or petroleum resin.

6. The organosilicon-based plastic caulking sealing material according to claim 1, wherein: The thickener is selected from amide compounds.

7. The organosilicon-based plastic caulking sealing material according to claim 1, wherein: The pigment is selected from one or more combinations of titanium dioxide, carbon black, white paste and black paste.

8. The organosilicon-based plastic caulking sealing material according to claim 1, wherein: The mildew inhibitor is selected from heterocyclic ketone compounds.

9. The organosilicon-based plastic caulking sealing material according to claim 1, wherein: The thixotropic agent is selected from one or a combination of fumed silica, organic bentonite and polyamide wax.

10. The method for preparing the organosilicon-based plastic caulking sealing material according to any one of claims 1 to 9, wherein: The preparation method comprises the following steps: (1) adding hydroxyl-terminated polydimethylsiloxane, filler and plasticizer to a kneader in batches, kneading at a kneading temperature of 130-170° C. for 30-60 minutes; then adding resin, thickener, pigment, mildewproofing agent and thixotropic agent in batches, maintaining the kneading temperature, and continuing kneading for 2-3 hours to obtain a mixture; (2) Extruding the mixture into a long strip shape through an extruder, cutting, and packaging to obtain the organosilicon-based plastic caulking sealing material.

11. Use of the organosilicon-based plastic caulking sealing material according to any one of claims 1 to 9, or the organosilicon-based plastic caulking sealing material prepared by the preparation method according to claim 9, in concrete face dams of hydraulic structures.

Images