Low modulus silicone sealing gum and its manufacturing method

A silicone sealant, low modulus technology, applied in chemical instruments and methods, other chemical processes, etc., can solve the problems of inability to ensure long-term sealing of joints, unsatisfactory concrete adhesion, and large permanent deformation of the sealant. Achieve excellent displacement ability, excellent expansion and recovery ability, and the effect of small permanent deformation

Active Publication Date: 2005-05-25
CHENGDU GUIBAO SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

General high-modulus or medium-modulus silicone sealants cannot meet the requirements of the height displacement capacity of concrete joints. After construction, the glue is easy to crack with the concrete, so that the sealing effect is lost, and the cost of repairing the joints is very high.
[0003] Chinese patent CN 1371953A "Neutral Silicone Stone Sealant and Its Manufacturing Method" provides a neutral silicone stone sealant with a tensile modulus greater than 0.4MPa. When applied to the sealing of concrete joints, if the joint The joint is wide, and the glue is easy to crack with the concrete after vulcanization, which cannot guarantee the long-term sealing of the joint
However, in practical application of this type of sealant, the modulus is too low, the elastic recovery rate is very poor, the permanent deformation of the sealant is large, and the adhesion to concrete is not ideal

Method used

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  • Low modulus silicone sealing gum and its manufacturing method
  • Low modulus silicone sealing gum and its manufacturing method
  • Low modulus silicone sealing gum and its manufacturing method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] Example 1: 200 parts by mass of a, ω-dihydroxy polydimethylsiloxane with a viscosity of 50 Pa·S at 25°C, and 180 parts by mass of nano-active light calcium carbonate, at a temperature of 120°C and a vacuum degree of 0.06 Dehydration and blending at ~0.095MPa for 60min, transferred into a high-speed dispersing mixer and cooled to room temperature to obtain a base material; at room temperature, 24 parts by mass of methyl vinyl bis (ε-caprolactamyl) silane, dimethyl bis (ethyl acetoacetate) 4 parts by mass of methyl) silane, 2 parts by mass of methyl tris (N-methylacetamido) silane, 5 parts by mass of fumed silica, 10 parts by mass of toluene diisocyanate, the viscosity at 25°C is 1 Pa· 40 parts by mass of polydimethylsiloxane of S was added into the high-speed disperser, stirred and mixed with the base material, and the chemical reaction was carried out for 80 minutes under the vacuum degree of 0.06-0.095MPa and the rotation speed of 350rpm to produce high elongation and l...

Embodiment 2

[0038] Example 2: 200 parts by mass of a, ω-dihydroxy polydimethylsiloxane with a viscosity of 30 Pa·S at 25° C., 100 parts by mass of nano-active light calcium carbonate, and 150 parts by mass of silicon micropowder were heated at a temperature of 120 ℃, the vacuum degree is 0.06~0.095MPa, dehydration and blending for 60min, transfer into a high-speed dispersing mixer and cool to room temperature to obtain the base material; at room temperature, 20 parts by mass of dimethylbis(ε-caprolactamyl)silane, methyl vinyl 18 parts by mass of bis(N-phenylacetamido)silane, aminooxysilane 2.5 parts by mass, 15 parts by mass of hydrogenated castor oil, 25 parts by mass of polydimethylsiloxane with a viscosity of 1 Pa·S at 25°C, and 6 parts by mass of toluene diisocyanate, which were added to a high-speed disperser and mixed with the base material. Stir and mix, carry out chemical reaction under vacuum degree of 0.06-0.095MPa and rotational speed of 350rpm for 80 minutes to manufacture hi...

Embodiment 3

[0039] Example 3: 200 parts by mass of a, ω-dihydroxy polydimethylsiloxane with a viscosity of 80 Pa·S at 25°C, 60 parts by mass of nano-active light calcium carbonate, 20 parts by mass of light calcium carbonate, 20 parts by mass of calcium carbonate are dehydrated and blended for 60 min at a high temperature of 120 ° C and a vacuum degree of 0.06 to 0.095 MPa, and then transferred into a high-speed dispersing mixer and cooled to room temperature to obtain the base material; 13 parts by mass of acetylacetamido)silane, 2 parts by mass of dimethylbis(N-methylacetamido)silane, and aminooxysilane 7.5 parts by mass, 20 parts by mass of fumed silica, 1.5 parts by mass of toluene diisocyanate, and 10 parts by mass of polydimethylsiloxane with a viscosity of 0.8 Pa·S at 25°C were added to the high-speed disperser, and mixed with the base material by stirring , under the vacuum degree of 0.06 ~ 0.095MPa, the chemical reaction was carried out at 350rpm for 90 minutes to manufacture hig...

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Abstract

A low-modulus silicone sealant for the expansion joint of express way, airport runway, tunnel, bridge, etc is prepared from alpha, omega-dihydroxy polydimethyl siloxane and filler through proportionally vacuum kneading at 80-150 deg.C while dewatering for 30-300 min, high-speed stirring while cooling to obtain basic material, proportionally mixing chain enlarging agent, cross-linking agent, thixotropic agent, polydimethyl siloxane and toluent diisocyanate, stirring, and vacuum reaction at 20-600 rpm for 30-90 min.

Description

1. Technical field [0001] The invention relates to a low-modulus silicone sealant and a manufacturing method thereof, belonging to the field of polymer sealing materials. 2. Background technology [0002] In order to adapt to the expansion and bending caused by external factors, such as temperature changes, concrete buildings are equipped with expansion joints during construction. Expansion joints are the weak link of concrete buildings. First, foreign matter accumulates in the gaps, hindering the normal expansion and contraction of the joints; second, the joints seep water, which erodes and softens the subgrade, so the expansion joints must be sealed. The concrete joint sealing materials currently used in China mainly include asphalt, modified asphalt, prefabricated neoprene, polysulfide and polyurethane materials. Service life of concrete buildings. These materials are toxic and easily pollute the environment. Silicone sealing material has excellent weathering resistanc...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09K3/10
Inventor 袁素兰王有治卢麟邹百军
Owner CHENGDU GUIBAO SCI & TECH
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