A construction sealant and a preparation method thereof

Abstract

The application provides a construction sealant and a preparation method thereof, and the construction sealant comprises the following components in percentage by mass: 15-25% of silane modified polyether resin, 1-5% of modulus regulator, 15-25% of plasticizer, 45-55% of reinforcing filler, and the rest is auxiliary agent, and the total is 100%. The construction sealant has low modulus, high tensile strength, excellent anti-aging performance, is applied to the joint sealing of fabricated buildings, has good adhesion with the base material, and has good waterproof sealing effect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of sealant, in particular to a low modulus and high tensile strength sealant for building and a preparation method thereof. BACKGROUND

[0002] It is known that prefabricated building is a batch processing production of concrete prefabricated components by residential industrialization factory, and then assembled and connected on site. Compared with the traditional construction method, prefabricated building has many advantages such as high efficiency, environmental protection, resource saving, less personnel on construction site, high equipment turnover rate and so on. However, there are a large number of joints in the assembly process of prefabricated building, which need to be waterproofed and sealed, especially the outer wall joints. As the first line of defense for waterproof sealing, the performance of sealant will directly affect the waterproof sealing effect.

[0003] Because the prefabricated building joints will change in displacement under the combined action of temperature, wind pressure, foundation settlement and other factors, the sealant at the joint will be subjected to repeated external forces of horizontal tension, compression or vertical shear for a long time. When the high modulus sealant is stretched, if the internal stress is greater than the adhesion to the base layer, it will cause the base layer to be detached and peeled off, resulting in failure of sealing and waterproofing. The low modulus and high displacement capacity sealant can adapt to the change of joint width when the gap is stretched, the internal stress is small, and the adhesion failure does not occur. After the gap is narrowed, it can also return to the original state without permanent deformation. In addition, the low modulus sealant also needs to have high tensile strength to avoid cohesive failure of the sealant when it is stretched, which is also not conducive to sealing and waterproofing. Therefore, the anti-aging sealant with low modulus and high tensile strength is more suitable for prefabricated building.

[0004] The currently marketed silane modified polyether sealant for assembled building can be divided into single component and double component according to the composition. The double component needs special mixing equipment and special glue gun for construction, and the operation is difficult, the construction requirement is high, and the mixed glue needs to be used in time. In actual engineering cases, the single component is mainly used. However, the currently marketed single component silane modified polyether sealant for assembled building has the problems of high modulus, poor displacement capacity or low modulus and small tensile strength. In order to obtain a sealant with low modulus, the following methods are usually adopted in the prior art: one is to increase the amount of plasticizer diisononyl phthalate or dioctyl phthalate. Although the modulus of the sealant can be effectively reduced, the intermolecular force is weakened, the tensile strength of the sealant is obviously reduced, the elastic recovery rate is reduced, and the anti-aging performance is also reduced due to the increase of the amount of low molecular plasticizer; the other is to increase the amount of inert filler heavy calcium. The heavy calcium has a large particle size and no reinforcing property. Although the modulus of the sealant is reduced, the tensile strength is also reduced, the thixotropy of the sealant is poor, and the sealant is prone to sagging. SUMMARY

[0005] Therefore, in order to solve the above problems, the present application provides a sealant for building with low modulus, high tensile strength and excellent anti-aging performance, which is applied to the joint sealing of assembled building and has good adhesion to the base material and good waterproof sealing effect.

[0006] In order to achieve the above purpose, the technical scheme of the present application is as follows:

[0007] In one aspect, the present application provides a sealant for building, which comprises the following components in mass percentage: 15-25% of silane modified polyether resin, 1-5% of modulus adjusting agent, 15-25% of plasticizer, 45-55% of reinforcing filler, and the rest is additives, and the total is 100%.

[0008] In some preferred embodiments of the sealant for building, the molecular main chain of the silane modified polyether resin is polyether structure, and the end group is a silane group containing a hydrolyzable group; the number average molecular weight of the silane modified polyether resin is 12000-17000, the weight average molecular weight is 20000-25000, and the polydispersity index is 1.5-1.8.

[0009] In some more preferred embodiments of the sealant for building, the end group is one or two of dimethoxy, trimethoxy or triethoxy.

[0010] In some more preferred embodiments of the construction sealant, the silane-modified polyether resin has a number average molecular weight of 15000-16000, a weight average molecular weight of 24000-25000, and a polydispersity index of 1.5-1.6.

[0011] The molecular weight and its distribution of the silane-modified polyether resin have a great influence on the performance of the sealant. If the molecular weight is too small, the segment between the crosslinking points is short after the sealant is cured, the crosslinking density is too large, the modulus of the sealant is high, and the elasticity is poor. If the molecular weight is too large, the reactivity is low, the viscosity of the resin is significantly increased, and the processing difficulty is increased. If the molecular weight is moderate, the segment between the crosslinking points is long, and the modulus is moderate. The narrower the molecular weight distribution, i.e. the smaller the polydispersity index, the more uniform the molecular weight of the resin, and the more stable the performance of the sealant.

[0012] In some preferred embodiments of the construction sealant, the plasticizer is one or more of dioctyl phthalate, diisononyl phthalate, and diisodecyl phthalate.

[0013] In some preferred embodiments of the construction sealant, the reinforcing filler comprises stearic acid-modified nano calcium carbonate and super-fine heavy calcium powder, and the mass ratio of the super-fine heavy calcium powder to the nano calcium carbonate is 1:1-1:4.

[0014] In some more preferred embodiments of the construction sealant, the nano calcium carbonate has a spherical or cubic crystal shape, and the average particle size is 60-80 nm; the average particle size of the super-fine heavy calcium powder is 2-3 μm.

[0015] In some preferred embodiments of the construction sealant, the auxiliary agent comprises a pigment, a thixotropic agent, a light stabilizer, an antioxidant, a water removal agent, a coupling agent, and a catalyst.

[0016] The construction sealant comprises the following components in terms of mass percentage:

[0017] The silane-modified polyether resin is 15-25%, the modulus adjusting agent is 1-5%, the plasticizer is 15-25%, the reinforcing filler is 45-55%, the pigment is 1-3%, the thixotropic agent is 1-5%, the light stabilizer is 0.1-0.5%, the antioxidant is 0.1-0.5%, the water removal agent is 1-3%, the coupling agent is 0.3-1%, and the catalyst is 0.1-0.3%.

[0018] In some more preferred embodiments of the construction sealant, the pigment is rutile titanium dioxide or carbon black.

[0019] In some more preferred embodiments of the construction sealant, the thixotropic agent is hydrophobic fumed silica and / or polyamide wax.

[0020] In some more preferred embodiments of the construction sealant of the present application, the light stabilizer is a hindered amine light stabilizer and / or a benzotriazole ultraviolet light absorber.

[0021] In some more preferred embodiments of the construction sealant of the present application, the antioxidant is a hindered phenol antioxidant.

[0022] In some more preferred embodiments of the construction sealant of the present application, the water-removing agent is vinyltrimethoxysilane and / or vinyltriethoxysilane.

[0023] In some more preferred embodiments of the construction sealant of the present application, the coupling agent is one or more of 3-aminopropyltrimethoxysilane, aminoalkyl-modified alkylsiloxane, bis-(3-trimethoxysilylpropyl)amine, 3-aminopropyltriethoxysilane, N-aminoethyl-3-aminopropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, and 3-glycidyloxypropyltriethoxysilane.

[0024] In some more preferred embodiments of the construction sealant of the present application, the catalyst is one or both of dibutyltin dilaurate, stannous octoate, and dibutyltin bis(acetylacetonate).

[0025] In some preferred embodiments of the construction sealant of the present application, the modulus regulator is a monoglyceride of a saturated or unsaturated fatty acid containing 16-18 carbons.

[0026] The monoglyceride has a hydrophilic hydroxyl group and a lipophilic carbon chain in its molecular structure, and monoglycerides of different carbon chain lengths have different hydrophilic-lipophilic balance values. When the carbon chain length is short, the hydrophilicity is strong, and no obvious plasticizing effect is achieved, and when the carbon chain length is too long, the lipophilicity is strong, and the hydroxyl group is easily shielded, and the reactivity is low.

[0027] In some more preferred embodiments of the construction sealant of the present application, the modulus regulator is one or more of monopalmitolein, monolein, monostearin, and monoricinolein.

[0028] In some more preferred embodiments of the construction sealant of the present application, the modulus regulator is prepared by the following method:

[0029] D1, mix 2-acrylamide-2-methylpropanesulfonic acid (AMPS), water, N, N'-methylene bisacrylamide, dissolve thoroughly, remove oxygen in an ice water bath, add ammonium persulfate, stir, then add tetramethyl ethylenediamine aqueous solution, stir; wherein the mass ratio of the addition amount of 2-acrylamide-2-methylpropanesulfonic acid, water, N, N'-methylene bisacrylamide, ammonium persulfate, tetramethyl ethylenediamine aqueous solution is 1:3-4:0.05-0.06:0.0015-0.0025:0.045-0.01;

[0030] The obtained material is injected into a mold, sealed and reacted to obtain a gel; the gel is taken out of the mold, sliced, soaked in distilled water to remove unreacted substances, dried to constant weight, crushed and sieved to obtain poly 2-acrylamide-2-methylpropanesulfonic acid (PAMPS) hydrogel catalyst with a particle size of 60-100 mesh;

[0031] D2, mix glycerol, acetone and PAMPS hydrogel catalyst, stir, heat to 65-70℃, and react for 6-8h under nitrogen protection; wherein the mass ratio of the addition amount of glycerol, acetone and PAMPS hydrogel catalyst is 1:1.2-1.4:0.04-0.06;

[0032] D3, cool the product obtained in D2 to 40-50℃, add 16-18 carbon saturated or unsaturated fatty acids, then add PAMPS hydrogel catalyst, stir and heat to 65-70℃, and react for 6-8h; wherein the molar ratio of the addition amount of 16-18 carbon saturated or unsaturated fatty acids to the glycerol described in D2 is 1-1.4:1, and the mass ratio of the addition amount of PAMPS hydrogel catalyst to the glycerol described in D2 is 0.04-0.06:1;

[0033] D4, cool to room temperature, remove the PAMPS hydrogel catalyst by filtration, remove excess acetone by distillation under reduced pressure, add water and boric acid, the mass ratio of the addition amount of water and boric acid to the glycerol described in D2 is 1.5-2:0.2-0.3:1, stir at room temperature for hydrolysis, separate the liquid, wash with water, filter, and dry to obtain monoglyceride as a modulus regulator.

[0034] The PAMPS hydrogel simultaneously acts as a catalyst and a water-carrying agent, a large number of sulfonic acid groups are distributed on the surface of the PAMPS hydrogel, which can effectively catalyze the esterification reaction, and the PAMPS hydrogel is a strong water-absorbing material, which can quickly swell and absorb water to promote the chemical equilibrium to move in the positive direction. Compared with the toxic organic solvents such as chloroform, benzene, toluene, cyclohexane and petroleum ether used in the prior art, the PAMPS hydrogel is green, environmentally friendly, reusable and easy to separate, reduces the residue in the monoglyceride, and is more suitable for preparing a modulus regulator for sealant.

[0035] The second aspect of the present application provides a preparation method of a modulus regulator, wherein the modulus regulator is a monoglyceride, and the preparation method is as described above.

[0036] The third aspect of the present application provides a preparation method of a building sealant, comprising the following steps:

[0037] S1, the silane modified polyether resin, modulus regulator, plasticizer, reinforcing filler, pigment, thixotropic agent, light stabilizer, antioxidant, water removal agent, coupling agent, catalyst are weighed according to the proportion; wherein the reinforcing filler is stearic acid modified nano calcium carbonate and superfine heavy calcium powder;

[0038] S2, the plasticizer, modulus regulator, light stabilizer, antioxidant, superfine heavy calcium powder and part of the nano calcium carbonate are mixed, first moderate stirring (revolution 20 rpm, dispersion 1560 rpm) for a period of time, so that the powder is wetted, then the rotation speed is increased (revolution 30 rpm, dispersion 3120 rpm), vacuum extraction to-0.08MPa~ -0.10MPa, continue to mix;

[0039] S3: the remaining nano calcium carbonate, thixotropic agent are added, high speed mixing (revolution 30 rpm, dispersion 3120 rpm), the pressure is controlled at-0.08MPa~ -0.10MPa, heating, the moisture content is controlled below 1000ppm, cooling to 40℃~ 50℃ by cooling water;

[0040] S4: the silane modified polyether resin, part of the water removal agent are added, moderate mixing (revolution 20rpm~ 30rpm, dispersion 1560rpm~ 2340rpm) for a period of time, the temperature is maintained at 40℃~ 50℃, and the pressure is controlled at-0.08MPa~ -0.10MPa;

[0041] S5: the remaining water removal agent is added, the pressure is controlled at-0.08MPa~ -0.10MPa, moderate stirring mixing (revolution 20rpm~ 30rpm, dispersion 1560rpm~ 2340rpm) for a period of time; the coupling agent is added, the pressure is continued to be maintained at-0.08MPa~ -0.10MPa, moderate stirring mixing (revolution 20rpm~ 30rpm, dispersion 1560rpm~ 2340rpm) for a period of time; the catalyst is added, the pressure is continued to be maintained at-0.08MPa~ -0.10MPa, moderate stirring mixing (revolution 20rpm~ 30rpm, dispersion 1560rpm~ 2340rpm) for a period of time; cooling to below 40℃, and discharging to obtain the building sealant.

[0042] The fourth aspect of the present application provides a building sealant for use in the sealing of the joints of the external wall of the fabricated building.

[0043] Compared with the prior art, the building sealant and the preparation method thereof have the following advantages:

[0044] (1) The building sealant has the modulus regulator added therein, which has the following effects: first, the end group of the modulus regulator contains two hydroxyl groups, which can participate in the reaction and be grafted to the molecular chain during the cross-linking and curing reaction of the sealant, so as to play a chain extending role and reduce the cross-linking density of the resin molecules, thereby reducing the tensile modulus of the sealant; second, the modulus regulator has a long branch, which can play an internal plasticizing role, so that the modulus of the sealant can be significantly reduced, and the modulus regulator cannot migrate from the molecular structure of the sealant, so that the physical and mechanical properties of the sealant can be maintained stable, and the aging resistance of the sealant can be improved; third, the carbon chain structure in the molecular structure of the modulus regulator is similar to the molecular structure of the fatty acid modifier used for the nano calcium carbonate, which is beneficial to increasing the dispersibility of the nano calcium carbonate and improving the compatibility between the organic resin and the inorganic filler, and finally beneficial to improving the tensile strength of the sealant;

[0045] (2) The building sealant has the characteristics of low modulus and high tensile strength, and by adding the modulus regulator, the amount of the small molecule phthalate plasticizer in the formula can be effectively reduced while ensuring low modulus, so as to avoid the problems of reduced tensile strength, reduced elastic recovery rate and reduced aging resistance of the sealant caused by the increase of the amount of the plasticizer, and reduce the migration of the plasticizer to the base material;

[0046] (3) The building sealant has good tensile bonding strength and fixed extension bonding with the prefabricated concrete member, so as to effectively reduce the interface peeling and debonding of the sealant and the base material;

[0047] (4) The building sealant has good aging resistance, low production cost, simple process, and is beneficial to industrialized production and actual engineering use. DETAILED DESCRIPTION

[0048] Except for the definitions, the technical terms used in the following examples have the same meanings as generally understood by those skilled in the art to which the present application belongs. The test reagents used in the following examples are conventional biochemical reagents unless otherwise specified; and the experimental methods are conventional methods unless otherwise specified.

[0049] The present application will be described in detail below with reference to the examples.

[0050] EXAMPLE

[0051] Examples 1 to 4

[0052] In the implementation modes of Examples 1 to 4, the building sealant is prepared in the following manner unless otherwise specified:

[0053] Step one, according to the proportion of silane modified polyether resin, modulus modifier, plasticizer, reinforcing filler, pigment, thixotropic agent, light stabilizer, antioxidant, water removal agent, coupling agent, catalyst; wherein, the reinforcing filler is stearic acid modified nano calcium carbonate and superfine heavy calcium powder; (the component proportion in examples 1-4 is shown in table 1-4)

[0054] Step two, the pigment, nano calcium carbonate and superfine heavy calcium powder are dried at 110℃ for 24h in advance;

[0055] Step three, the plasticizer, modulus modifier, light stabilizer, antioxidant, superfine heavy calcium powder and half of the nano calcium carbonate are added into the stirring kettle in turn, the stirring and dispersion are started, the powder is wetted by stirring at medium speed (revolution 20rpm, dispersion 1560rpm) for 1-2min, then the stirring speed is increased (revolution 30rpm, dispersion 3120rpm), the vacuum is extracted to-0.08MPa to-0.10MPa, and the mixing is continued for 10min;

[0056] Step four, the remaining nano calcium carbonate and thixotropic agent are added, the mixing is carried out at high speed (revolution 30rpm, dispersion 3120rpm), the vacuum is continuously extracted, the pressure is controlled at-0.08MPa to-0.10MPa, heating is carried out, the kettle temperature is controlled at 110℃, the time is started to be counted, and the process is ended after about 2h, the moisture content is controlled below 1000ppm, and the temperature is lowered to 45℃ by cooling water;

[0057] Step five, the silane modified polyether resin and two-thirds of the water removal agent are added, the mixing is carried out at medium speed (revolution 20rpm, dispersion 1560rpm) for 30min, the temperature is controlled at 45℃, and the pressure is controlled at-0.08MPa to-0.10MPa;

[0058] Step six, the remaining water removal agent is added, the vacuum is extracted, the pressure is controlled at-0.08MPa to-0.10MPa, the mixing is carried out at medium speed (revolution 20rpm, dispersion 1560rpm) for 10min, the coupling agent is added, the vacuum pressure is maintained at-0.08MPa to-0.10MPa, the mixing is continued at medium speed (revolution 20rpm, dispersion 1560rpm) for 10min, the catalyst is added, the vacuum pressure is maintained at-0.08MPa to-0.10MPa, the mixing is continued at medium speed (revolution 20rpm, dispersion 1560rpm) for 10min, the temperature is lowered to below 40℃, and the product is discharged to obtain the building sealant.

[0059] In the implementation of examples 1-4, the modulus modifier is prepared as follows unless otherwise specified:

[0060] D1, into a three-necked flask, 20.72 g of 2-acrylamide-2-methylpropanesulfonic acid (AMPS), 79.28 g of water and 1.08 g of N,N'-methylenebisacrylamide were added in turn, after being fully dissolved, it was placed in an ice water bath and deoxygenated by nitrogen, 0.03 g of ammonium persulfate APS was added, after stirring for 20 min, 100 μL of 2% tetramethylethylenediamine aqueous solution was added, and stirring was continued for 2 min;

[0061] The obtained material was injected into a 3 mm thick transparent glass mold, sealed, reacted in a 60°C water bath for 5 h, after the gel was taken out of the mold, cut into round pieces and soaked in distilled water, the water was changed twice a day, after removing the unreacted substances, it was placed in a 60°C oven and dried to constant weight, crushed and sieved to obtain poly 2-acrylamide-2-methylpropanesulfonic acid (PAMPS) hydrogel catalyst with a particle size of 60-100 mesh;

[0062] D2, 10 g of glycerol, 12 g of acetone and 0.4 g of PAMPS hydrogel catalyst were added to a three-necked flask, stirring was started, and heating was started to 65-70°C, and reaction was carried out under nitrogen protection for 6-8 h;

[0063] D3, the product obtained in D2 was cooled to 40-50°C, 25 g of 16-18 carbon saturated or unsaturated fatty acid (corresponding to, in example 1, stearic acid was added here, in example 2, oleic acid was added here, in example 3, palmitic acid was added here, in example 4, ricinoleic acid was added here) was added, and 0.4 g of PAMPS hydrogel catalyst was added, stirring and heating to 65-70°C, and reaction was continued for 6-8 h;

[0064] D4, cooling to room temperature, removing the PAMPS hydrogel catalyst by filtration, and removing the excess acetone by distillation under reduced pressure, adding 20 g of water and 0.2 g of boric acid, stirring at room temperature for 2-4 h, separating the liquid, washing with water, filtering, and drying to obtain monoglyceride.

[0065] Table 1 raw material component allocation ratio in example 1

[0066]

[0067] Table 2 raw material component allocation ratio in example 2

[0068]

[0069]

[0070] Table 3 raw material component allocation ratio in example 3

[0071]

[0072]

[0073] Table 4: Raw material component allocation ratio in Example 4

[0074]

[0075] Comparative Example

[0076] Comparative Examples 1-4

[0077] In Comparative Examples 1-4, the formulation components in Comparative Examples 1-3 correspond to those in Examples 1-3 respectively, except that the modulus modifier is replaced by an equal amount of plasticizer in the formulation, and the sealant samples are prepared according to the same preparation method.

[0078] The formulation components in Comparative Example 4 are shown in Table 5, and the preparation method is the same as in the examples.

[0079] Table 5: Raw material component allocation ratio in Comparative Example 4

[0080]

[0081] Performance Test

[0082] The performance test is performed on the sealant samples prepared in Examples 1-4 and Comparative Examples 1-4, and the test standards and test data are shown in Table 6.

[0083] Table 6: Performance test data

[0084]

[0085]

[0086] As shown in Table 6, the low modulus, high tensile strength and anti-aging sealant provided in Examples 1-4 has lower modulus and higher tensile strength than the comparative sealant samples provided in Comparative Examples 1-4, and is suitable for use in fabricated building joint sealing. After long-term heat aging, the tensile strength at break and elongation at break change little, and no obvious fine cracks appear on the surface, i.e., it has better anti-aging performance.

[0087] The above description is only preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A construction sealant, characterized by, The silane modified polyether resin comprises the following components by mass percentage: silane modified polyether resin 15-25%, modulus modifier 1-5%, plasticizer 15-25%, reinforcing filler 45-55%, and the rest is auxiliary agent, totaling 100%. The modulus modifier is a monoglyceride of saturated or unsaturated fatty acid containing 16-18 carbons. The modulus modifier is prepared by the following preparation process: D1, 2-acrylamide-2-methylpropane sulfonic acid, water, N, N'-methylene bisacrylamide are mixed and fully dissolved, oxygen is removed in an ice water bath by nitrogen blowing, ammonium persulfate is added, stirred, and 2% tetramethyl ethylenediamine aqueous solution is added, stirred; wherein the mass ratio of the addition amount of 2-acrylamide-2-methylpropane sulfonic acid, water, N, N'-methylene bisacrylamide, ammonium persulfate, and tetramethyl ethylenediamine aqueous solution is 1:3-4:0.05-0.06:0.0015-0.0025:0.045-0.01; The obtained material is injected into a mold, sealed and reacted to obtain a gel; the gel is taken out of the mold, sliced, soaked in distilled water to remove unreacted substances, dried to constant weight, crushed and sieved to obtain poly 2-acrylamide-2-methylpropane sulfonic acid hydrogel catalyst with a particle size of 60-100 mesh; D2, glycerol, acetone, and poly 2-acrylamide-2-methylpropane sulfonic acid hydrogel catalyst are mixed and stirred, heated to 65-70℃, and reacted for 6-8h under nitrogen protection; wherein the mass ratio of the addition amount of glycerol, acetone, and poly 2-acrylamide-2-methylpropane sulfonic acid hydrogel catalyst is 1:1.2-1.4:0.04-0.06; D3, the product obtained in D2 is cooled to 40-50℃, 16-18 carbon saturated or unsaturated fatty acid is added, and poly 2-acrylamide-2-methylpropane sulfonic acid hydrogel catalyst is added, stirred and heated to 65-70℃, and reacted for 6-8h; wherein the molar ratio of the addition amount of 16-18 carbon saturated or unsaturated fatty acid to the glycerol in D2 is 1-1.4:1, and the mass ratio of the addition amount of poly 2-acrylamide-2-methylpropane sulfonic acid hydrogel catalyst to the glycerol in D2 is 0.04-0.06:1; D4, cooled to room temperature, remove poly 2-acrylamide-2-methylpropane sulfonic acid hydrogel catalyst, remove excess acetone by distillation under reduced pressure, add water and boric acid, the mass ratio of the addition amount of water and boric acid to the glycerol in D2 is 1.5-2:0.2-0.3:1, stir hydrolysis at room temperature, separate, wash with water, filter, and dry to obtain monoglyceride as a modulus modifier.

2. The construction sealant according to claim 1, wherein: The molecular main chain of the silane modified polyether resin is polyether structure, and the end group is a silane group containing a hydrolyzable group; the number average molecular weight of the silane modified polyether resin is 12000-17000, the weight average molecular weight is 20000-25000, and the polydispersity index is 1.5-1.

8.

3. The construction sealant according to claim 2, wherein: The end group is one or two of dimethoxy, trimethoxy, or triethoxy end-capping.

4. The construction sealant according to claim 2, wherein: The silane modified polyether resin has a number average molecular weight of 15000-16000, a weight average molecular weight of 24000-25000, and a polydispersity index of 1.5-1.

6.

5. The construction sealant of claim 1, wherein: The plasticizer is one or more of dioctyl phthalate, diisononyl phthalate, and diisodecyl phthalate.

6. The construction sealant of claim 1, wherein: The reinforcing filler includes stearic acid modified nano calcium carbonate and superfine heavy calcium powder, and the mass ratio of the superfine heavy calcium powder to the nano calcium carbonate is 1:1-1:

4.

7. The construction sealant according to claim 6, wherein: The nano calcium carbonate has a spherical or cubic crystal shape, and an average particle size of 60-80 nm; and the superfine heavy calcium powder has an average particle size of 2-3 microns.

8. The construction sealant of claim 1, wherein: The auxiliary agent includes pigments, thixotropic agents, light stabilizers, antioxidants, water removal agents, coupling agents, and catalysts. The construction sealant includes the following components in percentage by mass: The silane modified polyether resin 15-25%, the modulus adjusting agent 1-5%, the plasticizer 15-25%, the reinforcing filler 45-55%, the pigment 1-3%, the thixotropic agent 1-5%, the light stabilizer 0.1-0.5%, the antioxidant 0.1-0.5%, the water removal agent 1-3%, the coupling agent 0.3-1%, and the catalyst 0.1-0.3%.

9. The construction sealant of claim 8, wherein: The pigment is rutile titanium dioxide or carbon black; and the thixotropic agent is hydrophobic fumed silica and / or polyamide wax. The light stabilizer is a hindered amine light stabilizer and / or a benzotriazole ultraviolet light absorber. The antioxidant is a hindered phenol antioxidant. The water removal agent is vinyl trimethoxysilane and / or vinyl triethoxysilane. The coupling agent is one or more of 3-aminoethylaminopropyltrimethoxysilane, aminoalkyl-modified alkylsiloxane, bis-(3-trimethoxysilylpropyl)amine, 3-aminopropyltriethoxysilane, N-aminoethyl-3-aminopropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, and 3-glycidyloxypropyltriethoxysilane. The catalyst is one or both of dibutyltin dilaurate, stannous octoate, and bis(acetylacetone) dibutyltin.

10. The construction sealant according to any one of claims 1-9, characterized in that: The modulus adjusting agent is one or more of monopalmitolein, monoolein, monostearin, and monoricinolein.

11. A process for the production of a construction sealant as claimed in any one of claims 1 to 10, characterized in that The method includes the following steps: S1. The silane modified polyether resin, the modulus adjusting agent, the plasticizer, the reinforcing filler, the pigment, the thixotropic agent, the light stabilizer, the antioxidant, the water removal agent, the coupling agent, and the catalyst are weighed according to the proportions; the reinforcing filler is stearic acid modified nano calcium carbonate and superfine heavy calcium powder; S2. The plasticizer, the modulus adjusting agent, the light stabilizer, the antioxidant, the superfine heavy calcium powder, and part of the nano calcium carbonate are mixed, first stirred at a medium speed so that the powders are wetted, then stirred at a higher speed, and vacuumized to -0.08-0.10 MPa and continuously mixed. S3: add the remaining nano calcium carbonate, thixotropic agent, high-speed mixing, control the pressure at -0.08MPa~ -0.10MPa, heating, control the moisture content below 1000ppm, cooling to 40℃~50℃ by cooling water; S4: add silane modified polyether resin, part of the water remover, medium-speed mixing, keep the temperature at 40℃~50℃, control the pressure at -0.08MPa~ -0.10MPa; S5: add the remaining water remover, control the pressure at -0.08MPa~ -0.10MPa, medium-speed stirring and mixing; add coupling agent, continue medium-speed stirring and mixing; add catalyst, continue medium-speed stirring and mixing; cool to below 40℃, discharge to obtain the building sealant.

12. Use of the construction sealant according to any one of claims 1 to 10, characterized in that: Application in the joint sealing of prefabricated building outer wall.

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