Marble glue for bearing and preparation method thereof

Abstract

The invention belongs to the technical field of marble glue preparation, and particularly relates to marble glue for bearing and a preparation method thereof. The marble glue capable of being used for bearing is prepared by synthesizing modified resin containing a carboxyl-terminated nitrile rubber chain segment, preparing A glue containing the modified resin, ground calcium carbonate, nano silicon dioxide, polystyrene powder and a silane coupling agent and then preparing B glue taking benzoyl peroxide and dibutyl phthalate as base materials. According to the marble adhesive, a resin matrix is synergistically modified through a carboxyl-terminated nitrile rubber flexible chain segment and nano silicon dioxide, curing shrinkage and a specific curing system are regulated and controlled in combination with polystyrene powder, the comprehensive performance is remarkably improved, all indexes basically meet the requirements of dry hanging adhesive, impact toughness, bonding strength and the like are remarkably improved, and durability and environmental adaptability are high; good industrial application prospects are realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of marble glue preparation, and particularly relates to a bearing marble glue and a preparation method thereof. BACKGROUND

[0002] In the field of building decoration materials, stone curtain walls are widely used in modern buildings due to their aesthetic appearance and durability. At present, the installation of stone curtain walls mainly relies on epoxy adhesives for dry hanging stone (industry standard JC 887-2001). The adhesives have a core of an epoxy resin system, excellent bonding strength, weather resistance and long-term stability, and can meet the stringent requirements of structural safety and environmental adaptability. The cost of epoxy dry hanging glue is relatively high, but in recent years, due to the overall downturn of the construction industry, the market demand and price of epoxy dry hanging glue have been declining.

[0003] On the other hand, traditional marble glue (non-structural bearing glue) is widely used in non-bearing scenarios such as stone repair and furniture bonding due to its relatively simple raw materials and preparation process and low cost. For example, the bonding of small stone products such as kitchen countertops and hand basins. However, the performance of traditional marble glue has significant shortcomings: its bonding strength is generally lower than that of epoxy dry hanging glue, and it has poor weather resistance and weak chemical resistance, and is prone to performance degradation in complex environments such as high temperature, humidity or freeze-thaw cycles, and cannot meet the needs of structural bearing scenarios such as stone curtain walls. In addition, the curing system of traditional marble glue is mostly "blue and white water" matched, such as peroxide cyclohexanone and cobalt salt synergistic curing, which has a narrow operation window and concentrated heat release in thick glue layers, resulting in defects, which further limits its application in high-end construction fields.

[0004] Therefore, how to significantly improve the comprehensive performance of marble glue while maintaining cost advantage has become a technical problem that the industry urgently needs to overcome. SUMMARY

[0005] In view of the deficiencies in the prior art, the present application provides a bearing marble glue and a preparation method thereof. The purpose of the present application is to significantly improve the comprehensive performance of marble glue while maintaining cost advantage, so as to meet or basically meet the performance requirements of epoxy adhesives for dry hanging stone.

[0006] The first aspect of the present application is to provide a bearing marble glue and a preparation method thereof, which comprises synthesizing a modified resin containing a carboxyl-terminated nitrile rubber segment, preparing an A glue containing the modified resin, heavy calcium carbonate, nano-silicon dioxide, polystyrene powder and silane coupling agent, and preparing a B glue with benzoyl peroxide and dibutyl phthalate as the base.

[0007] As a further optimization scheme of the bearing marble glue preparation method, the following steps are included:

[0008] (a) Synthesis of modified resin: under the protection of inert atmosphere, propylene glycol, phthalic anhydride, maleic anhydride and carboxyl-terminated butyl nitrile rubber are mixed, a catalyst is added after the temperature is raised to the reaction temperature to carry out esterification until the acid value is reduced to below 30 mgKOH / g, then the temperature is lowered and a diluent and a polymerization inhibitor are added and stirred to obtain the modified resin;

[0009] (b) Preparation of A glue: the heavy calcium carbonate and nano-silica are dried and treated, then the modified resin is heated and added to the polystyrene powder and stirred to dissolve, then the premixed dry heavy calcium carbonate and nano-silica, organic bentonite and silane coupling agent are added, mixed and vacuum degassed to obtain the A glue;

[0010] (c) Preparation of B glue: the benzoyl peroxide is mixed with dibutyl phthalate to obtain a uniform paste to obtain the B glue.

[0011] As a further optimized scheme of the preparation method of the supporting marble glue, in step (a), the components include, by mass fraction: propylene glycol 32-38 parts, phthalic anhydride 22-28 parts, maleic anhydride 12-18 parts, carboxyl-terminated butyl nitrile rubber 4-6 parts, catalyst 0.4-0.6 parts, diluent 18-22 parts, and polymerization inhibitor 0.08-0.12 parts.

[0012] As a further optimized scheme of the preparation method of the supporting marble glue, in step (a), the esterification is carried out at 180°C for 3.5-4.5 hours; after the temperature is lowered to 80°C, the diluent and the polymerization inhibitor are added and stirred for 0.8-1.2 hours; the catalyst is p-toluene sulfonic acid, the diluent is styrene, and the polymerization inhibitor is hydroquinone.

[0013] As a further optimized scheme of the preparation method of the supporting marble glue, in step (b), the components include, by mass fraction: heavy calcium carbonate 58-62 parts, nano-silica 4-6 parts, modified resin 22-28 parts, polystyrene powder 4-6 parts, organic bentonite 3-5 parts, and silane coupling agent 0.8-1.2 parts.

[0014] As a further optimized scheme of the preparation method of the supporting marble glue, in step (b), the particle size of the heavy calcium carbonate is 325-800 mesh, the average particle size of the nano-silica is 10-30 nm and the specific surface area is 150-300 m 2 / g, the particle size of the polystyrene powder and the organic bentonite is ≤200 mesh, and the silane coupling agent is KH-550.

[0015] As a further optimization scheme of the preparation method of the marble glue for bearing, in step (b), the drying treatment is carried out at 115-125℃ for 1.5-2.5 hours; the modified resin is heated to 60℃ before adding the polystyrene powder; the high-speed mixing is carried out in a high-speed dispersion machine for 25-35 minutes, and vacuum degassing is simultaneously implemented.

[0016] As a further optimization scheme of the preparation method of the marble glue for bearing, in step (c), the components include, by mass fraction: benzoyl peroxide 28-32 parts, dibutyl phthalate 68-72 parts.

[0017] As a further optimization scheme of the preparation method of the marble glue for bearing, the A glue and the B glue are mixed for use in a mass ratio of 100:(1.5-3.0).

[0018] The second aspect of the present application provides a marble glue for bearing, which is prepared according to the above preparation method of the marble glue for bearing.

[0019] Advantages

[0020] The present application significantly improves the comprehensive performance of the marble glue by introducing carboxyl-terminated butyl nitrile rubber flexible segments to cooperatively modify the resin matrix with nano-silica, combining polystyrene powder to regulate the curing shrinkage, and using a benzoyl peroxide / dibutyl phthalate composite curing system. The marble glue has both price advantage and excellent bearing capacity, and the performance indicators basically meet the dry hanging glue requirements, the impact toughness, compression-shear bonding strength, and bending strength are significantly improved, and the durability and environmental adaptability are strong, which has good industrial application prospect. DETAILED DESCRIPTION

[0021] 1. Synthesis of modified resin

[0022] Under nitrogen protection, 32-38 parts of propylene glycol, 22-28 parts of phthalic anhydride, 12-18 parts of maleic anhydride, and 4-6 parts of carboxyl-terminated butyl nitrile rubber (CTBN) are added into a reaction kettle. After being heated to 180℃, 0.4-0.6 parts of p-toluenesulfonic acid is added as a catalyst, and esterification is carried out for 3.5-4.5 hours until the acid value is reduced to below 30 mgKOH / g. Then, the temperature is lowered to 80℃, 18-22 parts of styrene is added as a diluent, and 0.08-0.12 parts of hydroquinone is added as a polymerization inhibitor, and stirring is continued for 0.8-1.2 hours to obtain the modified resin.

[0023] 2. Preparation of A glue

[0024] 58-62 parts of heavy calcium carbonate (particle size 325-800 mesh) and 4-6 parts of nano-silica (average particle size 10-30 nm, specific surface area 150-300 m 2g) drying at 115-125 °C for 1.5-2.5 hours; heating the modified resin prepared 22-28 parts to 60 °C, adding polystyrene powder 4-6 parts (particle size ≤ 200 mesh) and stirring until completely dissolved; adding the pre-mixed dried heavy calcium carbonate and nano-silica to the resin mixture, then adding organic bentonite 3-5 parts (particle size ≤ 200 mesh) and KH-550 silane coupling agent 0.8-1.2 parts; mixing with a high-speed disperser for 25-35 minutes, and simultaneously performing vacuum degassing treatment to obtain A glue.

[0025] 3. Preparation of B glue

[0026] Mixing benzoyl peroxide 28-32 parts and dibutyl phthalate 68-72 parts, grinding to uniform paste to obtain B glue.

[0027] The application is further illustrated by specific examples, which are exemplary and intended to illustrate the problem and explain the application, and are not a limitation.

[0028] Example 1

[0029] 1. Synthesis of modified resin

[0030] Under nitrogen protection, add 35 parts of propylene glycol, 25 parts of phthalic anhydride, 15 parts of maleic anhydride and 5 parts of carboxyl-terminated butyl nitrile rubber (CTBN) to a reaction kettle. After heating to 180 °C, add 0.5 parts of catalyst p-toluenesulfonic acid, and carry out esterification reaction for 4 hours until the acid value is reduced to below 30 mgKOH / g. Then, cool to 80 °C, add 20 parts of diluent styrene and 0.1 parts of polymerization inhibitor hydroquinone, and continue stirring for 1 hour to obtain the modified resin.

[0031] 2. Preparation of A glue

[0032] Drying heavy calcium carbonate 60 parts and nano-silica 5 parts at 120 °C for 2 hours; heating the modified resin prepared 25 parts to 60 °C, adding polystyrene powder 5 parts and stirring until completely dissolved; adding the pre-mixed dried heavy calcium carbonate and nano-silica to the resin mixture, then adding organic bentonite 4 parts and KH-550 silane coupling agent 1 part; mixing with a high-speed disperser for 30 minutes, and simultaneously performing vacuum degassing treatment to obtain A glue.

[0033] 3. Preparation of B glue

[0034] Mixing benzoyl peroxide 30 parts and dibutyl phthalate 70 parts, grinding to uniform paste to obtain B glue.

[0035] Example 2

[0036] 1. Synthesis of modified resin

[0037] Into a reaction kettle under nitrogen protection, 32 parts of propylene glycol, 28 parts of phthalic anhydride, 12 parts of maleic anhydride and 4 parts of carboxyl-terminated butadiene-acrylonitrile rubber (CTBN) were added. After being heated to 180℃, 0.4 parts of catalyst p-toluene sulfonic acid was added, and esterification was carried out for 4.5 hours until the acid value was reduced to below 28 mgKOH / g. Subsequently, the temperature was reduced to 80℃, 22 parts of diluent styrene and 0.08 parts of polymerization inhibitor hydroquinone were added, and stirring was continued for 1.2 hours to obtain the modified resin.

[0038] 2. Preparation of A glue

[0039] The heavy calcium carbonate 58 parts and nano-silica 6 parts were dried at 115℃ for 2.5 hours; the prepared modified resin 28 parts was heated to 60℃, and 4 parts of polystyrene powder was added and stirred until completely dissolved; the pre-mixed dried heavy calcium carbonate and nano-silica were added to the resin mixture, followed by the addition of 3 parts of organic bentonite and 1.2 parts of KH-550 silane coupling agent; a high-speed dispersing machine was used for mixing for 25 minutes, and vacuum degassing treatment was carried out simultaneously to prepare the A glue.

[0040] 3. Preparation of B glue

[0041] The benzoyl peroxide 28 parts was mixed with dibutyl phthalate 72 parts to obtain a uniform paste to prepare the B glue.

[0042] Example 3

[0043] 1. Synthesis of modified resin

[0044] Into a reaction kettle under nitrogen protection, 38 parts of propylene glycol, 22 parts of phthalic anhydride, 18 parts of maleic anhydride and 6 parts of carboxyl-terminated butadiene-acrylonitrile rubber (CTBN) were added. After being heated to 180℃, 0.6 parts of catalyst p-toluene sulfonic acid was added, and esterification was carried out for 3.5 hours until the acid value was reduced to below 25 mgKOH / g. Subsequently, the temperature was reduced to 80℃, 18 parts of diluent styrene and 0.12 parts of polymerization inhibitor hydroquinone were added, and stirring was continued for 0.8 hours to obtain the modified resin.

[0045] 2. Preparation of A glue

[0046] The heavy calcium carbonate 62 parts and nano-silica 4 parts were dried at 125℃ for 1.5 hours; the prepared modified resin 22 parts was heated to 60℃, and 6 parts of polystyrene powder was added and stirred until completely dissolved; the pre-mixed dried heavy calcium carbonate and nano-silica were added to the resin mixture, followed by the addition of 5 parts of organic bentonite and 0.8 parts of KH-550 silane coupling agent; a high-speed dispersing machine was used for mixing for 35 minutes, and vacuum degassing treatment was carried out simultaneously to prepare the A glue.

[0047] 3. Preparation of B glue

[0048] The benzoyl peroxide 32 parts and dibutyl phthalate 68 parts are mixed and ground to a uniform paste to produce the B glue.

[0049] Comparative Example 1

[0050] Based on Example 1, the carboxyl-terminated butadiene acrylonitrile rubber (CTBN) is removed in the modified resin synthesis step, and 5 parts of CTBN in the original formula are replaced with an equal amount of maleic anhydride, so that the total mass parts of maleic anhydride are increased to 20 parts, and the types and amounts of the remaining raw materials are consistent with Example 1.

[0051] Comparative Example 2

[0052] Based on Example 1, the polystyrene powder is removed in the A glue preparation step, and 5 parts of polystyrene in the original formula are replaced with an equal amount of heavy calcium carbonate, so that the total mass parts of heavy calcium carbonate are increased to 65 parts, and the types and amounts of the remaining raw materials are consistent with Example 1.

[0053] Comparative Example 3

[0054] Based on Example 1, 5 parts of nano-silicon dioxide are replaced with an equal amount of silicon powder (particle size 10 μm) in the A glue preparation step, and the KH-550 silane coupling agent is removed, and the types and amounts of the remaining raw materials are consistent with Example 1.

[0055] Comparative Example 4

[0056] Based on Example 1, in the B glue preparation step, the formula is changed to cyclohexanone peroxide 6 parts, cobalt naphthenate 2 parts, and dibutyl phthalate 92 parts, and the benzoyl peroxide in the original formula is removed, and the types and amounts of the remaining raw materials are consistent with Example 1.

[0057] Test Method

[0058] The prepared A glue and B glue are mixed in a mass ratio of 100:2, and an electric mixer is used to stir at a speed of 300 r / min for 3 minutes until uniform and free of lumps. The bonding sample is prepared as follows: for stone-stone bonding, a 40 mm x 40 mm x 10 mm granite test block is selected, the surface is cleaned and dried with anhydrous ethanol, and a glue layer about 1 mm thick is uniformly scraped and coated, a pressure of 0.05-0.1 MPa is applied to compact and remove the edge overflow; for stone-stainless steel bonding, the stainless steel plate is sanded to a roughness Ra = 3.2-6.3 μm and cleaned and dried, and then coated with glue in the same way. All samples are cured in an environment of 25°C ± 2°C and a relative humidity of 50% ± 10% for 24 hours, and then tested after standing for 72 hours.

[0059] Impact toughness test was carried out according to GB / T 2567-2008. The adhesive was cast in a 100 mm x 100 mm x 10 mm mold and cured, and then processed into 80 mm x 10 mm x 10 mm unnotched samples (5 parallel samples per group). A pendulum impact tester (pendulum energy 50 J, impact speed 3.8 m / s) was used for testing, and the impact absorption energy was recorded with a simply supported beam support (span 60 mm) and the average value was calculated.

[0060] The compressive shear bond strength test was performed according to JC / T 989-2016. In addition to the standard condition test, other conditions included: the sample was treated in an 80°C oven for 168 hours (high temperature treatment), soaked in 60°C deionized water for 168 hours (hot water treatment), soaked in 5% NaOH solution at room temperature for 168 hours (alkali treatment), and subjected to freeze-thaw cycles 25 times (-20°C to 50°C, 4 hours freezing / 4 hours thawing). The shear strength was tested respectively, and the breaking load was recorded and the strength was calculated when the shear force was applied at a loading speed of 5 mm / min.

[0061] The adhesive bending strength test was carried out according to JC / T 989-2016. Two 100 mm x 25 mm x 10 mm stone test blocks were bonded with the adhesive (bonding surface 25 mm x 10 mm), and a simply supported beam sample with a span of 150 mm was processed. A bending load was applied at a speed of 2 mm / min, the breaking load was recorded and the strength was calculated. All test items were averaged from 5 samples, and when the deviation of a single data from the average value was more than 15%, it was rejected and retested until the effective data was ≥3.

[0062] The test results of the examples are shown in Table 1, and the test results of the comparative examples are shown in Table 2.

[0063] Table 1

[0064]

[0065]

[0066] Table 2

[0067]

[0068] According to the test results in Tables 1 and 2, the performance indicators of the examples of the present application have basically reached the performance indicator requirements of dry hanging glue, and are significantly better than the comparative examples. The impact toughness of examples 1-3 all reached 4.8 kJ / m 2 which is significantly higher than each comparative example, especially comparative examples 1 and 4, whose impact toughness is only 2.3 kJ / m 2 and 1.5 kJ / m 2, which indicates that CTBN and BPO curing system plays a key role in toughening. In terms of compressive shear bonding strength, the examples maintain a high level after standard conditions and various environmental treatments, such as the standard strength of stone-stone bonding is more than 12 MPa, while the comparative examples are generally less than 11 MPa, especially after hot water, alkali treatment and freeze-thaw cycle, which indicates that the application has more advantages in durability and environmental adaptability. In addition, the bending strength of the examples is more than 16 MPa, which also shows good structural bearing capacity.

[0069] Further analysis shows that there is a synergistic effect between the components in the application, which is the key to achieving high performance. Among them, the introduction of carboxyl-terminated butyl nitrile rubber in the synthesis of modified resin not only improves the fracture toughness of the resin through its flexible segment, but also enhances the interfacial adhesion by forming hydrogen bonds or chemical bonds between the polar carboxyl group and the epoxy group or ester group. At the same time, the use of polystyrene powder in A glue can effectively control the shrinkage during curing, avoiding stress concentration and cracking problems caused by volume change. In Comparative Examples 1 and 2, the impact toughness of the material decreases significantly after removing CTBN or polystyrene, and cracks easily appear at the bonding edge. On the other hand, nano-SiO2 can form a firm interface with the resin matrix under the action of KH-550 silane coupling agent due to its high specific surface area and surface activity, thereby improving the dispersion of fillers and water resistance, which is reflected in Comparative Example 3 as an increase in filler sedimentation rate and a decrease in durability. In addition, B glue uses a combination of benzoyl peroxide (BPO) and dibutyl phthalate, which has a wider operating time window and more uniform curing characteristics compared to the traditional "blue-white water" system (Comparative Example 4), avoiding defects caused by heat concentration in thick glue layers. Therefore, through molecular structure design, interface regulation and process optimization, a stable, efficient and adaptable marble glue adhesive system is constructed, which can meet the application requirements of stone dry hanging glue.

[0070] The above embodiments are exemplary and are intended to illustrate the technical concept and characteristics of the application, so that those skilled in the art can understand the content of the application and implement it, and cannot limit the protection scope of the application. Any equivalent changes or modifications made in accordance with the spirit and essence of the application should be covered within the protection scope of the application.

Claims

1. A method for preparing a load-bearing marble glue, characterized in that: The method includes synthesizing a modified resin containing a terminal carboxyl nitrile rubber segment, preparing a glue A containing the modified resin, heavy calcium carbonate, nano silicon dioxide, polystyrene powder and a silane coupling agent, and preparing a glue B based on benzoyl peroxide and dibutyl phthalate.

2. The method for preparing the load-bearing marble glue according to claim 1, wherein: The following steps are involved: (a) Synthesis of a modified resin: Propylene glycol, phthalic anhydride, maleic anhydride, and carboxyl-terminated nitrile rubber are mixed under an inert atmosphere, heated to a reaction temperature, and then a catalyst is added to carry out an esterification reaction until the acid value drops below 30 mgKOH / g. The mixture is then cooled and a diluent and a polymerization inhibitor are added with stirring to obtain a modified resin. (b) preparing glue A: drying heavy calcium carbonate and nano-silica, then heating the modified resin, adding polystyrene powder, stirring and dissolving, and then adding pre-mixed dry heavy calcium carbonate and nano-silica, organic bentonite and silane coupling agent, mixing and vacuum degassing to obtain glue A; (c) Preparation of glue B: Benzoyl peroxide and dibutyl phthalate were mixed and ground into a uniform paste to prepare glue B.

3. The method for preparing the load-bearing marble glue according to claim 2, wherein: In step (a), the components include, by mass, 32 to 38 parts of propylene glycol, 22 to 28 parts of phthalic anhydride, 12 to 18 parts of maleic anhydride, 4 to 6 parts of carboxyl-terminated nitrile rubber, 0.4 to 0.6 parts of catalyst, 18 to 22 parts of diluent, and 0.08 to 0.12 parts of polymerization inhibitor.

4. The method for preparing the load-bearing marble glue according to claim 3, wherein: In step (a), the esterification reaction is carried out at 180° C. for 3.5 to 4.5 hours; after cooling to 80° C., a diluent and an inhibitor are added and stirred for 0.8 to 1.2 hours; the catalyst is p-toluenesulfonic acid, the diluent is styrene, and the inhibitor is hydroquinone.

5. The method for preparing the load-bearing marble glue according to claim 2, wherein: In step (b), the components include, by mass, 58 to 62 parts of heavy calcium carbonate, 4 to 6 parts of nano-silicon dioxide, 22 to 28 parts of modified resin, 4 to 6 parts of polystyrene powder, 3 to 5 parts of organic bentonite, and 0.8 to 1.2 parts of silane coupling agent.

6. The method for preparing the load-bearing marble glue according to claim 5, characterized in that: In step (b), the particle size of the heavy calcium carbonate is 325-800 mesh, the average particle size of the nano-silicon dioxide is 10-30 nm and the specific surface area is 150-300 m² / g, the particle size of the polystyrene powder and the organic bentonite is ≤200 mesh, and the silane coupling agent is KH-550.

7. The method for preparing the load-bearing marble glue according to claim 5 or 6, characterized in that: In step (b), the drying treatment is carried out at 115-125° C. for 1.5-2.5 hours; the modified resin is heated to 60° C. and then polystyrene powder is added; the high-speed mixing is carried out in a high-speed disperser for 25-35 minutes, and vacuum degassing is simultaneously performed.

8. The method for preparing the load-bearing marble glue according to claim 2, characterized in that: In step (c), the components include, by mass, 28 to 32 parts of benzoyl peroxide and 68 to 72 parts of dibutyl phthalate.

9. The method for preparing the load-bearing marble glue according to claim 2, wherein: The A glue and the B glue are mixed in a mass ratio of 100:(1.5~3.0).

10. A marble glue for bearing, characterized in that: Prepared according to the preparation method according to any one of claims 1 to 9.

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