CN105884250A - Polymer protective and decorative adhesive cement - Google Patents

Abstract

The invention relates to a polymer protective decorative mortar, the components of which are calculated in parts by mass: 6.0 to 12.0 parts of ester alcohol, 3.5 to 6.0 parts of cellulose ether, 1.5 parts of antifungal agent, 1.0 to 2.0 parts of ammonia water, dispersed 2.0 to 3.0 parts of agent, 12.0 to 16.0 parts of propylene glycol, 1.5 parts of defoamer, 0.2 to 1.2 parts of wood fiber, 450.0 to 600.0 parts of quartz sand, 200.0 to 300.0 parts of quartz powder; also including 100.0 to 150.0 parts of water and accounting for the total mass 14% to 16% polyacrylate emulsion, the polyacrylate emulsion is blended from ordinary polyacrylate emulsion and elastic polyacrylate emulsion. The invention can effectively solve various performance and construction problems existing in the existing polymer cement base or polymer latex powder type plastering mortar.

Description

A polymer protective decorative glue

technical field

The invention relates to the field of external wall thermal insulation systems, in particular to a polymer protective decorative glue.

Background technique

Polystyrene board thin plastering external wall thermal insulation system is the most widely used external wall thermal insulation technology in China. In terms of different types of insulation boards, there are two systems of polystyrene board thin plastering external wall insulation systems currently used in my country: molded polystyrene board and extruded polystyrene board. Among them, the application of molded polystyrene board thin plaster external wall insulation system is more extensive. In contrast, extruded polystyrene board thin plaster external wall insulation system is much less, but there is a gradual increase trend .

In terms of different plastering mortars, there are two types of polystyrene board thin plastering exterior wall insulation systems: polymer cement-based plastering mortars and polymer emulsion plastering mortars. The advantage of polymer cement-based plastering mortar is that it has the dual advantages of both organic materials and inorganic materials, such as water resistance and durability. However, polymer cement-based plastering mortar also has obvious performance deficiencies. First, the alkalinity is high, which has a serious corrosion effect on the alkali-resistant glass fiber mesh; second, it is easy to "pan alkali" and damage the decorative effect; The third is the most serious, because the lack of polymer components is often more rigid and less flexible. It is precisely because of these inherent performance defects of polymer cement-based plastering mortar that cracks, seepage, and "pan-alkaline" phenomenon of coating film finishes have occurred in many external wall insulation projects, which seriously affect the decorative effect and reduce the thermal insulation performance.

At present, almost all plastering mortars (including adhesives) used in thin plastering external wall insulation systems in my country are polymer-modified cement-based powder materials. Among them, the polymer component is latex powder. Latex powder is a powder product obtained by adding an anti-blocking agent to obtain a polymer emulsion after emulsion polymerization of an organic monomer, and then spray drying. Due to the complex processing, the energy consumption during the processing is large, and the processing cost is high. Therefore, its cost is about It is twice that of the polymer emulsion, and part of the properties of the polymer are lost during a series of processing. In order to reduce the production cost of plaster mortar, the amount of latex powder used is greatly limited, and the added amount of latex powder will become even lower in the case of fierce market competition. What's more, when the so-called "multifunctional latex powder" processed by secondary processing is used, the product quality will become worse (in this case, the amount of latex powder in the plastering mortar can even be negligible).

The anti-cracking effect in plastering mortar is mainly organic polymer components, so when the amount of latex powder added is very low, the anti-cracking effect of plastering mortar will be greatly reduced, which cannot meet the requirements of the external wall insulation system. Requirements for anti-crack performance of plaster mortar.

For this reason, polymer emulsion type non-cement base (or polymer base) plaster mortar is used for the surface of the thermal insulation layer of the external wall thermal insulation system with thin plastering of polystyrene board. Non-cement-based plastering mortar has excellent elongation, durability and weather resistance, and does not contain highly alkaline rigid materials such as cement, so it gives the system excellent flexibility and can resist severe temperature changes. At the same time, it has the advantages of excellent waterproof performance, excellent impact resistance, almost no damage to alkali-resistant glass fiber mesh, and no possibility of "pan-alkali" on the decorative layer, which can successfully solve the problems of polymer cement-based plastering mortar. Some defects have become a development direction of high-end external thermal insulation system.

In addition, because polystyrene board is an organic flammable material with poor fire resistance, fires occasionally occur during construction, and some cause serious consequences. In terms of structure, measures are taken to set up fire isolation belts.

Polymer-based (non-cementitious) mortars have many advantages over cement-based products and can solve many of the problems that arise with "polymer cement"-based mortars. However, the purpose of introducing such products to the market at present is to sell latex powder, and the non-cement-based polymer plastering mortar of latex powder also has problems such as high water absorption, poor water resistance, and significantly reduced impact strength after the water resistance test. . At the same time, there are sometimes problems with the construction performance of this plastering mortar, such as sticky batch coating and fast drying, which bring difficulties to construction. Therefore, since some large foreign companies began to promote this system in our country in 2009, it has not been practically applied.

Contents of the invention

The purpose of the present invention is to provide a polymer protective decorative mortar to solve various performance and construction problems existing in the existing polymer cement-based or polymer latex powder type plastering mortar.

The technical solution adopted by the present invention to solve the technical problem is: a polymer protective decorative mortar, the components of which include: 6.0-12.0 parts of ester alcohol, 3.5-6.0 parts of cellulose ether, antifungal agent 1.5 parts, ammonia water 1.0-2.0 parts, dispersant 2.0-3.0 parts, propylene glycol 12.0-16.0 parts, defoamer 1.5 parts, wood fiber 0.2-1.2 parts, quartz sand 450.0-600.0 parts, quartz powder 200.0-300.0 parts; It includes 100.0-150.0 parts of water and 14%-16% of the total mass of polyacrylate emulsion, and the polyacrylate emulsion is blended by ordinary polyacrylate emulsion and elastic polyacrylate emulsion.

Preferably, the polyacrylate emulsion is blended from Primal 2438 elastic emulsion and Primal AC 996 styrene-acrylate copolymer emulsion.

Further, the blending ratio of Primal 2438 elastic emulsion and Primal AC 996 styrene-acrylate copolymer emulsion is 5.5-4.0:4.5-6.0.

Preferably, the polyacrylate emulsion is blended from Primal 2438 type elastic polyacrylate emulsion and Primal AC-398A type polyacrylate emulsion.

Further, the blending ratio of Primal 2438 type elastic polyacrylate emulsion and Primal AC-398A type polyacrylate emulsion is 5.5-4.0:4.5-6.0.

Preferably, the fiber length is a short fiber with a length of less than 1 mm.

Preferably, the cellulose ether is M30 type Bermocoll high-viscosity cellulose ether, the ester alcohol is Texanol ester alcohol antifungal agent is A20 type antifungal agent, the dispersant is "quick and easy" dispersant, and the defoamer is 921 defoamer .

Preferably, the particle size of the quartz sand is 0.1mm-0.6mm, and the fineness of the quartz powder is 100 mesh.

In order to directly add weather-resistant pigments therein for coloring to make a decorative plaster mortar with a finishing function, the polymer protective decorative mortar also includes pigments or pigment pastes with good weather resistance.

In the case of maintaining the basic amount of polyacrylate emulsion, by adjusting the solid content of the polymer protective mortar, it is very convenient to maintain the ARS mortar with good initial drying crack resistance; the polymer protective decorative mortar The solid content accounts for 65% to 75% of the total mass.

Beneficial effects of the present invention: 1. Strong protective performance: the polymer protective decorative mortar is used to replace the usual cement-based thin plaster mortar, which can eliminate the cracking and water seepage phenomena that are common in the current thin plaster exterior wall external thermal insulation system, thereby produce better protection. 2. Solve the problem of "flooding alkali" and yellowing of the finishing layer: the polymer protective decorative mortar does not contain alkaline substances, but also has very good water impermeability, so there is no flooding of traditional cement-based plastering mortar The possibility of reducing and yellowing can completely eliminate the phenomenon of "pan-alkali", ensuring the decorative effect of the external wall insulation system. 3. Reduce the weight of the thin plastering external wall insulation system: the use of this polymer protective decorative mortar integrates protection and decoration, and can reduce the thickness of the thin plastering layer, thereby reducing the weight of the system ( 3~5) kg/m2, which makes the structural safety of the system relatively enhanced. 4. Simplify the structure of the external thermal insulation system of the external wall: due to the use of the polymer protective decorative mortar, the decorative layer can be canceled, and the protection and decoration are integrated, which simplifies the structure of the external thermal insulation system of the external wall and reduces the interface between the structural layers , so that the structural stability is enhanced, and the construction period is also shortened.

The present invention will be described in more detail below in conjunction with examples.

detailed description

Embodiment 1, a polymer protective decorative glue, its components include: 6.0 parts of ester alcohol, 3.5 parts of cellulose ether, 1.5 parts of antifungal agent, 1.0 parts of ammonia water, 2.0 parts of dispersant, propylene glycol 12.0 parts, 1.5 parts of defoaming agent, 0.2 part of wood fiber, 450.0 parts of quartz sand, 200.0 parts of quartz powder; also include 100.0 parts of water and 14% polyacrylate emulsion accounting for the total mass, polyacrylate emulsion is made of common polyacrylic acid Ester emulsion and elastic polyacrylate emulsion blended.

Example 2, a polymer protective decorative glue, its components include in parts by mass: 300.0 parts of polyacrylate emulsion, 12.0 parts of ester alcohol, 6.0 parts of cellulose ether, 1.5 parts of antifungal agent, 2.0 parts of ammonia water , 3.0 parts of dispersant, 16.0 parts of propylene glycol, 1.5 parts of defoamer, 1.2 parts of wood fiber, 600.0 parts of quartz sand, 300.0 parts of quartz powder; also include 150.0 parts of water and 16% of the total mass of polyacrylate emulsion, polyacrylic acid The ester emulsion is blended from ordinary polyacrylate emulsion and elastic polyacrylate emulsion.

Example 3, a polymer protective decorative glue, its components include in parts by mass: 250.0 parts of polyacrylate emulsion, 9.0 parts of ester alcohol, 4.0 parts of cellulose ether, 1.5 parts of antifungal agent, and 1.5 parts of ammonia water , 2.5 parts of dispersant, 14.0 parts of propylene glycol, 1.5 parts of defoamer, 0.7 parts of wood fiber, 525.0 parts of quartz sand, 250.0 parts of quartz powder; also include 125.0 parts of water and 15% of the total mass of polyacrylate emulsion, polyacrylic acid The ester emulsion is blended from ordinary polyacrylate emulsion and elastic polyacrylate emulsion.

Example 4, based on the basis of Examples 1 to 3, the polyacrylate emulsion was blended from Primal 2438 elastic emulsion and Primal AC 996 styrene-acrylate copolymer emulsion. The blending ratio of Primal 2438 elastic emulsion and Primal AC996 styrene-acrylate copolymer emulsion is 5.5-4.0:4.5-6.0.

Example 5, on the basis of Examples 1 to 3, the polyacrylate emulsion was blended from Primal 2438 elastic polyacrylate emulsion and Primal AC 996 styrene-acrylate copolymer emulsion. The blending ratio of Primal2438 elastic polyacrylate emulsion and Primal AC 996 styrene-acrylate copolymer emulsion is 5.5-4.0:4.5-6.0.

In Example 6, on the basis of Examples 1 to 5, the fiber length is short fibers with a length of less than 1 mm. The cellulose ether is M30 type Bermocoll high-viscosity cellulose ether, the ester alcohol is Texanol ester alcohol antifungal agent is A20 type antifungal agent, the dispersant is "quick and easy" dispersant, and the defoamer is 921 defoamer. The particle size of the quartz sand is 0.1 mm to 0.6 mm, and the fineness of the quartz powder is 100 mesh. The amount of water added is controlled. The solid content of the polymer protective decorative mortar accounts for 65% to 75% of the total mass. The polymer protective decorative mortar also includes pigments or pigment pastes with good weather resistance.

In terms of material selection, Primal 2438 elastic polyacrylate emulsion and Primal AC-398A polyacrylate emulsion produced by Rohm and Haas Company of the United States can be used; Texanol ester alcohol produced by Eastman Company of the United States; M30 type produced by AkzoNobel Bermocoll high-viscosity cellulose ether; A20 antifungal agent produced by Germany Shumei Company; reagent grade ammonia water; commercially available quartz sand (fineness 0.1mm～0.5mm); commercially available quartz powder (100 mesh), Shanghai Snow Chemical Co., Ltd. Produce 921 defoamer; Shanghai Kaiyuan Chemical Technology Co., Ltd. supplies wood fiber for putty.

In the production process of this polymer protective decorative mortar, water, antifungal agent, propylene glycol, Texanol ester alcohol, "quick and easy" dispersant, ammonia water and appropriate amount of defoamer are mixed evenly in a mixing tank to obtain After mixing the slurry, add the polyacrylate emulsion under low-speed stirring and stir evenly, and adjust the pH value to 8.5-9.0 again. Then, put in the filler (quartz sand, powder, pigment, etc.) and stir evenly. Finally, depending on the amount of foam in the ARS polymer protective decorative mortar, add defoamer and stir to defoam.

The following is a detailed description of the performance of the polymer protective decorative mortar according to the test results:

1. Selection of polyacrylate emulsion

Polyacrylate emulsion is generally used as a film-forming substance for paste and slurry products such as real stone paint for exterior walls. Polymer cement-based materials can be paste, paste products, or powder products. The polymer used in paste and slurry polymer cement-based materials is also polyacrylate emulsion; the polymer used in powdered polymer cement-based materials is VAE latex powder. Polyacrylate emulsion for exterior wall real stone paint is an emulsion with high glass transition temperature, low elongation at break, and does not meet the flexibility requirements of plastering mortar; polyacrylate emulsion for polymer cement-based materials The modified material has a low glass transition temperature and poor performance when used alone, so it cannot be used alone for exterior walls. Therefore, in order to meet the comprehensive performance requirements of this polymer protective decorative mortar, we chose the method of blending common and elastic polyacrylate emulsions, but the two should have a more appropriate ratio. The test conducted for this The results are shown in Table 3.

Table 3 Effect of different proportions of emulsion blending on the performance of the polymer protective decorative mortar

Blend ratio ^① Tensile bond strength (MPa) Tensile strength (MPa) Elongation at break (%) 10:0 0.36 2.21 362 8.5:1.5 0.63 2.13 330 7.0:3.0 0.97 1.95 260 5.5:4.5 1.32 1.80 114 4.0:6.0 1.67 1.77 103

Note: ① The emulsion is blended into Primal 2438 elastic emulsion Primal AC-398A type polyacrylate emulsion.

According to the obtained test results, it can be known that when the elastic building emulsion is used to prepare the polymer protective decorative mortar, good tensile strength and elongation at break can be obtained, but the bonding performance to the base layer is very poor, and the two emulsions are blended Use can make up for this deficiency. When the two emulsions are blended and used, as the blending ratio of the Primal AC-398A polyacrylate emulsion increases, the bonding performance of the polymer protective decorative mortar to the base layer is improved, but its tensile strength and elongation at break The elongation decreases accordingly, especially the elongation at break decreases greatly. Therefore, in order to make the polymer protective decorative glue have the required flexibility, it is feasible to mix elastic building emulsion and ordinary building emulsion in a suitable ratio. In particular, common building emulsions are styrene-acrylate copolymer emulsions, which are low in cost and better in water resistance than polyacrylate emulsions. However, when choosing two emulsions, attention should be paid to the compatibility of the two emulsions, especially to verify the compatibility test before use. Primal AC-398A type polyacrylate emulsion can be replaced by Primal AC 996 styrene-acrylate copolymer emulsion, the effect of Primal AC-398A type polyacrylate emulsion is better than Primal AC 996 styrene-acrylate copolymer emulsion, and Primal AC 996 styrene-acrylate copolymer emulsion has an advantage in terms of price.

When mixing two compatible emulsions, in addition to understanding the influence of the blended emulsion on the mechanical properties of the polymer protective decorative mortar through the above test, in order to ensure the stable performance of the polymer protective decorative mortar, it should also be Test the glass transition temperature of two blended emulsions, and use it as an index to control product quality. Generally speaking, in order to ensure the good flexibility of the polymer protective decorative mortar, the glass transition temperature of the two emulsions should not be higher than 10°C after blending.

2. Effect of the amount of polyacrylate emulsion on the tensile bond strength of the polymer protective decorative polymer protective decorative glue

(1) Tensile bond strength with extruded polystyrene board

Polyacrylate emulsion is the film-forming substance of the polymer protective decorative mortar, and its dosage significantly affects a series of physical and mechanical properties and durability of the polymer protective decorative mortar. However, when the material has good mechanical properties, it can also have corresponding durability properties. Therefore, the general research is to make the material have good mechanical properties first, because the detection of mechanical properties is more convenient and direct. The effect of the amount of polyacrylate emulsion on the tensile bond strength between the polymer protective decorative mortar and extruded polystyrene board is shown in Table 4.

Table 4 Effect of the amount of polyacrylate emulsion ^① on the tensile bond strength between the polymer protective decorative mortar and extruded polystyrene board

Note: ① Polyacrylate emulsion is used by blending two types of emulsions, Primal 2438 and Primal AC-398A.

②Water resistance is the test strength after soaking in water for 48 hours and drying for 7 days.

As can be seen from Table 4, in the proportioning ratio of the protective decorative polymer mortar of the polymer, along with the increase of the amount of polyacrylate emulsion, the gap between the protective decorative mortar of the polymer and the extruded polystyrene board Tensile bond strength increased uniformly. This shows that in order to ensure reliable bonding strength between the polymer protective decorative mortar and extruded polystyrene board, the amount of polyacrylate emulsion should not be lower than a certain minimum. Since the appropriate addition amount of polyacrylate emulsion in this polymer protective decorative glue is closely related to the particle size and amount of filler, in the case of materials used in the test, the amount of polyacrylate emulsion in this polymer protective decorative glue It should not be lower than 14%.

(2) Tensile bond strength with cement mortar board

Neither the JG 149-2003 standard nor the GB 30595-2014 standard stipulates the tensile bond strength between the plastering mortar and the cement mortar board, because the surface of the plastering mortar does not need to be bonded with cement mortar. However, in order to investigate the actual effect of the amount of polyacrylate emulsion on the protective decorative mortar of this polymer, we still conducted experiments on this, because the tensile bond strength between the protective decorative mortar of this polymer and extruded polystyrene board In the test, when the amount of polyacrylate emulsion in the polymer protective decorative glue increases to a certain extent, the actual change of the bond strength cannot be detected, but only the destruction of the extruded polystyrene board was detected during the test.

The influence of the amount of polyacrylate emulsion on the tensile bond strength between the protective decorative mortar of this polymer and the cement mortar board is shown in table 5.

Table 5 Effect of the amount of polyacrylate emulsion ^① on the tensile bond strength between the protective decorative mortar of the polymer and the cement mortar board

Note: ① Polyacrylate emulsion is used by blending two types of emulsions, Primal 2438 and Primal AC-398A.

②Water resistance is the test strength after soaking in water for 48 hours and drying for 7 days.

As can be seen from Table 5, in the polymer protective decorative mortar, the amount of polyacrylate emulsion added has a similar situation to that of the bond strength between the cement mortar board and the extruded polystyrene board, that is, first As the amount of emulsion added increases, it gradually increases, and when it reaches a certain level, the increase is not obvious.

On the other hand, after the water resistance test or the freeze-thaw resistance test of the bond strength sample, although the strength has decreased, it is not obvious, indicating that the water resistance of the selected emulsion is very good, and the decrease in strength after the freeze-thaw resistance test is still small These are also in line with the law that certain organic resin materials have a very strong ability to withstand water erosion damage.

(3) Effect of the amount of polyacrylate emulsion on the compressive shear bond strength of the polymer protective decorative polymer protective decorative glue

The effect of the amount of polyacrylate emulsion on the compressive shear bond strength of the polymer protective decorative mortar is shown in Table 6.

Table 6 Effect of the amount of polyacrylate emulsion ^① on the compressive shear bond strength

Note: ① Polyacrylate emulsion is used by blending two types of emulsions, Primal 2438 and Primal AC-398A.

②Water resistance is the test strength after soaking in water for 48 hours and drying for 7 days.

It can be seen from Table 6 that the effect of the amount of polyacrylate emulsion on the compressive shear bond strength of the polymer protective decorative mortar has a relationship and value similar to that of the bond strength.

3. The effect of the amount of polyacrylate emulsion on the water absorption of the polymer protective decorative polymer protective decorative glue

Water absorption is one of the important indicators of the protective performance of plastering mortar. Therefore, we also prepared samples of this polymer protective decorative mortar with different amounts of polyacrylate emulsion to investigate the effect of the amount of polyacrylate emulsion on its water absorption. The test results are shown in Table 7.

Table 7 Effect of the amount of polyacrylate emulsion ^① on the water absorption of the polymer protective decorative glue

Polyacrylate emulsion dosage (mass%) Water absorption(g/m ² ) 10.0 279 12.0 201 14.0 151 16.0 135

Note: ① Polyacrylate emulsion is used by blending two types of emulsions, Primal 2438 and Primal AC-398A.

The results in Table 7 show that when the amount of polyacrylate emulsion is 10%, the water absorption of the polymer protective decorative mortar is 279g/m2; when it is 14%, it is 151g/m2, it can be seen that the polymer protective decorative mortar The lower water absorption is an inherent property of organic materials and one of the properties that make polymer-based plasters superior to cement-based plasters.

4. Research on the impact strength of the polymer protective decorative mortar

Impact strength is an important performance index for the polymer protective decorative mortar and the external thermal insulation system of the exterior wall. The usual polymer cement-based plaster mortar (that is, the current powder product) is reinforced with a single layer of alkali-resistant glass fiber mesh cloth with high-quality latex powder and a sufficient amount of addition, and is cured by the 28d standard. Finally, its impact strength is generally 3J ~ 8J, and after the general immersion in water is completely hydrated, the flexibility of the mortar drops to 3J or even lower.

Table 8 shows the test results of the effect of the amount of polyacrylate emulsion on the impact strength of the polymer protective decorative mortar. The values in the table are the results of using a single layer of alkali-resistant glass fiber mesh reinforcement, and the thickness of the protective decorative glue layer of the polymer is 3mm.

Table 8 Effect of the amount of polyacrylate emulsion ^① on the impact strength of the protective decorative mortar of this polymer

Note: ① Polyacrylate emulsion is used by blending two types of emulsions, Primal 2438 and Primal AC-398A.

In Table 8, the impact strength after immersion in water refers to the test results after the specimen was cured for 14 days, soaked in water for 7 days, and then dried for 7 days. It can be seen from Table 8 that even when the amount of polyacrylate emulsion is as low as 10%, the impact strength of the plaster mortar reaches 12J. With the increase of the amount of polyacrylate emulsion, the impact strength can reach more than 20J, even after the water resistance test, the impact strength is as high as 16J. It can be seen that compared with the usual polymer cement-based plastering mortar, the polymer basic polymer protective decorative mortar has very good impact resistance. This is a manifestation of the good flexibility of this type of plastering mortar. On the other hand, the protective decorative polymer mortar of the polymer protective decoration still retains a high impact strength after being soaked in water for 7 days and then dried for 7 days, which fully demonstrates that the protective decorative decorative polymer mortar of the polymer has excellent long-term durability. Flexibility and impact resistance.

5. Research on Improving the Drying Performance of the Polymer Protective Decorative Glue

In polymer cement-based plastering mortar, due to the large amount of cement used, the hydration of cement needs to consume about 25% of its own weight of water, and its strength continues to increase after its initial setting. Therefore, in addition to the long drying time that cannot meet the requirements under the low temperature (such as below 5°C) that is not suitable for construction, there is usually no problem of slow drying, and even if the construction is carried out under low temperature that is not suitable for construction, it can be passed. It is very convenient to solve the problem by increasing the setting and hardening and strength growth rate of cement-based materials. However, for the polymer-based plastering mortar that is completely formed by water evaporation, deformation and coalescence of polymer particles, and drying into a film, solving the drying problem is an important technology in its practical application.

This is because the moisture evaporation rate in the polymer protective decorative glue is very dependent on the air humidity. For example, when the air humidity is high, that is, in the rainy season, the synthetic resin emulsion sand wall paint (compared with the polymer protective decorative glue) When there are similar compositions), the drying problem often affects the construction quality of the coating. This is the inherent performance of this type of material, and it can only be paid attention to during the construction process. At present, there is no way to solve it from the material itself. Another problem is that when the temperature is high and the air humidity is low in summer, this kind of material may cause inconsistent water loss between the surface layer and the interior due to the rapid drying during construction, so that the surface layer dries first, forming a dense and impermeable surface film. The evaporation of internal moisture is blocked, which affects the actual drying of the material. Measures need to be taken to solve this problem. The approach we take is to add wood fibers that can significantly improve drying performance.

The principle of wood fiber improving polymer-based plastering mortar is that the fiber can produce capillary effect to play a water-transporting function, and the drying process of the material system is more uniform due to the generation of air permeability, so as to avoid the polymer protective decorative plastering mortar layer in During construction in high-temperature and dry seasons, the actual drying phenomenon is affected due to surface crusting caused by excessive drying.

(1) Effect of wood fiber on the drying performance of the polymer protective decorative glue

Table 9 shows the test results of the effect of wood fiber on the drying performance of the polymer protective decorative mortar. The test conditions for the results in the table are: the thickness of the protective decorative glue layer of the polymer is 3mm; the drying environment temperature is 40°C; the relative humidity of the drying environment is 25%; the drying is accelerated by the wind force of 3m/s flow rate.

Table 9 Effect of wood fiber content on the drying performance of the polymer protective decorative glue

From the test results in Table 9, it can be seen that in the case of accelerated drying test, the addition of wood fiber can significantly improve the drying performance of the polymer protective decorative mortar, and with the increase of wood fiber addition, the polymer The drying time of the material protection decorative glue is shortened, and the internal and external drying tends to be consistent.

(2) Effect of wood fiber on the water absorption performance of the polymer protective decorative glue

Water absorption is also an important performance index of the polymer protective decorative glue layer. Since wood fiber has a water transport performance similar to capillary action, its use may increase the water absorption of the polymer protective decorative glue layer. However, the test proves that the addition of wood fiber has little effect on the water absorption of the protective decorative glue layer of the polymer, and the test results are shown in Table 10. In Table 10, only under the addition of 3% wood fiber, the water absorption rate of the polymer protective decorative glue layer is about 0.3% higher than that without addition.

Table 10 Effect of wood fiber content on the water absorption of the polymer protective decorative glue

Note: Wood fiber 1 is a product with shorter fiber length; wood fiber 2 is a product with longer fiber length.

From the test results in Table 10, it can be seen that wood fiber has almost no obvious adverse effects on the polymer protective decorative glue. When the addition of wood fiber is as high as 3%, the water absorption of the polymer protective decorative glue does not increase significantly, this is because when the polymer protective decorative glue is completely cured into a film, due to the excellent polyacrylate emulsion The film-forming performance and the good physical and mechanical properties of the film after film formation make the wood fibers in a closed state in the film layer, eliminating the adverse effects on water absorption.

When choosing wood fibers, it should be noted that short fibers with a fiber length of less than 1 mm should be selected, and the amount of addition should be limited, because long fibers will have a negative impact on the appearance and bonding performance of the polymer protective decorative glue layer.

6. Research on the construction performance of the polymer protective decorative mortar

From a practical point of view, construction performance is one of the important properties of the polymer protective decorative mortar. The polymer protective decorative mortar is mainly constructed in two ways: spraying and troweling. These two construction methods have different requirements on the construction performance of the polymer protective decorative mortar.

The requirement for the workability of this polymer protective decorative mortar for spraying construction is that it should have good cohesion and anti-sagging properties, which can be met by selecting hydroxyethyl cellulose products with moderate viscosity and increasing the dosage appropriately .

The requirements for the workability of this polymer protective decorative mortar for plastering construction are that it should have good thixotropy, smoothness and no sticky feeling when plastering, which can be achieved by choosing hydroxyethyl cellulose products with higher viscosity models. fulfil requirements.

Since the test is carried out by experienced construction personnel for actual construction inspection, the polymer protective decorative mortar for spraying construction and troweling construction has good construction performance, which meets the construction requirements of a large number of construction sites.

7. Research on the decorative performance of the polymer protective decorative mortar

The polymer protective decorative mortar adopts high water-resistant and high-weather-resistant polyacrylate emulsion, so it can be used as a decorative layer directly after color matching. This decorative layer can usually be called a texture coating, or a polymer decorative mortar. (or facing mortar).

The polymer protective and decorative glue is a material with dual functions of protection and decoration, so the decoration is its important performance index. The research on its decorative performance should be based on the requirements of decorative materials (such as real stone paint), such as initial drying crack resistance, scrub resistance and stain resistance. In order to ensure the decorative properties of the polymer protective decorative glue, we have studied these properties separately.

(1) Effect of the solid content of the polymer protective decorative mortar on the initial drying crack resistance

Table 11 shows the test results of the effect of the amount of polyacrylate emulsion on the initial drying crack resistance of the polymer protective decorative mortar.

Table 11 Effect of the solid content of the polymer protective decorative mortar on the initial drying crack resistance

Like real stone paint and other coatings, the initial drying and cracking of the protective decorative mortar layer of this polymer is due to the low solid content in its formula composition, and the volume shrinkage caused by excessive water loss during the drying process. When the shrinkage stress exceeds this polymer The tensile strength of the protective decorative glue layer sometimes cracks.

The test results in Table 11 are consistent with this cracking mechanism, that is, when the solid content of the polymer protective decorative mortar is very low, its initial drying crack resistance is poor, and more fine cracks appear on the surface of the test panel; And when the solid content is increased to 60%, the test plate has basically no cracks except the corners. It can be seen that, in the case of maintaining the basic amount of polyacrylate emulsion, by adjusting the solid content of the polymer protective decorative mortar, it is very convenient to maintain the good initial drying crack resistance of the polymer protective decorative mortar.

(2) Effect of the amount of polyacrylate emulsion on the scrub resistance of the polymer protective decorative mortar

See Table 12 for the test results of the effect of the amount of polyacrylate emulsion on the scrub resistance of the polymer protective decorative mortar.

Table 12 Effect of the amount of polyacrylate emulsion ^① on the scrub resistance of the polymer protective decorative glue

Note: ① Polyacrylate emulsion is used by blending two types of emulsions, Primal 2438 and Primal AC-398A.

The test results in Table 12 show that the polymer protective decorative glue has very good scrubbing resistance. Even for the case where the amount of emulsion is lower than 12%, the mass loss is only 0.16g after 2000 washes. This is because two types of polyacrylate emulsions, Primal 2438 and Primal AC-398A, with good performance are selected for blending, so that the protective decorative glue layer of this polymer has high cohesive strength, so it can withstand washing damage The ability is strong, which is shown in the test results that the washing resistance is good, and there is almost no quality loss after 2000 times of washing tests.

(3) Effect of the amount of polyacrylate emulsion on the stain resistance of the polymer protective decorative mortar

Factors that affect the stain resistance of the polymer protective decorative mortar include the amount of polyacrylate emulsion and the particle size of the sand particles. There are many constructions, so the effect of the amount of polyacrylate emulsion on the stain resistance of this polymer protective decorative mortar is mainly investigated, because the impact of the sand particle size on the stain resistance is due to the trowel pressure during trowel construction. is no longer obvious. Table 13 shows the test results of the impact of the amount of polyacrylate emulsion on the stain resistance of the polymer protective decorative glue. The stain resistance test is carried out in accordance with the method specified in JG/T 24-2000 "Synthetic Resin Emulsion Sand Wall Architectural Coatings".

Table 13 Effect of the amount of polyacrylate emulsion ^① on the stain resistance of the polymer protective decorative glue

Polyacrylate emulsion dosage (mass%) Stain resistance result (grade) 10 3 12 2 14 1 16 1

Note: ① Polyacrylate emulsion is used by blending two types of emulsions, Primal 2438 and Primal AC-398A.

In this polymer protective decorative mortar, when the amount of polyacrylate emulsion is 10%, the stain resistance of this polymer protective decorative mortar is grade 3, indicating that the sand particles on the surface of this polymer protective decorative mortar layer It may be enough to affect the stain resistance, but when the amount of polyacrylate emulsion is further increased, the stain resistance of the polymer protective decorative glue is improved. This shows that a sufficient amount of polyacrylate emulsion film has been gathered on the surface of the protective decorative glue layer of the polymer, thereby exerting a good effect on the stain resistance of the protective decorative glue layer of the polymer.

(4) Anti-yellowing performance analysis of the polymer protective decorative mortar

Primal 2438 and Primal AC-398A two types of polyacrylate emulsion blended elastic latex paint has good yellowing resistance, and its color difference value (△E) after 500h artificial aging test is less than 1. From this empirical analysis, it can be known that the polymer protective decorative glue will have good yellowing resistance.

At the same time, the material cost of the polymer protective decorative layer can reduce the material cost by 4.1 yuan compared with the cement-based thin plaster surface layer with real stone paint as the decorative layer; , can reduce the cost of materials by 2.3 yuan per square meter.

Claims (9)

1. a protective polymer decoration rubber cement, it is characterised in that: its component includes according to the mass fraction: ester alcohol 6.0～12.0 Part, cellulose ether 3.5～6.0 parts, antifungus agent 1.5 parts, ammonia 1.0～2.0 parts, dispersant 2.0～3.0 parts, propylene glycol 12.0 ～16.0 parts, defoamer 1.5 parts, wood fibre 0.2～1.2 parts, quartz sand 450.0～600.0 parts, silica flour 200.0～ 300.0 part；Also include water 100.0～150.0 parts and account for the polyacrylate dispersion of gross mass 14%～16%, polyacrylate Emulsion is formed by plain polypropylene acid esters emulsion and elastomeric polypropylenes acid esters emulsion blending.

Protective polymer the most according to claim 1 decoration rubber cement, it is characterised in that: polyacrylate dispersion is by Primal 2438 elastic emulsions and Primal AC 996 interpolymer latex of polystyrene and acrylic ester blending form.

Protective polymer the most according to claim 2 decoration rubber cement, it is characterised in that: Primal2438 elastic emulsion and The blending ratio of Primal AC 996 interpolymer latex of polystyrene and acrylic ester is 5.5～4.0:4.5～6.0.

Protective polymer the most according to claim 1 decoration rubber cement, it is characterised in that: polyacrylate dispersion is by Primal 2438 type elastomeric polypropylenes acid esters emulsions and Primal AC-398A type polyacrylate dispersion two kinds of emulsion blending and Become.

Protective polymer the most according to claim 4 decoration rubber cement, it is characterised in that: Primal 2438 type elastic poly-third The blending ratio of olefin(e) acid ester emulsion and Primal AC-398A type polyacrylate dispersion is 5.5～4.0:4.5～6.0.

Protective polymer the most according to claim 1 decoration rubber cement, it is characterised in that: fibre length for length at 1mm Following chopped fiber.

Protective polymer the most according to claim 1 decoration rubber cement, it is characterised in that: cellulose ether is M30 type Bermocoll high-viscosity cellulose ether, ester alcohol be Texanol ester alcohol antifungus agent be A20 type antifungus agent, dispersant is " the easiest " point Powder, defoamer is 921 defoamer.

Protective polymer the most according to claim 1 decoration rubber cement, it is characterised in that: the particle diameter of quartz sand be 0.1mm～ 0.6mm, the fineness of silica flour is 100 mesh.

Protective polymer the most according to claim 1 decoration rubber cement, it is characterised in that: this protective polymer decoration rubber cement Solids content accounts for the 65%～75% of gross mass, and this protective polymer decoration rubber cement also includes pigment or the pigment colour of good weatherability Slurry.