KR910002573B1 - Polymer cement mortar composition - Google Patents

Abstract

No content.

Description

Polymer Cement Mortar Composition

1 through 6 are graphs.

7 is a conceptual diagram of the peel test.

8 is a sample explanatory diagram after the abrasion test.

9 to 12 are graphs.

* Explanation of symbols for the main parts of the drawings

1 gas 2 coating film

3: bracket 4: specimen

5: home

The present invention relates to a polymer cement mortar composition used for coating steel structures, metal roofs, outer walls and civil engineering structures.

Among the coating treatments for steel structures, there is a typical anticorrosive coating, which is simply applying or blowing a suitable anticorrosive coating on the surface of the steel structure, but the anticorrosive effect of the steel structure coated with the anticorrosive coating is generally the thickness of the coating film. As it is thin, it is hard to expect to exhibit the desired effect for a long period of time under various weather conditions such as temperature, humidity, and artificial conditions, such as durability, especially durability due to wear.

From this situation, some are endured and some form of anticorrosive coating layer is applied to steel structures by cement mortar.

However, the biggest drawback of this cement mortar is that it is prone to cracking.

Although cracking is likely to occur in the coating film after hardening, it is also possible to mix and use asphalt etc. in a cement composition, for example, In this case, various components eluting from the plasticizers used, for example, soil, etc. In addition to polluting the surrounding environment, the odors from asphalt have a great impact on workers and nearby residents.

From these circumstances, so-called polymer cement mortar compositions in which synthetic resin components are blended in place of asphalt have been used.

This polymer cement mortar composition improves the bonding strength of the hardened body of cement and improves the adhesiveness to the steel structure, so that the polymer cement mortar composition is effective in terms of properties and methods as a structural material. It is used for covering the base of deck-covered vehicles.

The characteristics of these uses include adhesion to the base, abrasion resistance, waterproof effect, weather resistance, cracking prevention, impact resistance, chemical resistance, elasticity, and corrosion resistance to the coatings, and currently used polymer cement mortar compositions I thought it was about satisfying a lot.

However, in order to fully and fully satisfy each characteristic required from various uses expanding over various aspects, there was room for further improvement.

Specifically, as an example, (1) most of the polymer cements are polymers of latex or emulsion water dispersion type polymers mixed with hydraulic cements, aggregates, etc. Causes

These metallic rustings are called flush lasts, but the results show that most polymer cements have some degree of difference.

In the case of such a flush last, in particular, if it is placed in a corrosive environment at that time or afterwards, there is a concern that the polymer cement coating is peeled off from the steel surface in accordance with the volume expansion of the rust of the steel surface.

This is because the anticorrosive property is not considered in the polymer emulsion blended with the conventional polymer cement.

In general, it is thought to stabilize the steel when it is coated by alkali action of cement, but because of this, it is necessary to keep the pH above 12 at the steel surface, so it is simply alkaline, which overestimates the anticorrosive effect of polymer cement. It is dangerous to do.

That is, FIG. 1 shows Da W. Whiteman and Al. R. Russel's study shows the relationship between pH and corrosion in steel, and when pH is less than 12, corrosion is rapidly increased.

In addition, 100 g of aggregates and cements of sample No. 1-7 as shown in the table were taken, stirred and mixed with 900 cc of tap water, suspended in a suspended mild steel plate, and the pH value of the liquid was measured using a pH meter. The results of observing the rust state were as shown in the table and FIG.

In the case of tap water, slag and sand, the pH value is low and the corrosion is high, but in the case of Portland cement and blast furnace cement, the pH value is high (over 12) and there is no rust and cement + slack, cement + silica sand The pH is slightly lowered and it is found to be sparse but accompanied by rusting on the specimen.

(2) In the corrosive environment (e.g., exposure to the coastal district or places receiving dry moisture alternately) due to the fact that the base material and the anticorrosive treatment process are not sufficiently considered, the steel surface and It is a cause which rusts in the interface of a coating material, and causes the fall of adhesive force.

From this point of view, as a result of extensive research, the present invention provides a radiation coating composition comprising a mixture of blast furnace debris and polymer emulsions having a specific particle size in a range of specific quantitative relations (Public Works 57-29661). The polymer cement mortar was also developed by mixing a rust preventive agent with a blend of hydraulic cement containing polymer as a component of the composition (Special Office 58-38378), but it also needed to have various characteristics such as conformation, resistance to thermal changes, and abrasion resistance. In the conventional polymer cement mortar composition, there are occasions where scenes cannot sufficiently meet these stringent requirements and cannot be coped with by use.

The present inventors have intensively researched to develop a polymer cement mortar composition having better properties that can cope with such an expanding use. As a result, aggregates are included among the main essential components of the polymer, cement and aggregate constituting the polymer cement mortar composition. By selecting a specific one with respect to the present invention, a new polymer cement mortar composition capable of sufficiently satisfying the various properties required above has been found.

That is, in the polymer cement mortar composition comprising cement (C), aggregate (S) and polymer (P), the present invention uses aggregates having a glass content of at least 95% by weight and styrene-butadiene-based polymers, It relates to a polymer cement mortar composition characterized in that the / S ratio is 0.4-0.65 P / C ratio is 0.2-0.5.

Cement components used in the present invention are portland cement, blast furnace cement, etc. The main functions expected of this component are improvement and maintenance of strength and durability.

Moreover, as a polymer, styrene- butadiene type polymers, such as a styrene- butadiene polymer or an acryl-modified styrene- butadiene polymer, are used.

When a polymer other than this system is used, it is difficult to obtain the desired effect in terms of adhesion between the object and / or flush lasting effect, for example, as indicated by the result of the preliminary examination described below. .

In the present invention, it is also required to use an aggregate having a glass content of at least 95% by weight.

In general, when forming a polymer cement mortar composition, siliceous sand, blast furnace slack slabs, etc., such as angels and sansa, are used as aggregates, but polymer cement mortar compositions using these as aggregates are used. There is a drawback that cracks are likely to occur when applied as a packaging material or an exterior wall material for civil engineering.

In completing the present invention, a preliminary examination is carried out to understand the general tendency of the type of polymer (P), the type of aggregate (S), and the P / C weight ratio C / S weight ratio and the like between cement (C). The results described in.

In order to use the blast furnace cement as a cement component and to display it as a polymer component and to add various anti-corrosive materials, a polymer cement mortar obtained by adding 0.5% by weight of a rust preventive agent to the whole composition was applied onto a steel sheet. Observation of the progress resulted in display results.

The P / C ratio and the C / S ratio were provisionally set to 0.4 and 0.5, respectively.

* 1: ① acetate, ② meta-fulate, ③ amine.

* 2: A (St-Bd) acrylic acid ester modified styrene. Butadiene polymer.

SBR Styrene.

A-St acrylic ester. Styrene copolymer.

PAN polyacrylonitrile emulsion.

EVA Ethylene Vinyl Acetate Copolymer.

Evaluation ◎ Flush. Last inhibitory effect remarkable.

○ Some have been called.

× No effect or almost no effect.

As is apparent from the results of the table, it is recognized that styrene.butadiene-based polymers are the most preferable from the polymerization with the rust-preventing effect in terms of the fundamental coating and coating effect among the properties required for the polymer cement mortar.

In order to suppress flushing and lasting, a rust preventive agent may be blended in the polymer cement mortar composition or a priming coat may be applied to the surface of the coating object.

When using a rust preventive agent, an amount of 0.1-3% by weight, preferably 0.3-1.0% by weight is blended.

When the rust preventive agent is not used, it is the same as or when the anticorrosive agent is used by performing prime coating treatment on the surface of the coated object which has been descaled using, for example, a zinc powder dispersed in an epoxy resin or a silicate compound. The above flush. Last suppression effect can be obtained.

Of course, it is obvious that both the prime coat treatment and the use of the rust inhibitor may be employed as necessary.

In addition, after examining the aggregate in the polymer cement mortar composition, the relationship between the maximum deflection (Smax) and the glass content of the tendency of the bending resistance (F) and the compression resistance (C) of the molded article is shown in FIG. The same behavior was obtained.

From this result, it is recognized that the glass content of aggregate in the polymer cement mortar composition has a significant effect on the values of F and C. Ultimately, the glass content is hardly generated when using a glass content of about 95% by weight or more. It became clear.

In this way, the aggregate determined under conditions is preferable from the workability as the polymer cement mortar composition when the particle size is approximately 0.6 mm or less.

The aggregate having a glass content of 95% by weight or more is not particularly limited as long as it meets the above conditions, but specifically, blast furnace chain slag obtained by quenching the molten slag discharged from the furnace is used.

After the above-mentioned polymer (P) and bone aggregate (S) are selected, each quantitative relationship becomes an important item, but for the C / S ratio, other requirements within the preferable ranges identified by the above-described grounds are applied. 4 shows the behavior of the compressive strength (C), the bending strength (F) and the tensile strength (TS) by fixing and changing the C / S ratio.

From the behavior shown it is found that a coating film with balanced strength is obtained when the C / S ratio is within the range of 0.40-0.65.

Fig. 5 shows the data of the peeling strength according to the P / C ratio by the same method.

In this case, a certain range of peel strength is maintained when the P / C ratio is in the range of 0.20-0.50.

As will be apparent from the behavior in the figure, it will be understood that the smaller the value of the P / C ratio, the lower the strength, and when too large, no effect suitable for the addition of the polymer is expressed.

The actual application of the polymer cement mortar is performed by selecting from a known coating means depending on the position of the object to be applied, but for example, a spray gun in the case of an object having a large flat surface or vice versa It is convenient to carry out the blowing coating using a.

The polymer cement mortar composition of the present invention from the above-described configuration has excellent performance in terms of adhesion, wear resistance, waterproofing effect, weather resistance, impact resistance, chemical resistance, anticorrosion property, grain resistance, vibration damping and cold heat repetition, etc. It is a polymer cement composition capable of displaying and sufficiently covering the functions required in various applications.

The following examples further illustrate various properties and effects of the polymer cement mortar composition of the present invention.

Moreover, the following formulation was used as a common formulation of the polymer cement mortar composition used in the Example.

20 parts by weight of acrylic modified SBR latex (48% solids)

25 parts by weight of blast furnace cement

55 parts by weight of blast furnace slag (0.5 mm or less) with 99% vitrification rate

0-3 parts by weight of water

Example 1

As a test piece, an epoxy resin dispersion containing zinc powder was coated on a steel plate subjected to a blast treatment to a thickness of 15-20 µm, and then the common cemented polymer cement mortar composition was blown and coated to a thickness of 5 mm.

The test tube thus obtained was cured at room temperature for 28 days, followed by one year of wet and dry alternating tests, Sliary annealing test, natural seawater immersion test, and 1000 hours weathering force test. There was no change in the state of.

* Dry and wet test: Cyclic test of 6 hours in 3% saline at 40 ° C, 6 hours in warm air at 40 ° C and 24 hours in 12 hours of cooling.

Sliri: Sliri mainly composed of cow manure.

Weatherability test: UV irradiation tester is used.

Example 2

The polymer cement mortar composition obtained by the common formulation was blown onto the steel sheet, the glass plate, the acrylic plate, the wood laminate, and the concrete, and the peel strength after curing for 28 days was measured and the results are shown in FIG.

In addition, the measuring method of this peeling strength adhere | attaches the metal fitting 3 to the coating film 2 formed by apply | coating on the base | substrate 1, as shown in FIG. 7, and adhere | attached the metal fitting with a cyanoacrylate type adhesive agent. It cuts in the coating film 2 of a part, and raises a metal bracket, and peeling of the coating film 2 is investigated.

It is recognized from FIG. 6 that the polymer cement mortar composition of the present invention has excellent adhesion.

Example 3

The tendency of the wear resistance of the polymer cement mortar composition was compared with the material according to the following method.

The tires were wound around 12 chains in a -10 ℃ atmosphere to investigate wear caused by chain contact.

The specimen used a molded product of 400 × 150 × 40 mm and was reciprocated at a rate of 66 round trips / minute with respect to a tire rotating at 200 rpm.

Although its outline is shown in FIG. 8, the specimen 4 is abraded by the abutment of the chain to form the groove 5.

The judgment of this abrasion test showed the behavior by the test time (min) in FIG. 9 by making the area (cm <2>) of the cross section S of the groove | channel 5 into one measure.

In the figure, the behaviors indicated by black triangles are aggregates having a glass content of 0%, and the white rings have a polymer cement mortar composition using aggregates having a glass content of 50% and a black ring having a glass content of 99%.

From this figure, it is recognized that the polymer cement mortar composition of the present invention is particularly excellent in wear resistance.

Example 4

The polymer cement mortar composition was applied to a steel sheet having a thickness of 2 mm by varying the thickness of the coating.

The ratio of the thickness of the coating film to the plate thickness of the base steel sheet was denoted by n, and the vibration damping ability was investigated by giving a vibration of 500 Hz to a sample of n = 1-4 to obtain the behavior of FIG.

In general, it is said that it is better to use the loss factor in the range of use temperature in the civil engineering or construction materials field, but as is clear from the drawings, the loss factor is more than 0.1 in the range of 0-50 ° C at n≥2. Especially, in the vicinity of 20-30 degreeC, the value of the coefficient shows the high value around 0.2.

Example 6

A molded article of 160 × 40 × 40 mm was prepared by using a polymer cement mortar composition, and the relationship between the stress (S _S ) and the outer curvature (S _n ) during compression and bending was determined for the sample after 28 days of curing.

The result is shown in FIG.

It is found that the followability of the outer grain is recognized up to about 110 kgf / cm 2 and the stress is about 50 kgf / cm 2, and the relationship with the outer grain becomes almost straight, making the material extremely easy to control.

In the figures, white data is obtained for compression, and black data is obtained for curvature. Although each symbol overlaps and blocks data at the time of repeated experiments, it is recognized that the data is highly reproducible.

Example 7

160 × 40 × 40mm moldings were made by polymer cement mortar composition using 99% glass content and 0% aggregate, and cured for 28 days, followed by cold heat repetition test using 80 ° C for 6 hours and 5 ° C for 14 hours. Fig. 12 shows the measurement of the dimensional change amount δ and the program of the cooling cycle and the change amount δ.

Compared with the glass content of 0% (one dashed line), the 99% glass content is found to have a small amount of change, that is, a high dimensional stability.

Claims (3)

In the polymer cement mortar composition consisting of cement (C), aggregate (S) and polymer (P), a glass content of aggregate of 95% by weight or more and a styrene-butadiene polymer are used, and the C / S ratio by weight The polymer cement mortar composition characterized in that 0.4-0.65 and P / C ratio are 0.2-0.5. The polymer cement mortar composition according to claim 1, wherein blast furnace chain slag is used as aggregate. The polymer cement mortar composition according to claim 1, wherein the styrene-butadiene-based polymer is a styrene. Butadiene polymer or a polymer selected from an acryl-based styrene-butadiene-based polymer.

Images