HK1141269A1

HK1141269A1 - Self-leveling composition

Info

Publication number: HK1141269A1
Application number: HK10107864.6A
Authority: HK
Inventors: 山口雅人; 大内涉; 山下琢治; 佐佐木多闻
Original assignee: 吉野石膏株式会社
Priority date: 2007-04-05
Filing date: 2008-03-12
Publication date: 2010-11-05
Also published as: WO2008126596A1; CN101652335A; CN101652335B; JP5138966B2; KR101459806B1; TWI417267B; TW200840806A; KR20090127412A; JP2008254971A

Abstract

Disclosed is a self-leveling composition comprising: a self-leveling composition mainly composed of a plaster (calcium sulfate) and containing no building material; and a high-viscosity cellulose ether and a low-viscosity cellulose ether. The self-leveling composition has a long application time in the formation of a horizontal surface, has excellent fluidability and surface smoothness (with less wrinkling or cracking), and has high surface strength.

Description

Self-leveling composition

Technical Field

The present invention relates to a self-leveling composition used as a floor finishing base material or the like.

Background

Self-leveling materials (SL materials) are widely used as floor finish base materials because they naturally flow to form a horizontal surface and solidify by merely being mixed with water and poured onto the floor. Among SL materials, gypsum-based materials, cement-based materials, and the like are now in widespread use. As prior art documents relating to such SL materials, there are the following documents.

Patent document 1 discloses a self-leveling composition comprising, as essential components: cement and/or gypsum, a fine aggregate, a water reducing agent (a flow agent or a dispersant), an antifoaming agent, a retarder, a setting accelerator, a water-soluble cellulose ether having a residual amount of 5 mass% or less after being sieved with a sieve having a mesh size of 100 (mesh size of 150 μm) as described in 14 th modified Japanese pharmacopoeia B1061, and water. However, this self-leveling composition has a problem that the fluidity of the slurry is lowered and the workability is deteriorated because it is necessary to increase the viscosity in order to prevent the separation of the aggregate. Further, when the flow thickness is set to 5mm or less, the influence of the unevenness of the floor base layer is liable to be exerted, the surface smoothness of the formed horizontal surface is deteriorated, and the aggregate may be precipitated even in the case of a thick flow of about 50 mm. Therefore, the self-leveling composition is not satisfactory.

Further, when no aggregate is blended in the self-leveling material, there is a problem that a flow loss (a decrease in a flow value with time) due to hydration or aggregation of a reactant (cement, gypsum, or the like) is increased, and a working time for forming a horizontal floor surface cannot be sufficiently obtained.

Patent document 1: japanese laid-open patent publication No. 2006-56763

Disclosure of Invention

Accordingly, an object of the present invention is to provide a self-leveling composition which has a long working time (also referred to as working time) when formed into a horizontal plane, is excellent in fluidity and surface smoothness (substantially free from wrinkles and cracks), and can provide a horizontal plane having high surface strength.

The present inventors have conducted extensive studies to achieve the above object and, as a result, have found that a self-leveling composition which can be formed into a horizontal surface with a long working time and has excellent fluidity and surface smoothness and a horizontal surface having high surface hardness can be obtained by blending a specific self-leveling composition with a cellulose ether composed of a cellulose ether having high viscosity and a cellulose ether having low viscosity, and have completed the present invention.

That is, the present invention provides a self-leveling composition which comprises gypsum as a main material, does not contain an aggregate, and contains a high-viscosity cellulose ether and a low-viscosity cellulose ether. The self-leveling composition preferably further contains a chelating agent. By containing the chelating agent, a self-leveling composition capable of providing a level surface with further improved surface smoothness is formed.

According to the present invention, by adding a high-viscosity cellulose ether and a low-viscosity cellulose ether to a self-leveling composition of a gypsum base material containing no aggregate, a self-leveling composition which has excellent fluidity when formed into a horizontal plane, a long working time, excellent surface smoothness of the formed horizontal plane, and high surface hardness can be provided to the formed horizontal plane can be provided. Further, by further blending a chelating agent, a self-leveling composition which can prevent the occurrence of cracks on the surface and can provide a level surface having further improved surface smoothness can be provided.

Detailed Description

The present invention will be described in further detail below.

In the self-leveling composition of the present invention, powdered gypsum is used as a main material. Examples of the gypsum include alpha-hemihydrate gypsum, II-anhydrite gypsum, and beta-hemihydrate gypsum.

The self-leveling composition of the present invention does not contain an aggregate. When the self-leveling composition contains an aggregate, the slurry needs to have a viscosity of at least a certain level in order to prevent the aggregate from settling, and when water is mixed into the self-leveling composition when the ground level is formed, the resulting slurry has reduced fluidity. Therefore, in particular, when the flow thickness is 5mm or less, the slurry is likely to be affected by the unevenness of the floor mat, and the surface smoothness is deteriorated, and in the case of a thick flow of about 50mm, there is a risk that the aggregate is settled.

The self-leveling composition of the present invention contains at least 2 kinds of cellulose ethers. Specific examples of the cellulose ether include methyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, and hydroxyethyl ethyl cellulose.

Among the above cellulose ethers, cellulose ethers having high viscosity and cellulose ethers having low viscosity are used in the present invention in combination with the high-viscosity cellulose ethers and the low-viscosity cellulose ethers. The highly viscous cellulose ether preferably has a viscosity of 40,000 to 100,000 mPas when measured with a Brookfield type viscometer at 20 ℃ and 20rpm in the form of a 2 mass% aqueous solution. In addition, if expressed by molecular weight, it has a weight average molecular weight (molar molecular weight) of 5X 10⁵～7×10⁵(g/mol) molecular weight. The low-viscosity cellulose ether preferably has a viscosity of 200 to 1,000 mPas when measured with a Brookfield type viscometer at 20 ℃ and 20rpm in the case of being prepared as a 2 mass% aqueous solution. In addition, if expressed by molecular weight, it has a weight average molecular weight (molar molecular weight) of 1X 10⁵～2×10⁵(g/mol) molecular weight.

The total amount (a + B) of the high-viscosity cellulose ether (a) and the low-viscosity cellulose ether (B) is preferably 0.02 to 0.7 part by mass per 100 parts by mass of gypsum. The amount (A, B) of the highly viscous cellulose ether and the low viscous cellulose ether is preferably 0.01 to 0.6 parts by mass per 100 parts by mass of gypsum. If the amount of the cellulose ether used after adding the high viscosity and the low viscosity is less than 0.02 parts by mass per 100 parts by mass of gypsum, sufficient material separation resistance cannot be seen in the resulting self-leveling composition, and bleeding (sheeting) occurs, so that the strength of the self-leveling composition on the horizontal plane after curing becomes uneven. In addition, the bleeding may cause water loss (also referred to as blooming) or cracking of crystals. On the other hand, if the amount of gypsum used is more than 0.7 parts by mass per 100 parts by mass of gypsum, the viscosity of the slurry obtained is too high, and the slurry lacks fluidity, and the self-leveling property, which is an important characteristic of the self-leveling composition, is impaired. Such excessively high viscosity may cause wrinkles on the obtained horizontal surface, further impairing the appearance, and causing a decrease in strength. The mixing ratio of the amount (A) of the high-viscosity cellulose ether to the amount (B) of the low-viscosity cellulose ether is preferably 1: 0.02 to 1: 50, more preferably 1: 0.1 to 1: 10, in terms of mass ratio, A: B.

The self-leveling composition of the present invention is preferably further blended with a chelating agent in order to reduce the formation of a film on the surface or to prevent the formation of cracks when forming a ground surface level. Specific examples of the chelating agent include ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, hydroxyethylethylenediaminetriacetic acid, nitrilotriacetic acid (nitrilotriacetic acid), and dihydroxyethylglycine. Especially preferred is diethylenetriaminepentaacetic acid which is effective for retarding the coagulation of the aqueous slurry of the self-leveling composition of the present invention.

The amount of the chelating agent is preferably 0.02 to 0.5 part by mass per 100 parts by mass of gypsum. If the amount of the chelating agent is less than 0.02 parts by mass, the effect of preventing the formation of a coating on the surface cannot be sufficiently exhibited. On the other hand, if the amount is more than 0.5 parts by mass, the production cost is increased by using a large amount of the chelating agent, which is not preferable.

The self-leveling composition of the present invention may be appropriately blended with one or more of cement, a water reducing agent (a flow agent or a dispersant), an antifoaming agent, a retarder, a setting accelerator, an inorganic extender, a synthetic resin, and the like, as required.

As the cement, various cements such as ordinary portland cement, early strength portland cement, moderate heat portland cement, blast furnace slag cement, portland cement, fly ash cement, high alumina cement, and set-top cement can be used. The cement is added to improve the water resistance of the floor-facing base material to be formed, and the amount of the cement is preferably 5 to 50 parts by mass per 100 parts by mass of gypsum.

The water reducing agent (flow agent or dispersant) is not particularly limited as long as it is a water reducing agent generally commercially available. Generally, polycarboxylic acid-based, melamine-based, naphthalene-based, and other water reducing agents can be used. The amount of the water reducing agent is preferably 0.01 to 5 parts by mass per 100 parts by mass of gypsum. In the case of a self-leveling composition, since it is necessary to obtain excellent fluidity with as little water as possible, a water reducing agent may be blended, but if the blending amount is too small, the effect cannot be obtained, whereas if it is too large, bleeding or solid-liquid separation may occur, which may cause a decrease in strength of a formed level or cause blooming.

As the defoaming agent, polyether type, silicone type, alcohol type, mineral oil type, vegetable oil type, nonionic surfactant and the like can be used.

Examples of the retarder include citrates such as sodium citrate, borates such as succinate, acetate, malate, and borax, sucrose, hexametaphosphate, edetate, starch, and protein decomposition products. The amount of the retarder to be added may be set to such an extent that the retardation function can be exhibited as desired. Specifically, the retarder is preferably added in an amount of 0.005 to 1 part by mass per 100 parts by mass of gypsum.

Examples of the accelerator include soluble calcium salts such as calcium chloride, calcium nitrite, calcium nitrate, calcium bromide, and calcium iodide, chlorides such as iron chloride and magnesium chloride, sulfates such as potassium sulfate, formates such as potassium hydroxide, sodium hydroxide, carbonates, thiosulfates, formic acid, and calcium formate. As the inorganic extender, talc, calcium carbonate, or the like can be used.

As the synthetic resin, a powdery resin is preferable, and a vinyl acetate resin, versatic acid (versatic acid) vinyl ester resin, vinyl acetate-versatic acid vinyl ester copolymer, acrylic resin, vinyl acetate-acrylic acid copolymer, vinyl acetate-versatic acid vinyl ester-acrylic ester copolymer, styrene-butadiene copolymer, or the like can be used. The synthetic resin is blended for improving the surface hardness of the floor-facing base material to be formed, and the blending amount thereof is preferably 0.05 to 1 part by mass per 100 parts by mass of gypsum.

The self-leveling composition of the present invention can be formed into a floor surface finishing material by adding water to mix them thoroughly, pouring the resulting slurry onto a floor surface, spreading, leaving, curing, and drying. Examples of the floor surface include mortar, cement, wood, plastic bricks, sheets, ceramics, and metals such as stainless steel.

The amount of water is preferably 20 to 50 parts by mass per 100 parts by mass of gypsum. If the amount of water is too small, sufficient fluidity cannot be obtained, and the obtained slurry is difficult to spread, and workability may be deteriorated, whereas if too large, the obtained floor finish base material may have deteriorated strength. Therefore, it is not preferable to use water in an amount exceeding the above range.

Examples

The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

< materials used >

Gypsum: alpha-type hemihydrate gypsum

Cement: ordinary portland cement

Water reducing agent: polycarboxylic acids

Retarder: sodium citrate (reagent)

Chelating agent: diethylene triamine pentaacetic acid

(DTPA, reagent)

Retarder: sulfates (reagent)

Cellulose ether: highly viscous cellulose ethers

(viscosity 50,000 mPa. multidot.s)

Cellulose ethers of moderate viscosity

(viscosity 4,000 mPa. multidot.s)

Low viscosity cellulose ethers

(viscosity 300 mPas)

(the viscosity is a value measured by the above-mentioned measurement method and measurement conditions.)

Defoaming agent: polyether system

Synthetic resin: vinyl acetate-acrylic acid copolymer

Aggregate: silica sand (particle size 0.05 ~ 0.8mm)

[ example 1]

As shown in table 1, the powdery self-leveling composition was obtained by combining the materials such that the high-viscosity cellulose ether was 0.05 parts by mass and the low-viscosity cellulose ether was 0.12 parts by mass per 100 parts by mass of gypsum, and then mixing the materials with a predetermined amount (1.0 to 1.5 parts by mass per 100 parts by mass of gypsum in total) of a water reducing agent, a retarder, an accelerator, a synthetic resin, and a defoaming agent. Then, 45 parts by mass of water was added to 100 parts by mass of gypsum in the stirring bowl as shown in table 1, and the self-leveling composition obtained in the above procedure was gradually charged while stirring, and after the charging was completed, the mixture was mixed for 3 minutes using a test machine specified in 8.1 of JIS R5201 to obtain a slurry-like self-leveling composition.

[ example 2]

A self-leveling composition was obtained in the same manner as in example 1, except that a chelating agent was newly added in an amount of 0.08 parts by mass per 100 parts by mass of gypsum as shown in table 1.

[ example 3]

A self-leveling composition was obtained in the same manner as in example 1, except that the blending amount of the high-viscosity cellulose ether was 0.1 part by mass and the blending amount of the low-viscosity cellulose ether was 0.03 part by mass as shown in table 1.

[ example 4]

A self-leveling composition was obtained in the same manner as in example 2, except that the blending amount of the high-viscosity cellulose ether was 0.04 parts by mass and the blending amount of the low-viscosity cellulose ether was 0.3 parts by mass as shown in table 1.

Comparative example 1

A self-leveling composition was obtained in the same manner as in example 1, except that the amount of the high-viscosity cellulose ether was changed to 0.11 parts by mass and the low-viscosity cellulose ether was not added, as shown in table 2.

Comparative example 2

A self-leveling composition was obtained in the same manner as in example 1, except that 0.18 parts by mass of a medium-viscosity cellulose ether was newly blended per 100 parts by mass of gypsum, and a high-viscosity cellulose ether and a low-viscosity cellulose ether were not blended, as shown in table 2.

Comparative example 3

A self-leveling composition was obtained in the same manner as in example 1, except that the amount of the low-viscosity cellulose ether was changed to 0.5 parts by mass and the high-viscosity cellulose ether was not added, as shown in table 2.

Comparative example 4

A self-leveling composition was obtained in the same manner as in example 1, except that 0.08 parts by mass of a medium-viscosity cellulose ether was newly blended per 100 parts by mass of gypsum, the blending amount of the high-viscosity cellulose ether was set to 0.03 parts by mass, and a low-viscosity cellulose ether was not blended, as shown in table 2.

Comparative example 5

A self-leveling composition was obtained in the same manner as in example 1, except that 0.12 parts by mass of a medium-viscosity cellulose ether was newly blended per 100 parts by mass of gypsum, the blending amount of the low-viscosity cellulose ether was changed to 0.1 parts by mass, and a high-viscosity cellulose ether was not blended, as shown in table 2.

Comparative example 6

A self-leveling composition was obtained in the same manner as in example 1, except that 50 parts by mass of an aggregate was newly added per 100 parts by mass of gypsum, the amount of the high-viscosity cellulose ether was 0.1 part by mass, the amount of the low-viscosity cellulose ether was 0.1 part by mass, and the retarder was 0.09 part by mass per 100 parts by mass of gypsum, as shown in table 2.

The slurry-like self-leveling compositions obtained in examples 1 to 4 and comparative examples 1 to 6 were evaluated by conducting the following tests. The test results and evaluation criteria (appropriate values) for the self-leveling compositions obtained in examples 1 to 4 and comparative examples 1 to 6 are also shown in tables 1 and 2, respectively.

[ flow value ]

Measured according to JASS 15M-103 of the Japan society for construction and engineering standards.

[ viscosity ]

A predetermined amount of slurry was poured into a cup dedicated to the measuring apparatus using a viscosity measuring apparatus VISCOTESTER VT-04E (trade name, manufactured by RION, Ltd., shear rate: 4sec-1), and the viscosity of each slurry was measured.

[ flow velocity ]

Each slurry was poured into a slurry inlet (height 100 mm. times. length 50 mm. times. width 100mm) of an acrylic acid production measuring apparatus placed horizontally and having a height of 100 mm. times. total length 500 mm. times. width 100mm, and the apparatus was left to stand as it was until it was filled. After 7 minutes had elapsed from the start of the charge, the weir of the acrylic plate forming one surface of the slurry charging section was instantaneously lifted, the time until the slurry reached the end of the measuring apparatus was measured, and the flow rate was calculated by the following equation.

Flow rate (mm/s) is the distance moved by the slurry (450 mm)/measurement time(s)

[ working hours ]

The workable time was measured in the same manner as the above-described flow value measurement according to JASS 15M-103. A predetermined amount of each slurry was poured into a vinyl chloride pipe standing vertically, and left as it was. After the slurry spreading was stopped, the diameter of the horizontally spread slurry in the right-angled 2 directions was measured, and the average value was calculated. The time for which the average value is 190mm or more is ensured as the operable time.

[ surface hardness ]

The slurries were poured into a box-shaped container having a height of 20mm, a length of 100mm and a width of 100mm, allowed to stand at room temperature for 48 hours to cure the slurry, and then the cured product was placed in a dryer at 40 ℃ and dried to a constant amount, and then the cured product was taken out from the dryer, and a rubber durometer ("TYPE D", trade name, manufactured by TECCLOCK corporation) was pressed against the surface of the cured product to measure the surface hardness.

[ surface smoothness (surface State: presence or absence of wrinkles or cracks) ]

Each slurry was poured into a plastic container having a length of 30cm X50 cm to a thickness of 10mm, and after 30 minutes, about 250cc of the slurry was further poured into the central portion of the container from above, and the container was left as it was. The surface smoothness of the cured product was periodically confirmed by touch and sight until 4 weeks had elapsed.

The surface smoothness (wrinkles and cracks) was evaluated according to the following evaluation criteria.

< wrinkles >

A: every 1,500cm²The number of wrinkles having a width of 0.5mm or more and a length of 5mm or more is 0

B: every 1,500cm²Having a width of 0.5mm or more and a length of 5mm or moreThe number of wrinkles is 1

C: every 1,500cm²The number of wrinkles having a width of 0.5mm or more and a length of 5mm or more is 2 to 5

D: every 1,500cm²The number of wrinkles having a width of 0.5mm or more and a length of 5mm or more is 6 or more

The above-mentioned values of A, B, C, and D are particularly preferable, and very poor.

< cracks >

A: every 1,500cm²The number of cracks was 0

B: every 1,500cm²The number of cracks is 1

C: every 1,500cm²The number of cracks is 2-5

D: every 1,500cm²The number of cracks is more than 6

The results of evaluation on all of the above test items were particularly good or good for the self-leveling compositions of examples 1 to 4. That is, as shown in examples 1 to 4, by adding a high-viscosity cellulose ether and a low-viscosity cellulose ether to gypsum without adding an aggregate, a self-leveling composition which has excellent fluidity when formed into a horizontal plane, a long working time, excellent surface smoothness, and a horizontal plane having high surface hardness can be obtained.

The self-leveling compositions of examples 2 and 4 had better surface smoothness (as evidenced by the absence of cracks) than the self-leveling compositions of examples 1 and 3. That is, the self-leveling compositions of examples 2 and 4 had better surface smoothness by blending the chelating agent. In contrast, the self-leveling compositions of comparative examples 1 and 2 had low flow rate, short workable time, and poor surface smoothness; the self-leveling composition of comparative example 3 had a low surface hardness; the self-leveling composition of comparative example 4 had a low flow rate, a short working time, and poor surface smoothness; the self-leveling composition of comparative example 5 had poor surface smoothness; the self-leveling composition of comparative example 6 had a low flow rate, low surface hardness, and poor surface smoothness.

TABLE 1

TABLE 2

The present invention provides a self-leveling composition which has a long working time when formed into a horizontal plane, is excellent in fluidity and surface smoothness (substantially free from wrinkles and cracks), and can provide a horizontal plane having high surface strength.

Claims

1. A self-leveling composition which comprises gypsum as a main material and no aggregate, and further comprises a high-viscosity cellulose ether and a low-viscosity cellulose ether, wherein the total amount A + B of the amount A of the high-viscosity cellulose ether blended and the amount B of the low-viscosity cellulose ether blended is 0.02 to 0.7 part by mass per 100 parts by mass of the gypsum, and the ratio A: B of the amount A of the high-viscosity cellulose ether blended to the amount B of the low-viscosity cellulose ether blended is 1: 0.02 to 1: 50.

2. The self-leveling composition according to claim 1, wherein the high viscosity cellulose ether has a viscosity of 40,000 to 100,000 mPas when prepared as a 2 mass% aqueous solution and measured with a Brookfield type viscometer at 20 ℃ and 20rpm, and the low viscosity cellulose ether has a viscosity of 200 to 1,000 mPas when prepared as a 2 mass% aqueous solution and measured with a Brookfield type viscometer at 20 ℃ and 20 rpm.

3. A self-leveling composition according to claim 1 or 2, further comprising a chelating agent.

4. A self-leveling composition according to claim 3, wherein the chelating agent is contained in an amount of 0.02 to 0.5 parts by mass per 100 parts by mass of gypsum.