JPH08217521A - Gypsum composition for forming floor post - Google Patents

Abstract

PURPOSE: To obtain a gypsum composition for forming a long floor post with the amt. of kneading water reduced, with the drying time shortened and having a long working life. CONSTITUTION: This gypsum composition for forming a floor post contains 20-80vol.% foamed synthetic resin granular material based on 100vol.% calcined gypsum consisting of 10-40wt.% α-hemihydrate gypsum and 90-60wt.% β- hemihydrate gypsum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plaster composition for forming a floor bundle used for forming a floor bundle supporting a floor of a building or the like.

[0002]

2. Description of the Related Art Various materials are used for a floor bundle supporting a floor of a building. For example, Japanese Utility Model Publication No. 57-11066 discloses an example of using a metal fitting having a height adjusting portion, and Japanese Utility Model Publication No. 57-84235 discloses the use of mortar to form a floor bundle. Has been done. Further, JP-A-58-199964 describes a floor bundle forming material. Specifically, various gypsum, inorganic lightweight particles such as expanded vermiculite, expanded synthetic resin particles such as expanded polystyrene, thickener and water retention agent such as methyl cellulose, hardening modifier such as collagen, lignin sulfonate, etc. It is described that a water reducing dispersant, a fibrous material such as rock wool, a rust preventive such as calcium nitrite, and an alkali agent such as cement are used in combination. However, no specific composition is described. On the other hand, the floor of a building is required to have various characteristics such as strength, that vibration is not transmitted downstairs and that it is level, and in addition, it is easy to shorten the construction period during construction. Moreover, it is desired that the work can be performed in a short time. However, when using the metal fittings traditionally used to form the floor bundle, it is necessary to adjust the height of many metal fittings that will be the floor bundle to bring out the level, which is cumbersome and time consuming. Therefore, there is a problem that the construction period cannot be shortened.

On the other hand, there is a technique for facilitating horizontal adjustment, that is, a method for easily adjusting the height by using a mortar-like composition and forming a floor bundle after curing, but a normal cement is used. With the composition of mortar, strength development is slow,
In addition to the time required for drying, there are problems such as cracking due to drying shrinkage and the adhesion to the floor slab is reduced and peeling occurs. Further, the gypsum-based composition has no drying shrinkage, does not crack and does not peel off with good adhesion to the floor slab, but since it is kneaded with a large amount of water and used, it takes time to dry. In short, moisture is trapped under the floor, which tends to be sealed, which is inconvenient for hygiene (mold, etc.) and storage of the building (corrosion, etc.). Further, there is a problem in working since the pot life is short from the time when the plaster-based composition and water are kneaded to form a mortar-like slurry until the start of simulation.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a plaster composition for forming a floor bundle which can be kneaded with a small amount of water, can be dried in a short time, and has a long pot life.

[0005]

The present invention efficiently solves the above problems by combining a specific amount of expanded synthetic resin granules with calcined gypsum in which α-type hemihydrate gypsum and β-type hemihydrate gypsum are used in a specific ratio. It is based on the knowledge that it can be solved. That is, the present invention relates to a calcined gypsum 1 comprising 10 to 40% by weight of α-type hemihydrate gypsum and 90 to 60% by weight of β-type hemihydrate gypsum.
Provided is a plaster composition for forming a floor bundle, which contains 20 to 80 volumes of expanded synthetic resin particles with respect to 00 volumes. In the present invention, α-type hemihydrate gypsum 10-40% by weight (preferably 25-35% by weight) and β-type hemihydrate gypsum 90-6
Calcined gypsum consisting of 0% by weight (preferably 75 to 65% by weight) is used. Here, the amount of α-type hemihydrate gypsum is 40% by weight.
When the amount is larger, the amount of mixed water is reduced and the dry strength is increased, but it tends to drip during construction and it is difficult to put on the floor. On the other hand, if the amount of α-type hemihydrate gypsum is less than 10% by weight, the amount of mixed water will increase and sludge will not easily drip during construction and it will be easier to put it on the floor, but the target increase in drying strength and shortening of drying time will be achieved. Can not be.

The α-type hemihydrate gypsum and the β-type hemihydrate gypsum can be easily produced from gypsum rough stone, chemical gypsum, flue gas desulfurization gypsum and the like. In the present invention, it is preferable to use the foamed synthetic resin granules in a volume ratio of 20 to 80% by volume with respect to the calcined gypsum of the above composition when the calcined gypsum is 100. Here, the expanded synthetic resin granules have a bulk specific gravity of 0.01 to 0.
It is preferable that the average particle size is 05 and the average particle size is about 0.5 to 3 mm. In terms of weight, it is preferable that the foamed synthetic resin granules are about 0.2 to 4.0% by weight per 100 parts by weight of the calcined gypsum. The maximum diameter is preferably less than 3 mm so that the granules may be caught at the trowel end and a concave groove cannot be formed on the surface of the lower rub during rubbing.

The expanded synthetic resin granules used in the present invention include expanded polystyrene type particles, expanded urethane type particles, expanded polyethylene type particles, expanded polypropylene type particles, other urea type, styrene type and phenol type particles. , And one or a mixture of two or more kinds of granular materials obtained by crushing foamed synthetic resin such as vinyl chloride. Thus, it is preferable that it has almost no water absorption. The shape of the expanded synthetic resin granules used in the present invention can be arbitrary, but it is better that the expanded synthetic resin granules are not spherical but are angularly distorted. A spherical shape is not desirable in terms of work because it rolls when it is rubbed on the floor or rubbed. Therefore, a crushed product is preferable as the expanded synthetic resin granular material. In the present invention, when the ratio of the expanded synthetic resin granules is more than the specified value, not only the strength of the cured product decreases but also the workability deteriorates. On the other hand, when the ratio of the expanded synthetic resin granules is less than the specified value, the strength of the cured product increases, but the cured product tends to sag during the construction, which makes it difficult to serve.

The plaster composition for forming a floor bundle of the present invention contains the above-mentioned calcined gypsum and expanded synthetic resin granules as essential components, and various additives can be used in combination as necessary. Specifically, one or a mixture of two or more of a thickener (also serving as an adhesion promoter), a curing modifier, a water-reducing dispersant, a fibrous material, a fungicide and a rust preventive can be used in combination. Among them, examples of thickeners and adhesion promoters include methyl cellulose (MC), polyvinyl alcohol, carboxymethyl cellulose and the like. When such a thickener or an adhesion promoter is used, a moderate viscosity can be imparted to the slurry and the mortar can be easily formed at the time of construction to promote the adhesion to the floor substrate. When using a thickener or an adhesion promoter, it is preferable to use alkali-resistant MC. The addition amount is 0.1 to 1.5% by weight with respect to the entire plaster composition for forming a floor bundle.

Examples of the curing modifier include animal proteins such as collagen and keratin which have a delaying effect, peptone, citric acid or salts thereof, urea, amino acids, phosphates and the like, or a mixture of two or more thereof. To be The amount used is arbitrary, but it is preferable to adjust the amount added according to the setting time. As the water reducing dispersant, lignin sulfonate, alkylaryl sulfonate (Mighty-100 of Kao Atlas Co., Ltd.), sulfonate of melamine formalin resin (Merument of Showa Denko KK), alkylaryl formalin condensate Examples thereof include one or a mixture of two or more of sulfonates and the like. The amount used is arbitrary, but it is preferably about 0.01 to 0.3% by weight.

Examples of the fibrous material include cellulose fiber, rock wool, mineral wool, glass fiber, pulp, nylon, vinylon, polyester, polyvinyl chloride and the like, or a mixture of two or more thereof. When these fibrous materials are used, the strength of the hardened gypsum-based composition can be increased and the kneaded plaster composition for forming a floor bundle can be easily deposited. The length of the fiber is preferably 2 to 10 mm, more preferably 4 to 7 mm. The amount used is arbitrary, but from 0.03
1.0% is preferable, and more preferably 0.05 to 0.5% by weight.
Is. The mildew-proofing agent is used for preventing the generation of mildews, and includes 2- (4-thiazolyl) -benzimidazole, methyl-2-benzimidazole carbamate, methyl 1-butylcarbamate, dodecylguanidine hydrochloride, preventol A, 4-N-lauryl-β-alanine, binazine, nopcoside N96, siabendazole (TBZ) and the like can be mentioned. However, the antifungal agent used in the present invention is not limited to these, and various antifungal agents can be used as long as they have bactericidal properties. The amount used is optional, but it is from 0.05 to 0.15
It is preferably set to wt%.

As the rust preventive agent, basic substances such as nitrites such as calcium nitrite and sodium nitrite or slaked lime, alkali metals such as magnesium hydroxide, potassium hydroxide, sodium carbonate and calcium carbonate or alkaline earth metals are used. One or a mixture of two or more kinds of compounds (among others, preferably hydroxide) and alkali materials such as cement can be mentioned. The amount used is arbitrary, but 0.5-1.5% by weight
Is preferred. The floor plaster forming gypsum composition of the present invention, when used, contains 30 parts of water per 100 parts by weight of the composition.
It is preferable to use it after adding about 50 parts by weight and mixing uniformly.

[0012]

According to the present invention, the amount of water to be kneaded is small, the drying time can be as short as about 10 to 25 days, and the pot life is long as about 120 to 180 minutes. It is possible to provide a plaster composition for forming a floor bundle. Next, the present invention will be described with reference to examples.

[0013]

【Example】

Example 1 0.2 part by weight of peptone and 1 part by weight of polypinyl alcohol (PVA) per 100 parts by weight of calcined gypsum in which the ratio of α-type hemihydrate gypsum / β-type hemihydrate gypsum is 3: 7 (weight ratio). And 1 part by weight of styrofoam granules (5 parts per 100 parts by volume of calcined gypsum)
0 part by volume) was mixed to prepare a plaster composition for forming a floor bundle of the present invention. As the expanded styrene particles, those having an average particle size of 1 mm and a bulk specific gravity of 0.02 obtained by crushing expanded polystyrene were used. Comparative Example 1 100 parts by weight of β-type hemihydrate gypsum were mixed with 0.2 part by weight of peptone, 1 part by weight of PVA and 5 parts by weight of expanded vermiculite to prepare a plaster composition for forming a floor bundle for comparison. did. The following tests were conducted using the above-mentioned plaster composition for forming a floor bundle.

Standard amount of water mixed First, 900 g of the above composition and water were kneaded in a mortar mixer according to JIS R 5201 (physical test method for cement) (kneading conditions: 62 rpm, stirring for 1 minute 30 seconds after water addition). Fill the cement paste container specified in JIS R 5201 with the above slurry, and use the JIS A 6904 (Gypsum plaster) standard softness measuring softness bar to measure the amount of water used when the needle penetration depth of 6 ± 1 mm is reached. It was calculated by the following formula and used as the standard water mixture. Standard water mixture (%) = 100 x [Water consumption (g) / Sampling amount (900g)]

Visible time 900 g of the above composition and a standard amount of water are mixed with JIS R 5201.
Kneading with a mortar mixer according to (Physical test method for cement) (kneading conditions: 62 rpm, stirring for 1 minute and 30 seconds after water addition), the obtained sludge was packed in a closed container, and allowed to stand for a predetermined time, and the change in softness was measured. And the pot life was measured. The softness measuring instrument used is a softness measuring instrument (150 g) according to JIS A 6904.
The standard softness rod (19 g) of was changed to the standard softness rod for cement (35 g), and the total weight was 166 g.
Drop the softness bar from the surface of the sludge at minute intervals, and the penetration depth is 30 mm.
The working time was defined as the elapsed time until reaching. A bending strength test piece was prepared using a strength die with a size of 4 × 4 × 16 cm, and the measurement span was set to 10 cm. Others were in accordance with JIS A 6904 It was determined by averaging the remaining 4 data excluding the maximum and minimum values. Bending strength (kgf / cm2) = bending breaking load (kgf) x 0.234

A compressive strength test piece was prepared by using a strength die having a size of 4 × 4 × 4 cm, cured (terminated), dried at 40 ° C., measured with a compression measuring machine, and measured with respect to compression fracture strength. Was calculated, and the remaining 4 data excluding the maximum and minimum of the 6 values were averaged. Compressive strength (kgf / cm ² ) = Compressive breaking load (kgf) / 16cm ² Adhesive strength Rubbing the sludge obtained by the above kneading method onto a dry concrete paving concrete plate (JIS A 5304), and then hardening Previously, the surface was lightly smoothed and smoothed with a trowel or a ruler so that the coating thickness was about 10 mm. After curing for 24 hours in the room and confirming the curing, it was dried at 40 ± 2 ° C until a constant weight was obtained. After allowing to dry and cool
Use an electric cutter to remove the hardened and dried sludge until it hits the pavement board.
Cut to 40 x 40 mm. Clean the surface of the dried and hardened material and attach with an epoxy adhesive (40 x 40 mm)
Pasted. Leave it for about 2 hours, and after confirming that the adhesive has cured,
Tensile load was measured with a Kenken type simple tensile tester, and the adhesive strength was calculated by the following formula.

Adhesive strength (kgf / cm ² ) = measured value of tensile load (kgf) / 16 (cm ² ) Of the 6 measured values, the remaining 4 excluding the maximum and minimum values
The data was calculated by averaging the data. Drying days The cured product was left indoors and the number of days until a constant weight was obtained was determined.
The results obtained by the above tests are summarized in Table 1.

[0018]

[Table 1] Table-1 Comparative product Inventive product Water content% 41 31 Pot life 100 150 Bending strength kgf / cm2 41.8 50.6 Compressive strength kgf / cm2 79.3 111.2 Adhesive strength kgf / cm2 11.5 18.6 Drying time Day 30 20

In all of the characteristics, the product of the present invention is superior to the comparative product in that it has a particularly long pot life and a short drying time.

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Claims (1)

[Claims] 1. A foamed synthetic resin granule is contained in an amount of 20 to 80 volumes with respect to 100 volumes of calcined gypsum consisting of 10 to 40% by weight of α-type hemihydrate gypsum and 90 to 60% by weight of β-type hemihydrate gypsum. A plaster composition for forming a floor bundle.