JPH11157909A - Interior finishing material composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a plastered wall material for interior finishing capable of absorbing moisture under conditions of a specific humidity or above and desorbing the moisture under conditions below the prescribed moisture absorption and having great moisture absorbing and desorbing performances when used as a gypsum-based internal finishing plastered wall material by composing the plastered wall material of α-hemihydrate gypsum having a specific composition, β-hemihydrate gypsum and a moisture absorbing and desorbing substance. SOLUTION: This interior finishing material composition is composed by using 1-60 pts.wt. α-hemihydrate gypsum and 99-40 pts.wt. β-hemihydrate gypsum as principal agent gypsum, further 1-10 pts.wt. water-soluble sizing agent (e.g. polyvinyl alcohol), 1-20 pts.wt. aggregate (e.g. expanded vermiculite), 0.01-0.5 pt.wt. improving agent for kneading operating efficiency (e.g. soaps) and 0.01-2.0 pts.wt. hardening regulator (e.g. a retarder) as main components and adding a moisture absorbing and desorbing substance thereto. The moisture absorbing and desorbing substance is selected from a clay mineral such as sepiolite, a water-soluble polymer such as poval and an organic material such as natural fibers. The amount thereof added is preferably 0.5-10 pts.wt. based on 100 pts.wt. principal agent gypsum. α-Hemihydrate gypsum formed as a by-product in a wet process for producing phosphoric acid is preferred as the α- hemihydrate gypsum.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a painted wall material composition containing gypsum as a main material and containing a moisture absorbing / releasing substance, which is used for indoor ceilings and walls. It has improved moisture.

[0002]

2. Description of the Related Art In Japan, where humidity is high, wood has been used as an interior material and an inner wall material of a building for a long time as a material having a humidity control function. However, in recent years, with the development of new building materials and the adoption of non-combustible building materials, building materials are becoming airtight, and building materials or concrete walls having poor moisture absorption / release properties often directly constitute wall surfaces of buildings. For these reasons, at present, inside a highly airtight condominium or building, the relative humidity changes due to a change in temperature, and various adverse effects occur.
For example, the relative humidity increases due to a decrease in temperature, and dew condensation occurs inside or on the surface of the wall. Due to the moisture due to the dew condensation, wetting of the wall surface and generation of stains, propagation of mold and ticks, etc., lower the durability of the wall and impair the living environment. In recent years, various studies have been made as described below in order to avoid these adverse effects. Gypsum-based building materials generally used as interior materials include, for example, gypsum boards on which paper is arranged, fiber composite gypsum boards obtained by blending glass fibers, pulp, waste paper, wood flakes, and the like. AB as solid adsorbent
Gypsum board containing silica gel (Japanese Unexamined Patent Publication No.
No. 42110) and a humidity control material obtained by inserting and integrating a hydrophilic polymer into a viscous mineral (Japanese Patent Application Laid-Open No. 7-324390).

[0003]

However, such a building material having humidity control has a low release rate of water retained therein, and therefore, after a certain period of time, the water absorption becomes saturated, and again. Surface condensation may occur,
It has a drawback that it is inferior to the indoor humidity control function of releasing moisture according to the indoor dryness. The present invention has been made in view of such a problem, and there is a problem that conventional building materials do not have a large moisture absorbing / releasing performance, and that it is not possible to sufficiently adjust indoor humidity. Was.

[0004] In addition, there has been a problem that the adhesive strength, particularly the adhesive strength after one to two days after the construction, is weak when the painted wall is constructed.
Also, as a method of preparing this composition, it is usually used in the form of a paste by kneading with water. However, the workability during kneading and the workability of applying to the wall base are difficult to knead, difficult to apply, and the applied paste is dripping. It had problems such as falling.

[0005]

The coated wall material composition according to the present invention absorbs moisture under a condition of a predetermined humidity or more, releases moisture under a condition of less than a predetermined moisture absorption, and has a large moisture absorbing and releasing performance. It is characterized by having. INDUSTRIAL APPLICABILITY The present invention has a moisture absorbing / releasing property that is applied to a wall foundation, for example, a concrete surface, a lightweight concrete surface, a lightweight cellular concrete surface (ALC surface) mortar surface, a concrete block surface, a brick surface, a foamed polystyrene surface, a gypsum board surface, or the like. The present invention relates to a novel painted wall material composition.

That is, the present invention relates to an interior material composition comprising 1 to 60 parts by weight of gypsum α-hemihydrate, 99 to 40 parts by weight of gypsum β-hemihydrate, and a moisture-absorbing / desorbing substance.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
Α and β hemihydrate gypsum used in the present invention are not particularly limited, and any of natural gypsum and chemical gypsum can be used. Particularly, α-hemihydrate gypsum uses phosphate rock and sulfuric acid, and wet phosphoric acid production. It is preferable to use α-hemihydrate gypsum by-produced when phosphoric acid is produced by the method. Further, α-hemihydrate gypsum obtained by drying the α-hemihydrate gypsum and adding an inorganic alkali according to the present invention has high hydration reactivity and is more preferable. The added alkali is α
0.1 to 5 parts by weight per 100 parts by weight of hemihydrate gypsum is preferred. If the amount of the alkali added is less than 0.1 part by weight, the hydration rate is low and the strength is undesirably low. If it exceeds 5 parts by weight, the hydration rate is high and the pot life is shortened, which impairs the workability and is not preferred.

The alkali in the present invention may be either an organic substance or an inorganic substance, and is not particularly limited. Preferably, it is an inorganic substance showing alkali. For example, NaOH,
Hydroxides such as KOH and Ca (OH) ₂ , and CaC
O ₃ , K ₂ CO ₃ , Na ₂ CO ₃ , (NH ₄ ) ₂ CO ₃
Carbonates such as H ₂ O, basic oxides such as Na ₂ O, CaO, and MgO that generate hydroxides in an aqueous solution; and ammonia gas / solution.
H) ₂ , KOH and the like are preferred. Further, two or more of these may be mixed. These may be used as they are, or may be used as an aqueous solution. Naturally, a curable inorganic substance exhibiting inorganic alkalinity may be added.

The mixture of α-hemihydrate gypsum and β-hemihydrate gypsum used in the present invention exhibits self-hardening (hydration-hardening) when kneaded with water to form a paste. This paste can be applied to the wall base and used as a painted wall material. This paste has a thixotropic property, and can be formed into an arbitrary shape by applying an external force before curing. And shrink after curing,
It has properties such as a very small dimensional change such as expansion. Therefore, the present inventors have completed the present invention by adjusting a composition containing various additives in order to supplement the inherent characteristics of hemihydrate gypsum so that it can be used as a painted wall material suitable for the above-mentioned construction method.

That is, the present invention provides an improvement in workability starting from kneading a main gypsum (hereinafter, main gypsum) mainly composed of 1 to 60 parts by weight of α-hemihydrate gypsum and 99 to 40 parts by weight of β-hemihydrate gypsum; And for the purpose of adjusting the curing and drying speed of the painted wall material,
1 to 10 parts by weight of a water-soluble glue, 1 to 20 parts by weight of aggregate, 0.01 to 0.5 part by weight of a kneading workability improver and 0.01 to 2.0 parts by weight of a curing regulator It is a novel interior material composition which is constituted by adding a moisture absorbing / releasing substance to the composition.

The hygroscopic substance used in the present invention is an inorganic material comprising one or more kinds of viscous minerals selected from sepiolite, attapulgite, montmorillonite, diatomaceous earth, zonolite, silica gel A type or B type, activated clay and the like. -Based substances, poval, CMC, polyethylene oxide, starch, water-soluble polymer substances composed of sodium polyacrylate, or natural fibers, regenerated fibers, semi-synthetic fibers,
And an organic moisture-absorbing and desorbing substance comprising one or more organic substances selected from the group consisting of hygroscopic synthetic fibers.
The moisture-absorbing / desorbing substance may be any one or more of inorganic type, one or more types of organic type, and a mixture of inorganic type and organic type.

The amount of the moisture-absorbing and desorbing substance is based on
The amount is preferably 0.5 to 10 parts by weight, more preferably 3 to 6 parts by weight with respect to parts by weight. The amount added is 0.
If the amount is less than 5 parts by weight, the rate of moisture absorption and desorption is low, and the desired effect cannot be obtained. On the other hand, if the amount exceeds 10 parts by weight, the amount of kneading water used at the time of use increases, which impairs the coating operation and strength and is disadvantageous in terms of cost, which is not preferable.

As the sizing agent of the present invention, a water-soluble sizing agent is used. Specific examples include polyvinyl alcohol, dextrin, gelatinized starch, oxidized starch, and cellulose derivatives such as cationized starch methylcellulose and hydroxyethylcellulose.

These are added to and mixed with the base gypsum in powder form. The addition amount is preferably 1 to 10 parts by weight, more preferably 3 to 10 parts by weight, based on 100 parts by weight of the main gypsum.
6 parts by weight are preferred. In the composition of the present invention, these are used as auxiliaries for improving adhesive strength and workability. When used in an amount exceeding 10 parts by weight, these pastes extremely increase the viscosity of the paste, making the kneading and painting operations difficult.

As the aggregate, expanded olives, expanded perlite, shirasu balloon and the like, which are known as lightweight aggregates, are used to improve workability. Addition of these prevents sagging during application work. The amount to be used is 1 to 20 parts by weight, more preferably 5 to 10 parts by weight, based on 100 parts by weight of the main gypsum. When the amount is less than 1 part by weight, the effect of improving workability is not remarkable, and when the amount exceeds 20 parts by weight, the following adverse effects appear. That is, when producing a paste by kneading the composition of the present invention and water, the required amount of water is significantly increased, and the resulting paste has a large amount of water, so that the adhesive strength and strength are significantly reduced, and during the application operation. This causes problems such as dropping of the liquid.

[0016] Soaps, higher alcohol sulfonates, alkylbenzene sulfonates, alkyl sulfonates, alkyl naphthalene sulfonates, lignin sulfonates, water-soluble melamine sulfonates, etc. are used as kneading improvers. , These are at least one
Types or two or more types are used. The amount used is gypsum 10
0.01 to 0.5 parts by weight per 0 parts by weight is preferred.
If the amount is less than 0.01 part by weight, the paste does not elongate in kneading property and workability, the iron is not easily separated, and the workability is deteriorated.
When the amount exceeds 0.5 parts by weight, the cost is significantly increased more than the kneading property and the workability are improved, so that it is not practical.

As the curing regulator, those known as retarders are used. This is used to ensure a sufficient working time so that the kneaded paste does not harden during the period from kneading to application. Generally 0.01 to 100 parts by weight of the base gypsum
2.0 parts by weight is preferred. If the amount exceeds 2.0 parts by weight, the curing time of the kneading paste is delayed rather than the advantage that the working time can be extended, and the phenomenon that the ratio of needle-like or columnar crystals in the generated gypsum crystals becomes small is reduced. Occur. As a result, the strength and the adhesive strength after curing are reduced, which is not preferable. Working time is usually at least 3
0 minutes is required, and the amount of the retarder required to secure this time is preferably 0.01 part by weight or more.

The main components constituting the interior material composition of the present invention have been described above. As other additives, addition of a fungicide is effective, and fibrous materials such as asbestos, rock wool, and glass wool can also be used in combination. In this case, the dripping of the paste is improved and the paste is applied. Later strength is improved.

[0019]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Parts represent parts by weight unless otherwise specified. Example 1 20 parts of α-hemihydrate gypsum by-produced when phosphoric acid is produced by a wet phosphoric acid production method using phosphate rock and sulfuric acid, 80 parts of β-hemihydrate gypsum obtained by the same method, and 5 parts of silica gel B type , 10 parts of partially saponified vinyl alcohol (88% saponification degree), 10 parts of expanded vermiculite (high density 0.11), 0.1 part of water-soluble sodium melamine sulfonate (Merment F10, a product of Showa Denko KK) , And 0.8 part of potassium citrate were added and mixed using a ribbon mixer to obtain an interior material composition of the present invention. 100 parts of this interior material composition was placed in a kneading container, 40 parts of water was added, and the mixture was kneaded for 2 minutes with a small electric stirrer to obtain a uniform interior material paste. The paste was applied to a concrete wall base using a trowel to obtain an interior material having moisture absorption and desorption properties.

Evaluation method (A) Adhesive strength measurement: (1) Concrete pavement plate (6)
× 30 × 30cm) and paste into about 4 × 4cm
2 cm thick. (2) An epoxy adhesive is applied to a jig for an adhesion test, and the applied surface is pressed against the paste so that the thickness of the applied paste becomes 1 cm. The protruding paste was scraped off with a putty knife. (3) Twenty-four hours later, it was set on a jig for an adhesion test using an architectural laboratory-type adhesion tester (manufactured by Yamamoto Uchikiki Co., Ltd.) and measured.

(B) Curing time: Under adiabatic conditions where a part of the paste was taken and filled in a 100 ml polyethylene container, a thermometer (Alumel-Chromel thermocouple) connected to a temperature recorder was added thereto. The paste was inserted and the temperature change of the paste was measured. The time at which the temperature began to rise and the time at which the temperature reached the maximum were read from the recording paper, and these were taken as the curing start time and curing end time, respectively.

(C) Pot life: The time when the paste is exposed to the atmosphere in a room and the applicability such as the apparent coagulation state of the paste and elongation by a trowel is determined by the human senses.

(D) moisture absorption / desorption property: paste is 30 × 30 ×
After preparing a 5 cm plate sample, leaving it indoors for one week, masking the back surface and the kiguchi, (1) 20 ° C., 50% R
Cured in a constant temperature and humidity chamber of H for 72 hours, (2) 50 ° C,
The sample was transferred into a thermo-hygrostat at 80% RH, and the change in sample weight after 72 hours was measured (hygroscopicity).
The sample is transferred into a thermo-hygrostat at 20 ° C. and 50% RH, and the change in sample weight after 72 hours is measured (humidity release). The operations of (2) and (3) were defined as one cycle, and the weight change per surface area of each of (2) and (3) after three cycles was obtained (g / m ² ).

EXAMPLE 2 20 parts of α-hemihydrate gypsum was added to 40 parts, and 80 parts of β-hemihydrate gypsum was added to 60 parts.
The procedure was performed in the same manner as in Example 1 except that the parts were changed. The composition is shown in Table 1, and the evaluation of physical properties is shown in Table 2.

Example 3 The procedure of Example 1 was repeated except that 5 parts of silica gel was changed to 2 parts. The composition is shown in Table 1, and the evaluation of physical properties is shown in Table 2.

Comparative Example 1 The procedure of Example 1 was repeated, except that 5 parts of silica gel was changed to 0 parts. The composition is shown in Table 1, and the evaluation of physical properties is shown in Table 2.

Comparative Example 2 The procedure of Example 1 was repeated except that 5 parts of silica gel was changed to 15 parts and 40 parts of water was changed to 47 parts. The composition is shown in Table 1, and the evaluation of physical properties is shown in Table 2.

Comparative Example 3 The same procedure as in Example 1 was carried out except that the amount of α-hemihydrate gypsum was changed to 65 parts and the amount of β-hemihydrate gypsum was changed to 35 parts. The composition is shown in Table 1, and the evaluation of physical properties is shown in Table 2.

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

According to the present invention, by using a moisture-absorbing / desorbing substance for a gypsum-based interior coating wall material, moisture can be absorbed under a condition of a predetermined humidity or more, and released under a condition of less than a predetermined moisture absorption, and An interior painted wall material characterized by high moisture absorption / desorption performance and high durability with great surface strength and adhesive strength is obtained.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tadashi Yoshino 7-1-1, Hikoshimasako-cho, Shimonoseki City, Yamaguchi Prefecture Inside Mitsui Chemicals, Inc.

Claims (5)

[Claims] An interior material composition comprising 1 to 60 parts by weight of gypsum α-hemihydrate, 99 to 40 parts by weight of gypsum β-hemihydrate, and a moisture-absorbing / desorbing substance. 2. The interior material composition according to claim 1, which is α-hemihydrate gypsum by-produced when phosphoric acid is produced by a wet phosphoric acid production method using a phosphate rock and sulfuric acid. 3. An alkali is added in an amount of 0.1 to 5 parts by weight per 100 parts by weight of α-hemihydrate gypsum produced as a by-product when phosphoric acid is produced by a wet phosphoric acid production method using a phosphate rock and sulfuric acid. 3. The interior material composition according to item 2. 4. The interior material composition according to claim 2, wherein the phosphate rock is an igneous rock phosphate rock. 5. The interior material composition according to claim 4, wherein Na ₂ O contained in the igneous phosphorus ore is 0.05 to 0.15 wt%.