JP6207090B2 - Gypsum member, gypsum board, and method for manufacturing gypsum member - Google Patents

Description

  The present invention relates to a gypsum member, a gypsum board, and a method for manufacturing a gypsum member.

  Gypsum members such as gypsum board mainly composed of gypsum are excellent in fire resistance, heat insulation, sound insulation, and the like, and are widely used as building materials. For example, Patent Document 1 discloses a gypsum board used for a ceiling material or the like.

  By the way, as shown in Patent Document 1, when a gypsum member such as a gypsum board is used in a humid environment such as a kitchen, the moisture in the air may be absorbed and the strength may be reduced. . For example, when a gypsum board is used as a ceiling material, moisture may be absorbed and deformation such as bending or sagging may occur in the gypsum board. Buildings in recent years have become highly airtight, and gypsum members are easily placed in a humid environment when indoor humidity increases. For this reason, emphasis is placed on measures against moisture in the gypsum member.

  Moreover, high earthquake resistance is requested | required of the building in recent years, The weight reduction of the gypsum member by the density reduction is achieved as one part. However, when the density of the gypsum member is reduced, the strength of the gypsum member decreases, so that the gypsum member is easily affected when moisture in the air is absorbed, and deformation such as the above-described deformation is likely to occur. It has become.

  In order to suppress such deformation of the gypsum member due to moisture, Patent Document 1 discloses that boric acid or tartaric acid is added to the gypsum member (gypsum board).

  Patent Documents 2 and 3 show that sodium trimetaphosphate is added to a gypsum member so that deformation such as bending does not occur when the gypsum member is used in a humid environment.

Japanese Patent Laid-Open No. 9-328837 Japanese Patent No. 4332223 Japanese Patent No. 4618888

  When boric acid is contained in the gypsum member, the strength of the gypsum member is secured to some extent even in a humid environment, and deformation such as bending is suppressed. However, when applying joint treatment to the joint of a gypsum member (for example, gypsum board), boric acid reacts with polyvinyl alcohol or the like in the joint material (putty), and the joint material gels during the joint treatment, It was a cause that hindered joint processing. Therefore, the actual situation is that boric acid cannot be applied to the gypsum member.

  Further, when tartaric acid is contained in the gypsum member, the strength of the gypsum member is secured to some extent even in a humid environment, and deformation such as bending is suppressed. However, when tartaric acid is added, there is a problem that the setting time of calcined gypsum which is a raw material of the gypsum member is greatly delayed by the action of tartaric acid. Therefore, adding tartaric acid to the gypsum member has not been widely used.

  Further, when sodium trimetaphosphate is contained in the gypsum member, the strength of the gypsum member is secured to some extent, and deformation such as bending is suppressed. However, if sodium trimetaphosphate is not always added to calcined gypsum in a state dissolved in water, the effect of the gypsum member finally obtained does not appear, and there is a great restriction on the production method (addition method).

  An object of the present invention is to provide a plaster member and the like in which a delay in curing time is suppressed and deformation such as bending and sagging is suppressed even when used in a humid environment.

  The gypsum member according to the present invention is a gypsum member obtained by curing a slurry containing calcined gypsum and water, and the slurry is composed of potassium tartrate, potassium hydrogen tartrate, and sodium potassium tartrate tetrahydrate. It contains at least one tartrate selected from the group consisting of, and the content of the tartrate is 0.02 to 1.0 part by mass per 100 parts by mass of the calcined gypsum.

  In the gypsum member, it is preferable that the tartrate salt consists only of potassium tartrate.

  The gypsum member may be used as a core material for gypsum board.

The gypsum member may have a density of 0.4 g / cm ³ or more.

  The amount of sag (mm) after 48 hours under conditions of 35 ° C. and 90% RH is preferably 11.5 mm or less.

  Moreover, the gypsum board which concerns on this invention consists of the said gypsum member, and consists of what comprises a board-shaped core material and a pair of board base paper affixed on both surfaces of this core material.

  Moreover, the method for producing a gypsum member according to the present invention is a method for producing a gypsum member by curing a slurry containing calcined gypsum and water, and the slurry includes potassium tartrate and potassium hydrogen tartrate. , And at least one tartrate salt selected from the group consisting of sodium potassium tartrate tetrahydrate at a rate of 0.02-1.0 parts by mass per 100 parts by mass of the calcined gypsum, or water A step of being added in a state of being dispersed or dissolved in a solvent such as

  ADVANTAGE OF THE INVENTION According to this invention, the delay of hardening time is suppressed and even if it uses in a humid environment, the gypsum member etc. which can suppress deformation | transformation, such as bending and drooping, can be provided.

Explanatory drawing which represented typically the composition of the gypsum board which is an example of a gypsum member

[Gypsum materials]
The gypsum member of the present invention is formed by curing (cured body) a slurry containing at least calcined gypsum (CaSO ₄ .1 / 2H ₂ O), water, and a predetermined tartrate (described later).

  The gypsum member is used in various applications such as interior building materials (for example, ceiling materials, floor materials, wall materials), and is particularly preferably used in a place that tends to be in a humid environment such as a kitchen. There is no restriction | limiting in particular in the external appearance shape of a gypsum member, What is necessary is just to set suitably according to the objective. The gypsum member is used for, for example, a board-like core material 2 of a gypsum board 1 as shown in FIG. Board base papers 3 and 4 are laminated on both surfaces of the core material 2. Various conditions such as the thickness and density of the core material 2 are not particularly limited and are appropriately selected as long as the object of the present invention is not impaired.

(Tartrate)
The tartrate salt is added to the slurry for preparing the gypsum member at a predetermined ratio for the purpose of suppressing the delay of the setting time (curing end time) of the gypsum member and improving the moisture resistance of the gypsum member. It is what is done.

  As the tartrate, at least one selected from the group consisting of potassium tartrate, potassium hydrogen tartrate, and sodium potassium tartrate tetrahydrate is used.

  The content of the tartrate salt in the gypsum member (in the slurry) is 0.02 to 1.0 part by mass, preferably 0.02 to 0.8 part by mass, per 100 parts by mass of the calcined gypsum. When the content of the tartrate is within such a range, a decrease in strength of the gypsum member can be suppressed even if the gypsum member is placed in a humid environment without delaying the curing completion time of the slurry (gypsum member). As a result, the deformation of the plaster member, such as sagging and sagging, is suppressed.

  In particular, it is preferable to use only potassium tartrate as the tartrate. Compared with potassium hydrogen tartrate and sodium potassium tartrate tetrahydrate, potassium tartrate has a shorter set-up time of the slurry (gypsum member) and has various strengths such as compressive strength during drying of the gypsum member described later. It will be excellent.

  When the tartrate salt is added to the slurry, it may be added in a powder state, or may be added in a state dissolved or dispersed in a solvent such as water. Tartrate salts such as potassium tartrate used in the present invention have good solubility in water, and even when added to the slurry in the form of a powder, it is uniformly dispersed or dissolved during mixing (stirring) of the slurry, Easy to reach every corner. In addition, it may be dispersed or dissolved in a solvent such as water and added to the slurry.

  As a method for producing a gypsum member, a known method including a molding process, a drying process, a finishing process, and the like can be applied.

  In addition, unless the objective of this invention is impaired, other components other than calcined gypsum, water, and tartrate may be added to the slurry for manufacturing a gypsum member.

The density (g / cm ³ ) of the gypsum member is not particularly limited, and may be appropriately set depending on the purpose. In addition, the gypsum member of the present invention can suppress a decrease in strength in a humid environment and suppress deformation such as bending and sagging even if the density is about 0.5 g / cm ³ .

  The gypsum member of the present invention is prevented from being delayed in curing time and suppressed from deformation such as bending and sagging even when used in a humid environment. In addition, the gypsum member of the present invention is inhibited from reacting with the joint material used in the joint treatment and gelling the joint material during the treatment.

  Hereinafter, the present invention will be described in more detail based on examples. In addition, this invention is not limited at all by these Examples.

[Test 1]
(Hygroscopic sag test (cured body specific gravity: 0.50 g / cm ³ ))
In each Example and each Comparative Example, slurry was prepared by adding 600 g of water and additives of the types and addition amounts shown in Table 1 to 300 g of calcined gypsum and mixing them. This slurry was loaded into a 9 mm × 9 mm × 1000 mm mold and allowed to cure for 60 minutes. After the mold was removed from the mold, it was dried to a constant weight at 40 ° C. to obtain a square bar-like cured body having a specific gravity (density) of about 0.50 g / cm ³ . And what cut | disconnected this hardening body in length 650mm was used as the test piece.

  The test piece was supported at two points with a width of 600 mm under the conditions of 35 ° C. and 90% RH, and for each elapsed time shown in Table 1, the center position of the test piece (the center of the 600 mm width portion supported at two points) ) Was measured using a measuring device (manufactured by Mitutoyo Corporation, Digital Caliper). In addition, the position of the test piece in a state of extending straight at the start of the test is the reference position (0.0 mm) of the amount of sag (mm), and the distance that the center position of the test piece has moved downward from the reference position ( mm) is the amount of sag of the test piece (mm). The measurement results of the amount of sag (mm) in Test 1 are shown in Table 1.

As shown in Table 1, when the density of the gypsum member (test piece) is set to about 0.50 g / cm ³ , potassium tartrate, potassium hydrogen tartrate, and potassium sodium tartrate tetrahydrate are used as additives. It was confirmed that the amount of sag of the gypsum member (test piece) can be suppressed. In particular, when potassium tartrate was used, the amount of sag after 48 hours was less than 9.0 mm regardless of the amount added, and good results were obtained.

[Test 2]
(Hygroscopic sag test (cured body specific gravity: 0.75 g / cm ³ ))
Instead of adding “600 g of water and additives of the types and addition amounts shown in Table 1”, except adding “360 g of water and additives of the types and addition amounts shown in Table 2” to 300 g of calcined gypsum, In the same manner as in the case of the test 1, test pieces (9 mm × 9 mm × 650 mm square bar-shaped cured body, specific gravity: about 0.75 g / cm ³ ) of each example and each comparative example were produced.

  The obtained test piece was subjected to the same test as the above-mentioned test 1, and the amount of sag (mm) of the test piece in each example and each comparative example was measured. The measurement results of the amount of sag (mm) in Test 2 are shown in Table 2.

As shown in Table 2, when the density of the gypsum member (test piece) is set higher than the above case and is set to about 0.75 g / cm ³ , when potassium tartrate or the like is used as an additive, It was confirmed that the amount of sag of the member (test piece) can be suppressed. As described above, when the density of the gypsum member (test piece) is high, the amount of sag during moisture absorption is small. However, when potassium tartrate is used, it has been confirmed that the effect of suppressing the sag particularly appears.

[Test 3]
(Dry compressive strength test)
In each Example and each Comparative Example, 216 g of water and additives of the types and addition amounts shown in Table 3 were added to 300 g of calcined gypsum, and a slurry was prepared by mixing them. This slurry was loaded into a 50 mm × 50 mm × 50 mm mold and left to cure for 60 minutes. After the mold was removed from the mold, it was dried to a constant weight at 40 ° C. to obtain a cubic cured body having a specific gravity (density) of about 1.0 g / cm ³ . Using this cured body as a test piece, it was subjected to a measuring device (manufactured by Shimadzu Corporation, Autograph AG-10TE), applied to the test piece at a load speed of 1 mm / min, and the load value when the test piece was buckled. Measured as compressive strength (N / mm ² ). The measurement results of the compressive strength (N / mm ² ) of Test 3 are shown in Table 3.

As shown in Table 3, it was confirmed that when tartaric acid was used, when the amount added was increased (particularly, Comparative Example 19), the compressive strength during drying decreased. Further, potassium hydrogen tartrate, and the case of using potassium sodium tartrate tetrahydrate, compressive strength when dry, but is ensured 8.0 N / mm ² or more, and less than 9.0 N / mm ^2, potassium tartrate The result was inferior to the case of using. In the case of potassium tartrate (Examples 16 to 18), as shown in Table 3, the compressive strength is equivalent to that in the case where no additive is added (Comparative Example 16).

[Test 4]
(Hygroscopic compressive strength test)
Each test was conducted in the same manner as in Test 3 above, except that “the additive of the kind and addition amount shown in Table 4” was used instead of “the additive of the kind and addition amount shown in Table 3”. Test pieces of examples and comparative examples (50 mm × 50 mm × 50 mm cube-shaped cured body, specific gravity: about 1.0 g / cm ³ ) were prepared.

The obtained test piece was allowed to stand for 2 hours under the conditions of 35 ° C. and 90% RH, and then the compression strength (N / mm) of the test piece in each Example and each Comparative Example was conducted in the same manner as in Test 3 above. ² ) was measured. The measurement results of the compressive strength (N / mm ² ) of Test 4 are shown in Table 4.

As shown in Table 4, when tartaric acid is added (Comparative Example 23) and when sodium tartrate is added (Comparative Example 25), the compressive strength after moisture absorption is significantly reduced (5.9 N / mm ² or less).

[Test 5]
(Curing time measurement test)
In each example and each comparative example, 600 g of water and additives of the types and addition amounts shown in Table 5 were added to 300 g of calcined gypsum, and a slurry was prepared by mixing them. Using this slurry, the curing completion time of the slurry was measured in accordance with JIS-R9112. The measurement results of Test 5 are shown in Table 5.

  As shown in Table 5, it was confirmed that the curing completion time of the gypsum member (slurry) was shortened to the same level or shorter than that when the additive was not added when potassium tartrate was used as the additive. It was.

  In addition, when potassium hydrogen tartrate and sodium potassium tartrate tetrahydrate are used as additives, the completion time of setting of the gypsum member (slurry) is somewhat longer than when no additives are added, but tartaric acid is used. It was confirmed that there was no delay as compared with the case where ethylenediamine tartrate was added.

[Test 6]
(Gypsum board hanging amount test in actual machine)
Using a general gypsum board line (actual machine), a gypsum board was produced under the conditions shown below, and a sag test was performed using the produced gypsum board. Specifically, as Example 31, the amount of potassium tartrate added to calcined gypsum was set to 0.1 parts by mass with respect to 100 parts by mass of calcined gypsum, and both sides of the core material were used using a gypsum board line. A base paper for board (thickness of one sheet: about 0.2 mm) was laminated to prepare a gypsum board. Moreover, as Comparative Example 38, a gypsum board to which potassium tartrate was not added was produced in the same manner as in Example 31 except that potassium tartrate was not added. From each gypsum board of Example 31 and Comparative Example 38, the length of the base paper for board is 125 mm, and the length perpendicular to the flow direction (product width direction) is 650 mm. Each test piece was cut out (thickness of the core material of the test piece: about 9.5 mm). Then, the cut specimen is supported at two points with a width of 600 mm under the conditions of 35 ° C. and 90% RH, and the center position of the specimen (supported at two points) for each elapsed time shown in Table 6. The amount of sag (mm) at the center of 600 mm width was measured using a measuring instrument (manufactured by Mitutoyo Corporation, digital caliper). The measurement results are shown in Table 6.

  As shown in Table 6, it was confirmed that a gypsum board manufactured using an actual machine can obtain a drooping prevention effect when potassium tartrate is added.

  1 ... gypsum board, 2 ... core material, 3, 4 ... base paper for board (gypsum base paper fiber)

Claims (4)

A gypsum board comprising a calcined gypsum and a hardened slurry containing water, comprising a board-shaped core material and a pair of board base papers laminated on both sides of the core material,
The slurry contains only potassium tartrate as a tartrate, and the content of the tartrate is 0.02 to 1.0 parts by mass per 100 parts by mass of the calcined gypsum,
The core material has a density of 0.4 g / cm ³ or more and 1.04 g / cm ³ or less. The density of the core material is 0.4 g / cm. ³ 0.75 g / cm ³ The gypsum board according to claim 1 which is the following. The gypsum board according to claim 1 or 2, wherein the amount of sag (mm) after 48 hours under conditions of 35 ° C and 90% RH is 11.5 mm or less. A core material obtained by curing a pair of board base paper, calcined gypsum, and a slurry containing water between the pair of board base papers,
To the slurry, a tartrate salt consisting only of potassium tartrate is added in a powdered state or in a state dispersed or dissolved in water at a ratio of 0.02 to 1.0 part by weight per 100 parts by weight of the calcined gypsum. A method for producing a gypsum board having a process .

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