JP4448044B2 - Method for producing inorganic molded body - Google Patents

Description

  The present invention relates to a method for producing an inorganic molded body in which a molded body obtained by molding a cement-based molding material comprising a cement-containing inverse emulsion composition containing cement, water, and an oily substance is cured and cured.

  Cement-based molded articles formed by extrusion molding or the like are widely used as building materials because they are excellent in weather resistance and fire resistance and have low production costs.

  Conventionally, as an effective method for producing an inorganic molded body such as a cement-based molded article, a method using a cement-based molding material containing water, a hydraulic cement, and an inverse emulsion (W / O emulsion) containing an oily substance and an emulsifier. Has been proposed. This cement-based molding material is excellent in shape retention during molding and has the feature that the specific gravity of the cement-based molded product can be freely controlled by changing the water / cement ratio. (See Patent Document 1).

  When producing an inorganic molded body that can be applied to ceramic-type exterior materials and interior materials with such a cement-based molding material, the cement-based molding material is molded into a desired shape and desired on the outer surface as necessary. The pattern of the shape is formed, and this is hydrated and cured by steam curing or the like.

  However, in the curing and curing process of the molded body, a so-called dry-out phenomenon occurs in which water and oily substances evaporate from the surface of the molded body due to temperature rise and the hydration and curing of the surface layer portion does not proceed sufficiently. There was a problem.

  Such a dry-out phenomenon is considered not only because the amount of water in the surface layer portion of the molded body is reduced, but also because of the inhibition of curing due to the effect of the emulsifier in the surface layer portion. That is, conventionally, a mixture of sorbitan oleate and sorbide oleate has been widely used as an emulsifier, but since this emulsifier has the property of delaying the progress of hardening of the cement-based molding material, in the surface layer portion of the molded body. By increasing the concentration of the emulsifier as the amount of water decreases, the effect of inhibition of curing by the emulsifier on the surface layer portion is greater than that on other portions, resulting in insufficient curing of the surface layer portion. Dry out occurs.

  When such dryout occurs, the hardness of the surface of the molded product will not be sufficiently high, wear resistance will be reduced, and scratches may occur due to rubbing during loading, etc. In this case, the adhesion of the coating film was lowered.

For this reason, in the past, the part where dryout occurred from the product was also polished and removed, but the process for polishing became necessary and the manufacturing process became complicated, and especially when used as an exterior material When a pattern is formed on the surface, there is a problem that the aesthetics are impaired by polishing.
JP 61-26542 A

  The present invention has been made in view of the above points. An inorganic molded body is obtained by molding a cement-based molding material comprising a cement-containing inverse emulsion composition containing cement, water, and an oily substance, and curing and curing it. A method for producing an inorganic molded body capable of preventing the occurrence of dryout by sufficiently suppressing the inhibition of curing based on the concentration increase of the emulsifier resulting from the volatilization of water in the surface layer of the molded body during curing and curing. Is intended to provide.

  The method for producing an inorganic molded body according to the present invention relates to a method for producing an inorganic molded body for curing and curing a molded body obtained by molding a cement-based molding material comprising a cement-containing inverse emulsion composition containing cement, water, an oily substance and an emulsifier. .

  And what is obtained by reacting sorbitol and a fatty acid containing lauric acid as the emulsifier is used, and such an emulsifier rarely causes inhibition of curing of the cement-based molding material. Occasionally, even when water evaporates from the surface layer and the concentration of the emulsifier increases, it is possible to suppress insufficient curing.

  Moreover, you may use what was obtained by making sorbitol and the fatty acid containing a C18 branched saturated fatty acid react as an emulsifier, and also in this case, an emulsifier hardly causes the hardening inhibition of a cement-type molding material, Therefore Even when the moisture content evaporates from the surface layer and the concentration of the emulsifier increases when the molded body is cured and cured, it is possible to suppress insufficient curing. Further, this emulsifier can improve the stability of the inverse emulsion of the cement-containing inverse emulsion composition, and can impart high emulsification stability to the cement-based molding material.

  Further, as an emulsifier, those obtained by reacting sorbitol and a fatty acid containing lauric acid and those obtained by reacting sorbitol and a fatty acid containing a branched saturated fatty acid having 18 carbon atoms can be used. Even in this case, the emulsifier hardly inhibits the curing of the cement-based molding material, and therefore suppresses insufficient curing even if the concentration of the emulsifier increases due to evaporation of moisture from the surface layer during curing curing of the molded body. be able to. Further, this emulsifier can improve the stability of the inverse emulsion of the cement-containing inverse emulsion composition, and can impart emulsion stability to the cement-based molding material.

  As the fatty acid containing lauric acid, coconut oil fatty acid is particularly preferably used. In this case, the cost can be reduced.

  Moreover, it is preferable to use isostearic acid as the branched saturated fatty acid having 18 carbon atoms.

  According to the present invention, when the molded body is cured and cured to obtain an inorganic molded body, the occurrence of dry-out can be prevented, and the hardness of the surface of the molded body can be sufficiently increased. Without removing the dry-out portion by polishing or the like to the obtained inorganic molded body, the wear resistance of the inorganic molded body is improved, and when coating the inorganic molded body, the adhesion of the coating film is improved. It can be improved.

  The best mode for carrying out the present invention will be described below.

  The cement-based molding material used in the present invention is composed of a cement-containing inverse emulsion composition mainly composed of cement, water and an oily substance. In this composition, the ratio of cement to water can be set arbitrarily, but the mass ratio is generally preferably in the range of 0.3 to 2 water with respect to cement 1.

  The cement is not particularly limited, but Portland cement, fly ash cement, blast furnace cement, alumina cement, high alumina cement, silica fume, etc. can be used, or one kind can be used alone, or two or more kinds can be used. Can be used together.

  The oily substance is not particularly limited as long as it can form an inverse emulsion (W / O emulsion) with water, and usually a hydrophobic liquid substance is used. For example, toluene, xylene, kerosene, styrene , Divinylbenzene, methyl methacrylate, trimethylolpropane trimethacrylate, unsaturated polyester resin and the like. In particular, if an oily substance having a polymerizable double bond (vinyl monomer) such as styrene, divinylbenzene, methyl methacrylate, trimethylolpropane trimethacrylate, or unsaturated polyester resin is used, the hydration reaction of cement And an oily substance having a polymerizable double bond occur simultaneously, and the polymer forms a matrix, so that a cement molded article having excellent physical and mechanical properties can be obtained.

  When an oily substance having a polymerizable double bond is used, a polymerization initiator such as an organic peroxide or persulfate such as t-hexylperoxy-2 is used in order to accelerate the polymerization of the oily substance. -It is desirable to use ethyl hexanoate together. Further, a crosslinking agent such as trimethylolpropane trimethacrylate can be used in combination.

  The content of the oily substance in the cement-containing inverse emulsion composition is appropriately determined so that an inverse emulsion with water can be formed in the cement-containing inverse emulsion composition and desired properties are imparted to the resulting inorganic molded body. Although adjusted, it is preferable that it is the range of 5-10 volume% with respect to the total amount of the water and solid content, for example in a cement containing inverse emulsion composition.

  And in this invention, as an emulsifier (reverse emulsifier), what is obtained by making sorbitol and the fatty acid containing a lauric acid react, and sorbitol and the fatty acid containing a C18 branched saturated fatty acid are made to react. In this case, one or both of the emulsifiers can be used. These emulsifiers are less likely to cause hardening inhibition of the cement-based molding material.

  When using the emulsifier obtained by making the said sorbitol and the fatty acid containing lauric acid react, both reaction molar ratios are adjusted suitably, Preferably the fatty acid containing lauric acid is 1-1. Make 8 mol.

  In addition, the proportion of lauric acid in fatty acids containing lauric acid tends to increase the effect of suppressing dryout as lauric acid approaches 100%. It can be adjusted accordingly.

  At this time, the fatty acid other than lauric acid is not particularly limited, but for example, myristic acid, palmitic acid, capric acid, caprylic acid, caproic acid, oleic acid and the like may be contained. Examples of the fatty acid containing lauric acid include coconut oil fatty acid, palm kernel oil, and the like. Particularly, coconut oil fatty acid (lauric acid 45 to 51%, myristic acid 16.5 to 20%, palmitic acid. 4.3-7.5%, capric acid 4.5-10.7%, caprylic acid 6-9.5%, caproic acid 0.2-2%, oleic acid 2-10%) The cost can be reduced while sufficiently reducing the outage.

  In addition, when using a product obtained by reacting sorbitol with a fatty acid containing a branched saturated fatty acid having 18 carbon atoms, the reaction molar ratio between them is appropriately adjusted, but preferably the fatty acid is 1 mol of sorbitol. Of 1 to 1.8 mol.

  Further, the ratio of the branched saturated fatty acid having 18 carbon atoms in the fatty acid containing the branched saturated fatty acid having 18 carbon atoms is preferably 40 to 90%, particularly preferably 55 to 75%.

  At this time, the fatty acid other than the branched saturated fatty acid having 18 carbon atoms is not particularly limited, and may contain an appropriate fatty acid as in the case of the fatty acid containing lauric acid.

  In addition, as the fatty acid containing a branched saturated fatty acid having 18 carbon atoms, it is particularly preferable to use one containing isostearic acid as shown in the following chemical formulas (1) to (4).

  An emulsifier obtained by reacting such sorbitol with a fatty acid containing a branched saturated fatty acid having 18 carbon atoms can stably maintain an inverse emulsion of a cement-based molding material. Therefore, as an emulsifier, sorbitol and carbon When a product obtained by reacting a fatty acid containing a branched saturated fatty acid of formula 18 is used, the inverse emulsion can be stably maintained even when the cement-containing inverse emulsion composition is left for a long time. Here, although the fatty acid to be reacted with sorbitol can improve the emulsion stability when the number of carbons increases, it tends to cause dryout, but the number of carbons is 18 as described above. However, if branched fatty acids are used, the number of carbons in the main chain terminated with a carboxyl group is reduced to reduce dryout, while the total number of carbons is increased by having carbon chains branched from the carbon chain. High emulsification stability.

  Moreover, as an emulsifier, you may use what is obtained by making sorbitol react with the fatty acid which mixed the fatty acid containing the above lauric acids, and the fatty acid containing the C18 branched saturated fatty acid. Also in this case, since the fatty acid containing a branched saturated fatty acid having 18 carbon atoms is used as the fatty acid, the inverse emulsion can be stably maintained even when the cement-containing inverse emulsion composition is left for a long time. At this time, among the fatty acids containing lauric acid and fatty acids containing branched saturated fatty acids having 18 carbon atoms, the emulsification stability tends to improve as the latter ratio increases, but the required performance, the demand for cost reduction, etc. It can be appropriately adjusted according to the above. For example, the mass ratio of the former to the latter of the amount of fatty acid containing coconut oil fatty acid and branched saturated fatty acid having 18 carbon atoms can be set to 9: 1.

  The content of these emulsifiers can be appropriately adjusted. For example, when styrene is used as the oily substance, the total content of the emulsifiers is in the range of 20 to 40% by mass with respect to the styrene content. It is preferable to do so.

  In the cement-containing inverse emulsion composition, an appropriate amount of a lightweight aggregate, a silica-based aggregate, a reinforcing material such as an organic fiber, and various additives can be further blended.

  Examples of lightweight aggregates include fly ash balloons, perlite, shirasu balloons, and the like, as well as organic foams such as expanded polystyrene and polyvinylidene chloride foam, and the content thereof is 20 with respect to 100 parts by mass of cement. It is preferable to set it as the range of -40 mass parts.

  Moreover, as a silica type aggregate, gravel, glass powder, an alumina silicate etc. can be used, for example, It is preferable that the content shall be 100 mass parts or less with respect to 100 mass parts of cement.

  Moreover, as an organic fiber, a polypropylene fiber, an acrylic fiber, a vinylon fiber etc. can be used, for example, and it is preferable to make the content into the range of 3-6 mass parts with respect to 100 mass parts of cement.

  Next, a method for producing an inorganic plate using the cement-containing inverse emulsion composition as a cement-based molding material will be described.

  First, a molded body is produced by molding a cement-based molding material into a plate shape or the like. The molded body can be molded by commonly used means such as a casting method, an extrusion molding method, an injection molding method, and a press molding method.

  An inorganic molded body can be obtained by curing and curing the molded body thus obtained, and further drying as necessary. Conditions for performing curing and curing are appropriately set. For example, heating can be performed at 40 to 100 ° C. for 20 to 48 hours. At this time, steam curing may be performed, but the molded body may be heated by other appropriate means.

  Thus, when an inorganic molded body is produced by curing and curing, even if moisture is evaporated from the surface layer of the molded body during the curing process and the concentration of the emulsifier in the surface layer increases, sorbitol and lauric acid are added as described above. The emulsifier obtained by reacting the fatty acid containing and the emulsifier obtained by reacting sorbitol and the fatty acid containing a branched saturated fatty acid having 18 carbon atoms hardly cause hardening inhibition of the cement-based molding material. The hardness of the surface of the inorganic molded body called dryout can be suppressed by suppressing the poor curing of the surface of the inorganic molded body, and the resulting inorganic molded body can be removed without removing the dryout portion by polishing or the like. The wear resistance of the inorganic molded body can be improved, and the adhesion of the coating film can be improved when the inorganic molded body is coated. Than is.

(Examples 1 to 3, Comparative Example 1)
After mixing an oily substance and an emulsifier with the composition shown in Table 1 below, water, organic fibers, a crosslinking agent, a polymerization initiator are added, and the mixture is mixed with a mixer to form an inverse emulsion, and further cemented, lightweight. Aggregates and silica-based aggregates were added and kneaded to prepare a cement-based molding material composed of a cement-containing inverse emulsion composition.

  This cement-based molding material is molded with an extruder to form a plate-like molded body. After forming a concavo-convex pattern with a roll on the surface, it is loaded in a state where it is placed in a closed tray, and is placed in a steam curing chamber. The temperature was raised from room temperature to 60 ° C. over 1.5 hours using a heater curing method using steam as a heat source, held at 60 ° C. for 10 hours, then raised to 90 ° C. over 2 hours, and then heated at 90 ° C. for 10 hours. After curing for 5 hours, it was dried to obtain an inorganic molded body.

(Evaluation test)
About the inorganic molded body obtained in each of the above Examples and Comparative Examples, after sticking the gum tape to the surface, the occurrence of dry-out by checking the presence or absence of peeling of the inorganic molded body when it was peeled off Investigate whether or not peeling is observed (no occurrence of dry-out) is evaluated as “○”, and peeling is observed (when dry-out occurs) is evaluated as “x”. did.

  In each of the examples and comparative examples, the cement-based molding material immediately after preparation was gripped three times by hand, and then left at an ambient temperature of 30 ° C. and a material temperature of 25 ° C. until the cement-based molding material begins to release water. Emulsification stability was evaluated at the time required for.

  The above results are also shown in Table 1 below.

  In addition, the emulsifier shown by the said Table 1 makes reaction molar ratio of sorbitol and a fatty acid 1: 1.5.

  Among these, the trade name “Sorgen 90” manufactured by Daiichi Kogyo Seiyaku Co., Ltd. was obtained by reacting sorbitol and coconut oil fatty acid, and the isostearic acid emulsifier was manufactured by Daiichi Kogyo Seiyaku Co., Ltd. Fatty acid (isostearic acid-containing, which is an experimental product and is a mixture of sorbitol and isostearic acid (shown in the above formulas (2) to (4), the average number of methyl group side chains per molecule is 1.3)) (64.0% in amount). The content of other fatty acids in the fatty acid is 3.1% carbon (3.1% linear), 7.5% carbon (7.5%), 16% carbon (straight) 6.2%, Carbon number 18 (straight chain) 2.6%, carbon number 18 (C18 ′ linear unsaturated fatty acid) 2.7%, carbon number 20 (branched) 8.1%, carbon number 22 (branched) 3.7%, carbon number 22 (linear) 0.3%, carbon number 23 or more and 1.4%. The mixed emulsifier is obtained by reacting sorbitol with a mixture of isostearic acid and coconut oil fatty acid (the mass ratio of the former to the latter is 2: 8). The name “Sorgen 40D” is a mixture of sorbitan oleate and sorbide oleate.

  As is clear from the above results, dry out occurred in Comparative Example 1, whereas no dry out was observed in Examples 1 to 3. In particular, in Examples 2 and 3, the emulsion stability is higher than that in Example 1, and only the emulsifier obtained by reacting sorbitol with a fatty acid containing a branched saturated fatty acid having 18 carbon atoms is used as an emulsifier. In No. 2, emulsion stability equivalent to that of Comparative Example 1 was obtained.

Claims (5)

  In a method for producing an inorganic molded body for curing and curing a molded body obtained by molding a cement-based molding material comprising a cement-containing inverse emulsion composition containing cement, water, an oily substance and an emulsifier, a fatty acid containing sorbitol and lauric acid as the emulsifier A method for producing an inorganic molded body characterized by using a product obtained by reacting.   In a method for producing an inorganic molded body for curing and curing a molded body obtained by molding a cement-based molding material comprising a cement-containing inverse emulsion composition containing cement, water, an oily substance, and an emulsifier, a branched state having 18 carbon atoms and sorbitol as the emulsifier What is claimed is: 1. A method for producing an inorganic molded body comprising using a product obtained by reacting a fatty acid containing a saturated fatty acid.   In a method for producing an inorganic molded body for curing and curing a molded body obtained by molding a cement-based molding material comprising a cement-containing inverse emulsion composition containing cement, water, an oily substance and an emulsifier, sorbitol is used as the emulsifier, and fatty acid containing lauric acid And a method obtained by reacting with a fatty acid mixed with a fatty acid containing a branched saturated fatty acid having 18 carbon atoms.   The method for producing an inorganic molded body according to claim 1 or 3, wherein the fatty acid containing lauric acid is coconut oil fatty acid. The method for producing an inorganic molded body according to claim 2 or 3, wherein the branched saturated fatty acid having 18 carbon atoms is isostearic acid.