JP4614468B2 - Powdery shrinkage reducing agent and cement premix product for cement premix product - Google Patents

Description

  The present invention relates to a powdery shrinkage reducing agent for a cement premix product and a cement premix product. Cement premix products used for grout fillers, mortars, self-leveling flooring materials and the like use powdery shrinkage reducing agents for the purpose of preventing cracks. The present invention relates to a powdery shrinkage reducing agent for such a cement premix product and a cement premix product prepared using the same.

  Conventionally, various kinds of powdery shrinkage reducing agents for cement premix products are known (see, for example, Patent Documents 1 to 4). However, the conventional powder shrinkage reducing agents have a problem that if the packed ones are stacked and stored, the powder shrinkage reducing agents are fused or fixed to each other and block. In addition, since the compound itself used in the powdery shrinkage reducing agent has high air entrainment, the amount of air entrainment tends to be excessive when kneading the cement premix product prepared using this, and the resulting cured product There is a problem that the compressive strength of the resin tends to decrease. Further, if the powdery shrinkage reducing agent is stored together with, for example, an antifoaming agent for a long time, there is a problem that the air entrainment property is further improved due to oxidative deterioration, and the compression strength of the resulting cured product may be greatly reduced.

JP-A-2-164754 Special table 2001-518871 gazette JP 2005-126268 A JP 2006-193416 A

  The problem to be solved by the present invention is that even if the bags are stacked and stored, they do not block, and the amount of air entrainment becomes excessive when mixing the cement premix product prepared using the same. This prevents a decrease in compressive strength and an increase in the drying shrinkage rate of the cured product obtained by preventing the above-mentioned problem, and even when stored for a long time in combination with, for example, an antifoaming agent. The present invention provides a powdery shrinkage reducing agent for a cement premix product and a cement premix product prepared using the same.

  As a result of studies conducted by the present inventors to solve the above-mentioned problems, it is correctly and appropriately used that the powdery shrinkage reducing agent for cement premix products has a specific ratio of each of three specific components. I found out.

  That is, the present invention is a powdery shrinkage reducing agent for cement premix products, which comprises the following A component, B component and C component, and 49.5 to 65 mass% of the A component, The present invention relates to a powdery shrinkage reducing agent comprising 34.5 to 50% by mass and 0.001 to 0.5% by mass (100% by mass in total) of the C component.

Component A: composed of a compound represented by the following chemical formula 1 and a compound represented by chemical formula 2, and 95 to 99.9 mass% of the compound represented by chemical formula 1 and 0.1 to 5 mass of the compound represented by chemical formula 2 % (Total 100% by mass) of polyether mixture.

In Chemical Formula 1 and Chemical Formula 2,
R ¹ : Aliphatic hydrocarbon group having 3 to 5 carbon atoms R ² : Aliphatic hydrocarbon group having 12 to 20 carbon atoms A ¹ : All hydroxyl groups from (poly) ethylene glycol having 1 to 5 repeating oxyethylene units Or a residue obtained by removing all hydroxyl groups from a polyalkylene glycol having 2 to 7 repeating oxyalkylene units composed of both oxyethylene units and oxypropylene units. A ² : oxyethylene unit repeating 4 Residues obtained by removing all hydroxyl groups from 10 to 10 polyethylene glycol A ³ : Residues obtained by removing all hydroxyl groups from polypropylene glycol having 20 to 50 repeating oxypropylene units

  Component B: porous silica fine powder

  Component C: Antioxidant

  Further, the present invention is a cement premix product containing at least cement and a powdery shrinkage reducing agent, and 0.5 to 10 parts by weight of the powdery shrinkage reducing agent according to the present invention per 100 parts by weight of cement. It is related with the cement premix product characterized by comprising by the ratio.

First, the powdery shrinkage reducing agent for cement premix products according to the present invention (hereinafter simply referred to as the powdery shrinkage reducing agent of the present invention) will be described. The powdery shrinkage reducing agent of the present invention is composed of three components, A component, B component and C component. The component A used in the powdery shrinkage reducing agent of the present invention is a polyether mixture composed of the compound represented by Chemical Formula 1 and the compound represented by Chemical Formula 2. In the compound represented by Chemical Formula 1, R ^{1 in} Chemical Formula ¹ is a carbon number such as propyl group, isopropyl group, normal butyl group, isobutyl group, secondary butyl group, tertiary butyl group, pentyl group, isopentyl group, neopentyl group, etc. 3 to 5 aliphatic hydrocarbon groups. Among them, R ¹ is preferably an aliphatic hydrocarbon group having 4 carbon atoms such as a normal butyl group, an isobutyl group, a secondary butyl group, or a tertiary butyl group, and more preferably a normal butyl group. A ^{1 in} Chemical Formula ¹ is 1) a residue obtained by removing all hydroxyl groups from ethylene glycol, 2) a residue obtained by removing all hydroxyl groups from polyethylene glycol having 2 to 5 repeating oxyethylene units, and 3) oxy It is a residue obtained by removing all hydroxyl groups from a polyalkylene glycol having 2 to 7 repeating oxyalkylene units composed of both an ethylene unit and an oxypropylene unit. In particular, A ¹ is preferably a residue obtained by removing all hydroxyl groups from a polyalkylene glycol having 3 to 6 repeating oxyalkylene units composed of both oxyethylene units and oxypropylene units. It is more preferable that the unit is bonded in a block form.

In the compound represented by Chemical Formula ² , R ^{2 in} Chemical Formula ² is 1) 12 to 12 carbon atoms such as dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, etc. 20 saturated aliphatic hydrocarbon groups, 2) unsaturated aliphatic hydrocarbon groups having 12 to 20 carbon atoms, such as an 8-hexadecenyl group, a 9-octadecenyl group, and a 10-eicocenyl group. Among these, as R ² , an unsaturated aliphatic hydrocarbon group is preferable, and a 9-octadecenyl group is more preferable. A ^{2 in} Chemical Formula ² is a residue obtained by removing all hydroxyl groups from polyethylene glycol having 4 to 10 repeating oxyethylene units, and all hydroxyl groups from polyethylene glycol having 5 to 9 repeating oxyethylene units. Excluded residues are preferred. Further, A ^{3 in} Chemical Formula 2 is a residue obtained by removing all hydroxyl groups from polypropylene glycol having 20 to 50 repeating oxypropylene units, and all hydroxyl groups from polypropylene glycol having 35 to 45 repeating oxypropylene units. Excluded residues are preferred.

  The component A is a polyether mixture comprising the compound represented by the chemical formula 1 and the compound represented by the chemical formula 2 described above, and the compound represented by the chemical formula 1 is represented by 95 to 99.9% by mass and the chemical formula 2 The compound contains 0.1 to 5% by mass (100% by mass in total) of the compound. The compound represented by Chemical formula 1 is 97 to 99.7% by mass and the compound represented by Chemical formula 2 is 0.3 to What contains 3 mass% (total 100 mass%) is preferable. The polyether mixture is preferably a liquid at a temperature of 5 to 50 ° C.

  Both the compound represented by Chemical Formula 1 and the compound represented by Chemical Formula 2 described above can be synthesized by known methods. For example, in the case of the compound represented by Chemical Formula 1, it can be synthesized by a method of subjecting an aliphatic alcohol to an addition polymerization reaction of ethylene oxide or ethylene oxide and propylene oxide under heating and pressurization using an alkali catalyst. . Further, in the case of the compound represented by Chemical Formula 2, synthesis is performed by a method in which an ethylene oxide is subjected to an addition polymerization reaction with an aliphatic alcohol under heating and pressurization using an alkali catalyst, and then propylene oxide is subjected to an addition polymerization reaction. Can do.

The B component used in the powdery shrinkage reducing agent of the present invention is a porous silica fine powder. Such porous silica fine powder is generally obtained by neutralizing water glass with an acid such as hydrochloric acid, washing the deposited precipitate with water, and drying to form a powder, which is represented by a composition of SiO ₂ · nH ₂ O. Amorphous silicic acid, which is known per se can be used. Among them, those having a specific surface area of 50 to 450 m ² / g and an average particle diameter in the range of 0.1 to 500 μm More preferably, the oil absorption amount (the oil absorption amount according to JIS-K5101-13) exceeds 100 ml / 100 g.

  The C component used in the powdery shrinkage reducing agent of the present invention is an antioxidant. As such an antioxidant, known ones can be used, and examples thereof include hydroquinone, hydroquinone monomethyl ether, phenothiazine, dibutylhydroxytoluene, butylhydroxyanisole, tributyl phosphate, triphenyl phosphate, and the like. Of these, hydroquinone, dibutylhydroxytoluene, and butylhydroxyanisole are preferable. With such an antioxidant, it is possible to prevent the above-described component A from being oxidized and deteriorated and air entrainment from being increased even when stored for a long period of time.

  The powdery shrinkage reducing agent of the present invention comprises the A component, the B component, and the C component as described above, the A component is 49.5 to 65% by mass, the B component is 34.5 to 50% by mass, and the C component. Components are contained in an amount of 0.001 to 0.5% by mass (total 100% by mass). A component is 54.8 to 63% by mass, B component is 36.8 to 45% by mass, and C component. Is preferably contained in an amount of 0.003 to 0.2 mass% (total 100 mass%).

  The powdery shrinkage reducing agent of the present invention can be prepared by a known method (for example, a method described in JP-A-2004-0491288), but the antioxidant used as the C component is previously added to the A component at a predetermined ratio. After mixing and dissolving so as to become, a method of mixing with porous silica fine powder as the component B is preferable. For example, using a mixer equipped with a stirring blade, mix A component and C component in advance and mix with B component at room temperature, without drying or crushing, and uniform powder-like shrinkage without blocking A reducing agent can be obtained. Such a powdery shrinkage reducing agent preferably has a uniform particle size for use in cement premix products, and is classified using a sieve so that the particle size is in the range of 1 to 2000 μm. It is preferable that

  Next, the cement premix product according to the present invention (hereinafter simply referred to as the cement premix product of the present invention) will be described. The cement premix product of the present invention comprises at least cement and the powdery shrinkage reducing agent of the present invention described above. As cement, various portland cements such as ordinary portland cement, early-strength portland cement, medium heat portland cement, low heat portland cement, blast furnace cement, fly ash cement, various mixed cements such as silica fume cement, and alumina cement are used. However, in particular, when it is necessary to shorten the construction time, early-strength Portland cement is preferable.

  In the cement premix product of the present invention, the blending ratio of the powdery shrinkage reducing agent of the present invention to cement is 0.5 to 10 parts by mass of the powdery shrinkage reducing agent of the present invention per 100 parts by mass of cement. However, it is preferable that the ratio is 1 to 8 parts by mass.

  As the cement premix product of the present invention, 1) cement, a grout cement premix product containing the powder, the powdery shrinkage reducing agent of the present invention, and other powder additives (for example, powdered cement dispersant), 2) cement , Fine aggregate, powdery shrinkage reducing agent of the present invention, cement premix product for mortar or self-leveling flooring containing powdered cement dispersant, and the like.

  The powdery shrinkage reducing agent of the present invention described above does not block even when the bags packed in it are stacked and stored, and the air entrainment amount when mixing the cement premix product prepared using the same is reduced. Preventing the excessively large cured body from being reduced in compressive strength and increasing the drying shrinkage rate, etc., and even when stored for a long time in combination with an antifoaming agent, for example. This has the effect of preventing the occurrence of this.

  Hereinafter, in order to make the configuration and effects of the present invention more specific, examples and the like will be described. However, the present invention is not limited to the examples. In the following examples and the like, unless otherwise indicated,% means mass%, and part means mass part.

Test category 1 (Preparation of polyether mixture of component A)
Synthesis of compound (M-1) represented by chemical formula 1 Normal butyl alcohol 74 g (1 mol) was charged into an autoclave, 0.2 g of potassium hydroxide was added as a catalyst, and then the inside of the autoclave was purged with nitrogen. While stirring, the reaction temperature was kept at 115 to 125 ° C., and 88 g (2 mol) of ethylene oxide was injected to carry out the addition reaction. After the press-fitting, aging was performed for 1 hour at the same temperature. While stirring, the reaction temperature was kept at 125 to 135 ° C., and 116 g (2 mol) of propylene oxide was injected to carry out an addition reaction. After completion of the press-fitting, the reaction was terminated by aging at the same temperature for 2 hours to obtain a product. This product was treated with an adsorbent and purified by filtration. As a result of analysis, R ^{1 in} Chemical Formula ¹ is a normal butyl group, A ¹ is composed of a total of 4 oxyethylene units and oxypropylene units in the molecule, and these units are combined in a block form. It was a compound (M-1) represented by Chemical Formula 1 in the case of a residue obtained by removing all hydroxyl groups from a polyalkylene glycol having an alkylene group.

Synthesis of compounds (M-2) to (M-5) and (m-1) to (m-3) represented by chemical formula 1 In the same manner as the synthesis of compound (M-1) represented by chemical formula 1, Compounds (M-2) to (M-5) and (m-1) to (m-3) represented by Chemical Formula 1 were synthesized. Table 1 summarizes the contents of the compounds (M-1) to (M-5) and (m-1) to (m-3) represented by Chemical Formula 1 synthesized above.

In Table 1,
EO: oxyethylene unit PO: oxypropylene unit

-Synthesis | combination of compound (N-1) shown by Chemical formula 2 After charging 269g (1 mol) of oleyl alcohols into the autoclave and adding 0.7g of potassium hydroxide as a catalyst, the inside of the autoclave was purged with nitrogen. While stirring, the reaction temperature was kept at 115 to 125 ° C., and 264 g (6 mol) of ethylene oxide was injected to carry out an addition reaction. After the press-fitting, aging was performed for 1 hour at the same temperature. The reaction temperature was maintained at 125 to 135 ° C. while stirring, and 2320 g (40 mol) of propylene oxide was injected to carry out an addition reaction. After completion of the press-fitting, the reaction was terminated by aging at the same temperature for 2 hours to obtain a product. This product was treated with an adsorbent and purified by filtration. As a result of analysis, R ^{2 in} Chemical Formula 1 is a 9-octadecenyl group, A ² is a residue obtained by removing all hydroxyl groups from polyethylene glycol having 6 repeating oxyethylene units, and A ³ is the repeating number of oxypropylene units. It was a compound (N-1) represented by Chemical formula 2 when it was a residue obtained by removing all hydroxyl groups from 40 polypropylene glycols.

Synthesis of compounds (N-2) to (N-4) and (n-1) to (n-4) represented by Chemical formula 2 In the same manner as the synthesis of compound (N-1) represented by Chemical formula 2, Compounds (N-2) to (N-4) and (n-1) to (n-4) represented by Chemical Formula 2 were synthesized. Table 2 summarizes the contents of the compounds (N-1) to (N-4) and (n-1) to (n-4) represented by Chemical Formula 2 synthesized above.

Preparation of polyether mixture of component A (A-1) to (A-10) and (a-1) to (a-13) 99 parts of compound (M-1) represented by Chemical Formula 1 synthesized above And the compound (N-1) represented by the chemical formula 2 synthesized above in a ratio of 1 part at room temperature with stirring to obtain a polyether mixture (A-1). In the same manner, polyether mixtures (A-2) to (A-10) and (a-1) to (a-13) were prepared. The contents of these preparations are summarized in Table 3.

In Table 3,
* 1: A component at a temperature of 5 to 50 ° C. m-4: Normal butanol

Test Category 2 (Preparation of powder shrinkage reducing agent)
Example 1 {Preparation of powdery shrinkage reducing agent (P-1)}
8 kg of porous silica fine powder (trade name Tokuseal NR, specific surface area 180 m ² / g, average particle size 85 μm, manufactured by Tokuyama Corporation) as component B was charged into a ribbon mixer. Separately, 11.988 kg of the above-mentioned polyether mixture (A-1) of component A and 0.012 kg of hydroquinone as an antioxidant of component C were mixed, and 12 kg of the liquid mixture was stirred into the ribbon mixer. While being added in portions, the mixture was mixed well. The mixture was classified using a sieve to obtain 20 kg of a powdery shrinkage reducing agent (P-1) having a particle diameter of 1 to 500 μm of Example 1.

Examples 2 to 15 and Comparative Examples 1 to 20 {Preparation of powdery shrinkage reducing agents (P-2) to (P-15) and (r-1) to (r-20)}
In the same manner as in the preparation of the powdery shrinkage reducing agent (P-1) of Example 1, the powdery shrinkage reducing agents (P-2) to (P-15) of Examples 2 to 15 and Comparative Examples 1 to 20 and (R-1) to (r-20) were prepared. Table 4 summarizes the composition and properties (blocking resistance, etc.) of the powdery shrinkage reducing agents of each example prepared above.

In Table 4,
A-1 to A-10, a-1 to a-13: Polyether mixture prepared in Test Category 1 B-1: Porous silica fine powder having a specific surface area of 180 m ² / g and an average particle size of 85 μm B-2: Porous silica fine powder having a specific surface area of 140 m ² / g and an average particle diameter of 75 μm B-3: Porous silica fine powder having a specific surface area of 220 m ² / g and an average particle diameter of 60 μm B-4: Specific surface area of 110 m ² / g, average Porous silica fine powder having a particle size of 70 μm C-1: Hydroquinone C-2: Dibutylhydroxytoluene C-3: Butylhydroxyanisole * 2: Silica fume fine powder having a specific surface area of 20 m ² / g and an average particle size of 0.3 μm * 3 : Calcium carbonate fine powder having a specific surface area of 0.8 m ² / g and an average particle size of 2.5 μm * 4: The particle size was not determined because it was not powdered.
* 5: Value obtained from sieve opening of vibration sieve * 6: The blocking resistance of the powdery shrinkage reducing agent was evaluated as follows. That is, 100 g of the prepared powdery shrinkage reducing agent is sealed in a plastic sachet, loaded with a load of 3 kg from the top, left at 40 ° C. for 7 days, removed from the load, and observed for appearance. Those that did not change were marked with ◯, those that were partly fused or stuck, and those that were fused or stuck to the whole, and x.

Test Category 3 (Preparation of aging-treated powder shrinkage reducing agent)
20 g of powdery shrinkage reducing agents (P-1) to (P-15) and (r-1) to (r-15) prepared in Test Category 2 were sampled in a petri dish and placed in a hot air dryer at 40 ° C. The powdery shrinkage reducing agents (P-1) to (P-15) and (r-1) to (r-15), which were allowed to stand for a day and treated with aging, were prepared.

Test Category 4 (Preparation of shrinkage-reducing cement premix product)
5 L Hobart mixer with early strong Portland cement (density = 3.13 g / cm ³ , brain value 4350) and powdery shrinkage reducing agent prepared in Test Category 2 or powdered shrinkage reducing agent treated with Test Category 3 over time Were dry-mixed at a ratio shown in Table 5 to prepare a cement premix product. The contents are summarized in Table 5.

In Table 5,
S-1: Early strong Portland cement (density = 3.13 g / cm ³ , brain value 4350)
S-2: Ordinary Portland cement (density = 3.16 g / cm ³ , brain value 3250)
(P-1) to (P-15) and (r-1) to (r-15): the powdery shrinkage reducing agent described in Table 4 prepared in Test Category 2 or the powder subjected to aging treatment in Test Category 3 Shrinkage reducing agent. Regarding (r-16) to (r-20), no powder was obtained, so no cement premix product was prepared.

Test category 5 (preparation and evaluation of cement paste)
20 parts of 2000 parts of cement premix product prepared in test category 4, 7 parts of powdered cement dispersant (polycarboxylic acid powder cement dispersant manufactured by Takemoto Yushi Co., Ltd., trade name Tupole SD-100) and 550 parts of water, A cement paste having a flow value in the range of 250 ± 30 mm was prepared by kneading for 3 minutes at a temperature of ° C. The amount of air, compressive strength, and drying shrinkage of the prepared cement paste were measured as follows. The results are summarized in Table 6.

-Air amount: Measured according to JIS-R5201.
-Compressive strength: Measured according to JIS-R5201 at a material age of 28 days.
-Drying shrinkage: Based on JIS-A1129, the dry shrinkage distortion was measured by the comparator method about the specimen of the age of 13 weeks preserve | saved on the conditions of 20 degreeC x 60% RH, and the drying shrinkage was calculated | required. The smaller this value, the smaller the shrinkage.

Test Category 6 (Preparation of cement premix product)
5L Hobart mixer with early strength Portland cement, fine aggregate (JIS-R5201 standard sand, density 2.64 g / cm ³ ), powder shrinkage reducing agent prepared in test category 2 or test category 3 The processed powder shrinkage reducing agent was dry-mixed in the proportions shown in Table 7 to prepare a cement premix product. The contents are summarized in Table 7.

In Table 7,
S-1: Early strong Portland cement (density = 3.13 g / cm ³ , brain value 4350)
S-2: Ordinary Portland cement (density = 3.16 g / cm ³ , brain value 3250)
G-1: Standard sand of JIS-R5201 (density 2.64 g / cm ³ )
(P-1) to (P-15) and (r-1) to (r-15): The powdery shrinkage reducing agent prepared in Test Category 2 or the powdery shrinkage reducing agent treated with time in Test Category 3.

Test Category 7 (Preparation and evaluation of mortar)
Add 5050 parts of cement premix product prepared in Test Category 6, 6 parts of powdered cement dispersant (polycarboxylic acid powder cement dispersant manufactured by Takemoto Yushi Co., Ltd., trade name Tupole SD-100) and 500 parts of water, The mixture was kneaded for 3 minutes at a temperature of 20 ° C. to prepare a mortar having a flow value in the range of 220 ± 20 mm. The amount of air, compressive strength, and drying shrinkage of the prepared mortar were measured in the same manner as in Test Category 5. The results are summarized in Table 8.

Claims (9)

It is a powdery shrinkage reducing agent for cement premix products, comprising the following A component, B component and C component, the A component being 49.5 to 65% by mass, and the B component being 34.5 to 50 A powdery shrinkage reducing agent comprising 0.001 to 0.5% by mass (total 100% by mass) of the C component and the C component.
Component A: composed of a compound represented by the following chemical formula 1 and a compound represented by chemical formula 2, and 95 to 99.9 mass% of the compound represented by chemical formula 1 and 0.1 to 5 mass of the compound represented by chemical formula 2 % (Total 100% by mass) of polyether mixture.

(In Chemical Formula 1 and Chemical Formula 2,
R ¹ : Aliphatic hydrocarbon group having 3 to 5 carbon atoms R ² : Aliphatic hydrocarbon group having 12 to 20 carbon atoms A ¹ : All hydroxyl groups from (poly) ethylene glycol having 1 to 5 repeating oxyethylene units Or a residue obtained by removing all hydroxyl groups from a polyalkylene glycol having 2 to 7 repeating oxyalkylene units composed of both oxyethylene units and oxypropylene units)
A ² : residue obtained by removing all hydroxyl groups from polyethylene glycol having 4 to 10 repeating oxyethylene units A ³ : residue obtained by removing all hydroxyl groups from polypropylene glycol having 20 to 50 repeating oxypropylene units)
B component: Porous silica fine powder C component: Antioxidant   The powdery shrinkage reducing agent according to claim 1, wherein the component A is a polyether mixture which is liquid at a temperature of 5 to 50 ° C. The powder shrinkage reducing agent according to claim 1 or 2, wherein the compound represented by Chemical formula 1 is a compound in which R ^{1 in} Chemical formula ¹ is an aliphatic hydrocarbon group having 4 carbon atoms. The compound represented by the formula ¹ is a residue in which A 1 in the formula ¹ is a residue obtained by removing all hydroxyl groups from a polyalkylene glycol having 3 to 6 repeating oxyalkylene units composed of both oxyethylene units and oxypropylene units. The powdery shrinkage reducing agent according to any one of claims 1 to 3, which is a case in some cases. The powder shrinkage reducing agent according to any one of claims 1 to 4, wherein the compound represented by Chemical Formula ² is a compound in which R ^{2 in} Chemical Formula ² is a 9-octadecenyl group. The powdery shrinkage reducing agent according to any one of claims 1 to 5, wherein the component B is a porous silica fine powder having a specific surface area of 50 to 450 m ² / g and an average particle size of 0.1 to 500 µm.   The powdery shrinkage reducing agent according to any one of claims 1 to 6, wherein the component C is one or more antioxidants selected from hydroquinone, dibutylhydroxytoluene and butylhydroxyanisole.   The powdery shrinkage reducing agent according to any one of claims 1 to 7, which has a particle size of 1 to 2000 µm.   A cement premix product containing at least cement and a powdery shrinkage reducing agent, wherein the powdery shrinkage reducing agent according to any one of claims 1 to 8 is added in an amount of 0.5 to 10 per 100 parts by mass of cement. Cement premix product characterized by containing in the ratio of a mass part.