JP6055304B2 - Copolymer and its use - Google Patents

Description

The present invention relates to a copolymer and its use. More specifically, the present invention relates to a copolymer useful for various uses such as a dispersant and a cement admixture, and a dispersant, a cement admixture and a cement composition containing the copolymer.

Copolymers are used for various applications such as water treatment agents and scale inhibitors in addition to dispersants and cement admixtures. Among them, cement paste, mortar, concrete, etc. are the main components of cement admixtures. It is indispensable for building civil engineering and building structures from the cement composition. A cement admixture containing such a copolymer is used as a water reducing agent, etc., and improves the strength and durability of the cured product by increasing the fluidity of the cement composition to reduce the water content of the cement composition. Will have. In addition, as a water reducing agent, a water reducing agent such as a naphthalene type has been conventionally used. However, a cement admixture mainly composed of a copolymer such as a polycarboxylic acid type copolymer has a high water reducing performance. Therefore, it has come to have many use results as a high performance AE water reducing agent.

In recent years, such a cement admixture has been desired to improve the delay in curing and develop the strength at an early stage in addition to the water reduction performance (dispersion performance) with respect to the cement composition. For example, secondary concrete products (precast concrete products) are made by pouring concrete into a formwork at the factory, then transported to the site and assembled, which improves productivity, increases work efficiency, and saves labor Therefore, it is required to remove the mold from the mold early. Also, in the field of ready-mixed concrete, if the concrete hardens quickly after being placed, it is possible to quickly move on to the next step. Therefore, it is desired to develop a cement admixture that develops strength at an early stage. However, the conventional cement admixture has a large degree of curing delay and cannot exhibit sufficient strength at the initial stage of curing.

Therefore, a cement dispersant essentially comprising a copolymer containing a structural unit derived from an unsaturated (poly) alkylene glycol ether monomer having an alkenyl group having 4 carbon atoms and a structural unit derived from an unsaturated monocarboxylic acid monomer. (See Patent Document 1), a cement admixture containing a copolymer having both a long-chain alkylene glycol chain and a short-chain alkylene glycol chain (see Patent Documents 2 and 3), and a structure derived from an unsaturated polyalkylene glycol ether monomer A cement admixture (see Patent Document 4) containing a unit, a structural unit derived from an unsaturated carboxylic acid monomer, and a structural unit derived from an ester unsaturated monomer has been developed. The improvement of the cure delay and early manifestation of strength are realized.

JP 2002-121055 A JP 2003-221266 A JP 2001-302305 A JP 2011-84459 A

As described above, various cement admixtures have been developed. Particularly, the copolymers for cement admixtures described in Patent Documents 1 to 4 are extremely useful in the art. However, the use of cement is included by further improving the early strength development, in particular, the compression strength development in the initial stage of curing (after 12 to 24 hours), and further exhibiting excellent fluidity retention at the same time. There was room for contrivance to make it suitable for various uses.

The present invention has been made in view of the above situation, and can exhibit water-reducing properties, early strength development and fluidity retention at the same time and in a well-balanced manner, and can be used in various applications such as dispersants and cement admixtures. It is an object of the present invention to provide useful copolymers, and dispersants, cement admixtures and cement compositions containing such copolymers.

The present inventors have studied a copolymer that can be suitably applied to various uses such as a cement admixture, and in order to enhance early strength development of a cement composition or the like, a long-chain (poly) alkylene is added as an additive component. It was considered to use a copolymer having a glycol chain. However, the longer the (poly) alkylene glycol chain is, the more insufficient the fluid retention of the cement composition and the like, and the higher the fluid retention, the more the copolymer is added. As a result, the dispersibility became insufficient.
As a result of further studies based on the above studies, the present inventors have found that the structural unit derived from the (poly) alkylene glycol ether monomer has a chain length difference (difference in the average added mole number of oxyalkylene groups) of the chain. When a plurality of constituent units derived from unsaturated (poly) alkylene glycol ether monomers that are 20 or more (particularly preferably 100 or more) are used, in addition to dispersibility (also referred to as dispersibility, water reduction or fluidity), early It has been found that the copolymer is excellent in strength development performance, particularly strength development performance in the initial stage of curing (for example, after 12 to 24 hours), and at the same time excellent in fluidity retention performance (fluid retention). Moreover, the average addition mole number of the oxyalkylene group of the structural unit derived from the unsaturated polyalkylene glycol ether monomer having a long chain length is 111 to 300, and the alkenyl group of the structural unit derived from the (poly) alkylene glycol ether monomer It has been found that by setting the number of carbon atoms to 3 to 8, the copolymer is extremely useful for various uses such as a dispersant and a cement admixture.
Furthermore, in addition to the structural unit derived from the plurality of unsaturated (poly) alkylene glycol ether monomers, a fluid having at least a ternary copolymer obtained by further adding a structural unit derived from a hydrolyzable monomer As a result, the present inventors have found that the above-mentioned problems can be solved brilliantly.

That is, the present invention comprises a structural unit (A) derived from an unsaturated polyalkylene glycol ether monomer (a), a structural unit (B) derived from an unsaturated (poly) alkylene glycol ether monomer (b), and a hydrolyzable property. A copolymer containing the structural unit (C) derived from the monomer (c),
The unsaturated polyalkylene glycol ether monomer (a) has the following general formula (i):
Y ¹ O (R ¹ O) _n R ² (i)
(In the formula, Y ¹ represents an alkenyl group having 3 to 8 carbon atoms. R ¹ O is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. N represents R ¹ O. The average addition mole number of the oxyalkylene group represented is a number from 111 to 300. R ² represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms.
The unsaturated (poly) alkylene glycol ether monomer (b) has the following general formula (ii):
Y ² O (R ³ O) _m R ⁴ (ii)
(In the formula, Y ² represents an alkenyl group having 3 to 8 carbon atoms. R ³ O is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. M represents R ³ O. The average added mole number of the oxyalkylene group represented is a number of 1 to 280 and satisfies nm ≧ 20, and R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. )
The hydrolyzable monomer (c) has the following general formula (iii):

(Wherein R ⁵ , R ⁶ and R ⁷ represent a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms. R ⁸ O may be the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. L represents the average added mole number of the oxyalkylene group represented by R ⁸ O, and is a number from 0 to 300. R ⁹ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. However, when l = 0, R ⁹ represents a hydrocarbon group having 1 to 30 carbon atoms.)

The present invention is also a dispersant containing the above copolymer.
The present invention is also a cement admixture containing the above copolymer.
The present invention is also a cement composition comprising the above cement admixture, cement and water.
The present invention is described in detail below. In addition, what combined two or three or more of the preferable forms of this invention described in a paragraph below is also a preferable form of this invention.

In the present specification, the unsaturated polyalkylene glycol ether monomer (a) is also referred to as “monomer (a)”, and the unsaturated (poly) alkylene glycol ether monomer (b) is also referred to as “monomer (b)”. The decomposable monomer (c) is also referred to as “monomer (c)”, the unsaturated carboxylic acid monomer (d) is also referred to as “monomer (d)”, and the other monomer (e) is also referred to as “monomer (e)”. .

[Copolymer]
The copolymer of the present invention comprises a structural unit (A) derived from an unsaturated polyalkylene glycol ether monomer (a) represented by the general formula (i) and an unsaturated compound represented by the general formula (ii). It contains the structural unit (B) derived from the (poly) alkylene glycol ether monomer (b) and the structural unit (C) derived from the hydrolyzable monomer (c), and if necessary, the unsaturated described later The structural unit (D) derived from the carboxylic acid monomer (d) may further be included. Moreover, each structural unit contained in a copolymer may be 1 type, respectively, and 2 or more types may be sufficient as it.

In the copolymer, the proportion of the structural units (A), (B), and (C) is preferably 1% by mass or more with respect to 100% by mass of all the structural units. If the structural unit (A) is less than 1% by mass, early strength development may not be sufficiently exhibited, and if the structural unit (B) is less than 1% by mass, sufficient dispersibility and dispersibility retention will be obtained. There is a possibility that it cannot be demonstrated. Further, if the structural unit (C) is less than 1% by mass, the dispersibility and dispersibility retention may not be sufficiently exhibited.
The content ratio of the structural unit (A) in the total amount of 100% by mass of the structural units (A), (B) and (C) is preferably 10 to 98% by mass, more preferably 30 to 98% by mass, More preferably, it is 50-96 mass%, Most preferably, it is 70-94 mass%. Moreover, as a content rate of the structural unit (B) which occupies in the total amount 100 mass% of structural unit (A), (B) and (C), Preferably it is 1-89 mass%, More preferably, it is 1-69 mass. %, More preferably 2 to 48% by mass, particularly preferably 3 to 27% by mass. Moreover, as a content rate of the structural unit (C) which occupies in the total amount 100 mass% of structural unit (A), (B) and (C), Preferably it is 1-89 mass%, More preferably, it is 1-69 mass. %, More preferably 2 to 48% by mass, particularly preferably 3 to 27% by mass.

In the copolymer, the total ratio (% by mass) of the structural units (A), (B) and (C) is preferably 70 to 100% by mass with respect to 100% by mass of all the structural units. is there. That is, the total content ratio of the structural unit (D) derived from the unsaturated carboxylic acid monomer (d) and the structural unit (E) derived from the other monomer (e) is 0 to 100% by mass with respect to 100% by mass of all the structural units. It is preferably 30% by mass. The total ratio of the structural units (A), (B) and (C) in 100% by mass of all the structural units is more preferably 80 to 100% by mass, still more preferably 85 to 100% by mass, and particularly preferably 90 to 100%. % By mass.
In addition, in this specification, when calculating the ratio of the structural unit (D) derived from the unsaturated carboxylic acid monomer (d), the structural unit (D) is derived from a completely neutralized monomer (salt). When calculating the proportion of the unsaturated carboxylic acid monomer (d), it is assumed that the monomer (d) is a completely neutralized monomer (salt). It shall be. For example, when acrylic acid is used as the monomer (d) and neutralization is complete with sodium hydroxide in the polymerization reaction, it is assumed that sodium acrylate is used as the monomer (d). To do.

In the copolymer, the proportion of the total of the structural units (A) and (B) is preferably 50 mol% or less with respect to 100 mol% of all the structural units. This is because the monomers (a) and (b) constituting the structural units (A) and (B) are not sufficiently polymerizable, and in order to obtain a highly dispersible copolymer in a high yield, the monomer ( This is because the total use ratio of a) and (b) is preferably 50 mol% or less with respect to 100 mol% of all monomer components. More preferably, it is 40 mol% or less, More preferably, it is 35 mol% or less, Most preferably, it is 30 mol% or less.

Next, the monomer component forming the copolymer will be described.
In addition, each monomer can use 1 type (s) or 2 or more types, respectively.
The unsaturated polyalkylene glycol ether monomer (a) and the unsaturated (poly) alkylene glycol ether monomer (b) are monomers represented by the above-described general formulas (i) and (ii), respectively. The structural unit (A) derived from the monomer (a) means a structure in which the polymerizable double bond (carbon-carbon double bond) portion of the monomer (a) is a single bond, and is derived from the monomer (b). The structural unit (B) means a structure in which a polymerizable double bond (carbon-carbon double bond) portion of the monomer (b) is a single bond.

Y ¹ in the general formula (i) represents an alkenyl group having 3 to 8 carbon atoms. Among these, from the viewpoint of further developing early strength development and dispersibility, an alkenyl group having 3 to 5 carbon atoms is preferable. For example, an alkenyl group having 3 carbon atoms such as an allyl group; a methallyl group, 3- C4 alkenyl groups such as butenyl, 2-butenyl, 1-methyl-2-propenyl, etc .; 3-methyl-2-butenyl, 3-methyl-3-butenyl, 2-methyl-2- Examples thereof include alkenyl groups having 5 carbon atoms such as butenyl group and 2-methyl-3-butenyl group. More preferred is an alkenyl group having 3 to 4 carbon atoms, still more preferred is an alkenyl group having 4 carbon atoms, and particularly preferred is a methallyl group.

Y ² in the general formula (ii) also represents an alkenyl group having 3 to 8 carbon atoms. Among these, an alkenyl group having 5 to 8 carbon atoms is preferable from the viewpoint of more expressing early strength development and dispersibility. More preferably, it is an alkenyl group having 5 carbon atoms.
The embodiment in which Y ¹ is an alkenyl group having 3 to 4 carbon atoms and Y ² is an alkenyl group having 5 to 8 carbon atoms is one of the preferred embodiments of the present invention.

R ² in the general formula (i) and R ⁴ in the general formula (ii) represent a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, but the number of carbon atoms of the hydrocarbon group is increased. Accordingly, the hydrophobicity increases and the dispersibility does not become more satisfactory, so that the hydrocarbon group preferably has 1 to 20 carbon atoms. More preferably, it is 1-12, More preferably, it is 1-10, Most preferably, it is 1-6, Most preferably, it is 1-4.
Specific examples of the hydrocarbon group include an alkyl group (straight chain, branched chain, or cyclic), a phenyl group, an alkyl-substituted phenyl group, an alkenyl group, an alkynyl group, and an aryl group. Of these, an alkyl group (straight chain, branched chain or cyclic) is preferable.
R ² and R ⁴ are particularly preferably a hydrogen atom, a methyl group or an ethyl group.
R ² and R ⁴ may be the same or different.

R ¹ O in the general formula (i) and R ³ O in the general formula (ii) represent an oxyalkylene group having 2 to 18 carbon atoms. Among them, an oxyalkylene group having 2 to 8 carbon atoms is preferable, and examples thereof include an oxyethylene group, an oxypropylene group, an oxybutylene group, an oxyisobutylene group, an oxymethylethylene group, an oxyoctylene group, and an oxystyrene group. An oxyalkylene group having 2 to 4 carbon atoms is more preferable, and an oxyethylene group is more preferable. R ¹ O and R ³ O may be the same or different.
Here, the polyalkylene glycol chain represented by (R ¹ O) _n and the polyalkylene glycol chain represented by (R ³ O) _m are each formed by two or more oxyalkylene groups. It may be. In this case, the addition form of two or more oxyalkylene groups may be any form such as random addition, block addition, and alternate addition.

In the general formulas (i) and (ii), it is preferable that the ratio of oxyethylene groups in 100 mol% of all oxyalkylene groups is 50 mol% or more. Thereby, further sufficient dispersibility can be exhibited. More preferably 70 mol% or more, still more preferably 80 mol% or more, particularly preferably 90 mol% or more, most preferably 100 mol%, that is, a polyalkylene represented by (R ¹ O) _n only by an oxyethylene group That is, a glycol chain or a (poly) alkylene glycol chain represented by (R ³ O) _m is constituted. In addition, as the combination having two or more oxyalkylene groups, (oxyethylene group, oxypropylene group), (oxyethylene group, oxybutylene group), (oxyethylene group, oxystyrene group) are preferable. . Among these, (oxyethylene group, oxypropylene group) is more preferable.

Here, the average chain length of the polyalkylene glycol chain represented by n (average number of moles of oxyalkylene group added) is 1 mol of the polyalkylene glycol chain derived from the monomer (a) of the copolymer. It means the average number of moles of oxyalkylene groups added. The average chain length of the (poly) alkylene glycol chain represented by m (average added mole number of oxyalkylene group) is the (poly) alkylene glycol chain 1 derived from the monomer (b) of the copolymer. It means the average value of the number of moles of oxyalkylene group added in the mole.

As a combination of the average addition mole number n of the oxyalkylene group in the general formula (i) and the average addition mole number m of the oxyalkylene group in the general formula (ii), n is a number of 111 to 300, and m is 1. A combination that is a number of ˜280 and the difference (nm) is 20 or more is appropriate. As a result, the copolymer can exhibit water reduction, early strength development and fluidity retention at the same time and remarkably in a well-balanced manner, but the larger the difference between n and m, Since the effects of the present invention can be further exhibited, it is preferable that nm is 100 or more. More preferably, it is 120 or more, More preferably, it is 140 or more. Moreover, although the upper limit of nm should just be 299 or less, for example, 279 or less is preferable, More preferably, it is 259 or less, More preferably, it is 239 or less.

The n is a number from 111 to 300, and the lower limit of n is preferably 120 or more from the viewpoint of further improving the early strength development performance of the copolymer. More preferably, it is 141 or more. On the other hand, if n exceeds 300, the copolymerizability may not be sufficient, and the dispersibility retention performance may not be fully exhibited. The upper limit of n is preferably 280 or less, more preferably 260 or less, and still more preferably 240 or less.

The m is a number from 1 to 280, and the upper limit of m is preferably 200 or less from the viewpoint of further improving the dispersion holding performance of the copolymer. More preferably, it is 150 or less, More preferably, it is 100 or less, More preferably, it is 75 or less, More preferably, it is 50 or less, Especially preferably, it is 25 or less, Most preferably, it is 20 or less. Further, from the viewpoint of fully expressing the dispersion performance, the lower limit of m is preferably 3 or more, more preferably 5 or more, still more preferably 7 or more, and particularly preferably 10 or more.
In addition, the said n is the number of 111-300, the said m is the number of 1-280, and satisfy | fills nm> = 20; the said n is the number of 120-300, and the said m is 1-200. A form satisfying nm ≧ 100; a form wherein n is a number from 141 to 300, a form wherein m is a number from 1 to 200, and NM ≧ 100 is satisfied; This is a particularly preferred form.

Specific examples of the unsaturated polyalkylene glycol ether monomer (a) and the unsaturated (poly) alkylene glycol ether monomer (b) include (meth) allyl alcohol alkylene oxide adducts and 3-buten-1-ol alkylene. Oxide adduct, isoprenol alkylene oxide adduct (3-methyl-3-buten-1-ol alkylene oxide adduct), 3-methyl-2-buten-1-ol alkylene oxide adduct, 2-methyl-3- A buten-2-ol alkylene oxide adduct, a 2-methyl-2-buten-1-ol alkylene oxide adduct, a 2-methyl-3-buten-1-ol alkylene oxide adduct, and the like are preferable.

More specifically, for example, methoxy polyethylene glycol methallyl ether, ethoxy polyethylene glycol methallyl ether, propoxy polyethylene glycol methallyl ether, butoxy polyethylene glycol methallyl ether, phenoxy polyethylene glycol methallyl ether, polyethylene glycol monoallyl ether, polyethylene glycol monomethallyl ether, Polyethylene glycol mono (2-methyl-2-propenyl) ether, polyethylene glycol mono (2-butenyl) ether, polyethylene glycol mono (3-methyl-3-butenyl) ether, polyethylene glycol mono (3-methyl-2-butenyl) Ether, polyethylene glycol mono (2-methyl-3-butenyl) ether, polyethylene Ethylene glycol mono (2-methyl-2-butenyl) ether, polyethylene glycol mono (1,1-dimethyl-2-propenyl) ether, polyethylene polypropylene glycol mono (3-methyl-3-butenyl) ether, methoxypolyethylene glycol (3 -Methyl-3-butenyl) ether, ethoxypolyethylene glycol (3-methyl-3-butenyl) ether, 1-propoxypolyethylene glycol (3-methyl-3-butenyl) ether, cyclohexyloxypolyethylene glycol (3-methyl-3- Butenyl) ether, phenoxy polyethylene glycol (3-methyl-3-butenyl) ether, methoxy polyethylene glycol allyl ether, ethoxy polyethylene glycol allyl ether, Nonoxypolyethylene glycol allyl ether, methoxypolyethylene glycol (2-methyl-2-propenyl) ether, ethoxy polyethylene glycol (2-methyl-2-propenyl) ether, phenoxy polyethylene glycol (2-methyl-2-propenyl) ether, etc. Is preferred.

The hydrolyzable monomer (c) is a monomer represented by the general formula (iii) described above, and the structural unit (C) derived from the monomer (c) is an unsaturated divalent monomer (c). A structure in which a double bond (carbon-carbon double bond) portion is a single bond is meant.

In formula ^{(iii), R 5, R} 6 and ^{R 7} represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms. R ⁵ , R ⁶ and R ⁷ may be the same or different, and among them, it is preferable that R ⁵ , R ⁶ and R ⁷ are all hydrogen atoms. It is also preferred that R ⁵ and R ⁶ are hydrogen atoms and R ⁷ is a methyl group.

In the general formula (iii), R ⁸ O represents an oxyalkylene group having 2 to 18 carbon atoms. Among them, an oxyalkylene group having 2 to 8 carbon atoms is preferable, and examples thereof include an oxyethylene group, an oxypropylene group, an oxybutylene group, an oxyisobutylene group, an oxymethylethylene group, an oxyoctylene group, and an oxystyrene group. An oxyalkylene group having 2 to 4 carbon atoms is more preferable, and an oxyethylene group is particularly preferable. The polyalkylene glycol chain represented by (R ⁸ O) ₁ may be formed by two or more oxyalkylene groups. In this case, two or more oxyalkylene groups are randomly added. Any addition form such as block addition or alternate addition may be used.

In the general formula (iii), the ratio of oxyethylene groups in 100 mol% of all oxyalkylene groups is preferably 50 mol% or more. Thereby, sufficient dispersibility can be exhibited. More preferably 70 mol% or more, still more preferably 80 mol% or more, particularly preferably 90 mol% or more, and most preferably 100 mol%, that is, represented by (R ⁸ O) ₁ only by an oxyethylene group. ) An alkylene glycol chain is formed.
As the combination having two or more oxyalkylene groups, (oxyethylene group, oxypropylene group), (oxyethylene group, oxybutylene group), (oxyethylene group, oxystyrene group) are preferable. . Among these, (oxyethylene group, oxypropylene group) is more preferable.

In the general formula (iii), R ⁹ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms (however, when l = 0, it represents a hydrocarbon group having 1 to 30 carbon atoms). However, as the number of carbon atoms in the hydrocarbon group increases, the hydrophobicity increases and the dispersibility does not become sufficient. Therefore, the number of carbon atoms in the hydrocarbon group is preferably 1-20. More preferably, it is 1-12, More preferably, it is 1-10, Most preferably, it is 1-6, Most preferably, it is 1-4.
As the hydrocarbon group, for example, an alkyl group (straight chain, branched chain or cyclic), a phenyl group, an alkyl-substituted phenyl group, an alkenyl group, an alkynyl group, an aryl group and the like are preferable. Of these, an alkyl group (straight chain, branched chain or cyclic) is preferable.
R ⁹ is particularly preferably a hydrogen atom, a methyl group or an ethyl group.

In the above general formula (iii), the average chain length of the (poly) alkylene glycol chain (average added mole number of oxyalkylene group) l is a number from 0 to 300. By setting it as such a form, it becomes possible for a copolymer to exhibit the dispersion | distribution holding property simultaneously with the outstanding dispersibility and early strength expression. Here, if l exceeds 300, the copolymerizability may not be sufficient and the dispersibility retention performance may not be sufficiently exhibited. Therefore, the upper limit value of l is preferably not more than a specific value in the following order (a smaller numerical value is preferable). That is, 250 or less, 200 or less, 150 or less, 100 or less, 75 or less, 50 or less, 25 or less, 10 or less, 7 or less, 5 or less, or 3 or less is preferable. Further, when l is 0, the hydrolyzable monomer (c) represented by the general formula (iii) is an unsaturated carboxylic acid alkyl ester. It is preferable because it can be hydrolyzed with time and exhibit dispersion retention. A form in which the lower limit value of l is 1 or more is also a preferred form.

Specific examples of the hydrolyzable monomer (c) include unsaturated carboxylic acid alkyl esters such as alkyl (meth) acrylates which are esterified products of alcohol and (meth) acrylic acid; alkylene having 2 to 18 carbon atoms (Poly) alkylene glycol mono (meth) acrylate which is an esterified product of glycol (alkylene oxide) and (meth) acrylic acid; alkoxy (poly) alkylene obtained by adding alkylene glycol having 2 to 18 carbon atoms to alcohol An alkoxy (poly) alkylene glycol (meth) acrylate, which is an esterified product of glycol and (meth) acrylic acid, is suitable.

Examples of the alcohol include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 1-hexanol, 2-hexanol, C1-C30 aliphatic alcohols such as 3-hexanol, octanol, 2-ethyl-1-hexanol, nonyl alcohol, lauryl alcohol, cetyl alcohol, stearyl alcohol; C3-C30 alicyclics such as cyclohexanol Alcohol; unsaturated alcohols having 1 to 30 carbon atoms such as (meth) allyl alcohol, 3-buten-1-ol, 3-methyl-3-buten-1-ol, and the like, and one or two of these The above can be used. Among these, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and 2-butanol are preferable.

As said C2-C18 alkylene glycol, C2-C8 alkylene glycol is preferable, for example, ethylene glycol, propylene glycol, butylene glycol, isobutylene glycol, methylethylene glycol, octylene glycol, styrene glycol etc. are mentioned. It is done. More preferred is alkylene glycol having 2 to 4 carbon atoms, and particularly preferred is ethylene glycol. Two or more kinds of alkylene glycols may be used. In this case, the addition reaction may be in any form such as random addition, block addition, and alternate addition.
Further, it is preferable that the proportion of ethylene glycol in the total amount of alkylene glycol used of 100 mol% is 50 mol% or more. Thereby, sufficient dispersibility can be exhibited. More preferably, it is 70 mol% or more, More preferably, it is 80 mol% or more, Especially preferably, it is 90 mol% or more, Most preferably, it is 100 mol%. That is, it is using only ethylene glycol as said alkylene glycol.

Preferable examples of the unsaturated carboxylic acid alkyl ester include (meth) acrylic acid alkyl esters such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and glycidyl (meth) acrylate. Moreover, methyl crotonate, ethyl crotonate, propyl crotonate, etc. are also mentioned. Among these, alkyl acrylates such as methyl acrylate, ethyl acrylate, and propyl acrylate are particularly preferable from the viewpoints of polymerizability and hydrolyzability.

The above (poly) alkylene glycol mono (meth) acrylate is preferably, for example,
Hydroxyalkyl (meth) acrylates such as hydroxymethyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate; 1,4-butanediol mono (meth) acrylate, 1, Alkanediol mono (meth) acrylates such as 5-pentanediol mono (meth) acrylate and 1,6-hexanediol mono (meth) acrylate; polyethylene glycol mono (meth) acrylate, {polyethylene glycol (poly) propylene glycol} mono ( (Meth) acrylate, {polyethylene glycol (poly) butylene glycol} mono (meth) acrylate, {polyethylene glycol (poly) propylene glycol (poly) butylene glycol Lumpur} mono (meth) polyalkylene glycol mono (meth) acrylate such as acrylate.
Among these, hydroxyalkyl acrylates such as hydroxyethyl acrylate (particularly 2-hydroxyethyl acrylate) and hydroxypropyl acrylate (particularly 2-hydroxypropyl acrylate) are preferred from the viewpoints of polymerizability and hydrolyzability.

The alkoxy (poly) alkylene glycol (meth) acrylate is preferably methoxyethylene glycol (meth) acrylate, methoxy polyethylene glycol (meth) acrylate, methoxy {polyethylene glycol (poly) propylene glycol} (meth) acrylate, methoxy { Polyethylene glycol (poly) butylene glycol} (meth) acrylate, methoxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} (meth) acrylate; ethoxyethylene glycol (meth) acrylate, ethoxypolyethylene glycol (meth) acrylate, ethoxy {Polyethylene glycol (poly) propylene glycol} (meth) acrylate, ethoxy {polyethylene Glycol (poly) butylene glycol} (meth) acrylate, ethoxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} (meth) acrylate; propoxyethylene glycol (meth) acrylate, propoxypolyethylene glycol (meth) acrylate, propoxy {Polyethylene glycol (poly) propylene glycol} (meth) acrylate, propoxy {polyethylene glycol (poly) butylene glycol} (meth) acrylate, propoxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} (meth) acrylate; butoxy Ethylene glycol (meth) acrylate, butoxypolyethylene glycol (meth) acrylate, butoki {Polyethylene glycol (poly) propylene glycol} (meth) acrylate, butoxy {polyethylene glycol (poly) butylene glycol} (meth) acrylate, butoxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} (meth) acrylate; pentyl Oxyethylene glycol (meth) acrylate, pentyloxypolyethylene glycol (meth) acrylate, pentyloxy {polyethylene glycol (poly) propylene glycol} (meth) acrylate, pentyloxy {polyethylene glycol (poly) butylene glycol} (meth) acrylate, pentyl Oxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} (meth) acryl rate;

Hexyloxyethylene glycol (meth) acrylate, hexyloxypolyethylene glycol (meth) acrylate, hexyloxy {polyethylene glycol (poly) propylene glycol} (meth) acrylate, hexyloxy {polyethylene glycol (poly) butylene glycol} (meth) acrylate, Hexyloxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} (meth) acrylate; heptyloxyethylene glycol (meth) acrylate, heptyloxypolyethylene glycol (meth) acrylate, heptyloxy {polyethylene glycol (poly) propylene glycol} (Meth) acrylate, heptyloxy {polyethylene glycol (poly) butylene glycol } (Meth) acrylate, heptyloxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} (meth) acrylate; octyloxyethylene glycol (meth) acrylate, octyloxypolyethylene glycol (meth) acrylate, octyloxy { Polyethylene glycol (poly) propylene glycol} (meth) acrylate, octyloxy {polyethylene glycol (poly) butylene glycol} (meth) acrylate, octyloxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} (meth) acrylate; Nonyloxy polyethylene glycol (meth) acrylate, nonyloxy {polyethylene glycol (poly) propylene glycol Lumpur} (meth) acrylate, nonyloxy {polyethylene glycol (poly) butylene glycol} (meth) acrylate, nonyloxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} (meth) acrylate.

The copolymer also includes a structural unit (D) derived from an unsaturated carboxylic acid monomer (d) in addition to the monomers (a), (b) and (c) which are essential monomers. Also good.

The unsaturated carboxylic acid monomer (d) is a monomer containing a polymerizable double bond (carbon-carbon double bond) and a carboxyl group and / or a carboxylate. The structural unit (D) derived from the unsaturated carboxylic acid monomer (d) means a structure in which the polymerizable double bond portion of the monomer (d) is a single bond.

Here, including a carboxyl group and / or a carboxylate salt means that a group represented by —COOZ (Z represents a hydrogen atom, a metal atom, an ammonium group, or an organic amine group) is 1 per molecule. It means having two or more species. Examples of metal atoms include alkali metals such as sodium, lithium, potassium, rubidium and cesium; alkaline earth metals such as magnesium, calcium, strontium and barium; aluminum and iron. Organic amine groups include monoethanolamine groups, diethanolamine groups, triethanolamine groups and other alkanolamine groups; monoethylamine groups, diethylamine groups, triethylamine groups and other alkylamine groups; ethylenediamine groups, triethylenediamine groups and other polyamines Groups and the like. Among these, the carboxylate is preferably an ammonium salt, a sodium salt, or a potassium salt, and more preferably a sodium salt.

Examples of the unsaturated carboxylic acid monomer (d) include an unsaturated monocarboxylic acid monomer containing a polymerizable double bond and one carboxyl group or carboxylate in one molecule, and a polymerizable dicarboxylic acid monomer in one molecule. An unsaturated dicarboxylic acid-based monomer containing a heavy bond and two carboxyl groups or carboxylates is preferred.

Specific examples of the unsaturated monocarboxylic acid-based monomer include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, α-hydroxyacrylic acid, α-hydroxymethylacrylic acid and derivatives thereof, and the like. Examples include salts.
Specific examples of the unsaturated dicarboxylic acid-based monomer include unsaturated dicarboxylic acids such as maleic acid, itaconic acid, citraconic acid, fumaric acid, and mesaconic acid, salts thereof, and anhydrides thereof. .
Among these, acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid and salts thereof are preferable from the viewpoint of polymerizability. Of these, acrylic acid, methacrylic acid, and salts thereof are more preferable. That is, the unsaturated carboxylic acid monomer (d) preferably contains (meth) acrylic acid or a salt thereof. More preferably, it is acrylic acid or a salt thereof. By including a structure derived from acrylic acid or a salt thereof, the obtained copolymer can exhibit further excellent dispersibility in a smaller amount.
Acrylic acid and methacrylic acid are collectively referred to as “(meth) acrylic acid”.

The copolymer may also contain a structural unit (E) derived from another monomer (e). Such a monomer (e) should just be a monomer copolymerizable with monomer (a), (b) and / or (c), for example, uses 1 type (s) or 2 or more types, such as the following compound. Can do.

Half esters and diesters of the above unsaturated dicarboxylic acid monomers and alcohols having 1 to 30 carbon atoms; Half amides and diamides of the above unsaturated dicarboxylic acid monomers and amines having 1 to 30 carbon atoms; and the above alcohols And half esters and diesters of an alkyl (poly) alkylene glycol obtained by adding 1 to 500 moles of an alkylene oxide having 2 to 18 carbon atoms to an amine and the unsaturated dicarboxylic acid monomer; and the unsaturated dicarboxylic acid monomer Half esters and diesters of alkylene glycols having 2 to 18 carbon atoms or polyalkylene glycols having 2 to 500 addition moles of the alkylene glycol;

Half amides of maleamic acid and glycols having 2 to 18 carbon atoms or polyalkylene glycols having 2 to 500 addition moles of these glycols; hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tri Polyfunctional (meth) acrylates such as methylolpropane di (meth) acrylate; (poly) alkylene glycol dimaleates such as triethylene glycol dimaleate and polyethylene glycol dimaleate; vinyl sulfonate, (meth) allyl sulfonate, 2- ( (Meth) acryloxyethyl sulfonate, 3- (meth) acryloxypropyl sulfonate, 3- (meth) acryloxy-2-hydroxypropyl sulfonate, 3- (meth) acryloxy-2-hydroxypropyls Phophenyl ether, 3- (meth) acryloxy-2-hydroxypropyloxysulfobenzoate, 4- (meth) acryloxybutyl sulfonate, (meth) acrylamidomethylsulfonic acid, (meth) acrylamidoethylsulfonic acid, 2-methylpropanesulfone Unsaturated sulfonic acids such as acid (meth) acrylamide and styrene sulfonic acid, and monovalent metal salts, divalent metal salts, ammonium salts and organic amine salts thereof; unsaturated monocarboxylic acids such as methyl (meth) acrylamide and carbon atom Amides with amines of 1 to 30; Vinyl aromatics such as styrene, α-methylstyrene, vinyltoluene, p-methylstyrene;

Dienes such as butadiene, isoprene, 2-methyl-1,3-butadiene, 2-chloro-1,3-butadiene; (meth) acrylamide, (meth) acrylalkylamide, N-methylol (meth) acrylamide, N, Unsaturated amides such as N-dimethyl (meth) acrylamide; unsaturated cyanides such as (meth) acrylonitrile and α-chloroacrylonitrile; unsaturated esters such as vinyl acetate and vinyl propionate; aminoethyl (meth) acrylate , Unsaturated amines such as methylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, dibutylaminoethyl (meth) acrylate, vinylpyridine, and the like; Divinyl aromatics such as triallyl cyanurate Anurates; Allyls such as (meth) allyl alcohol and glycidyl (meth) allyl ether; Unsaturated amino compounds such as dimethylaminoethyl (meth) acrylate; Methoxypolyethylene glycol (meth) allyl ether, Polyethylene glycol mono (meth) Allyl ethers such as allyl ether; polydimethylsiloxanepropylaminomaleamic acid, polydimethylsiloxaneaminopropyleneaminomaleamic acid, polydimethylsiloxane-bis- (propylaminomaleamic acid), polydimethylsiloxane-bis- (dipropylene) Aminomaleamic acid), polydimethylsiloxane- (1-propyl-3-acrylate), polydimethylsiloxane- (1-propyl-3-methacrylate), polydimethylsiloxane Siloxane derivatives such as xan-bis- (1-propyl-3-acrylate) and polydimethylsiloxane-bis- (1-propyl-3-methacrylate);

The weight average molecular weight (Mw) of the copolymer is preferably 500,000 or less in consideration of its handleability and fluidity retention. More preferably, it is 300,000 or less, More preferably, it is 200,000 or less, Most preferably, it is 100,000 or less. Moreover, it is preferable that Mw is 3000 or more from a viewpoint of improving a dispersibility more. More preferably, it is 5000 or more, More preferably, it is 10,000 or more. Moreover, it is preferable that Mw is 10,000 or more from the viewpoint that adsorbing power to cement particles to some extent tends to exhibit performance, and that the adsorption power increases as Mw increases. More preferably, it is 10,000-100000, More preferably, it is 20000-80000.
In addition, the weight average molecular weight of the said copolymer can be calculated | required by the gel permeation chromatography (GPC) analysis method mentioned later.

Next, a method for obtaining the copolymer will be described.
As a method of obtaining the copolymer, a monomer (a), a monomer (b) and a monomer (c), and a monomer containing the monomer (d) and the monomer (e) as necessary, using a polymerization initiator The components may be copolymerized, but it is preferable to appropriately set the type and amount of the monomer contained in the monomer component so that each structural unit constituting the copolymer falls within the above-described range. That is, it is preferable to appropriately set the type and amount of the monomer contained in the monomer component so that the proportion of the constituent units constituting the copolymer is within the above-described preferred range.

Therefore, it is preferable that the content of each of the monomers (a), (b) and (c) is 1% by mass or more with respect to 100% by mass of all monomer components used for obtaining the copolymer. is there. Further, the content ratio of each of the monomers (a), (b) and (c) in the total amount of 100% by mass of the monomers (a), (b) and (c) is preferably (a) 10 to 98. Mass%, (b) 1-89 mass%, (c) 1-89 mass%, more preferably (a) 30-98 mass%, (b) 1-69 mass%, (c) 1- 69% by mass, more preferably (a) 50 to 96% by mass, (b) 2 to 48% by mass, and (c) 2 to 48% by mass, particularly preferably (a) 70 to 94% by mass. %, (B) 3 to 27 mass%, and (c) 3 to 27 mass%.

The total ratio (mass%) of the monomers (a), (b) and (c) is preferably 70 to 100 mass% with respect to 100 mass% of all monomer components. That is, the total content of the unsaturated carboxylic acid monomer (d) and the other monomer (e) is preferably 0 to 30% by mass with respect to 100% by mass of all monomer components. The total ratio of monomers (a), (b) and (c) in 100% by mass of all monomer components is more preferably 80 to 100% by mass, still more preferably 85 to 100% by mass, and particularly preferably 90 to 100% by mass. %.
In order to obtain a highly dispersible copolymer in a high yield, the proportion of the total of the monomers (a) and (b) is 50 mol% or less with respect to 100 mol% of all monomer components. Is preferred. More preferably, it is 40 mol% or less, More preferably, it is 35 mol% or less, Most preferably, it is 30 mol% or less.

The polymerization process (copolymerization process) for obtaining the copolymer can be performed by a usual method such as solution polymerization or bulk polymerization. The solution polymerization can be carried out either batchwise or continuously. Examples of the solvent used here include water; alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol; benzene, toluene, xylene, cyclohexane, n- Examples include aromatic or aliphatic hydrocarbons such as hexane; ester compounds such as ethyl acetate; ketone compounds such as acetone and methyl ethyl ketone; and cyclic ether compounds such as tetrahydrofuran and dioxane. Among these, from the viewpoint of the solubility of the raw material monomer and the polymer to be obtained, it is preferable to use at least one selected from the group consisting of water and a lower alcohol having 1 to 4 carbon atoms. Is more preferable in that it can be omitted.

When the polymerization step is performed by an aqueous solution polymerization method, a water-soluble polymerization initiator, for example, a persulfate such as ammonium persulfate, sodium persulfate, or potassium persulfate; hydrogen peroxide; 2 Azoamidine compounds such as 2,2′-azobis-2-methylpropionamidine hydrochloride, cyclic azoamidine compounds such as 2,2′-azobis-2- (2-imidazolin-2-yl) propane hydrochloride, 2-carbamoylazoiso It is preferable to use a water-soluble azo initiator such as an azonitrile compound such as butyronitrile. In addition, at this time, alkali metal sulfites such as sodium hydrogen sulfite, metabisulfite, sodium hypophosphite, Fe (II) salts such as molle salt, sodium hydroxymethanesulfinate dihydrate, hydroxylamine hydrochloride, Accelerators such as thiourea, L-ascorbic acid (salt), and erythorbic acid (salt) can also be used in combination. Among these, a combination of a persulfate and an accelerator such as L-ascorbic acid (salt) and a combination of hydrogen peroxide and an accelerator such as L-ascorbic acid (salt) are preferable. These radical polymerization initiators and accelerators may be used alone or in combination of two or more.

When performing solution polymerization using a lower alcohol, aromatic or aliphatic hydrocarbon, ester compound or ketone compound as a solvent, examples of radical polymerization initiators include benzoyl peroxide, lauroyl peroxide, and sodium peroxide. Peroxides; hydroperoxides such as t-butyl hydroperoxide and cumene hydroperoxide; azo compounds such as azobisisobutyronitrile are preferably used. At this time, an accelerator such as an amine compound can be used in combination.
Further, when a water-lower alcohol mixed solvent is used, it can be appropriately selected from the above-mentioned various radical polymerization initiators or combinations of radical polymerization initiators and accelerators.

When the polymerization step is carried out by a bulk polymerization method, for example, as a radical polymerization initiator, peroxides such as benzoyl peroxide, lauroyl peroxide, sodium peroxide; t-butyl hydroperoxide, cumene hydroperoxide, etc. It is preferable to perform polymerization at a temperature of 50 to 200 ° C. using hydroperoxide; an azo compound such as azobisisobutyronitrile.

In the polymerization step, the reaction temperature is not particularly limited. For example, when a persulfate is used as an initiator, the reaction temperature is preferably in the range of 30 to 100 ° C. More preferably, it is the range of 40-95 degreeC, More preferably, it is the range of 45-90 degreeC. Moreover, when combining a persulfate and L-ascorbic acid (salt) as a promoter and making it an initiator, it is preferable to make reaction temperature into the range of 30-100 degreeC. More preferably, it is the range of 40-95 degreeC, More preferably, it is the range of 45-90 degreeC.
Moreover, although superposition | polymerization time is not specifically limited, For example, it is preferable to set it as the range of 0.5 to 10 hours. If the polymerization time is too long or too short, the polymerization rate may not be sufficient or the productivity may not be improved. More preferably, it is 0.5-8 hours, More preferably, it is the range of 1-6 hours.

The amount of all monomer components used in the polymerization step is preferably in the range of 10 to 99% by mass with respect to 100% by mass of all raw materials including other raw materials and the polymerization solvent. In particular, if the amount of all the monomer components used is too lower than this range, the polymerization rate may not be sufficient or the productivity may not be improved. More preferably, it is 20-98 mass%, More preferably, it is 25-95 mass%, More preferably, it is 30-90 mass%, Especially preferably, it is 30-80 mass%, Most preferably, it is the range of 40-70 mass%.

In the above polymerization step, the method for charging each monomer component into the reaction vessel is not particularly limited, a method in which the entire amount is initially charged into the reaction vessel; a method in which the entire amount is divided or continuously charged into the reaction vessel; a part of the reaction vessel And a method of dividing or continuously charging the remainder into the reaction vessel. In addition, the monomer ratio varies by changing the charging rate of each monomer per unit time continuously or stepwise by changing the charging rate of each monomer into the reaction vessel continuously or stepwise during the reaction. Two or more types of copolymers may be synthesized simultaneously during the polymerization reaction. The radical polymerization initiator may be charged into the reaction vessel from the beginning, may be dropped into the reaction vessel, or may be combined according to the purpose.

In the polymerization step, a chain transfer agent can be used for adjusting the molecular weight of the copolymer to be obtained. In particular, a chain transfer agent is preferably used when the polymerization reaction is performed at a high concentration where the amount of all monomer components used is 30% by mass or more with respect to 100% by mass of the total amount of raw materials used during polymerization. Examples of chain transfer agents include mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, octyl thioglycolate, octyl 3-mercaptopropionate, 2-mercaptoethanesulfonic acid, etc. These thiol chain transfer agents can be used, and two or more types of chain transfer agents can be used in combination. Furthermore, in order to adjust the molecular weight of the copolymer, it is also effective to use a monomer having high chain mobility such as (meth) allylsulfonic acid (salt) as the other monomer (e).

In addition, in order to obtain a copolymer having a predetermined molecular weight with good reproducibility, it is important to allow the copolymerization reaction to proceed stably. Therefore, when performing solution polymerization, the dissolved oxygen concentration of the solvent used at 25 ° C. Is preferably 5 ppm or less. More preferably, it is 0.01-4 ppm, More preferably, it is 0.01-2 ppm, Most preferably, it is 0.01-1 ppm. In addition, what is necessary is just to make the dissolved oxygen concentration of the type | system | group containing a monomer into the said range when performing nitrogen substitution etc. after adding a monomer to a solvent. The dissolved oxygen concentration of the solvent may be adjusted in a polymerization reaction tank, or a solvent in which the dissolved oxygen amount is adjusted in advance may be used. Examples of the method for driving off oxygen in the solvent include the following methods (1) to (5).

(1) After an inert gas such as nitrogen is pressure-filled in a sealed container containing a solvent, the partial pressure of oxygen in the solvent is lowered by lowering the pressure in the sealed container. You may reduce the pressure in an airtight container under nitrogen stream.
(2) The liquid phase portion is vigorously stirred for a long time while the gas phase portion in the container containing the solvent is replaced with an inert gas such as nitrogen.
(3) An inert gas such as nitrogen is bubbled in the solvent in the container for a long time.
(4) The solvent is once boiled and then cooled in an inert gas atmosphere such as nitrogen.
(5) A static mixer (static mixer) is installed in the middle of the pipe, and an inert gas such as nitrogen is mixed in the pipe for transferring the solvent to the polymerization reaction tank.

In the above polymerization step, when a solvent is used, the polymerization may be performed at a pH of 5 or more. In that case, the copolymerization is not sufficient at the same time as the polymerization rate is lowered. Therefore, the copolymerization reaction is preferably carried out at a pH of less than 5. The pH can be adjusted by, for example, inorganic salts such as monovalent or divalent metal hydroxides and carbonates; alkaline substances such as ammonia; organic amines; inorganic acids such as hydrochloric acid, phosphoric acid, sulfuric acid, acetic acid, para It can carry out using organic acids, such as toluenesulfonic acid.

The polymerization step may further include other steps. The other steps are not particularly limited as long as they are steps performed in a usual copolymer production method.

The copolymer obtained by the polymerization step can be used for various purposes as it is, for example, it can be used as a main component such as a dispersant or a cement admixture. Is preferably adjusted to 5 or more. As described above, the copolymerization reaction is preferably performed at a pH of less than 5, and the pH is preferably adjusted to 5 or more after the copolymerization. The pH can be adjusted using, for example, an alkaline substance such as an inorganic salt such as a monovalent metal or divalent metal hydroxide or carbonate; ammonia; an organic amine; Further, after the reaction is completed, the concentration can be adjusted if necessary. The copolymer may be used in various forms in the form of an aqueous solution, or neutralized with a divalent metal hydroxide such as calcium or magnesium to obtain a polyvalent metal salt, followed by drying. Alternatively, it may be used after being powdered by supporting it on an inorganic powder such as silica-based fine powder and drying it.

The copolymer obtained by the polymerization step may be subjected to a step of isolating individual polymers, if necessary, from the viewpoint of work efficiency, production cost, etc. It can be used for various purposes without isolation.

[Application of copolymer]
The copolymer of the present invention exhibits good performance as a water-insoluble inorganic or organic dispersant. For example, good performance can be exhibited as a dispersant for inorganic pigments such as heavy or light calcium carbonate and clay used for paper coating; a dispersant for water slurry such as cement and coal; In addition, water treatment agents for scale prevention in cooling water systems, boiler water systems, seawater desalination equipment, pulp digesters, and black liquor concentration tanks; scale treatment agents; textile treatments such as dyeing aids and textile antistatic aids Agent; Adhesive; Sealing agent; Flexibility-imparting component for various polymers; Detergent builder and the like. Furthermore, it can be widely applied in the fields of body detergents such as shampoos, rinses, body soaps, fiber processing, building material processing, paints, ceramics and the like. Especially, it is suitable to use for a cement admixture use. In this case, a cement admixture that can remarkably exhibit water-reducing properties, early strength development and fluidity retention at the same time in a well-balanced manner can be provided. It is particularly useful as a cement admixture for concrete secondary products (precast concrete products). Thus, the form in which the copolymer is a copolymer for cement admixture is a preferred form of the present invention, and the dispersant containing the copolymer and the cement containing the copolymer. Admixtures are also included in the present invention.
Hereinafter, a cement admixture will be described as a typical dispersant.

[Cement admixture]
The cement admixture of the present invention essentially contains the above-mentioned copolymer, but may contain two or more kinds of the above-mentioned copolymers, and contains one or more kinds of copolymers different from the above-mentioned copolymers. May be.
The content of the copolymer in the cement admixture (when two or more copolymers are included, the total content thereof) is not particularly limited, but the solid content (that is, the non-volatile content) in the cement admixture is 100. It is preferable that it is 20 to 100 mass% in mass%. More preferably, it is 40 mass% or more, More preferably, it is 50 mass% or more, Most preferably, it is 60 mass% or more.
In the present specification, the “cement admixture” refers to a cement additive added to a cement composition such as cement paste, mortar, and concrete, and may be an agent composed only of the above copolymer. Moreover, it may be an agent containing not only the above copolymer but also other components and additives as required.

The cement admixture preferably further contains polyalkylene glycol in addition to the copolymer. As content of polyalkylene glycol, it is preferable to set it as 1-50 mass% with respect to 100 mass% of said copolymers. By further containing polyalkylene glycol, the workability of the cement composition such as mortar and concrete can be further improved, but if it is less than 1% by mass, the workability improvement effect will not be more sufficient. If it exceeds 50% by mass, dispersibility with respect to cement may not be improved. More preferably, it is 2-50 mass%, More preferably, it is 2-40 mass%, Most preferably, it is 3-30 mass%.

As said polyalkylene glycol, it is suitable that the oxyalkylene group which forms this is comprised from 1 type, or 2 or more types of a C2-C18 oxyalkylene group. More preferably, it is 2-8 as a carbon atom number, More preferably, it is 2-4. In addition, since the polyalkylene glycol is preferably water-soluble, it is preferable that the polyalkylene glycol has at least an oxyethylene group having a high hydrophilicity, ie, an oxyethylene group having 2 carbon atoms. More preferably, oxyethylene groups are 50 mol% or more in 100 mol% of all oxyalkylene groups forming the polyalkylene glycol. More preferably, it is 90 mol% or more, Most preferably, it is 95 mol% or more. In addition, the repeating unit of the oxyalkylene group may be the same or different, and when the oxyalkylene group is in the form of a mixture of two or more, block addition, random addition, alternating Any additional form such as addition may be used.

The terminal group of the polyalkylene glycol is preferably a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or an (alkyl) phenyl group. The number of carbon atoms is preferably 1 to 22, more preferably 1 to 18, still more preferably 1 to 12, and particularly preferably 1 to 4. Especially, it is preferable that a terminal group is a hydrogen atom.
The average molecular weight of the polyalkylene glycol is preferably in the range of 500 to 200,000. More preferably, it is 1000-100,000, More preferably, it is 2000-50,000.

Specific examples of the polyalkylene glycol include polyethylene glycol, polypropylene glycol, polyethylene polypropylene glycol, and polyethylene polybutylene glycol. Among these, since the polyalkylene glycol is preferably water-soluble, polyethylene glycol or polyethylene polypropylene glycol containing an oxyethylene group having high hydrophilicity as an essential component is preferable, and polyethylene glycol is most preferable.

The cement admixture further containing the polyalkylene glycol may be produced, for example, by blending the polyalkylene glycol after the production of the copolymer, and when the copolymer is produced, The monomer component essentially comprising (a), (b) and (c) can be obtained by further carrying out a copolymerization reaction using polyalkylene glycol as a raw material. The monomer (a) and monomer (b) can be obtained by addition reaction of an alkylene oxide to an unsaturated alcohol such as (meth) allyl alcohol or 3-buten-1-ol. In the reaction, if a compound having an active hydrogen such as a saturated aliphatic alcohol (methanol, ethanol, etc.) or water other than the unsaturated alcohol is present in the reaction system, the target monomer (a) and / or In addition to monomer (b), polyalkylene glycol may be produced as a by-product. If the product obtained by the addition reaction is used as it is as a raw material (monomer (a) and / or monomer (b)) without removing this by-produced polyalkylene glycol, the purification process and the like can be simplified. At the same time, a cement admixture further containing the polyalkylene glycol can be easily obtained. Thus, the cement admixture which further contains the said polyalkylene glycol by performing the said copolymerization using the monomer composition which contains polyalkylene glycol as an impurity as said monomer (a) and / or monomer (b). The form to obtain is one of the preferred forms of the present invention.

When a monomer composition containing polyalkylene glycol as an impurity is used as the monomer (a), the content of the polyalkylene glycol is the total amount of the monomer (a) (pure monomer (a)) and polyalkylene glycol. It is preferable that it is 0.5-50 mass% with respect to 100 mass%. When the polyalkylene glycol exceeds 50% by mass, the cement particle dispersion performance of the polyalkylene glycol itself is not sufficient, so that the amount used as a cement admixture increases, which is not preferable. More preferably, it is 1-40 mass%, More preferably, it is 2-30 mass%, Most preferably, it is 3-20 mass%.
Similarly, when a monomer composition containing polyalkylene glycol as an impurity is used as the monomer (b), the content of the polyalkylene glycol is such that the monomer (b) (pure monomer (b)), polyalkylene glycol, It is preferable that it is 0.5-50 mass% with respect to the total amount of 100 mass%. When the polyalkylene glycol exceeds 50% by mass, the cement particle dispersion performance of the polyalkylene glycol itself is not sufficient, so that the amount used as a cement admixture increases, which is not preferable. More preferably, it is 1-40 mass%, More preferably, it is 2-30 mass%, Most preferably, it is 3-20 mass%.
Moreover, when using the monomer composition which contains a polyalkylene glycol as an impurity as both a monomer (a) and a monomer (b), content of this polyalkylene glycol is monomer (a) (pure monomer (a)) and The total amount of the monomer (b) (pure monomer (b)) and the polyalkylene glycol is preferably 100 to 50% by mass. When the polyalkylene glycol exceeds 50% by mass, the cement particle dispersion performance of the polyalkylene glycol itself is not sufficient, so that the amount used as a cement admixture increases, which is not preferable. More preferably, it is 1-40 mass%, More preferably, it is 2-30 mass%, Most preferably, it is 3-20 mass%.

In addition to fluidity (easy to flow when poured), early strength development and fluidity retention, the cement admixture also includes viscosity (workability, for example, It is also possible to improve the ease of kneading of mortar and scoop work in the concrete.

The cement admixture may further contain other commonly used cement dispersants and can be used in combination. Other cement dispersants are not particularly limited. For example, various sulfonic acid dispersants having a sulfonic acid group in the molecule, and various polycarboxylic acid dispersants having a polyoxyalkylene chain and a carboxyl group in the molecule. Etc. Also, for example, water-soluble polymer substances, polymer emulsions, retarders, early strengthening agents / accelerators, mineral oil-based antifoaming agents, fat-based antifoaming agents, fatty acid-based antifoaming agents, fatty acid ester-based antifoaming agents, oxy Alkylene-based antifoaming agent, alcohol-based antifoaming agent, amide-based antifoaming agent, phosphate ester-based antifoaming agent, metal soap-based antifoaming agent, silicone-based antifoaming agent, AE agent, surfactant, waterproofing agent, anti-foaming agent Rust agent, crack reducing agent, expansion agent, cement wetting agent, thickening agent, separation reducing agent, flocculant, drying shrinkage reducing agent, strength enhancer, self-leveling agent, rust inhibitor, coloring agent, antifungal agent, blast furnace One or more cement additives (materials) such as slag, fly ash, cinder ash, clinker ash, husk ash, silica fume, silica powder, and gypsum may be included.
The blending ratio of these cement dispersant and cement additive (material) is preferably set so that the total amount is 10% by mass or less with respect to 100% by mass of the solid content of the copolymer.

The cement admixture can be used for various hydraulic materials, that is, cement compositions such as cement and gypsum, and other hydraulic materials. As a specific example of a hydraulic composition containing such a hydraulic material, water and the above cement admixture, and further containing fine aggregate (sand, etc.) and coarse aggregate (crushed stone, etc.) as necessary, Cement paste, mortar, concrete, plaster, etc. are mentioned. Among these hydraulic compositions, a cement composition using cement as the hydraulic material is most preferable, and a cement composition containing the cement admixture, cement, and water as essential components is also one aspect of the present invention. .

[Cement composition]
In the cement composition of the present invention, as the cement, Portland cement (ordinary, early strength, ultra-early strength, moderate heat, sulfate resistance and low alkali type thereof); various mixed cements (blast furnace cement, silica cement, fly ash) Cement); white Portland cement; alumina cement; super fast cement (1 clinker fast cement, 2 clinker fast cement, magnesium phosphate cement); grout cement; oil well cement; low heat cement (low heat blast furnace cement, fly Ash mixed low heat generation type blast furnace cement, cement with high belite content); ultra high strength cement; cement-based solidified material; eco-cement (cement produced from one or more of municipal waste incineration ash and sewage sludge incineration ash), etc. Besides these, blast furnace slag, fly ash, shi Dar ash, clinker ash, husk ash, silica fume, silica powder, and a film obtained by adding a fine powder and gypsum limestone powder.
As the above aggregate, in addition to gravel, crushed stone, granulated slag, recycled aggregate, etc., siliceous, clay, zircon, high alumina, silicon carbide, graphite, chrome, chromic, magnesia, etc. Refractory aggregate and the like.

In the cement composition, the unit water amount per 1 m ³ , the cement use amount, and the water / cement ratio are not particularly limited. For example, the unit water amount is 100 to 185 kg / m ³ , the cement amount used is 250 to 800 kg / m ³ , It is preferable that water / cement ratio (weight ratio) = 0.12 to 0.74. More preferably, the unit water amount is 120 to 175 kg / m ³ , the amount of cement used is 270 to 800 kg / m ³ , and the water / cement ratio (weight ratio) = 0.15 to 0.65. As described above, the cement composition of the present invention can be used widely from poor blending to rich blending, and is effective for both high-strength concrete having a large unit cement amount and poor blending concrete having a unit cement amount of 300 kg / m ³ or less. It is. In addition, the cement composition of the present invention has a relatively high water reduction rate, that is, water / cement ratio (weight ratio) = 0.15 to 0.5 (preferably 0.15 to 0.4). Even in a low cement ratio region, it can be used satisfactorily.

Further, the cement admixture of the present invention can exhibit various performances with high performance even in a high water reduction rate region and has excellent workability. For example, ready mixed concrete, concrete for concrete secondary products (precast Concrete), concrete for centrifugal molding, concrete for vibration compaction, steam-cured concrete, shotcrete, etc. Also, medium-fluidity concrete (concrete with a slump value of 22-25 cm), high-fluidity concrete (concrete with a slump value of 25 cm or more and a slump flow value of 50-70 cm), self-filling concrete, self-leveling material It is also effective for mortar and concrete that require high fluidity.

In the above cement composition, the blending ratio of the cement admixture of the present invention is, for example, the copolymer (the total amount when there are a plurality of components) as an essential component of the present invention, the total amount of cement mass in terms of solid content. It is preferable to set so that it may be 0.01-10 mass% with respect to 100 mass%. If it is less than 0.01% by mass, the performance may not be sufficient. On the other hand, if it exceeds 10% by mass, the effect will substantially reach its peak, which may be disadvantageous in terms of economy. More preferably, it is 0.02-5 mass%, More preferably, it is 0.05-3 mass%. In the present specification, the solid content can be measured as follows.
(Solid content measurement method)
1. Weigh the aluminum dish.
The solid content to be measured is precisely weighed on the aluminum dish precisely weighed in 2.1.
3. A solid content measurement product precisely weighed in 2 is placed in a dryer adjusted to 130 ° C. in a nitrogen atmosphere for 1 hour.
4. After 1 hour, remove from the dryer and allow to cool in a desiccator at room temperature for 15 minutes.
5. After 15 minutes, remove from the desiccator and precisely weigh the aluminum dish and the measurement object.
The solid content is measured by subtracting the mass of the aluminum pan obtained in 1 from the mass obtained in 6.5 and dividing by the mass of the solid content measurement product obtained in 2.

Since the cement admixture of the present invention is configured as described above, it has high water reduction (dispersibility) and can achieve both early strength development performance and fluidity retention performance in the field of handling it. Productivity and workability can be further improved. Therefore, the cement composition containing this is suitably used in the civil engineering / architectural field.

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. Unless otherwise specified, “%” means “% by mass”.
In the following production examples, the measurement conditions of the weight average molecular weight (GPC measurement method) were as follows.

<GPC measurement conditions>
The GPC measurement conditions are as follows.
Column used: TSK guard column SWXL manufactured by Tosohichi Corporation
TSKgel G4000SWXL
TSKgel G3000SWXL
TSKgel G2000SWXL connected in this order.
Eluent: A solution prepared by dissolving 115.6 g of sodium acetate trihydrate in a solution of 6001 g of acetonitrile and 10999 g of water and further adjusting the pH to 6.0 with acetic acid was used.
Sample: A polymer aqueous solution dissolved in the eluent so that the polymer concentration is 0.5% by mass.
Sample injection amount: 100 μL
Flow rate: 1.0 mL / min Column temperature: 40 ° C
Detector: Empower Software manufactured by Japan Waters
Standard material for preparing a calibration curve: polyethylene glycol [peak top molecular weight (Mp) 272500, 219300, 107000, 50000, 24000, 11840, 6450, 4250, 1470]
Calibration curve: Prepared by a cubic equation based on the Mp value and elution time of the polyethylene glycol.

[Production Example 1] Polymer 1
In a glass reactor equipped with a thermometer, a stirrer, a dropping device, a nitrogen introduction tube and a reflux cooling device, 105.4 g of ion-exchanged water, unsaturated polyalkylene glycol ether in which an average of 120 moles of ethylene oxide is added to methallyl alcohol 105.5 g, 10.1 g of unsaturated polyalkylene glycol ether in which 10 mol of ethylene oxide was added to methallyl alcohol on average, and 0.209 g of acrylic acid were charged, and the reactor was purged with nitrogen under stirring. Heated to ° C. While maintaining the inside of the reaction vessel at 58 ° C., 20.8 g of a 2% hydrogen peroxide aqueous solution was added. While maintaining the inside of the reaction vessel at 58 ° C., an aqueous solution in which 7.15 g of acrylic acid and 12 g of 2-hydroxyethyl acrylate were dissolved in 17.8 g of ion-exchanged water was dropped over 3 hours, and at the same time, ion-exchanged water was used. An aqueous solution in which 1.08 g of L-ascorbic acid and 0.78 g of 3-mercaptopropionic acid were dissolved in 19.1 g was dropped over 3.5 hours. Then, after maintaining the temperature at 58 ° C. for 1 hour, the polymerization reaction was terminated. Thereafter, the acidic reaction solution was neutralized to pH 6 using an aqueous sodium hydroxide solution at a temperature not higher than the reaction temperature to obtain a polymer aqueous solution (polymer 1) having a weight average molecular weight of 37,000.

[Production Example 2] Polymer 2
In Table 1, instead of the unsaturated polyalkylene glycol ether in which an average of 10 mol of ethylene oxide was added to methallyl alcohol in Production Example 1, an unsaturated polyalkylene glycol ether in which an average of 50 mol of ethylene oxide was added to methallyl alcohol was used. Polymerization and neutralization were carried out in accordance with Production Example 1 except that the monomer composition described was prepared, to obtain a polymer aqueous solution (polymer 2) having a weight average molecular weight of 40,000.

[Production Example 3] Polymer 3
In Table 1, instead of the unsaturated polyalkylene glycol ether in which an average of 120 moles of ethylene oxide was added to methallyl alcohol in Production Example 1, an unsaturated polyalkylene glycol ether in which an average of 150 moles of ethylene oxide was added to methallyl alcohol was used. Polymerization and neutralization reaction were carried out according to Production Example 1 except that the monomer composition described was prepared, to obtain a polymer aqueous solution (polymer 3) having a weight average molecular weight of 45,000.

[Production Example 4] Polymer 4
In place of the unsaturated polyalkylene glycol ether in which an average of 120 mol of ethylene oxide was added to methallyl alcohol in Production Example 1, an unsaturated polyalkylene glycol ether in which an average of 150 mol of ethylene oxide was added to methallyl alcohol was used and produced In Table 1, an unsaturated polyalkylene glycol ether in which an average of 50 mol of ethylene oxide was added to methallyl alcohol was used instead of the unsaturated polyalkylene glycol ether in which an average of 10 mol of ethylene oxide was added to methallyl alcohol. Except that the monomer composition was prepared, polymerization and neutralization reaction were performed according to Production Example 1 to obtain a polymer aqueous solution (polymer 4) having a weight average molecular weight of 48,000.

[Production Example 5] Polymer 5
In place of the unsaturated polyalkylene glycol ether in which an average of 120 mol of ethylene oxide was added to methallyl alcohol in Production Example 1, an unsaturated polyalkylene glycol ether in which an average of 150 mol of ethylene oxide was added to methallyl alcohol was used and produced In Table 1, an unsaturated polyalkylene glycol ether in which an average of 100 mol of ethylene oxide was added to methallyl alcohol was used instead of the unsaturated polyalkylene glycol ether in which an average of 10 mol of ethylene oxide was added to methallyl alcohol. Except that the monomer composition was prepared, polymerization and neutralization reaction were performed according to Production Example 1 to obtain a polymer aqueous solution (polymer 5) having a weight average molecular weight of 50000.

[Production Example 6] Polymer 6
In place of the unsaturated polyalkylene glycol ether in which an average of 120 mol of ethylene oxide was added to methallyl alcohol in Production Example 1, an unsaturated polyalkylene glycol ether in which an average of 200 mol of ethylene oxide was added to methallyl alcohol was used and produced In Table 1, an unsaturated polyalkylene glycol ether in which an average of 50 mol of ethylene oxide was added to methallyl alcohol was used instead of the unsaturated polyalkylene glycol ether in which an average of 10 mol of ethylene oxide was added to methallyl alcohol. Except that the monomer composition was prepared, polymerization and neutralization reaction were performed according to Production Example 1 to obtain a polymer aqueous solution (polymer 6) having a weight average molecular weight of 56000.

[Production Example 7] Polymer 7
In place of the unsaturated polyalkylene glycol ether in which an average of 120 mol of ethylene oxide was added to methallyl alcohol in Production Example 1, an unsaturated polyalkylene glycol ether in which an average of 200 mol of ethylene oxide was added to methallyl alcohol was used and produced In Table 1, an unsaturated polyalkylene glycol ether in which an average of 100 mol of ethylene oxide was added to methallyl alcohol was used instead of the unsaturated polyalkylene glycol ether in which an average of 10 mol of ethylene oxide was added to methallyl alcohol. Except that the monomer composition was prepared, polymerization and neutralization reaction were carried out according to Production Example 1 to obtain a polymer aqueous solution (polymer 7) having a weight average molecular weight of 57,000.

[Production Example 8] Polymer 8
In place of the unsaturated polyalkylene glycol ether in which an average of 120 mol of ethylene oxide was added to methallyl alcohol in Production Example 1, an unsaturated polyalkylene glycol ether in which an average of 150 mol of ethylene oxide was added to methallyl alcohol was used and produced Instead of the unsaturated polyalkylene glycol ether obtained by adding an average of 10 moles of ethylene oxide to methallyl alcohol in Example 1, an unsaturated polyalkylene glycol ether obtained by adding an average of 10 moles of ethylene oxide to isoprenol was used. Except for the preparation of the polymer composition, polymerization and neutralization were performed according to Production Example 1 to obtain a polymer aqueous solution (polymer 8) having a weight average molecular weight of 44,000.

[Production Example 9] Polymer 9
In place of the unsaturated polyalkylene glycol ether in which an average of 120 mol of ethylene oxide was added to methallyl alcohol in Production Example 1, an unsaturated polyalkylene glycol ether in which an average of 150 mol of ethylene oxide was added to methallyl alcohol was used and produced In place of the unsaturated polyalkylene glycol ether obtained by adding an average of 10 mol of ethylene oxide to methallyl alcohol in Example 1, an unsaturated polyalkylene glycol ether obtained by adding an average of 50 mol of ethylene oxide to isoprenol was used. Except for the preparation of the polymer composition, polymerization and neutralization were performed according to Production Example 1 to obtain a polymer aqueous solution (polymer 9) having a weight average molecular weight of 48,000.

[Production Example 10] Polymer 10
In a glass reactor equipped with a thermometer, a stirrer, a dripping device, a nitrogen introduction tube and a reflux cooling device, an unsaturated polyalkylene glycol ether obtained by adding 110 g of ion-exchanged water and an average of 150 moles of ethylene oxide to methallyl alcohol. 4 g, 8.8 g of an unsaturated polyalkylene glycol ether obtained by adding 10 moles of ethylene oxide on average to methallyl alcohol, and 2.464 g of a 15% aqueous solution of paratoluenesulfonic acid were substituted with nitrogen in the reactor under stirring. Heated to 58 ° C. under atmosphere. While maintaining the inside of the reaction vessel at 58 ° C., 11.6 g of a 2% aqueous hydrogen peroxide solution was added. While maintaining the inside of the reaction vessel at 58 ° C., an aqueous solution in which 11.8 g of 2-hydroxyethyl acrylate was dissolved in 20 g of ion-exchanged water was dropped over 3 hours, and at the same time, L-ascorbic acid was added to 20 g of ion-exchanged water. An aqueous solution in which 0.6 g and 3-mercaptopropionic acid 0.43 g were dissolved was dropped over 3.5 hours. Then, after maintaining the temperature at 58 ° C. for 1 hour, the polymerization reaction was terminated. Thereafter, the acidic reaction solution was neutralized to pH 6 using an aqueous sodium hydroxide solution at a temperature not higher than the reaction temperature to obtain a polymer aqueous solution (polymer 10) having a weight average molecular weight of 45,000.

[Production Example 11] Polymer 11
Instead of the unsaturated polyalkylene glycol ether in which an average of 10 mol of ethylene oxide was added to methallyl alcohol in Production Example 10, an unsaturated polyalkylene glycol ether in which an average of 50 mol of ethylene oxide was added to methallyl alcohol was used. Polymerization and neutralization were carried out according to Production Example 10 except that the monomer composition described was prepared, to obtain a polymer aqueous solution (polymer 11) having a weight average molecular weight of 48,000.

[Production Example 12] Polymer 12
In Table 1, instead of the unsaturated polyalkylene glycol ether having an average of 10 moles of ethylene oxide added to methallyl alcohol in Production Example 10, an unsaturated polyalkylene glycol ether having an average of 100 moles of ethylene oxide added to methallyl alcohol was used. Polymerization and neutralization reaction were carried out according to Production Example 10 except that the monomer composition described was prepared, to obtain a polymer aqueous solution (polymer 12) having a weight average molecular weight of 51,000.

[Production Example 13] Polymer 13
Instead of the unsaturated polyalkylene glycol ether in which an average of 10 moles of ethylene oxide was added to methallyl alcohol in Production Example 10, an unsaturated polyalkylene glycol ether in which an average of 50 moles of ethylene oxide was added to isoprenol was used. Except for preparing the monomer composition, polymerization and neutralization reaction were performed according to Production Example 10 to obtain a polymer aqueous solution (polymer 13) having a weight average molecular weight of 48,000.

[Comparative Production Example 1] Comparative polymer 1
In a glass reactor equipped with a thermometer, a stirrer, a dropping device, a nitrogen inlet tube and a reflux cooling device, 116.3 g of ion-exchanged water, unsaturated polyalkylene glycol ether in which 150 mol of ethylene oxide is added to methallyl alcohol on average 118.5 g, 9.1 g of an unsaturated polyalkylene glycol ether obtained by adding 10 moles of ethylene oxide to methallyl alcohol on average, and 0.231 g of acrylic acid were charged, and the reactor was purged with nitrogen under stirring. Heated to ° C. While maintaining the inside of the reaction vessel at 58 ° C., 11.7 g of a 2% aqueous hydrogen peroxide solution was added. While maintaining the inside of the reaction vessel at 58 ° C., an aqueous solution in which 7.13 g of acrylic acid was dissolved in 16 g of ion exchange water was dropped over 3 hours, and at the same time, 0.61 g of L-ascorbic acid was added to 20 g of ion exchange water. And an aqueous solution in which 0.44 g of 3-mercaptopropionic acid was dissolved was dropped over 3.5 hours. Then, after maintaining the temperature at 58 ° C. for 1 hour, the polymerization reaction was terminated. Thereafter, the acidic reaction solution was neutralized to pH 6 using an aqueous sodium hydroxide solution at a temperature equal to or lower than the reaction temperature to obtain a polymer aqueous solution (Comparative Polymer 1) having a weight average molecular weight of 44,000.

[Comparative Production Example 2] Comparative polymer 2
It replaces with the unsaturated polyalkylene glycol ether which added the average 10 mol ethylene oxide to the methallyl alcohol in the comparative manufacture example 1, and uses the unsaturated polyalkylene glycol ether which added the average 10 mol ethylene oxide to the isoprenol, and is described in Table 1 A polymer aqueous solution (comparative polymer 2) having a weight average molecular weight of 45,000 was obtained by performing polymerization and neutralization reaction according to Comparative Production Example 1 except that the monomer composition was prepared.

[Comparative Production Example 3] Comparative Polymer 3
In a glass reactor equipped with a thermometer, a stirrer, a dropping device, a nitrogen introducing tube and a reflux cooling device, 105.4 g of ion-exchanged water, unsaturated polyalkylene glycol ether in which an average of 150 moles of ethylene oxide is added to methallyl alcohol 115.6 g and acrylic acid 0.209 g were charged, the inside of the reaction apparatus was purged with nitrogen under stirring, and heated to 58 ° C. in a nitrogen atmosphere. While maintaining the inside of the reaction vessel at 58 ° C., 19 g of a 2% aqueous hydrogen peroxide solution was added. While maintaining the inside of the reaction vessel at 58 ° C., an aqueous solution in which 7.15 g of acrylic acid and 12 g of 2-hydroxyethyl acrylate were dissolved in 19.7 g of ion-exchanged water was dropped over 3 hours, and at the same time, ion-exchanged water was used. An aqueous solution in which 0.98 g of L-ascorbic acid and 0.71 g of 3-mercaptopropionic acid were dissolved in 19.3 g was added dropwise over 3.5 hours. Then, after maintaining the temperature at 58 ° C. for 1 hour, the polymerization reaction was terminated. Thereafter, the acidic reaction solution was neutralized to pH 6 using an aqueous sodium hydroxide solution at a temperature lower than the reaction temperature to obtain a polymer aqueous solution (comparative polymer 3) having a weight average molecular weight of 51,000.

[Comparative Production Example 4] Comparative polymer 4
In a glass reactor equipped with a thermometer, a stirrer, a dropping device, a nitrogen introduction tube and a reflux cooling device, 110 g of ion-exchanged water, unsaturated polyalkylene glycol ether 123 having an average of 150 moles of ethylene oxide added to methallyl alcohol. 2 g and 2.46 g of a 15% aqueous solution of paratoluenesulfonic acid were charged, the inside of the reactor was purged with nitrogen under stirring, and the mixture was heated to 58 ° C. in a nitrogen atmosphere. While maintaining the inside of the reaction vessel at 58 ° C., 10.2 g of 2% aqueous hydrogen peroxide solution was added. While maintaining the inside of the reaction vessel at 58 ° C., an aqueous solution in which 11.8 g of 2-hydroxyethyl acrylate was dissolved in 21.3 g of ion-exchanged water was dropped over 3 hours, and at the same time, 20.1 g of ion-exchanged water was added. An aqueous solution in which 0.53 g of L-ascorbic acid and 0.38 g of 3-mercaptopropionic acid were dissolved was dropped over 3.5 hours. Then, after maintaining the temperature at 58 ° C. for 1 hour, the polymerization reaction was terminated. Thereafter, the acidic reaction solution was neutralized to pH 6 using an aqueous sodium hydroxide solution at a temperature lower than the reaction temperature to obtain a polymer aqueous solution (comparative polymer 4) having a weight average molecular weight of 53,000.

Table 1 shows the types and composition ratios of the raw material monomers of the polymers obtained in each Production Example and Comparative Production Example.

Each abbreviation in Table 1 is as follows.
MAL10: Unsaturated polyalkylene glycol ether in which an average of 10 mol of ethylene oxide is added to methallyl alcohol MAL50: Unsaturated polyalkylene glycol ether in which an average of 50 mol of ethylene oxide is added to methallyl alcohol MAL100: An average of 100 mol of methallyl alcohol Unsaturated polyalkylene glycol ether MAL120 with ethylene oxide added: Unsaturated polyalkylene glycol ether MAL150 with an average of 120 moles of ethylene oxide added to methallyl alcohol MAL150: Unsaturated polyalkylene glycol ether with an average of 150 moles of ethylene oxide added to methallyl alcohol MAL200: Unsaturated polyalkylene glycol having an average of 200 moles of ethylene oxide added to methallyl alcohol Ether IPN10: isoprenol an average 10 moles of unsaturated polyalkylene glycol ether obtained by adding ethylene oxide IPN50: isoprenol unsaturated polyalkylene glycol ether obtained by adding average 50 moles of ethylene oxide HEA: 2-hydroxyethyl acrylate AA: acrylic acid

[Mortar test]
The mortar was adjusted using the polymers obtained in Production Examples 1 to 13 and the comparative polymers obtained in Comparative Production Examples 1 to 4, and the slump flow value, the change in the slump flow value with time, the amount of air, and the compression were as follows. The strength was measured. In addition, the materials used in the test, the forced kneading mixer, and the measuring instruments are conditioned in this test temperature atmosphere so that the temperature of the mortar is 20 ° C. The kneading and each measurement are also performed in this test temperature atmosphere. I went there. The results are shown in Tables 2 and 3.
In addition, the result shown in Table 3 is the comparative polymer 1 which is a well-known polymer, any of the polymers 10-13 obtained in Production Examples 10-13, or the comparative polymer obtained in Comparative Production Example 4. It is a result at the time of using 4 together.
In Tables 2 and 3, “polymer use amount (% / cement)” means the ratio (mass%) of the weight of the copolymer in terms of solid content to 100 mass% of the total cement mass.

(Adjustment of cement admixture aqueous solution)
A predetermined amount of the polymer aqueous solution is weighed, and 10% by mass of the antifoaming agent MA404 (manufactured by Pozzolith Products Co., Ltd.) is added to the polymer, and ion-exchanged water is further added to make 210 g, which is sufficiently homogeneously dissolved. It was.
(Contains mortar)
The mortar formulation was C / S / W / = 600/1350/210 (g). However,
C: Ordinary Portland cement (manufactured by Taiheiyo Cement)
S: ISO standard sand (made by Cement Association)
W: Cement admixture aqueous solution.
(Mortar test environment)
The test environment was a temperature of 20 ° C. ± 1 ° C. and a relative humidity of 60% ± 10%.

(Measurement of flow value (15 stroke flow value))
After 600 g of the cement and 210 g of the cement admixture aqueous solution were kneaded at a low speed for 30 seconds with a Hobart type mortar mixer (model No. N-50, manufactured by Hobart), 1350 g of the ISO standard sand was charged over 30 seconds. Next, after kneading at high speed for 30 seconds, the kneading was stopped and the mortar on the wall of the kettle was scraped off over 15 seconds. The mixture was further left for 75 seconds and then kneaded at high speed for 60 seconds to adjust the mortar.
Half of the adjusted mortar is packed into a hollow cone-shaped flow cone (JIS R5201; 1997) having an upper base inner diameter of 70 mm, a lower base inner diameter of 100 mm, and a height of 60 mm placed on a horizontal flow table (JIS R5201; 1997). I struck 15 times with a stick. Further, the mortar was filled to the full extent of the flow cone, and poke 15 times with a stab. The flow cone filled with mortar was then gently lifted vertically. Thereafter, the handle is rotated 15 times at a rate of once per second to give an up-and-down motion, the major axis (mm) and minor axis (mm) of the mortar spread on the table are measured, and the average value is obtained as the flow value (15 Stroke flow value).
The time when this measurement was performed was set to 0 minute, and after that, the entire amount of the mortar was allowed to stand in a sealed container for a predetermined time, and then the same operation as above was repeated to measure a change in flow value with time.
In Tables 2 and 3, the change over time in the flow value after 30 minutes, 65 minutes, and 100 minutes of standing was shown as “flow retention”.

(Measurement of mortar air volume)
About 200 mL of mortar was packed in a 500 mL glass graduated cylinder, struck with a round bar having a diameter of 8 mm, and the container was vibrated to remove coarse bubbles. Furthermore, after adding about 200 mL of mortar and extracting air bubbles similarly, the volume and the mass were measured, and the amount of air was calculated from the mass and the density of each material.

(Measurement of compressive strength)
The mortar adjusted by the above method is packed into a cylindrical formwork (diameter 5cm, height 10cm) placed on a horizontal table to one third of the formwork capacity, and struck 20 times with a stick, then the mold The frame container was vibrated to remove coarse bubbles. Further, the mortar was filled to the full extent of the formwork, struck 20 times with a stick, and then the formwork container was vibrated. In order to prevent drying, the specimen was covered with a PET film and cured for 12 hours and 24 hours in an environment at room temperature of 20 ° C.
Using the specimen prepared by the above method, the compressive strength was measured according to the compressive strength measuring method of the concrete test (JIS A1108; 2006).

Table 2 shows that the smaller the amount of polymer used, the higher the water reduction performance, and the higher the compressive strength, the better the early strength development. In addition, the larger the flow retention rate, the better the fluid retention property. However, when the flow retention rate after 30 minutes and 65 minutes exceeds 130%, aggregate separation tends to occur, which is actually harmful. From the above viewpoint, each measured value was evaluated based on the following criteria. The results are shown in Table 4.

(Evaluation criteria)
The amount of the polymer used was O for less than 0.14, Δ for 0.14 or more and less than 0.15, and x for 0.15 or more.
The flow retention after 30 minutes is less than 80% x, 80% or more and less than 90% Δ, 90% or more and less than 100% ○, 100% or more and less than 120% ◎, 120% or more and 130 Less than% was marked with ○, and 130% or more was marked with ×.
After 65 minutes, the flow retention rate is less than 80% x, 80% or more and less than 90% Δ, 90% or more and less than 100% ○, 100% or more and less than 120% ◎, 120% or more and 130 Less than% was marked with ○, and 130% or more was marked with ×.
The compressive strength after 12 hours was evaluated as x for less than 13, ◯ for 13 or more and less than 14, and ◎ for 14 or more.
The compressive strength after 24 hours was evaluated as x for less than 25, ◯ for 25 or more and less than 26, and ◎ for 26 or more.

As shown in Table 4, the polymers 1 to 9 obtained in Production Examples 1 to 9 are less water-reducible, early strength development, compared to Comparative Polymers 1 to 3 obtained in Comparative Production Examples 1 to 3. All of fluid retention is expressed in a well-balanced manner.

In Table 3, it shows that it is excellent in early stage strength expressivity, so that compressive strength is large. In addition, the larger the flow retention rate, the better the fluid retention property. However, when the flow retention rate after 30 minutes, 65 minutes, and 100 minutes exceeds 130%, aggregate separation is likely to occur, which has a practically harmful effect. is there. From the above viewpoint, each measured value was evaluated based on the following criteria. The results are shown in Table 5.

(Evaluation criteria)
The flow retention after 30 minutes is less than 80% x, 80% or more and less than 90% Δ, 90% or more and less than 100% ○, 100% or more and less than 120% ◎, 120% or more and 130 Less than% was marked with ○, and 130% or more was marked with ×.
After 65 minutes, the flow retention rate is less than 80% x, 80% or more and less than 90% Δ, 90% or more and less than 100% ○, 100% or more and less than 120% ◎, 120% or more and 130 Less than% was marked with ○, and 130% or more was marked with ×.
The flow retention after 100 minutes is x for less than 70%, Δ for 70% or more and less than 80%, ○ for 80% or more and less than 90%, ◎ for 90% or more and less than 120%, for 120% or more and 130 Less than% was marked with ○, and 130% or more was marked with ×.
The compressive strength after 12 hours was evaluated as x for less than 13, ◯ for 13 or more and less than 14, and ◎ for 14 or more.
The compressive strength after 24 hours was evaluated as x for less than 25, ◯ for 25 or more and less than 26, and ◎ for 26 or more.

As shown in Table 5, the polymers 10 to 13 obtained in Production Examples 10 to 13 are used in combination with a known polymer (Comparative Polymer 1) to exhibit long-term fluidity retention. Comparative Production Example 4 Compared with the comparative polymer 4 obtained in (1), all of water reduction, early strength development and fluidity retention are expressed in a balanced manner.

Claims (6)

Structural unit (A) derived from unsaturated polyalkylene glycol ether monomer (a), structural unit (B) derived from unsaturated (poly) alkylene glycol ether monomer (b), and hydrolyzable monomer (c) A structural unit (C) and a structural unit (D) derived from an unsaturated carboxylic acid monomer (d) ,
The unsaturated polyalkylene glycol ether monomer (a) has the following general formula (i):
Y ¹ O (R ¹ O) _n R ² (i)
(In the formula, Y ¹ represents an alkenyl group having 3 to 8 carbon atoms. R ¹ O is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. N represents R ¹ O. The average addition mole number of the oxyalkylene group represented is a number from 111 to 300. R ² represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms.
The unsaturated (poly) alkylene glycol ether monomer (b) has the following general formula (ii):
Y ² O (R ³ O) _m R ⁴ (ii)
(In the formula, Y ² represents an alkenyl group having 3 to 8 carbon atoms. R ³ O is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. M represents R ³ O. The average added mole number of the oxyalkylene group represented is a number of 1 to 280 and satisfies nm ≧ 20, and R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. )
The hydrolyzable monomer (c) has the following general formula (iii):

(Wherein R ⁵ , R ⁶ and R ⁷ represent a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms. R ⁸ O may be the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. L represents the average added mole number of the oxyalkylene group represented by R ⁸ O, and is a number from 0 to 300. R ⁹ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. represented. However, for l = 0, ^{R 9} is represented by represents.) a hydrocarbon group having 1 to 30 carbon atoms,
The unsaturated carboxylic acid monomer (d) is (meth) acrylic acid or a salt thereof,
The copolymer, the structural unit (A), (B) and wherein the content is a 8.7 to 27% by mass Rukoto structural units in the total amount of 100 wt% of (C) (C) A copolymer. The copolymer according to claim 1 , wherein n is a number from 141 to 300. N is a number from 141 to 300;
2. The copolymer according to claim 1 , wherein m is a number from 1 to 200 and satisfies nm ≧ 100. The dispersing agent characterized by including the copolymer in any one of Claims 1-3 . A cement admixture comprising the copolymer according to any one of claims 1 to 3 . A cement composition comprising the cement admixture according to claim 5 , cement and water.