JPS60104108A - Production of polymer - Google Patents

Abstract

PURPOSE:To obtain a decolored polymer having excellent dispersibility in cement, by polymerizing sulfonated product of dicyclopentadiene in the presence of an acidic compound catalyst, and contacting the obtained polymer with hydrogen peroxide. CONSTITUTION:For example, an aqueous solution of a polymer (having a weight- average molecular weight of preferably 3,500-50,000) obtained by the polymerization of sulfonated dicyclopentadiene in the presence of an acidic compound catalyst (e.g. sulfuric acid) is added with preferably 0.01-10pts.wt., based on 100pts.wt. of the polymer, of hydrogen peroxide, and the mixture is stirred and made to react preferably at 7-1pH and 0-60 deg.C for 30min to effect the decoloring of the polymer. The polymer may be a copolymer containing preferably >=90% sulfonated dicyclopentadiene and obtained by the copolymerization of the sulfonated dicyclopentadiene with a monomer copolymerizable with the sulfonated dicyclopentadiene. USE:Concrete or mortar having light color can be produced by using the above polymer as a dispersant in the kneading of cement.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an IM process for making certain polymers, and more particularly, involves contacting a polymer of a sulfonate of dicyclopentadiene with hydrogen peroxide (to form an improved polymer). Relating to a method of manufacturing.

The present inventors polymerized a sulfonated product of dicyclobenzene and L in the presence of an acidic catalyst and discovered that the resulting polymer had extremely excellent cement I dispersion performance, and would like to apply for a patent. (Gan Sho 57-175666). However, since this IR polymer is produced by heating in the presence of an acidic compound catalyst, it is colored black to brown, and when used as a cement dispersant, it has the disadvantage that concrete and mortar are colored black to brown. It had

It is an object of the present invention to provide a method for producing decolorized sulfonated dicyclopentadiene polymers.

In order to achieve the objective, the present inventors conducted careful tests d and j, and found that when a polymer of sulfonated dicyclopencdiene was brought into contact with a trace amount of hydrogen peroxide, the color ranged from black to brown to pale yellow. It was also confirmed that by using this bleached dispersant, concrete was hardly colored, and the present invention was achieved by using this bleached dispersant.

That is, the present invention is characterized in that a polymer obtained by polymerizing a sulfonated product of dicyclopentadiene in the presence of an acidic compound catalyst is brought into contact with hydrogen peroxide.

The polymer of sulfonated dicyclopentadiene used in the present invention is a polymer obtained by polymerizing at least 1:1 sulfonated dicyclopentadiene, and therefore also includes copolymers copolymerized with the sulfonated product. It will be done. (
Hereinafter, the polymer and copolymer will be collectively referred to as a (co)polymer. ) The (co)polymer of sulfonated dicyclopentadiene, which is the object of the present invention, is produced as follows.

Incidentally, the sulfonated product of dicyclor:I pentadiene used in the present invention is mainly represented by general formula (1).

(In the formula, M represents a hydrogen atom, an alkali metal atom, an alkaline earth metal atom, ammonium or an amine, n is an integer of 1 or 2, and when M is an alkaline earth metal atom, n is 2. ) The starting material, dicyclopentadiene, may contain impurities such as other hydrocarbons and water, as long as they do not interfere with the reaction. Further, there is no particular problem even if alkyl-substituted dicyclopentadiene such as methyldicyclopentadiene is mixed.

In the sulfonated product of dicyclopentadiene used in the present invention, a method for sulfonating dicyclopentadiene is Gilper 1-(E,E).

G11bert) [Sulfonation and Related Reactions J
(”5ulfonation and Re1ate
d Reaction”) InterScience
Publishers Inc.

(1965). Also, Charles G.A.

The Journal of Organic Chemistry (J. Norton) et al.
of Or-ganic Chenistry) 415
Sulfonated products can also be obtained by the addition reaction of sulfites to unsaturated bonds, as shown in the work on page 8 (1968). As the sulfonating agent in this case, usually an acidic sulfite, metasulfite, or sulfite of an alkali metal can be used alone or in a mixture. The amount of these sulfonating agents varies depending on the degree of sulfonation required, but is usually used at a ratio of 0.1 to 10 molecules per molecule of dicyclopentadiene.

In this sulfonation reaction, +'14! Although the use of a medium is not required, the reaction time can usually be reduced by using a catalyst, such as a non-oxidizing agent. Examples of the inorganic oxidizing agent include nitrates, nitrites, chlorates, etc. Among these, nitrates are particularly preferred.

Furthermore, an appropriate solvent can be used to allow the reaction to proceed uniformly and smoothly. Examples of solvents that can be advantageously used include water, lower alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, and tertiary butyl alcohol, lower glycols, ketones, ethers, and esters. can be mentioned. These solvents can be used as appropriate.
Can be used in combination of more than one species. Among these, mixed solvents of lower alcohols and water, especially mixed solvents of propyl alcohol and water, are recommended as excellent solvents.

The reaction temperature in the sulfonation reaction is usually 50 to 200°C.
, preferably 70-150°C, more preferably 90-1
The temperature is 20°C, and it can be carried out either under normal pressure or under increased pressure. In addition, in order to suppress the progress of side reactions and reduce the formation of unnecessary inorganic salts, the pH of the reaction system is usually 2 to 2.
It is desirable to keep it at 9, preferably between 5 and 7.

The sulfonated product thus obtained can be separated from unreacted organic compounds, for example, by extraction with water. Furthermore, by removing unreacted inorganic salts present in the aqueous phase by a method such as crystallization, the water of the sulfonate can be removed. 6? & can be obtained. This aqueous solution is evaporated to dryness, for example, to obtain the desired sulfonated product as a solid.

The sulfonated product thus obtained has 1 mol per molecule.
It is a mixture of those with a sulfonic acid group of 1 and 21, and the ratio of these depends on the type and amount of the sulfonating agent, the ratio of the sulfonating agent to dicyclopentadiene, and the inorganic It can be changed as appropriate depending on the type and amount of the oxidizing agent or solvent, the reaction temperature, etc.

The sulfonated product may be any of the two types of sulfonated products mentioned above, but it is preferable that double bonds remain in view of the ease in which the polymerization progresses when polymerizing to obtain a polymer.

In addition, in order to increase the air entrainment property by 1n when the polymer is used as a cement dispersant, the sulfonated compound preferably contains 20% or more of a substance having N11il of sulfonic acid groups per molecule, and preferably contains 50% or more of a sulfonic acid group per molecule. More preferably, those containing 80% or more are even more preferable.

The number of sulfonic acid groups in the sulfonated product can be determined by a conventional method such as titration with an alkali. Examples of the base of the sulfonic acid (M in general formula (1)) include alkali metal salts such as sodium and potassium, alkyl amines such as methylamine and ethylamine, alkaline earth metal salts such as calcium and magnesium, The (co)polymer used in the present invention includes ammonium salts, dicyclopentadiene having a sulfonic acid group,
Alternatively, the dicyclopene compound is polymerized by polymerizing the compound and a monomer copolymerizable therewith, for example, in the presence of an acidic compound catalyst. Examples of acidic compounds used as polymerization catalysts include sulfuric acid, phosphoric acid, hydrogen fluoride, boron trifluoride and its complexes, aluminum chloride, aluminum bromide, tin tetrachloride, zinc chloride, and Lewis acid compounds such as titanium chloride. Mention may be made of acids or organic protic acids. The amount of the acidic compound catalyst used is not particularly limited and can be arbitrarily changed depending on the target molecular weight, and is generally 0.01 to 10 times the weight of the sulfonated product. In the presence of such a catalyst, a sulfonated product of dicyclopentadiene or a monomer copolymerizable with it is heated at a reaction temperature of -20 to 300°C, preferably 8°C.
The reaction is carried out at 0 to 180°C for several hours to several tens of hours. In this polymerization reaction, a solvent for the polymerization reaction can be used in order to carry out the reaction, and as a solvent for the polymerization reaction, polar solvents such as water or hydrocarbons can be used as long as they do not interfere with the polymerization reaction. , halogenated hydrocarbons and the like can be used.

In addition, in order to adjust the surface activity of the polymer, the sulfonated product and a copolymerizable monomer F11 (hereinafter simply referred to as "comonomer") are copolymerized to adjust the HLB (surface active property). I can also frog.

Examples of copolymerizable monomers include aliphatic, alicyclic, and aromatic hydrocarbons having olefinic double bonds, unsaturated amides, unsaturated alcohols, unsaturated esters, unsaturated di-lyl,
Examples include unsaturated carboxylic acids and esters thereof, unsaturated sulfonic acids and esters thereof. in particular,
Examples include dicyclopentadiene, styrene, acrylic acid, methacrylic acid, ethyl acrylate, methyl acrylate, butyl acrylate, allylsulfonic acid, and the like.

These copolymerized monomers can be used in any proportion from Katsura group to L, but when the copolymer is used as a cement dispersant, in order to keep the air entrainment property low, the copolymer is The content of the sulfonated compound in the polymer is desirably 50% or more, preferably 70% or more2, and more preferably 90% or more3.The molecular weight of the (co)polymer used in the present invention depends on the reaction conditions, In particular, it can be changed as appropriate depending on the type and amount of the acidic compound catalyst, the type and amount of the solvent, or the reaction temperature and reaction time.

When the above (co)polymer is used as a dispersant for cement, the weight average amount is preferably 500 or more, more preferably 2,000 or more, most preferably 3
, 500 to 50,000. Further, the above (co)polymer can be mutually exchanged into an acid form or a salt of an alkali metal, alkaline earth metal, ammonium, amine, etc. by an ion exchange method or a neutralization reaction.

The (co)polymer produced as described above has a brown to black color, but in the present invention, this (co)polymer is brought into contact with hydrogen peroxide to decolorize it. Generally speaking, the larger the amount of hydrogen peroxide used, the greater the decolorizing effect.
01 to 10 parts by weight.

If the amount does not reach 0.01 part by weight, the decolorized fruit will be small and 10
Using an amount exceeding 1 part by weight does not lead to an increase in the effect, which is economically disadvantageous.

Within the above range, and since the decolorizing effect is proportional to the amount of hydrogen peroxide used, it is desirable to determine the amount used depending on the degree of decolorization required.

The method of contacting the (co)polymer with hydrogen peroxide is not particularly limited, but is generally carried out by adding aqueous hydrogen peroxide to an aqueous solution of the (co)polymer and stirring. The contact temperature is usually adjusted to keep the hydrogen peroxide in the system.
A temperature in the range of 0°C to 60°C may be selected. Further, the contact time is determined by the degree of decolorization and is not particularly limited, but the contact time is 30 minutes or more.

The pl of the above mixed solution is preferably 8 or less, especially 7 to 1.As described in the examples below, the pH strongly influences the decolorizing effect, and especially when il H is 8 or less, the decolorizing effect is extremely large. , the hydrogen peroxide used is, for example, 0.03
It is possible to decolorize even if the amount is less than 30%. I) When H exceeds 8, the decolorizing effect is weakened.

Next, a method for stopping the decolorizing action will be described.

One method is to use a small amount of dihydrogen peroxide to
This is a method in which the polymer is decolorized at a pH of 8 or less, and then a suitable alkali is used to maintain the pH above 8. Another method is to heat the system at a temperature of 60° C. or higher after decolorization, and it is preferable to combine the two methods.

As described above, according to the present invention, it is possible to produce a (co)polymer of sulfonated dicyclopentadiene that has excellent cement dispersibility and extremely low coloring property, and therefore,
If this (co)polymer is used as a 7-ment dispersant,
Workability during cement kneading is facilitated, and high-strength concrete or mortar can be produced with less coloring.

Hereinafter, the present invention will be specifically explained with reference to Examples.

Reference Example 1 (Manufacture of polymer) 3,000 g of dicyclopentadiene was placed in a stainless steel autoclave with a capacity of 30 A equipped with a stirring device and a thermometer.
, 1 lithium hydrogen sulfite 1,888 g, potassium nitrate 9
1.7 g of isopropyl alcohol, and 3,000 g of distilled water were added, and the internal pressure in the autoclave reached 1.7 g at room temperature. After supplying nitrogen until the pressure reaches Okg/cJ (gauge pressure), close the valve and mix under strong stirring.
The reaction was carried out at 10°C for 5 hours. After that, let it cool to room temperature, remove most of the isopropyl alcohol by distillation, add distilled water and petroleum ether, mix thoroughly, remove the separated petroleum ether layer and precipitate, and concentrate the resulting aqueous layer. and distilled to dryness. This was dissolved in glacial acetic acid, and the acetic acid insoluble portion consisting of inorganic salts was separated using a centrifuge. By concentrating the obtained acetic acid soluble content, 2,800 g of a white solid was obtained. (This is sulfonated compound A
(Next, 1 hour of the above sulfonated compound A was placed in a 5,000 ml glass-lined autoclave equipped with a stirring device.
．． 5 kg of sulfuric acid, 1.0 kg of sulfuric acid, and 1.5 kg of water were charged, and the polymerization reaction was carried out at 120°C for 6 hours.The weight average molecular weight (measured by GPC) of this product was 8°850.

Reference Example 2 (Production of copolymer) Volume I300 m equipped with a reflux condenser and a stirring device
1 of the sulponide A of Reference Example 1 was placed in a three-liter Mitsuro flask.
3g, dicyclopentadiene 2g, sulfuric acid 6.88g
The copolymerization reaction was carried out at a temperature of 120° C. for 20 hours. After the reaction, liming and soap-Johning were performed to obtain a copolymer. The surface tension of a 4% by weight aqueous solution of the obtained copolymer was 40 dyn/cm, indicating an excellent surfactant effect.

Examples 1 to 8, Comparative Example 1 After adjusting the pH by adding CaC○3 aqueous solution to the polymer obtained in Reference Example 1 and filtering off the generated CaSO4, an aqueous solution containing 20% by weight of the polymer was added. Prepared. A 31% by weight hydrogen peroxide solution was added to this aqueous solution, and the polymer was decolorized under the conditions shown in Table 1. Then excess C
After adding aCO3 and heating at 70°C for 2 hours, the mixture was filtered, and the degree of coloration and dispersibility of the resulting polymer were examined. The degree of coloration is 100 ppm of the obtained polymer.
Solutions were prepared and examined for light transmission at 600 nm. Cement dispersibility was determined by adding 200 g of commercially available Portland cement to an aqueous solution prepared by adding 2 g of the flocculated polymer to 56 g of water and kneading it by hand for 3 minutes.
It was investigated by measuring the flow value according to the method of JISR5201 using a cc flow cone. These results are shown in Table 1. Note that Comparative Example 1 was shown in which no hydrogen peroxide solution was added.

Example 9 In Example 1, the transmittance and flow value were determined in the same manner as in Example I except that the copolymer subjected to R7 in Reference Example 2 was used. The results are shown in Table 1.

From the results shown in Table 1 in the margin below, it is clear that the addition of hydrogen peroxide reduces coloration without reducing cement dispersibility, and that high transmittance can be obtained depending on the conditions. It is also clear that the degree of decolorization largely depends on the pH, and that excellent decolorized 'A' fruit can be obtained at a pH of 8 or less, especially 7.0 or less.

Agent: Patent Attorney Kawakita Takecho

Claims (1)

[Claims] (1) A method for producing a polymer, which comprises polymerizing a sulfonated product of dicyclopentadiene in the presence of an acidic compound catalyst and contacting the resulting polymer with hydrogen peroxide.