JPH0660206B2 - Polymerization method of vinyl monomer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] The present invention relates to the polymerization of vinyl monomers,
More specifically, it relates to a method for preventing adhesion of scale formed on the inner surface of a polymerization apparatus when polymerizing a vinyl monomer in an aqueous medium.

When polymerizing vinyl monomers in the presence of a dispersant or emulsifier and a polymerization initiator, solid polymer called scale adheres to the inner surface of the polymerization reactor, that is, the inner walls, stirring blades, baffle plates, condensers, etc. There are many. Due to this scale, the heat transfer efficiency is reduced, the product yield is reduced, the quality is deteriorated due to the inclusion of the exfoliation scale into the product, the labor required for scale removal and the productivity loss due to the waste of time required for it It brings many disadvantages such as causing occupational health and safety problems.

[Conventional technology]

To solve these problems, many methods have been proposed to prevent scale formation and its adhesion to the polymerizer.

For example, dyes, pigments, other polar organic compounds, inorganic acids and their salts, polyvalent metal salts, etc. may be applied to the inner surface of the polymerization vessel or added to an aqueous medium. It has various drawbacks such as poor sustainability and deterioration of various properties of the product.

As a method for improving these, a method of applying a polymer compound having a functional group that prevents scale formation to the inner surface of the polymerization vessel has been proposed.

Conventionally, phenol compounds have been used as polymerization inhibitors, and many methods utilizing them have been proposed.

For example, in JP-A-55-16004, a phenol aldehyde initial condensation product is reacted with nitrophenols, and in US Pat. No. 4,080,173, self-condensed polyhydric phenol and polyhydric naphthol are disclosed. JP-A-55-54317 discloses a condensate of a phenolic compound and an aromatic aldehyde, JP-A-55-102610.
In the publication, propylene glycol alginate,
Japanese Patent Application Laid-Open No. 55-11209, Nitrile-containing polymers, Japanese Patent Application Laid-Open No. 58-7401, modified rosin, Japanese Patent Application Laid-Open No. 58-
No. 168601 discloses a resin extracted from pine trees,
JP-A-180511 and JP-A-58-204006 disclose a method of applying a rosin or rosin ester, a drying oil or a semi-drying oil, a phenol compound, and a reaction product of an aldehyde, etc., to the inner surface of a polymerization vessel. Has been done.

However, when these methods are used, there are many points to be improved, for example, the polymerization rate is lowered, and the durability of the coating film is insufficient, which causes a problem in the sustainability of the descaling effect.

[Structure of Invention]

The present inventors, as a result of earnest research to eliminate these drawbacks, a certain polymer compound, particularly during the polymerization of a vinyl-based monomer, when this is applied to the inner surface of the polymerization vessel for polymerization, The inventors have found that scale adhesion can be remarkably prevented and that adhesion to metal is extremely excellent, and the present invention has been completed.

That is, the present invention, when polymerizing a vinyl-based monomer in an aqueous medium, a resin collected from a pine root strain, a phenolic compound, and optionally an aldehyde compound and a reaction product are pre-applied to the inner surface of the polymerization equipment. By doing so, a method for polymerizing a vinyl-based monomer that prevents scale adhesion on the inner surface of the polymerization equipment is provided.

As a method of synthesizing a reaction product of a resin, a phenolic compound, and an aldehyde compound, if desired, collected from a pine root strain used in the present invention, (1) a resin collected from a pine root strain, a phenolic compound And a method of simultaneously reacting an aldehyde compound as desired, (2) after reacting a resin and a phenolic compound collected from a pine root strain,
A typical method is to react this with an aldehyde compound, and (3) a method of reacting a phenolic compound with an aldehyde compound and then reacting this with a resin collected from a Matsune strain.

In the case of the above method (1), the reaction is carried out in accordance with a usual method for producing a phenol resin, except that a resin collected from a pine root strain is allowed to coexist.

In the case of the method (2), first, a resin and a phenolic compound collected from a pine root strain are mixed with an acid catalyst in a nitrogen atmosphere at 50 to 250 ° C, preferably 100 to 180 ° C.
For 5 minutes to 10 hours, preferably 1 to 5 hours. Then, the modified phenol compound is mixed with an aldehyde compound and then synthesized according to a usual method for producing a phenol resin. The acid catalyst used here includes aluminum, boron, iron, zinc, tin,
Illustrative are fluorides such as titanium, metal halides such as chlorides, complex compounds thereof, inorganic acids and organic acids such as hydrochloric acid, sulfuric acid and paratoluenesulfonic acid.

Furthermore, in the case of the method of (3), after the phenol compound and the aldehyde compound are reacted in advance according to a conventional method, a resin collected from a pine root strain is added, and a modified phenol resin is obtained by heating. . in this case,
The reaction temperature is preferably 50 to 140 ° C., and the reaction time is preferably 1 to 5 hours.

The ratio of the phenolic compound used for producing the phenolic polymer compound in the present invention to the resin collected from the pine root strain is usually 100 parts by weight of the phenolic compound, and the resin collected from the pine root strain is 100 parts by weight. 5 to 500 parts, preferably 10 to 300 parts are applied. The ratio of the phenolic compound to the aldehyde compound is 0.1 to 1.5 mol, preferably 0.5 to 1.1 mol, of the aldehyde compound per mol of the phenolic compound.

If the usage ratio is out of this range, the effect of preventing scale adhesion is significantly reduced.

The resin collected from the pine root strain used in the present invention is a blackish-brown solid having a softening point of 100 ° C. or lower, which is produced from a residue obtained by extracting so-called wood rosin, wood turpentine oil, and pine oil by a conventional extraction process. is there. It is also available as a commercial product.

Examples of the phenolic compound used in the present invention include monohydric phenols such as phenol, cresol, P-chlorophenol and xylenol, dihydric phenols such as resorcin, hydroquinone, catechol and bisphenol A, pyrogallol and hydroxyhydroquinone. Examples include hydric phenols. Further, the aldehyde compound may be one that is usually used, and examples thereof include formaldehyde, paraformaldehyde, acetaldehyde and the like.

The phenolic polymer compound thus synthesized is
It is used by dissolving it in a hydrocarbon polar solvent.

This solution is used by being applied by a method such as a spray method or a rinsing method at a rate of 0.01 g / m ^{2 to} 10 g / m ² (as a polymer) per square meter on the surface of the subject polymerization vessel.

The polymerization of the vinyl monomer used in the present invention includes suspension polymerization,
Emulsion polymerization is adopted. Dispersant used for this polymerization,
There are no particular restrictions on the emulsifier, initiator, etc., and commonly used ones can be used.

For example, as a dispersant and an emulsifier, a partially saponified product of polyvinyl acetate, an acrylic acid copolymer, a cellulose derivative,
Protective colloidal compounds such as gelatin and starch, esters of higher fatty acids and polyhydric alcohols, anionic surfactants such as polyoxyethylene derivatives, metal salts of higher fatty acids, metal salts of alkylbenzene sulfonic acid, etc. An agent or the like is used.

As the polymerization initiator, organic peroxides such as benzoyl peroxide, lauroyl peroxide, dioctyl peroxydicarbonate, azo compounds such as azobisisodimethylvaleronitrile, and persulfates such as potassium persulfate and ammonium persulfate are used. To be done.

The vinyl-based monomer mentioned here is a monomer having a vinyl group, and includes, for example, olefins such as ethylene and propylene, vinyl halides such as vinyl chloride and vinylidene chloride, vinyl esters such as vinyl acetate. , Vinyl ethers such as ethyl vinyl ether, acrylic acid ethers such as methyl methacrylate, metal salts or esters such as maleic acid and fumaric acid, aromatic vinyls such as styrene, and diene-based monomers such as butadiene, chloroprene and isoprene Body, acrylonitrile and the like.

The polymerization temperature is usually in the range of 30 ° C to 80 ° C.

INDUSTRIAL APPLICABILITY The present invention can be used for the polymerization of the above vinyl-based monomers alone or a mixture of two or more vinyl-based monomers, and particularly shows a remarkable effect on the polymerization of vinyl chloride-based monomers. .

The present invention will be specifically described below with reference to examples.

[Reference Example 1] A four-necked flask was charged with 100 parts by weight of pyrogallol, 100 parts by weight of a resin collected from a pine root strain having a softening point of 60 ° C, and 1 part by weight of paratoluenesulfonic acid at 150 ° C under a nitrogen atmosphere. The reaction was carried out for 4 hours. 100 after completion of the reaction
Cool to below ℃, then add 400 parts of water to dehydrate,
After washing, it was dried to obtain a reaction product.

[Reference Example 2] A four-necked flask was charged with 100 parts by weight of pyrogallol, 50 parts by weight of a resin collected from a pine root strain having a softening point of 60 ° C, and 1 part by weight of aluminum chloride, and charged in a nitrogen atmosphere at 160 parts.
After reacting at 0 ° C. for 1 hour, the mixture was cooled, 75 parts by weight of formaldehyde (35% concentration) was added, and the mixture was reacted under reflux for 1 hour. Then, 400 parts of water was added to dehydrate, wash and dry to obtain a reaction product.

Reference Example 3 Pyrogallol 100 parts by weight, formaldehyde 68 parts by weight (35% concentration), 50% phosphoric acid 20 in a four-necked flask.
00 parts by weight was reacted at 60 ° C. for 1 hour to obtain a reddish purple precipitate. This precipitate was dehydrated and dried. 100 parts by weight of this and 50 parts by weight of a resin collected from a pine root strain were reacted in the same manner as in Reference Example 1 to obtain a product.

[Reference Example 4] A four-necked flask was charged with 100 parts by weight of pyrogallol, 75 parts of formaldehyde (concentration 35%), 50 parts by weight of a resin collected from a pine root strain, and 2 parts by weight of oxalic acid dihydrate under a nitrogen atmosphere. The reaction was carried out for 4 hours. The reaction temperature was controlled by reflux condensation of water in the system. After the reaction,
400 parts by weight of water was added, dehydrated, washed, and dried to obtain a reaction product.

[Reference Example 5] A reaction product was obtained in the same manner as in Reference Example 1, except that hydroxyhydroquinone was used instead of pyrogallol.

In the Comparative Example 1] Explanation polymerization vessel product 1 m ^3, pure water 250 parts, partially saponified polyvinyl acetate 0.25 parts were charged 2,2'-azobis-2,4-dimethyl valeronitrile 0.05 parts under a reduced pressure 100 parts of vinyl chloride monomer was injected.

Then, the mixture was heated to 57 ° C. with stirring, and when the pressure in the polymerization reactor dropped from the pressure in the steady state of the polymerization reaction by 2 kg / cm ² , the collection of the reaction monomer was started.

The polymerization time at this time was 10 hours.

Then, after recovering the unreacted monomer, the polymerization suspension was taken out from the polymerization vessel, and the inner surface was washed with low pressure water.

After that, when the amount of scale attached to the inner surface of the polymerization vessel was measured, the results shown in Table 1 were obtained.

[Comparative Example 2] A resin obtained from the pine root strain used in Reference Example 1 was used as a 3% acetone solution, and spray-coated on the inner surface of the polymerization vessel used in Comparative Example 1 and dried. The coating amount at this time was about 0.4 g / m ² .

When a polymerization reaction was carried out in the same manner as in Comparative Example 1 using this polymerization vessel, the polymerization time was 10 hours, and the amount of scale adhesion was as shown in Table 1.

Comparative Example 3 An aqueous solution containing 126 parts of pyrogallol and 85 parts of formaldehyde with a concentration of 35% was added to 2000 parts of a 50% by weight aqueous solution of phosphoric acid,
The mixture was reacted at 60 ° C for 1 hour to obtain a water-insoluble solid. This solid was washed with water and dried, then made into a 3% acetone solution, spray-coated on the inner surface of the polymerization vessel used in Comparative Example 1, and dried. The coating amount at this time was about 0.4 g / m ² .

When a polymerization reaction was carried out in the same manner as in Comparative Example 1 using this polymerization vessel, the polymerization time was 10 hours, and the scale adhesion amount was the result shown in Table 1.

Examples 1 to 5 The products obtained by the methods of Reference Examples 1 to 5 were each made into a 3% acetone solution, spray-coated on the inner surface of the polymerization vessel used in Comparative Example 1, and dried.

The coating amount at this time was about 0.4 g / m ² .

When a polymerization reaction was carried out in the same manner as in Comparative Example 1 using this polymerization vessel, the polymerization time was 10 hours, and the amount of scale adhesion was as shown in Table 1.

[Comparative Example 4] In a polymerization vessel having an internal volume of 1 m ³ , 250 parts of pure water, 5 parts of vinyl acetate,
After charging 0.25 parts of partially saponified polyvinyl acetate and 0.05 parts of 2,2'-azobis-2,4 dimethylvaleronitrile,
100 parts of vinyl chloride monomer was injected under reduced pressure, then heated to 60 ° C with stirring, and when the pressure inside the polymerization reactor dropped 2 kg / cm ² from the pressure in the steady state of the polymerization reaction, unreacted Recovery of the monomer was started.

The polymerization time at this time was 8.5 hours. Then, after recovering the unreacted monomer, the polymerization suspension was taken out from the polymerization vessel, and the inner surface was washed with water. After that, when the amount of scale attached to the inner surface of the polymerization vessel was measured, the results shown in Table 2 were obtained.

[Comparative Example 5] The resin collected from the pine root strain used in Reference Example 1 was used as a 3% acetone solution, and spray-coated on the inner surface of the polymerization vessel used in Comparative Example 4 and dried. The coating amount at this time was about 0.4 g / m ² . Using this polymerization vessel, a polymerization reaction was carried out in the same manner as in Comparative Example 4. As a result, the polymerization time was 8.5 hours and the scale adhesion amount was as shown in Table 2.

[Comparative Example 6] The solid obtained by the method of Comparative Example 3 was used as a 3% acetone solution and spray-coated on the inner surface of the polymerization vessel used in Comparative Example 5 and dried.

The coating amount at this time was about 0.4 g / m ² .

Using this polymerization vessel, a polymerization reaction was carried out in the same manner as in Comparative Example 4. As a result, the polymerization time was 8.5 hours and the amount of scale adhesion was as shown in Table 2.

[Examples 6 to 10] The products obtained by the methods of Reference Examples 1 to 5 were each made into a 3% acetone solution, and spray-coated on the inner surface of the polymerization vessel used in Comparative Example 4 and dried.

The coating amount at this time was about 0.4 g / m ² .

When a polymerization reaction was carried out using this polymerization vessel in the same manner as in Comparative Example 4, the polymerization time was both 8.5 hours, and the amount of scale deposition was as shown in Table 2.

[Comparative Example 7] 100 parts of pure water and 100 parts of chloroprene were placed in a polymerization vessel having an internal volume of 1 m ^3.
Parts, polyoxystyrene beef tallow alkyl propylene diamine 4 parts, acetic acid 1 part, alumina sol 0.5 part, sodium formaldehyde sulfoxylate 0.02 part, and then polymerized at 40 ° C. for 10 hours while adding t-butyl hydroperoxide 0.01 part. Completed. After the polymerization was completed, the amount of scale attached to the inner surface of the polymerization vessel was measured, and the results shown in Table 3 were obtained.

[Comparative Example 8] A resin obtained from the pine root strain used in Reference Example 1 was used as a 3% acetone solution, and spray-coated on the inner surface of the polymerization vessel used in Comparative Example 7 and dried.

The coating amount at this time was about 0.4 g / m ² .

When a polymerization reaction was carried out in the same manner as in Comparative Example 7 using this polymerization vessel, the polymerization time was both 8.5 hours, and the amount of scale adhesion was as shown in Table 3.

[Comparative Example 9] The solid obtained by the method of Comparative Example 3 was used as a 3% acetone solution and spray-coated on the inner surface of the polymerization vessel used in Comparative Example 7 and dried.

The coating amount at this time was about 0.4 g / m ² .

When a polymerization reaction was carried out in the same manner as in Comparative Example 7 using this polymerization vessel, the amount of scale adhesion was as shown in Table 3.

[Comparative Examples 11 to 15] The products obtained in Reference Examples 1 to 5 were each made into a 3% acetone solution, spray-coated on the inner surface of the polymerization vessel used in Comparative Example 7, and dried.

The coating amount at this time was about 0.4 g / m ² .

When a polymerization reaction was carried out in the same manner as in Comparative Example 7 using this polymerization vessel, the amount of scale adhesion was as shown in Table 3.

As described above, in any of the examples, the number of effective batches was improved by remarkably reducing the amount of scale deposit and improving the durability of the coating film as compared with the comparative example.

* 1 The number of effective batches in the table means that the scale adhesion preventive agent applied will be exfoliated by stirring the slurry due to polymerization, so that the scale adhesion prevention effect will be lost, and the quality of foreign matter and hue will be adversely affected. It means the number of batches that can be effectively used until polymerization cannot be continued without a washing operation.

Claims (4)

[Claims] 1. When polymerizing a vinyl-based monomer in an aqueous medium, a reaction product of a thermoplastic resin, a phenolic compound, and an aldehyde compound, which are collected from a pine root, is preliminarily prepared on the inner surface of a polymerization apparatus. A method for polymerizing a vinyl-based monomer, which comprises applying to a vinyl monomer. 2. The polymerization method according to claim 1, wherein the vinyl-based monomer is vinyl chloride alone or a mixture of vinyl chloride and a monomer copolymerizable therewith. 3. A thermoplastic resin collected from a pine root strain,
The polymerization method according to claim 1, which is a resin produced from a residue obtained by extracting so-called wood rosin, wood turpentine oil, and pine oil. 4. The polymerization method according to claim 1, wherein the phenolic compound is pyrogallol or hydroxyhydroquinone.