JP2001031709A - Block polymerization of acrylic monomer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a block polymn. method of a high product yield, which is a two catalyst component system and less susceptible to temp. then a polymn. method with a thermal polymn. initiator and will not run away. SOLUTION: This block polymn. method of an acrylic monomer users as a polymn. initiator a compd. (A) having a thiol group but no secondary hydroxyl group in the molecule ad as a catalyst of the compd. (A) a compd. (B) having a secondary hydroxyl group but no thiol group in a molecule, and polymerizes polymerizable monomers mainly comprising an alkyl acrylate and/or an alkyl mechacrylate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention uses a compound having a thiol group in a molecule as a polymerization initiator in the presence of an inert gas, and a compound having a secondary hydroxyl group in a molecule as a catalyst for the polymerization initiator. And polymerizing a polymerizable monomer containing an alkyl acrylate or an alkyl methacrylate as a main component.

[0002]

BACKGROUND OF THE INVENTION Emulsion polymerization, suspension polymerization, solution polymerization and bulk polymerization are known as radical polymerization methods for acrylic monomers containing alkyl acrylate or alkyl methacrylate as a main component. Are known. Among these polymerization methods, emulsion polymerization method, suspension polymerization method,
In the solution polymerization method, a polymerization reaction is performed by dissolving or dispersing a polymerizable monomer in a reaction medium, so that the polymerization temperature is easily controlled, and even when the polymerization rate is high or the molecular weight of the polymer is high. There is an advantage that the reaction solution has fluidity.

However, in such an emulsion polymerization method and a suspension polymerization method, filtration is performed to remove a polymer from a dispersion medium.
Operations such as sedimentation and separation are required, and the process becomes complicated. Moreover, the dispersant or emulsifier used in such a polymerization method is difficult to completely separate from the polymer,
Such a remaining emulsifier or dispersant often has a bad influence on the inherent properties of the acrylic polymer, such as water resistance and weather resistance. In addition, in the solution polymerization method, since a large amount of an organic solvent is used, it is easy to control the polymerization reaction temperature, and since the reaction is a homogeneous reaction, the design of the polymer (such as the mixing ratio of the monomer) is relatively low. It has the advantage that it can be easily carried out, but there is also a problem that a large difference occurs in the monomer concentration between the initial stage and the latter half of the polymerization, a low molecular weight compound is easily generated, and the molecular weight distribution is widened. I have. As a solution to these problems, attempts have been made to solve the above problems by employing a method of dividing and adding a monomer or a method of dropping a monomer. In addition, the convenience of the solution polymerization method that the reaction step is simple is impaired.

The organic solvent used as a reaction solvent in the solution polymerization is generally involved in a polymerization reaction such as a termination reaction or a chain transfer reaction in a polymerization reaction involving chain transfer. This complicates the design of the polymer.

Further, the polymer obtained by the solution polymerization contains a large amount of an organic solvent. Therefore, when these polymers are used, it is necessary to remove a large amount of the organic solvent used in the reaction, resulting in low productivity. In addition, when these polymer solutions are used as they are outdoors or the like, there is a problem that the load on the natural environment due to the volatilization of the organic solvent increases.

On the other hand, the bulk polymerization method does not require the use of a dispersant, an emulsifier, or the like, and does not contain impurities such as an organic solvent involved in the polymerization. Therefore, the reaction system can be simplified and obtained. No impurities such as an emulsifier and a dispersant are mixed in the polymer, and further, it is not necessary to remove a solvent in order to obtain a target polymer.

However, in general, such a bulk polymerization method has a remarkably high polymerization reaction rate, and it is difficult to control the bulk polymerization method. In addition, the polymer produced at a high temperature without controlling the polymerization rate was in a state where the terminal group of the molecule became unstable due to the termination of disproportionation, became low molecular weight, or conversely produced earlier Branching or gelling of the polymer is likely to occur due to abstraction of hydrogen from the polymer. For this reason, not only is it difficult to design the molecular weight and molecular weight distribution of the polymer, but also it becomes difficult to design a clear molecular structure due to the branching of the polymer and the generation of the disproportionation termination terminal. In addition, gellings can form rapidly and in large quantities, and in the worst case, there is even a risk of explosion due to runaway reactions.

Under these circumstances, there has been proposed a method of controlling the progress of a bulk polymerization reaction using mercaptan. Japanese Patent Publication No. 55-401 discloses that an ethylenically unsaturated polymerizable monomer having an organic mercaptan having at least one thiol group at a temperature of about 20 ° C. to about 200 ° C. in the presence of oxygen is substantially completely dissolved. Polymerization process characterized by contacting for a time sufficient to obtain conversion of the monomer to polymer. " In this reaction, the presence of oxygen is indispensable, and bulk polymerization of the ethylenically unsaturated monomer is performed using mercaptan together with oxygen. Therefore, this reaction does not effectively proceed in an atmosphere where oxygen is not present. When polymerization is performed using mercaptan and oxygen described in this publication, oxygen is positively blown into the reaction system, so there is a high risk of explosion and fire, and the obtained polymer is colored. There are also problems.

[0009] The claims of Japanese Patent No. 2582510 include a method for producing an acrylic polymer by bulk polymerization of a monomer component containing an acrylic acid monomer as a main component. A, wherein the polymerization system in which the bulk polymerization of the monomer components is performed is in an inert gas atmosphere and contains mercaptan, and an acrylic polymer characterized by being substantially free of a polymerization initiator. Manufacturing method. " The role of mercaptan in the invention described in this publication is to control the molecular weight and molecular weight distribution of one of the polymers, and the other is to allow the bulk polymerization of the monomer components to proceed gently to a high polymerization rate, and It is stated that in order to moderately control the polymerization rate when no initiator is contained. Comparative Example 3 described in this publication is an experimental example in which the reaction was carried out without using 30 parts of octyl thioglycolate, which is a mercaptan used in Example 1, and according to the description, the reaction was carried out under a nitrogen atmosphere. In 1), only the monomer that is a polymerizable monomer is heated, and the temperature rises to 130 ° C. 1 hour and 30 minutes after the start of polymerization, so that stable polymerization cannot be performed, and the obtained polymer becomes a gel. Is indicated. That is, when Comparative Example 3 and Example 1 described in this publication were compared, the initiation of polymerization was initiated by the heat of the monomer monomer, and the role of octyl thioglycolate, which is the mercaptan used, was heavy. It is shown to be used for adjusting the molecular weight of the coalescing and suppressing the rapid progress of the bulk polymerization reaction.

As described above, in a conventional bulk polymerization reaction of an unsaturated monomer using a mercaptan, mercaptan is used so as to suppress the progress of the bulk polymerization reaction that easily runs away. There was no technical idea of using mercaptan as a polymerization initiator in a bulk polymerization reaction.

[0011]

An object of the present invention is to provide a bulk polymerization of a polymerizable monomer containing an alkyl acrylate and / or an alkyl methacrylate as a main component, with a high polymerization rate and a small dispersion index of the obtained molecular weight. It is another object of the present invention to provide a method for performing bulk polymerization while reliably controlling the reaction.

[0012]

SUMMARY OF THE INVENTION The present invention relates to a compound having a thiol group in a molecule and having no secondary hydroxyl group as a polymerization initiator under an inert gas atmosphere, and a secondary hydroxyl group in a molecule as a catalyst for the polymerization initiator. And a compound having no thiol group and having a polymerizable monomer having an alkyl acrylate or an alkyl methacrylate as a main component.

In the present invention, a monomer having a very high reactivity, such as a polymerizable monomer containing an alkyl acrylate or an alkyl methacrylate as a main component, is used as a main component. By using a compound having a thiol group in the molecule and having no secondary hydroxyl group as a polymerization initiator and a compound having a secondary hydroxyl group in the molecule and having no thiol group as a catalyst of the polymerization initiator, The bulk polymerization reaction can be performed under mild conditions without runaway of the bulk polymerization reaction, the molecular weight distribution of the obtained polymer is narrow, and an unplanned polymer such as the formation of a gelled product is hardly generated. Furthermore, there is no need for other reaction initiators, such as oxygen, to coexist in the reaction system, and there is no need to perform two-stage polymerization using other reaction initiators.

[0014]

Next, the polymerization method of the present invention will be specifically described.

According to the present invention, a compound (A) having a thiol group in the molecule and having no secondary hydroxyl group and a compound having a secondary hydroxyl group and having no thiol group are used as polymerization initiators in an inert gas atmosphere. It is characterized in that a polymerizable monomer having an alkyl acrylate and / or an alkyl methacrylate as a main component is subjected to bulk polymerization using the compound (B).

In the present invention, specific examples of the compound (A) having a thiol group in the molecule and having no secondary hydroxyl group include ethyl mercaptan, butyl mercaptan, hexyl mercaptan, octyl mercaptan, normal dodecyl mercaptan, and tertiary. Alkyl thiols such as dodecyl mercaptan; alkylene oxide thiols such as methoxy mercaptan, ethoxymercaptan, butoxymercaptan, methoxymethyl mercaptan, ethoxybutyl mercaptan, butoxybutyl mercaptan, and methoxybutyl β-mercaptopropionate;
Thiols having an allyl group such as allyl mercaptan;
Thiols having a reactive silyl group such as 3-mercaptopropyltrimethoxysilane; thiols having a carboxyl group such as β-mercaptopropionic acid, thioglycolic acid, thiosalicylic acid, thiomalic acid, o-thiocoumaric acid; 2- Thiols having a primary hydroxyl group such as mercaptoethanol and 3-mercaptopropanol; thiol compounds such as aliphatic thiols such as phenylmercaptan and benzylmercaptan; thiols such as mercaptopropyl-trimethoxysilane; and pentaerythritol A polyfunctional thiol compound esterified with β-mercaptopropionic acid; and a polymer thiol having an active thiol group such as a polysulfide-based polymer. Among them, at least one selected from the group consisting of an alkyl group having 22 or less carbon atoms, an alkylene oxide group having 24 or less carbon atoms, an allyl group having 18 or less carbon atoms, a reactive silyl group, a primary hydroxyl group and a carboxyl group. Thiols having different types of organic groups are preferred.

In the present invention, the compound (A) used as a polymerization initiator does not act alone as a polymerization initiator, and the compound (B) must be used as a catalyst for the polymerization initiator.

The compound (B) having a secondary hydroxyl group and no thiol group in the molecule includes R1-CH (OH) -R
2 (R1 and R2 are organic groups other than a thiol group), but any specific examples may be used, such as 2-propanol,
Examples thereof include 2-butanol, 2-octanol, 1,2-propanediol, 1,2-butanediol, 1,2,3-propanetriol, and polypropylene glycol. Among them, compounds having a molecular weight of 1,000 or less are exemplified. preferable.

In the present invention, a compound (A) having a thiol group in the molecule and having no secondary hydroxyl group as a polymerization initiator under an inert gas atmosphere and having a secondary hydroxyl group as a catalyst of the polymerization initiator. By using the compound (B) having no thiol group, the reaction rate can be controlled even when using a polymerizable monomer, such as an alkyl acrylate, in which the bulk polymerization reaction rate is difficult to control. Within such a range, the bulk polymerization reaction of the polymerizable monomer can proceed. In the bulk polymerization method of the present invention, when oxygen is present in the reaction system, a dehydration condensation reaction between thiol groups proceeds. Therefore, in the present invention, it is necessary to purge the reaction system with an inert gas. The inert gas to be used may be any gas that is inactive to the polymerization reaction, and examples thereof include nitrogen gas, argon gas, helium gas, and carbon dioxide gas.

The polymerizable monomer used in the present invention contains alkyl acrylate and / or methacrylate as a main component. Specific examples of the alkyl acrylate include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate,
Pentyl acrylate, hexyl acrylate, acrylic acid
-2-ethylhexyl, octyl acrylate, nonyl acrylate, decyl acrylate, dodecyl acrylate, and the like. Specific examples of the alkyl methacrylate include methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate. , Pentyl methacrylate, hexyl methacrylate, methacrylic acid-2-
Examples include ethylhexyl, octyl methacrylate, nonyl methacrylate, decyl methacrylate, dodecyl methacrylate and the like.

The polymerizable monomer used in the present invention may be one type of monomer such as alkyl acrylate or alkyl methacrylate, or may be a combination of two or more types of monomers. Further, monomers other than alkyl acrylate or alkyl methacrylate may be combined, and examples thereof include the following monomers. Salts such as (meth) acrylic acid and alkali metal (meth) acrylate; (meth) such as phenyl (meth) acrylate and benzyl (meth) acrylate
Aryl acrylates; (meth) such as methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxypropyl (meth) acrylate Alkoxyalkyl acrylate; di (meth) acrylate of ethylene glycol, di (meth) acrylate of diethylene glycol, di (meth) acrylate of triethylene glycol, di (meth) acrylate of polyethylene glycol, propylene Glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth)
Di (meth) acrylates of (poly) alkylene glycols such as acrylates; polyvalent (meth) acrylates such as trimethylolpropane tri (meth) acrylate; (meth) acrylonitrile; vinyl acetate; Vinyl chloride; vinylidene chloride; 2-chloroethyl (meth) acrylate, 2-methacrylic acid-2-
Vinyl halide compounds such as chloroethyl; (meth) acrylate esters of alicyclic alcohols such as cyclohexyl (meth) acrylate; 2-vinyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline; An oxazoline group-containing polymerizable compound such as 2-isopropenyl-2-oxazoline; an aziridine group-containing polymerizable compound such as (meth) acryloyl aziridine and (meth) acrylate-2-aziridinylethyl; allyl glycidyl ether; Epoxy group-containing vinyl monomers such as (meth) acrylic acid glycidyl ether and (meth) acrylic acid-2-ethyl glycidyl ether; (meth) acrylic acid-2-hydroxyethyl, methacrylic acid-2-
Monoesters with hydroxyethyl, 2-hydroxypropyl (meth) acrylate, polypropylene glycol or polyethylene glycol (meth) acrylate,
Hydroxyl group-containing vinyl compounds such as adducts of lactones and 2-hydroxyethyl (meth) acrylate; fluorine-containing vinyl monomers such as fluorine-substituted alkyl (meth) acrylate; and (meth) acrylic acid except,
Unsaturated carboxylic acids such as itaconic acid, crotonic acid, maleic acid and fumaric acid, salts thereof, and (partially) ester compounds and acid anhydrides thereof; reactive halogens such as 2-chloroethyl vinyl ether and vinyl monochloroacetate Containing vinyl monomer; (meth) acrylamide,
Amide group-containing vinyl monomers such as N-methylol (meth) acrylamide, N-methoxyethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide; vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, Organosilicon group-containing vinyl compound monomers such as allyltrimethoxysilane, trimethoxysilylpropylallylamine and 2-methoxyethoxytrimethoxysilane; and ethyldennorbornene, piperidine, isoprene, pentadiene, vinylcyclohexene, chloroprene, butadiene, Diene compounds such as methylbutadiene, cyclobutadiene and methylbutadiene.

Other examples include macromonomers having a radical polymerizable vinyl group at the terminal of a monomer obtained by polymerizing a vinyl group (for example, a fluorine-based macromonomer, a silicon-containing macromonomer, etc.).

In the bulk polymerization method of the present invention, solvents other than the compound (A) having a thiol group in the molecule and having no secondary hydroxyl group and the compound (B) having a secondary hydroxyl group and having no thiol group are used. Is reacted under conditions that are not substantially used. However,
In order to disperse the compound (A) and the compound (B) uniformly throughout the monomer, the solvent used when dissolving or dispersing in a very small amount of solvent, the solvent remaining in the raw materials, and the like, affect the polymerization reaction. A small amount of solvent may be included.

In the present invention, the compound (A) having a thiol group and having no secondary hydroxyl group has a thiol group mole number of 0.1 per 100 moles of the unsaturated group of the polymerizable monomer.
５０50 mol, preferably 0.1-30 mol. Further, the compound (B) having a secondary hydroxyl group and not having a thiol group is preferably a compound having an unsaturated group mole number of 10
With respect to 0, it is used in the range of 0.01 to 2.0 as the number of moles of the secondary hydroxyl group. Further, the compound (B) is preferably used in a range of not more than an equimolar amount of the thiol group to the compound (A). Number of moles of unsaturated group of polymerizable monomer 10
When the number of moles of the thiol group of the compound (A) is 0.1 mol or less with respect to 0, even when the compound (B) is used in a predetermined amount, the polymerization by the compound (A) does not efficiently proceed. further,
When the number of moles of the secondary hydroxyl group of the compound (B) is 0.01 or less relative to 100 moles of the unsaturated group of the polymerizable monomer,
The effect of catalysis on compound (A) is low, and the polymerization does not proceed efficiently. Further, when the number of moles of the secondary hydroxyl group of the compound (B) exceeds 2.0, the solid content (nonvolatile content) of the final product is reduced even if the compound (A) is in a predetermined amount.

In the present invention, a conventionally used polymerization initiator can be used in combination. Even when such a polymerization initiator is used in combination, the bulk polymerization of the present invention proceeds smoothly without runaway.

The bulk polymerization reaction can be carried out under heating or heating, or under cooling, depending on the type of the polymerizable monomer. The bulk polymerization reaction temperature needs to be set in consideration of the boiling point in the reaction system. For example, when 2-propanol is used as the compound (B), the polymerization reaction temperature is set to 75 at normal pressure.
It is preferably performed at a temperature of not more than ℃. The boiling point of the reaction system is 150 ° C
, The polymerization reaction temperature is 0 to 150 ° C.
Is preferably set within the range of 20 to 12
It is particularly preferable to set the temperature within the range of 0 ° C. By setting the polymerization reaction temperature within the above range, the compound (A)
And compound (B) can exhibit each function efficiently. Depending on the activity of the unsaturated group of the polymerizable monomer used, even when a relatively polymerizable acrylate-based polymerizable monomer is used, the reaction temperature is set to 0 ° C.
When it is less than the above, the activities of the compound (A) and the compound (B) become low, the time required for obtaining a sufficient polymerization rate becomes long, and the efficiency is poor. Furthermore, even when a monomer having a relatively low polymerization activity such as methyl methacrylate is used,
If the temperature is 20 ° C. or higher, a sufficient polymerization rate can be obtained. When the reaction temperature is 150 ° C. or higher,
Although depending on the activity of the polymerizable monomer, polymerization of alkyl acrylate and the like due to thermal initiation also occurs simultaneously, and in addition to the polymer produced using compound (A) as an initiator, the polymer produced by thermal initiation is also used. In addition to the coalescence, not only the desired polymer cannot be obtained, but also a runaway reaction due to remarkable heat generation during the polymerization reaction. By setting the polymerization temperature to 120 ° C. or lower, a polymer to be produced can be efficiently obtained, and the progress of the reaction can be maintained without runaway of the reaction.

In the bulk polymerization reaction of the present invention, N-dodecylmercaptan is used as the compound (A) and 2
Taking octanol as an example, it cannot be concluded, but it is presumed to proceed as follows.

In the first step, the hydrogen atom of the thiol group of N-dodecyl mercaptan is attracted to the secondary hydroxyl group of 2-octanol, and a thio radical (.S radical) is generated, and this thio radical is used to convert the polymerizable monomer. It is presumed that the initiation of the initial polymerization reaction occurs by radical addition. Next, it is presumed that chain transfer and growth reaction to N-dodecyl mercaptan, 2-octanol and the polymerizable monomer proceed. The termination reaction of this reaction is the termination of the chain transfer to N-dodecyl mercaptan, 2-octanol and the polymerizable monomer, the termination of the recombination between the growing radicals, and the presence of N in the thio radical state.
-It is estimated to be due to termination of recombination with the dodecyl mercaptan radical. In this case, the N-dodecylmercaptan radical from which hydrogen has been abstracted by chain transfer is again added to the monomer as a starting terminal, or recombines with a growing radical and added to the polymer terminal as a terminator.

Therefore, most of the molecular terminals of the polymer obtained by the bulk polymerization method of the present invention are composed of residues or hydrogen atoms from which hydrogen has been eliminated from N-dodecylmercaptan. Therefore, the polymer obtained by the bulk polymerization method of the present invention does not have a conventional polymerization initiator fragment or an unsaturated group due to termination of disproportionation of a monomer at a terminal, and has storage stability and weather resistance. Are better.

As described above, by using the compound (A) and the compound (B) for initiation of polymerization, the reaction rate of this bulk polymerization is usually 50% or more, preferably 70% or more.
% Or more. Despite the high response rate,
For example, even when a highly reactive polymerizable unsaturated compound such as an acrylate ester is used, the reaction does not run away and a bulk polymerization reaction can be stably performed.

The bulk polymer (including the composition) produced as described above varies depending on the type of the polymerizable monomer used and the types and amounts of the compound (A) and the compound (B). The average molecular weight is in the range of 500 to 100,000, and the weight average molecular weight is usually 1000 to 30.
0000.

The bulk polymer thus obtained is purified, if necessary, and used in the same manner as a usual polymer.

[0033]

According to the present invention, a highly reactive monomer such as a polymerizable monomer mainly composed of an alkyl acrylate or an alkyl methacrylate is used as a main component, but an inert gas is used. In an atmosphere, a compound having a thiol group in the molecule and having no secondary hydroxyl group as a polymerization initiator and a compound having a secondary hydroxyl group in the molecule and having no thiol group as a catalyst for the polymerization initiator are used. By
The bulk polymerization reaction can be performed under mild conditions without runaway of the bulk polymerization reaction, the molecular weight distribution of the obtained polymer is narrow, and it is difficult to generate an unplanned polymer such as formation of a gelled product. Further, there is no need for other reaction initiators, such as oxygen, to coexist in the reaction system, and there is no need to perform two-stage polymerization using another reaction initiator. Further, a polymer in which a polymer molecule end is composed of only a residue in which a hydrogen atom is eliminated from a thiol group of the compound (A) and a hydrogen atom can be easily obtained.

[0034]

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

[0035]

Example 1 A butyl acrylate 10 was placed in a flask equipped with a stirrer, a nitrogen gas inlet tube, a thermometer and a reflux condenser.
0 parts by weight, nitrogen gas is introduced into the flask,
The air in the flask was replaced with nitrogen gas. Further, the contents of the flask were gently heated to a temperature of 40 ° C. while introducing nitrogen gas.

Then, 4 parts by weight of N-dodecyl mercaptan sufficiently substituted with nitrogen gas and 2-octanol 1
Parts by weight were added to the flask with stirring. After the addition of N-dodecyl mercaptan and 2-octanol, the mixture was reacted for 4 hours while cooling and heating so that the temperature in the flask during stirring was maintained at 40 ° C.

After a lapse of 4 hours, the temperature of the reaction product was returned to room temperature, and a benzoquinone solution (benzoquinone was added to THF) was added to the reaction product.
(A solution diluted to 5% by weight) was added to terminate the polymerization.

With respect to the THF solution of the reaction product thus obtained, the residual amount of the monomer was measured by gas chromatography, and the conversion was determined. As a result, the conversion was 4
5.7%, and no runaway of the polymerization reaction was observed at the time of the above polymerization.

[0039]

Example 2 After the inside of a flask equipped with a stirrer, a nitrogen gas inlet tube, a thermometer and a reflux condenser was replaced with nitrogen gas, the flask was charged with 1200 parts by weight of ethyl methacrylate, 225 parts by weight of methyl methacrylate, 75 parts by weight of butyl acid, 20 parts by weight of butyl mercaptan and s
4 parts by weight of ec-butyl alcohol were charged and stirred.
The mixture was heated to 70 ° C. with stirring while gently blowing nitrogen gas through the mixture. Polymerization was continued at this temperature for 6 hours.

After a lapse of 6 hours, the temperature of the reaction product was returned to room temperature, and a benzoquinone solution (benzoquinone was added to THF) was added to the reaction product.
300 parts by weight of a solution diluted to 5% by weight in the above was added to terminate the polymerization.

With respect to the THF solution of the reaction product thus obtained, the amount of the remaining monomer was measured by gas chromatography to determine the degree of polymerization. As a result, the conversion was 60
%, And no runaway of the polymerization reaction was observed during the polymerization.

[0042]

Example 3 A flask equipped with a stirrer, a nitrogen gas inlet tube, a thermometer and a reflux condenser was charged with 1000 parts by weight of 2-ethylhexyl acrylate and N-dodecyl mercaptan 4
0 parts by weight and 500 parts by weight of polypropylene glycol were charged, nitrogen gas was introduced into the flask, and the air in the flask was replaced with nitrogen gas. Further, the contents of the flask were gently heated to a temperature of 40 ° C. while introducing nitrogen gas. Polymerization was carried out at a temperature of 40 ° C. for 1 hour, and subsequently at 70 ° C. for 4 hours.

After 5 hours, the temperature of the reaction product was returned to room temperature, 100 parts by weight of the contents of the flask were weighed into a glass bottle, sealed, and stored in a cool and dark place kept at 10 ° C. for 15 days. On the other hand, 200 parts by weight of a benzoquinone solution (a solution of benzoquinone diluted to 5% by weight with THF) was added to the reaction product in the flask to terminate the polymerization.

With respect to the THF solution of the reaction product thus obtained, the amount of the remaining monomer was measured by gas chromatography to determine the degree of polymerization. As a result, the polymerization rate was 60%, and no runaway of the polymerization reaction was observed at the time of the above polymerization.

After 15 days, 20 parts by weight of a benzoquinone solution (a solution of benzoquinone diluted to 5% by weight with THF) was added to the reaction product in the glass bottle to terminate the polymerization.
With respect to the THF solution of the reaction product thus obtained, the residual amount of the monomer was measured using gas chromatography.
The conversion was determined. As a result, the polymerization rate was 92.2%, and no runaway of the polymerization reaction was observed during the storage.

[0046]

Example 4 A flask equipped with a stirrer, a nitrogen gas inlet tube, a thermometer, and a reflux condenser was charged with 1000 parts by weight of 2-ethylhexyl acrylate, and nitrogen gas was introduced into the flask, and air in the flask was aired. Was replaced with nitrogen gas. Further, the contents of the flask were gently heated to a temperature of 70 ° C. while introducing nitrogen gas.

Next, 80 parts by weight of N-dodecyl mercaptan sufficiently substituted with nitrogen gas and 2-octanol 2
0 parts by weight were added to the flask with stirring. After adding N-dodecyl mercaptan and 2-octanol, the mixture was reacted for 3 hours while cooling and heating so that the temperature inside the flask during stirring was maintained at 70 ° C.

After a lapse of 3 hours, the temperature of the reaction product was returned to room temperature, and a benzoquinone solution (benzoquinone was added to THF) was added to the reaction product.
(A solution diluted to 5% by weight) was added to stop the polymerization.

With respect to the THF solution of the thus obtained reaction product, the residual amount of the monomer was measured by gas chromatography, and the conversion was determined. As a result, the conversion was 7
It was 9.6%, and no runaway of the polymerization reaction was observed at the time of the above polymerization.

Subsequently, the obtained reaction product was transferred to an evaporator, and while gradually heating to 70 ° C. under reduced pressure, TH
F, residual monomer, residual N-dodecyl mercaptan and residual 2-octanol were removed. The residue obtained by heating the polymer thus obtained at 150 ° C. was 99.8%.

The molecular weight measured by gel permeation chromatography (GPC) was as follows: weight average molecular weight = 3200, number average molecular weight = 1800, dispersion index =
The viscosity was 1.7 and the viscosity at 25 ° C. was 890 centipoise (cps).

[0052]

Example 5 After replacing the inside of a flask equipped with a stirrer, a nitrogen gas inlet pipe, a thermometer and a reflux condenser with nitrogen gas, the flask was charged with 500 parts by weight of ethyl acrylate and N
-20 parts by weight of dodecyl mercaptan and 5 parts by weight of 2-octanol were charged, and the contents of the flask were stirred while maintaining the temperature at 25 ° C while introducing nitrogen gas.
Polymerization was continued at this temperature for 5 days.

After 5 days, 100 parts by weight of a benzoquinone solution (a solution obtained by diluting benzoquinone to 5% by weight with THF) was added to the reaction product to terminate the polymerization. With respect to the THF solution of the reaction product thus obtained, the residual amount of the monomer was measured by gas chromatography to determine the conversion. As a result, the polymerization rate was 92.8%, and no runaway of the polymerization reaction was observed during the polymerization.

[0054]

Comparative Example 1 A flask equipped with a stirrer, a nitrogen gas inlet tube, a thermometer and a reflux condenser was charged with butyl acrylate 100
0 parts by weight, nitrogen gas is introduced into the flask,
The air in the flask was replaced with nitrogen gas. Further, the contents of the flask were gently heated to a temperature of 70 ° C. while introducing nitrogen gas.

Next, 80 parts by weight of N-dodecyl mercaptan sufficiently substituted with nitrogen gas was added to the flask with stirring. After the addition of N-dodecyl mercaptan, the mixture was reacted for 3 hours while heating so that the temperature inside the flask during stirring was maintained at 70 ° C.

After 3 hours, the temperature of the reaction product was returned to room temperature, and a benzoquinone solution (benzoquinone was added to THF) was added to the reaction product.
(A solution diluted to 5% by weight) was added. With respect to the THF solution of the reaction product thus obtained, the residual amount of the monomer was measured by gas chromatography to determine the conversion. As a result, the conversion was 2%, and the conversion was extremely low.

[0057]

Comparative Example 2 A flask equipped with a stirrer, an air inlet tube, a thermometer and a reflux condenser was charged with 1,000 parts by weight of 2-ethylhexyl acrylate, nitrogen gas was introduced into the flask, and air in the flask was cooled. Was replaced with nitrogen gas.
Further, the contents of the flask were gently heated to a temperature of 70 ° C. while introducing nitrogen gas.

Next, 20 parts by weight of 2-octanol sufficiently substituted with nitrogen gas was added to the flask with stirring. After the addition of 2-octanol, the mixture was stirred for 3 hours while heating so that the temperature inside the flask during stirring was maintained at 70 ° C.

After 3 hours, the temperature of the contents of the flask was returned to room temperature, and a benzoquinone solution (benzoquinone was added to THF)
(A solution diluted to 5% by weight) was added.
About the THF solution of the content thus obtained, the residual amount of the monomer was measured using gas chromatography.
The conversion was determined. As a result, the conversion was 0%, and the polymerization did not proceed.

[0060]

Comparative Example 3 A flask equipped with a stirrer, an air inlet tube, a thermometer and a reflux condenser was charged with 1,000 parts by weight of 2-ethylhexyl acrylate, air was blown into the flask, and the flask was filled with air. The contents of the flask were slowly heated to a temperature of 75 ° C.

Next, 80 parts by weight of N-dodecyl mercaptan and 20 parts by weight of 2-octanol were added to the flask with stirring. N-dodecyl mercaptan and 2-
After the addition of octanol, the temperature in the flask during stirring was reduced to 7
While cooling and heating to be maintained at 0 ° C,
The reaction was performed for 3 hours.

After a lapse of 3 hours, the temperature of the reaction product was returned to room temperature, and a benzoquinone solution (benzoquinone was added to THF) was added to the reaction product.
(A solution diluted to 5% by weight) was added to stop the polymerization.

With respect to the THF solution of the reaction product thus obtained, the amount of the remaining monomer was measured by gas chromatography to determine the degree of polymerization. As a result, the conversion was 3
4.3%, and the polymerization was inhibited by oxygen.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J015 EA03 EA05 4J100 AC03Q AC04Q AE09Q AE18Q AG04Q AG08Q AJ01Q AJ02Q AJ03Q AJ08Q AJ09Q AK08Q AK31Q AK32Q AL03P AL04P AL05P AL08Q AL09Q AL11Q AL14Q16 AR16Q AS01Q AS02Q AS03Q AS04Q AS07Q AS15Q AU21Q BA02Q BA03Q BA04Q BA05Q BA06Q BA08Q BA20Q BA77Q BB01Q BB07Q BC04Q BC43Q BC54Q CA01 CA04 FA03 FA18 FA27 FA28

Claims (5)

[Claims] 1. A compound (A) having a thiol group in the molecule and not having a secondary hydroxyl group as a polymerization initiator in an inert gas atmosphere, and a compound (A) having a thiol group in the molecule as a catalyst for the compound (A). Compound having a graded hydroxyl group and no thiol group (B)
And a polymerizable monomer having an alkyl acrylate and / or an alkyl methacrylate as a main component is polymerized by using the above method. 2. With respect to 100 mol of the polymerizable monomer,
The polymerization method according to claim 1, wherein the compound (A) is used in a range of 0.1 to 30.0 mol and the compound (B) is used in a range of 0.01 to 2.0 mol. 3. The compound (A) comprises an alkyl group having 22 or less carbon atoms, an alkylene oxide group having 24 or less carbon atoms, an allyl group having 18 or less carbon atoms, a reactive silyl group, a primary hydroxyl group and a carboxyl group. The polymerization method according to claim 1, wherein the compound is a compound having at least one kind of organic group selected from the group consisting of: 4. The polymerization method according to claim 1, wherein the compound (B) has a molecular weight of 1,000 or less. 5. The polymerization of the polymerizable monomer is carried out at 20 to 12
2. The method according to claim 1, wherein the heating is performed at a temperature within a range of 0 ° C.
The polymerization method described in the above item.