KR100948871B1 - Lacton ring-containing polymer having a little foreign substances and being difficult to be gelled, and use thereof - Google Patents

Abstract

The present invention not only provides excellent transparency and heat resistance, but also provides desired properties such as mechanical strength and molding processability, and in particular, provides a lactone ring-containing polymer containing less foreign matter and less likely to gel.

The lactone ring-containing polymer of the present invention has a content of a polymer gel having an average particle diameter of 50 μm or more and 100 or less 100 g, a weight-average molecular weight of 50,000 to 170,000, and / or a viscosity increase after heating at 280 ° C. for 30 minutes for 2.0 Less than twice Molding materials formed by heating and granulating such polymers are preferable for optical parts such as light guides, optical lenses, and optical films.

Description

Lacton ring-containing polymer having a little foreign substances and being difficult to be gelled, and use else}

The present invention relates to a lactone ring-containing polymer containing less foreign matter and less likely to gel, and its use.

Conventionally, methacryl-type resin is known as resin which has transparency. Methacrylic resins not only have transparency but also have excellent surface gloss and weather resistance, and are well balanced in mechanical strength, molding processability and surface hardness, and thus are widely used for optical-related applications in automobiles and home appliances. However, since the glass transition temperature of methacryl-type resin is about 110 degreeC, use in the field | area where heat resistance is calculated | required was difficult.

As a transparent heat-resistant resin having transparency and heat resistance and also having various properties such as mechanical strength and molding processability, the lactone ring content obtained by lactone cyclization condensation reaction of a polymer having a hydroxy group and an ester group in a molecular chain has recently been performed. Several polymers have been proposed. For example, by reacting a 2-hydroxymethyl acrylic acid alkyl ester / methyl methacrylate copolymer with a de-alcohol, which is a kind of transesterification, a lactone ring is formed by condensation of hydroxy groups and ester groups present in the same molecule. Polymer.

In the production of the lactone ring-containing polymer, a polymer having a hydroxy group and an ester group is obtained in the molecular chain, and then subjected to a lactone cyclization condensation step. Therefore, when a branch is present in the polymer chain, a dealcohol reaction occurs between the molecules, so-called polymer. Gel is likely to occur.

In addition, in the conventional manufacturing method, as described in the Example of patent document 1, normally, t-butyl-type peroxide was used as a polymerization initiator, but this kind of polymerization initiator is carried out from a polymer molecular chain. The ability to extract hydrogen is high, whereby branching of the polymer molecular chains and intermolecular crosslinking occur, and polymer gels are likely to occur.

In addition, although the experimental example using t-amyl peroxide and an azo initiator was described in the Example of patent document 2, the obtained polymer has a weight-average molecular weight of 180,000-500,000 relatively high, and a polymer gel generate | occur | produces in such a molecular weight range. easy.

(Patent Document 1) Japanese Unexamined Patent Publication No. 2000-230016

(Patent Document 2) Japanese Unexamined Patent Publication No. 2005-146084

By the way, for example, in optical use, such as an optical film, it exists as a problem that a foreign material exists in an optical material, and it is necessary to reduce foreign material as much as possible. The lactone ring-containing polymer obtained by the conventional manufacturing method is a molding material having excellent optical properties. However, the polymer gel is present as a foreign material in the polymer pellets, and there is a problem that gelation occurs by applying heat during molding. . Therefore, in optical applications, there has been a demand for molding materials which are less foreign matter even in the step of polymer pellets and are less likely to cause gelation even when heat is applied during molding.

Under the above circumstances, the problem to be solved by the present invention is not only excellent in transparency and heat resistance, but also has desired characteristics such as mechanical strength and molding processability, and in particular, provides a lactone ring-containing polymer containing less foreign matter and difficult to gel. It's there.

As a result of various studies, the present inventors have found that in the production of lactone ring-containing polymers, hydrogen is removed from the polymer molecular chain, such as t-amyl peroxide, azo initiator, living radical initiator, and the like instead of t-butyl peroxide. By using a polymerization initiator having a low ability to extract the resin and limiting the molecular weight within a predetermined range, the production of the polymer gel can be suppressed, and when used as a molding material, for example, extrusion may be performed even if heat is applied. It was found that a lactone ring-containing polymer, which is hard to increase by gelation even when thermally retained during molding, is obtained, and 2-hydroxymethylacrylic acid ester purified by a specific method for producing a lactone ring-containing polymer is obtained. When used as a monomer and a t-amyl peroxide is used as a polymerization initiator, the polyols in the lactone ring-containing polymer It found that it is possible to suppress the generation of meogel very effective and have completed the present invention.

That is, in the present invention, the content of the polymer gel having an average particle diameter of 50 µm or more is 100 g / lactone ring-containing polymer 100 g or less, the weight-average molecular weight is 50,000 to 170,000, and / or the viscosity increase rate after heating at 280 ° C. for 30 minutes. It provides the lactone ring containing polymer characterized by being 2.0 times or less. In the present invention, "polymer gel" refers to ²² which polymer constitutes a three-dimensional network structure by chemical bonds, í �� by interaction between polymer molecular chains. The content of the polymer gel in the present invention is that the lactone ring-containing polymer is soluble in 100 g of a lactone ring-containing polymer and dissolved in 500 ml of a solvent (for example, methyl ethyl ketone, etc.) purified by microfiltration, and then the average pore size. Filtration is performed with a 1.0 micrometer polytetrafluoroethylene membrane filter, and the number of polymer gels with an average particle diameter of 50 micrometers or more remaining on the filter is counted visually under a microscope, and is computed.

The lactone ring-containing polymer of the present invention preferably has a lactone ring structure represented by the following formula (1):

Where

R ¹ , R ² and R ³ independently of one another represent a hydrogen atom or an organic moiety having 1 to 20 carbon atoms. In addition, the organic residue may contain an oxygen atom.

The present invention also provides a molding material which is formed by heating and granulating the lactone ring-containing polymer, and an optical part, which is formed from the molding material. As said optical component, a light guide, an optical lens, an optical film, etc. are mentioned, for example.

Moreover, in this invention, when manufacturing the said lactone ring 유 containing polymer, it is a preferable monomer when using a t-amyl type peroxide as a polymerization initiator, It is 90 degreeC as 2-hydroxymethylacrylic acid ester represented by following formula (2). The 2-hydroxymethylacrylic acid ester is characterized by having a turbidity of 0.05 or less after a 2 hour heating test.

Where

R ⁴ and R ⁵ independently of one another represent a hydrogen atom or an organic moiety having 1 to 20 carbon atoms. In addition, the organic residue may contain an oxygen atom.

≪Lactone ring 유 containing polymer≫

In some aspects, the lactone ring-containing polymer of the present invention is characterized in that the content of the polymer gel having an average particle diameter of 50 µm or more is 100 g / lactone ring-containing polymer or less, and the weight-average molecular weight is 50,000 to 170,000. Here, "polymer gel" means that the polymer constitutes a three-dimensional network structure by chemical bonding or by interaction between polymer molecular chains. In the present invention, "polymer gel" and "foreign substance" are used to be interchangeable. In the present invention, the content of the polymer gel is 100 g of the lactone ring-containing polymer is soluble in the lactone ring-containing polymer and dissolved in 500 ml of a solvent (for example, methyl ethyl ketone, etc.) purified by microfiltration, and then the average pore size is 1.0 µm. It filters by using a polytetrafluoroethylene membrane filter, and counts the number of polymer gels with an average particle diameter of 50 micrometers or more which remained on the filter visually under a microscope, and computes it.

When the lactone ring-containing polymer is used for optical purposes as a molding material, a polymer gel having an average particle diameter of 50 µm or more becomes a problem. Therefore, in this invention, content of the polymer gel of average particle diameter 50 micrometers or more was prescribed | regulated to 100g / lactone ring containing polymer 100g or less. In addition, the content of the polymer gel is 100 g of the lactone ring-containing polymer is soluble in the lactone ring-containing polymer, and dissolved in 500 ml of a solvent (for example, methyl ethyl ketone, etc.) purified by microfiltration, and the average pore size is 1.0 µm. It filters by the membrane filter made from polytetrafluoroethylene, and counts and calculates the number of polymer gels with an average particle diameter of 50 micrometers or more remaining on the filter visually under a microscope. When the content of the polymer gel exceeds 100 g of the 100-lactone ring-containing polymer, it may not be suitable for optical use when used as a molding material. The content of the polymer gel is preferably 100 g or less of 50 / lactone ring-containing polymer, more preferably 100 g or less of 20 / lactone ring-containing polymer. Ideally, no polymer gel is included in the lactonation containing polymer.

In addition, the lactone ring-containing polymer tends to easily generate a polymer gel when the molecular weight is high. Therefore, in the present invention, the weight-average molecular weight is defined as 50,000 to 170,000. The weight-average molecular weight is preferably in the range of 100,000 to 150,000. In addition, a weight: average molecular weight shall be the value computed by polystyrene conversion using the gel permeation chromatograph. When the weight average molecular weight of the polymer is less than 50,000, the melt flow rate is high, and when used as a molding material, for example, molding may be difficult by the melt extrusion method or the like. On the contrary, when the weight-average molecular weight of the polymer exceeds 170,000, the polymer gel is easily generated, the melt flow rate is lowered, and when used as a molding material, molding may be difficult, for example, by injection molding.

In another aspect, the lactone ring-containing polymer of the present invention is characterized by having a viscosity increase rate of 2.0 times or less after heating at 280 ° C. for 30 minutes. Here, the "viscosity increase rate" is obtained by measuring the melt viscosity under conditions of a temperature of 250 ° C., a load of 10 kgf / cm 2, and a die shape of 0.5 mmφ × 1 mm before and after heating the polymer at 280 ° C. for 30 minutes. The ratio of melt viscosity (after heating / before heating) is meant. When the viscosity increase rate of the polymer exceeds 2.0 times, when used as a molding material, molding processability may decrease. The lower limit of the viscosity increase rate of the polymer is ideally 1.0 times, but considering the case where a part of the polymer is decomposed, it is 0.8 times. In addition, the viscosity increase rate is an index of gelation that occurs when heat is added to the polymer, and a smaller value hardly causes gelation.

The lactone ring -containing polymer of the present invention preferably has a mass reduction rate in the range of 150 to 300 ° C in the dynamic TG measurement, preferably 1% or less, more preferably 0.5% or less, and still more preferably 0.3% or less.

Since the lactone ring containing polymer of this invention has a high cyclization condensation reaction rate, the fault that a foam and a silver streak enter in the molded article after shaping | molding can be avoided. In addition, since the lactone ring structure is sufficiently introduced into the polymer by a high cyclization condensation reaction rate, the obtained lactone ring-containing polymer has sufficiently high heat resistance.

When the lactone ring-containing polymer of the present invention is a chloroform solution having a concentration of 15% by mass, the degree of coloring (YI) is preferably 6 or less, more preferably 3 or less, more preferably 2 or less, particularly preferably 1 It is as follows. When coloring degree (YI) exceeds 6, transparency may be impaired by coloring, and it may not be able to use especially for optical use.

The lactone ring -containing polymer of the present invention has a 5% mass reduction temperature in thermal mass spectrometry (TG), preferably 300 ° C or more, more preferably 320 ° C or more, and even more preferably 330 ° C or more. 5% mass loss temperature in thermal mass spectrometry (TG) is an index of thermal stability, and when this is less than 300 ° C, sufficient thermal stability may not be exhibited.

The lactone ring-containing polymer of the present invention preferably has a glass transition temperature (Tg) of at least 100 ° C, more preferably at least 110 ° C, more preferably at least 120 ° C, particularly preferably at least 130 ° C.

In the lactone ring-containing polymer of the present invention, the total amount of remaining volatile matter contained therein is preferably 1,500 ppm or less, more preferably 1,000 ppm. If the total amount of remaining volatile matter exceeds 1,500 ppm, it may cause molding defects such as coloring, foaming, and silver streak due to deterioration during molding or the like.

The lactone ring-containing polymer of the present invention preferably has a total light transmittance of 85% or more, more preferably 88% or more, more preferably measured by a method according to ASTM-D-1003 for a molded article obtained by injection molding. Is more than 90%. The total light transmittance is an index of transparency, and if it is less than 85%, the transparency is lowered, and in particular, it may not be used for optical applications.

The lactone ring-containing polymer of the present invention preferably has a lactone ring structure represented by the following formula (1).

Where

R ¹ , R ² and R ³ independently of one another represent a hydrogen atom or an organic moiety having 1 to 20 carbon atoms. In addition, the organic residue may contain an oxygen atom.

Preferably the content rate of the lactone ring structure represented by said Formula (1) in the structure of a lactone ring 유 containing polymer is 5-90 mass%, More preferably, it is 10-70 mass%, More preferably, it is 10-60 mass %, Especially preferably, it is 10-50 mass%. When the content rate of lactone ring structure is less than 5 mass%, the heat resistance, solvent resistance, and surface hardness of the obtained polymer may fall. On the contrary, when the content rate of a lactone ring structure exceeds 90 mass%, the moldability of the obtained polymer may fall.

The lactone ring-containing polymer may have a structure other than the lactone ring structure represented by the formula (1). Although the structure other than the lactone ring structure represented by said formula (1) is not specifically limited as a structure, For example, the (meth) acrylic acid ester, the hydroxyl group containing monomer, and the following which are mentioned later as a manufacturing method of a lactone ring containing polymer, Polymer structural units (repeated structural units) formed by polymerizing at least one monomer selected from the group consisting of monomers represented by formula (3) are preferred:

Where

R ⁶ represents a hydrogen atom or a methyl group,

X represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group, -OAc group, -CN group, -CO-R ⁷ group, or -COOH group,

Ac represents an acetyl group,

R ⁷ represents a hydrogen atom or an organic residue having 1 to 20 carbon atoms.

Although the manufacturing method of a lactone ring containing polymer is not specifically limited, For example, after obtaining the polymer (a) which has a hydroxyl group and an ester group in a molecular chain by a polymerization process, it heat-processes the obtained polymer (a). It can obtain by performing the lactone cyclization condensation process which introduce | transduces a lactone ring structure into a polymer by this.

In the polymerization step, for example, a molecule is formed by carrying out a polymerization reaction of a monomer component blended with a monomer represented by the following formula (2) (hereinafter sometimes referred to as "2-hydroxymethylacrylic acid ester"). Polymers having hydroxyl and ester groups in the chain are obtained:

Where

R ⁴ and R ⁵ independently of one another represent a hydrogen atom or an organic moiety having 1 to 20 carbon atoms. In addition, the organic residue may contain an oxygen atom.

As a monomer represented by the said Formula (2), the monomer whose substituent represented by (a) R <^4> is a hydrogen atom, for example, 2-hydroxymethyl acrylic acid, 2- (1-hydroxyethyl) acrylic acid, 2 -(1-hydroxybutyl) acrylic acid, 2- (1-hydroxy-2-ethyl hexyl) acrylic acid, etc .; (b) Monomer whose substituent represented by R <^4> is a C1-C18 alkyl group, for example, 2-hydroxymethyl acrylate, methyl 2- (1-hydroxyethyl) acrylate, 2- (1-hydroxybutyl) Methyl acrylate, 2- (1-hydroxy-2-ethylhexyl) methyl acrylate, 2-hydroxymethyl acrylate, ethyl 2- (1-hydroxyethyl) acrylate, 2- (1-hydroxybutyl) acrylic acid Ethyl, 2- (1-hydroxy-2-ethyl hexyl) ethyl acrylate, 2-hydroxymethyl acrylate n-propyl, 2- (1-hydroxyethyl) acrylate n-propyl, 2- (1-hydroxybutyl N-propyl acrylate, 2- (1-hydroxy-2-ethylhexyl) n-propyl acrylate, isopropyl 2-hydroxymethyl acrylate, isopropyl 2- (1-hydroxyethyl) acrylate, 2- (1) -Hydroxybutyl) isopropyl acrylate, 2- (1-hydroxy-2-ethyl hexyl) isopropyl acrylate, n-butyl 2-hydroxymethyl acrylate, 2-hydroxymeth Isobutyl acrylate, t-butyl 2-hydroxymethyl acrylate, n-octyl 2-hydroxymethyl acrylate, isooctyl 2-hydroxymethyl acrylate, 2-ethylhexyl 2-hydroxyhexyl acrylate, 2-hydroxymethyl acrylate Stearyl and the like; (c) Monomer whose substituent represented by R <^4> is a C3-C10 cycloalkyl group, for example, 2-hydroxymethyl acrylate cyclopentyl, 2- (1-hydroxyethyl) acrylic acid cyclopentyl, 2- (1- Hydroxybutyl) acrylic acid cyclopentyl, 2- (1-hydroxy-2-ethylhexyl) cyclopentyl acrylate, 2-hydroxymethylacrylic acid cyclohexyl and the like; (d) Monomer whose substituent represented by R <^4> is an aryl group, for example, 2-hydroxymethyl acrylate, phenyl 2- (1-hydroxyethyl) acrylate, phenyl 2- (1-hydroxybutyl) acrylate, 2 -(1-hydroxy-2-ethylhexyl) phenyl acrylate, 2-hydroxymethyl acrylate o-methoxyphenyl, 2-hydroxymethyl acrylate p-methoxyphenyl, 2-hydroxymethyl acrylate p-nitrophenyl, 2-hydroxymethyl acrylate o-methylphenyl, 2-hydroxymethyl acrylate p-methylphenyl, 2-hydroxymethyl acrylate pt-butyl phenyl, etc. are mentioned. These monomers can be used alone or in combination of two or more. Among these monomers, methyl 2-hydroxymethyl acrylate, 2-hydroxymethyl acrylate, n-butyl 2-hydroxymethyl acrylate, 2-ethylhexyl 2-hydroxymethyl acrylate, 2-hydroxymethyl acrylate 2- Hydroxyethyl and 2-hydroxymethylacrylic acid 2-hydroxypropyl are preferable, and 2-hydroxymethylacrylic methyl is especially preferable at the point that the effect of improving heat resistance is high.

Preferably the content rate of the monomer represented by the said Formula (2) in the monomer component injected into a polymerization process becomes like this. 2.5-50 mass%, More preferably, it is 5-40 mass%, More preferably, it is 5-35 mass %, Especially preferably, it is 5-30 mass%. When the content rate of the monomer represented by the said Formula (2) is less than 2.5 mass%, the heat resistance, solvent resistance, and surface hardness of the obtained polymer may fall. On the contrary, when the content rate of the monomer represented by the said Formula (2) exceeds 50 mass%, gelation may arise in a superposition | polymerization process or a lactone cyclization condensation process, and the molding processability of the obtained polymer may fall.

Monomers other than the monomer represented by the said Formula (2) can be mix | blended with the monomer component input to a superposition | polymerization process. Although it does not specifically limit as such a monomer, For example, the (meth) acrylic acid ester, the monomer represented by following formula (3), etc. are mentioned:

Where

R ⁶ represents a hydrogen atom or a methyl group,

X represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group, -OAc group, -CN group, -CO-R ⁷ group, or -COOH group,

Ac represents an acetyl group,

R ⁷ represents a hydrogen atom or an organic residue having 1 to 20 carbon atoms.

These monomers can be used individually or in combination of 2 or more types.

As (meth) acrylic acid ester, although it is not specifically limited as long as it is (meth) acrylic acid ester other than the monomer represented by the said Formula (2), For example, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, Acrylic esters such as t-butyl acrylate, cyclohexyl acrylate, and benzyl acrylate; Methacrylic acid, such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, cyclohexyl methacrylate, and benzyl methacrylate ester; Etc. can be mentioned. These (meth) acrylic acid esters can be used individually or in combination of 2 or more types. Among these (meth) acrylic acid esters, methyl methacrylate is particularly preferable in terms of excellent heat resistance and transparency of the obtained polymer.

When using (meth) acrylic acid esters other than the monomer represented by the said Formula (2), the content rate in the monomer component thrown into a polymerization process fully exhibits the effect of this invention, Preferably it is 10-97.0. It is mass%, More preferably, it is 10-95 mass%, More preferably, it is 40-95 mass%, Especially preferably, it is 50-95 mass%.

As a monomer represented by the said Formula (3), styrene, (alpha) -methylstyrene, vinyl toluene, acrylonitrile, methyl vinyl ketone, ethylene, propylene, vinyl acetate etc. are mentioned, for example. These monomers may be used alone or in combination of two or more.

When using the monomer represented by the said Formula (3), the content rate in the monomer component thrown into a polymerization process fully exhibits the effect of this invention, Preferably it is 0-30 mass%, More preferably, 0-20 mass%, More preferably, it is 0-15 mass%, Especially preferably, it is 0-10 mass%.

As a form of the polymerization reaction for superposing | polymerizing a monomer component and obtaining the polymer which has a hydroxyl group and an ester group in a molecular chain, it is preferable that it is a polymerization form using a solvent, and solution polymerization is especially preferable. In addition, since living radical polymerization consists only of an initiation reaction and a growth reaction, there is no side reaction that inactivates growth ends such as stop or chain transfer, so that hydrogen is rarely extracted from the polymer molecular chain, and it is particularly preferable to suppress the generation of polymer gel. .

The polymerization temperature and the polymerization time vary depending on the type and proportion of the monomer to be used. For example, the polymerization temperature is preferably 0 to 150 ° C, the polymerization time is 0.5 to 20 hours, and more preferably the polymerization temperature is 80 to 80 ° C. 140 degreeC and polymerization time are 1 to 10 hours.

In the case of the polymerization form using a solvent, it is not specifically limited as a polymerization solvent, For example, aromatic hydrocarbon solvents, such as toluene, xylene, ethylbenzene; Ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; Ether solvents such as tetrahydrofuran; Etc. can be mentioned. These solvents can be used alone or in combination of two or more. Moreover, when the boiling point of a solvent is too high, the solvent with a boiling point of 50-200 degreeC is preferable at the point that the residual volatile matter of the lactone ring 유 containing polymer finally obtained increases.

At the time of a polymerization reaction, a polymerization initiator can be added as needed. Examples of the polymerization initiator include, but are not limited to, t-amylperoxy-2-ethylhexanoate and t-amylperoxyisononano as long as it is an initiator having a low ability to extract hydrogen from the polymer molecular chain. T-amyl peroxides such as acetate, t-amylperoxyacetate, t-amylperoxybenzoate and 1,1-di (t-amylperoxy) cyclohexane; 2,2'-azobis (isobutylonitrile), 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), dimethyl Azo initiators such as 2,2'-azobis isobutyrat; Living radical initiators such as dichlorotris (triphenylphosphine) ruthenium, aluminum triisopropoxide, 2,2'-dichloro acetophenone, and the like. This polymerization initiator can be used alone or in combination of two or more. As described later in these polymerization initiators, when the monomer represented by the formula (2) is purified by a specific method, t-amyl can be very effectively suppressed from generation of the polymer gel in the lactone ring-containing polymer. Type peroxides are particularly preferred. In addition, the usage-amount of a polymerization initiator can be suitably set according to a combination of monomers, k ° condensation conditions, etc., and is not specifically limited.

When performing polymerization, in order to suppress gelation of a reaction liquid, it is preferable to control so that the density | concentration of the polymer produced | generated in a polymerization reaction mixture may be 50 mass% or less. Specifically, in the case where the concentration of the polymer produced in the polymerization reaction mixture exceeds 50 mass%, it is preferable to control the polymerization solvent so as to be 50 mass% or less by appropriately adding the polymerization solvent. The concentration of the polymer produced in the polymerization mixture is more preferably 45 mass% or less, and more preferably 40 mass% or less. Moreover, since productivity will fall when the density | concentration of the polymer produced | generated in a polymerization reaction mixture is too low, the density | concentration of the polymer produced | generated in a polymerization reaction mixture becomes like this. Preferably it is 10 mass% or more, More preferably, it is 20 mass% or more.

Although it does not specifically limit as a form which adds a polymerization solvent suitably to a polymerization reaction mixture, For example, a polymerization solvent may be added continuously and a polymerization solvent may be added intermittently. By controlling the concentration of the polymer produced in the polymerization reaction mixture in this way, the gelation of the reaction solution can be more fully suppressed, and in particular, the hydroxyl group and the ester group in the molecular chain can be improved in order to increase the lactone ring-containing content and improve heat resistance. Even when the ratio of is increased, gelation can be sufficiently suppressed. The polymerization solvent to be added may be, for example, a solvent of the same kind as the solvent used during the initial charging of the polymerization reaction, or may be a different kind of solvent. It is preferable to use. Moreover, the polymerization solvent to add may be only one type of single solvent, or 2 or more types of mixed solvent.

In the polymerization reaction mixture obtained at the end of the above polymerization process, a solvent is usually contained in addition to the obtained polymer. However, it is not necessary to completely remove the solvent to remove the polymer from the solid state. It is preferable to introduce into a lactone cyclization condensation process. Moreover, if necessary, after taking out in a solid state, the solvent suitable for the subsequent lactone cyclization condensation process may be added again.

The polymer obtained in the polymerization step is a polymer (a) having a hydroxyl group and an ester group in the molecular chain, and the weight-average molecular weight of the polymer (a) is preferably 50,000 to 170,000, more preferably 60,000 to 170,000, and more preferably 70,000-170,000. In the subsequent lactone cyclization condensation step, the polymer (a) obtained in the polymerization step is subjected to heat treatment to introduce the lactone ring structure into the polymer, thereby forming a lactone ring 유 containing polymer.

The reaction for introducing the lactone ring structure into the polymer (a) is a reaction in which the hydroxy group and the ester group present in the molecular chain of the polymer (a) undergo cyclization condensation to generate a lactone ring structure. This is a byproduct. The lactone ring structure is formed in the molecular chain of the polymer (in the main skeleton of the polymer), thereby providing high heat resistance. If the reaction rate of the cyclization condensation reaction leading to the lactone ring structure is insufficient, the heat resistance may not be sufficiently improved, or the condensation reaction may occur during molding by the heat treatment at the time of molding, and the alcohol generated may be bubbled or silver streak in the molded product. There may be it.

The lactone ring-containing polymer obtained in the lactone cyclization condensation step preferably has a lactone ring structure represented by the following formula (1):

Where

R ¹ , R ² and R ³ independently of one another represent a hydrogen atom or an organic moiety having 1 to 20 carbon atoms. In addition, the organic residue may contain an oxygen atom.

It does not specifically limit about the method of heat-processing a polymer (a), A conventionally well-known method can be used. For example, the polymerization reaction mixture containing the solvent obtained by the polymerization step may be heat treated as it is. Or in the presence of a solvent, you may heat-process using a ring-closure catalyst as needed. Alternatively, the heat treatment may be performed using a vacuum apparatus for removing volatile matter, a heating furnace equipped with a devolatilization device, a reactor, or an extruder equipped with a devolatilization device.

When performing a cyclization condensation reaction, you may add to a polymer (a) and coexist other thermoplastic resins. When carrying out the cyclization condensation reaction, an esterification catalyst or a transesterification catalyst such as k-toluenesulfonic acid, which is generally used as a catalyst for cyclization condensation reaction, can be used, if necessary, and acetic acid, propionic acid, benzoic acid, acrylic acid and methacrylic acid. Organic carboxylic acids, such as an acid, can also be used as a catalyst. Further, for example, as disclosed in Japanese Patent Laid-Open No. S61-254608 and Japanese Patent Laid-Open No. S61-261303, basic compounds, organic carboxylates, carbonates and the like can also be used.

Or you may use an organophosphorus compound as a catalyst of a cyclization condensation reaction. Examples of the organophosphate compound that can be used include, for example, alkyl (aryl) phosphonic acids such as methylaphosphonic acid, ethylaphosphonic acid, and phenylaphosphonic acid (however, these may be alkyl (aryl) phosphinic acids which are tautomers). And mono esters or diesters thereof; Dialkyl (aryl) phosphinic acids such as dimethylphosphinic acid, diethylphosphinic acid, diphenylphosphinic acid, phenylmethylphosphinic acid and phenylethylphosphinic acid and esters thereof; Alkyl (aryl) phosphonic acids such as methyl phosphonic acid, ethyl phosphonic acid, trifluoromethyl phosphonic acid and phenyl phosphonic acid and monoesters or diesters thereof; Alkyl (aryl) aphosphinic acids and esters thereof such as methyl aphosphinic acid, ethyl aphosphinic acid and phenyl aphosphinic acid; Phosphorous acid monoesters, diesters or triesters such as methyl phosphite, ethyl phosphite, phosphite phenyl, phosphite dimethyl, phosphite diethyl, phosphite diphenyl, trimethyl phosphite, triethyl phosphite and triphenyl phosphite; Methyl phosphate, ethyl phosphate, 2-ethylhexyl phosphate, octyl phosphate, isodecyl phosphate, lauryl phosphate, stearyl phosphate, isostearyl phosphate, phenyl phosphate, dimethyl phosphate, diethyl phosphate, di-2-ethylhexyl phosphate, Diisodecyl phosphate, dilauryl phosphate, distearyl phosphate, diisostearyl phosphate, diphenyl phosphate, trimethyl phosphate, triethyl phosphate, triisodecyl phosphate, trilauryl phosphate, tristearyl phosphate, triisoste phosphate Phosphoric acid monoesters, diesters or triesters such as aryl and triphenyl phosphate; Mono-, di- or tri-alkyl such as methylphosphine, ethylphosphine, phenylphosphine, dimethylphosphine, diethylphosphine, diphenylphosphine, trimethylphosphine, triethylphosphine, triphenylphosphine (Aryl) phosphine; Alkyl (aryl) halogen phosphines such as methyldichlorophosphine, ethyldichlorophosphine, phenyldichlorophosphine, dimethylchlorophosphine, diethylchlorophosphine and diphenylchlorophosphine; Methyl phosphine oxide, ethyl phosphine oxide, phenyl phosphine oxide, dimethyl phosphine oxide, diethyl phosphine oxide, diphenyl phosphine oxide, trimethyl phosphine oxide, triethyl phosphine oxide, triphenyl phosphine oxide, etc. Oxidized mono-, di- or tri-alkyl (aryl) phosphines; Halogenated tetraalkyl (aryl) phosphoniums such as tetramethylphosphonium chloride, tetraethylphosphonium chloride and tetraphenylphosphonium chloride; Etc. can be mentioned. These organophosphorus compounds can be used individually or in combination of 2 or more types. Among these organophosphorus compounds, alkyl (aryl) aphosphonic acid, phosphorous acid monoester or diester, phosphoric acid monoester or diester and alkyl (aryl) phosphonic acid are preferable in view of high catalytic activity and low colorability. More preferred are alkyl (aryl) aphosphonic acid, phosphorous acid monoesters or diesters, phosphoric acid monoesters or diesters, with alkyl (aryl) aphosphonic acid, phosphoric acid monoesters or diesters being particularly preferred.

The amount of the catalyst used in the cyclization condensation reaction is not particularly limited, but for example, the polymer (a) is preferably 0.001-5% by mass, more preferably 0.01-2.5% by mass, more preferably. Preferably it is 0.01-1 mass%, Especially preferably, it is 0.05-0.5 mass%. When the usage-amount of a catalyst is less than 0.001 mass%, the reaction rate of a cyclization condensation reaction may not fully improve. On the contrary, when the usage-amount of a catalyst exceeds 5 mass%, the obtained polymer may color, or a polymer may bridge | crosslink and melt molding may become difficult.

The addition time of a catalyst is not specifically limited, For example, you may add in the initial stage of reaction, you may add in the middle of reaction, or you may add in both of them.

It is preferable to perform a cyclization condensation reaction in presence of a solvent, and to use a devolatilization process together at the time of a cyclization condensation reaction. In this case, the form which uses a devolatilization process together through the whole cyclization condensation reaction, and the form which uses only a part of process without using together the devolatilization process throughout the process of cyclization condensation reaction is mentioned. In the method using the devolatilization step together, alcohol produced by condensation in the condensation cyclization reaction is forcibly devolatilized and removed, so that the reaction equilibrium is advantageous to the production side.

The devolatilization step means a step of removing and removing volatile components such as solvents and residual monomers, and alcohol produced by cyclization condensation reaction leading to a lactone ring structure under reduced pressure heating conditions as necessary. When this removal process is inadequate, the amount of residual volatiles in the obtained polymer increases, which may result in coloration due to deterioration or the like during molding, or poor molding such as foam or silver streaks.

In the case of using the devolatilization step in combination throughout the cyclization condensation reaction, the apparatus to be used is not particularly limited. For example, in order to implement the present invention more effectively, a heat exchanger and a devolatilization tank are provided. It is preferable to use a devolatilization device or an extruder with a vent, or a devolatilizer and an extruder arranged in series, and more preferably a devolatilizer or a extruder with a vent composed of a heat exchanger and a devolatilization tank. .

When using the devolatilization apparatus comprised from a heat exchanger and a devolatilization tank, reaction reaction temperature becomes like this. Preferably it is 150-350 degreeC, More preferably, it is 200-300 degreeC. When reaction process temperature is less than 150 degreeC, cyclization condensation reaction may become inadequate and residual volatile matter may increase. In contrast, when the reaction treatment temperature exceeds 350 ° C, coloring or decomposition of the obtained polymer may occur.

The reaction treatment pressure in the case of using a devolatilization device composed of a heat exchanger and a devolatilization tank is preferably 931 to 1.33 hPa (700 to 1 mmHg), more preferably 798 to 66.5 hPa (600 to 50 mmHg). When reaction process pressure exceeds 931 hPa (700 mmHg), the volatile matter containing alcohol will remain easy. On the contrary, industrial reaction may become difficult when reaction process pressure is less than 1.33 hPa (1 mmHg).

When using an extruder with a vent, one or more vents may be used, but it is preferable to have a some vent.

The reaction treatment temperature in the case of using an extruder with a vent is preferably 150 to 350 ° C, more preferably 200 to 300 ° C. If the reaction treatment temperature is less than 150 ° C, the cyclization condensation reaction may be insufficient, and the remaining volatile content may increase. In contrast, when the reaction treatment temperature exceeds 350 ° C, coloring or decomposition of the obtained polymer may occur.

The reaction treatment pressure when using an extruder with a vent is preferably 931 to 1.33 hPa (700 to 1 mmHg), more preferably 798 to 13.3 hPa (600 to 10 mmHg). When reaction process pressure exceeds 931 hPa (700 mmHg), the volatile matter containing alcohol will remain easy. Conversely, when the reaction treatment pressure is less than 1.33 hPa (1 mmHg), industrial implementation may be difficult.

In the case of using the devolatilization step in combination throughout the cyclization condensation reaction, as described below, the physical properties of the lactone ring-containing polymer obtained may be deteriorated under severe heat treatment conditions, and thus the catalyst for the dealcoholization reaction described above. It is preferable to carry out using an extruder with a vent or the like, under conditions that are as gentle as possible.

In the case of using the devolatilization step in combination throughout the cyclization condensation reaction, the polymer (a) obtained in the polymerization step is preferably introduced into the cyclization condensation reaction apparatus together with the solvent. It may also be passed through a cyclization condensation reaction apparatus such as an extruder with a vent.

The devolatilization process may not be used throughout the course of the cyclization condensation reaction, but may be used in combination with only a part of the process. For example, the apparatus which manufactured the polymer (a) is further heated, the partial devolatilization process is used together as needed, the cyclization condensation reaction is advanced to some extent, and the devolatilization process is then used simultaneously simultaneously. It is a form which performs a cyclization condensation reaction and completes a reaction.

In the form which uses a devolatilization process together through the whole cyclization condensation reaction mentioned above, the heat history difference when a polymer (a) is heat-processed at the high temperature of 250 degreeC or more using a twin screw extruder, for example. As a result, some decomposition or the like occurs before the cyclization condensation reaction occurs, and the physical properties of the resulting lactone ring-containing polymer may deteriorate. Therefore, if the cyclization condensation reaction is performed to some extent before the cyclization condensation reaction using the devolatilization step simultaneously, the reaction conditions in the latter stage can be alleviated, and the deterioration of the physical properties of the resulting lactone ring-containing polymer is suppressed. It is preferable because it can be done. As a particularly preferred embodiment, for example, the devolatilization process is started over time from the start of the cyclization condensation reaction, that is, the hydroxy group and the ester group present in the molecular chain of the polymer (a) obtained in the polymerization process are previously cyclized condensation reaction. By raising the cyclization condensation reaction rate to some extent, the cyclization condensation reaction which used the devolatilization process simultaneously is mentioned. Specifically, for example, a kettle-type reactor is previously used to advance the cyclization condensation reaction to a certain reaction rate in the presence of a solvent, and then a reactor equipped with a devolatilization device, for example, a heat exchanger and a devolatilization tank. The form which completes a cyclization condensation reaction is preferable in the devolatilization apparatus comprised, the extruder with a vent, etc. which are comprised. Especially in this form, it is more preferable that the catalyst for cyclization condensation reaction exists.

As described above, the cyclization condensation reaction of the hydroxy group and the ester group present in the molecular chain of the polymer (a) obtained in the polymerization step is carried out in advance to raise the degree of cyclization condensation reaction to some extent, followed by the simultaneous use of the devolatilization step. The method of performing a reaction is a preferable aspect in obtaining a lactone ring containing polymer in this invention. With this form, the glass transition temperature is higher, the cyclization condensation reaction rate is also higher, and a lactone ring-containing polymer having excellent heat resistance can be obtained. In this case, as a target of the cyclization condensation reaction rate, the mass reduction rate in the range of 150-300 degreeC in the dynamic TG measurement shown in an Example, for example, Preferably it is 2% or less, More preferably, it is 1.5% or less, More preferably, it is 1% or less.

The reactor that can be employed during the cyclization condensation reaction that is performed in advance before the cyclization condensation reaction using the devolatilization process simultaneously is not particularly limited, but includes, for example, an autoclave, a kettle-type reactor, a heat exchanger, and a devolatilization tank. And a devolatilization device. Moreover, the vented extruder which is preferable for the cyclization condensation reaction which used the devolatilization process simultaneously can also be used. Of these reactors, autoclaves and kettle reactors are particularly preferred. However, even in the case of using a reactor such as an extruder with a vent, the autoclave or the cavern may be adjusted by gentle venting, no venting, or adjustment of temperature conditions, barrel conditions, screw shapes, screw operating conditions, and the like. It is possible to carry out the cyclization condensation reaction in the same state as that of the framework reactor.

In the case of the cyclization condensation reaction which is carried out before the cyclization condensation reaction using the devolatilization process simultaneously, for example, a mixture containing the polymer (a) and the solvent obtained in the polymerization step and (i) is added to the catalyst and heated to react. The method, (ii) the method of heat-reacting with a catalyst, and the method of performing said (i) or (ii) under pressurization, etc. are mentioned.

In addition, the "mixture containing a polymer (a) and a solvent" introduced into the cyclization condensation reaction in the lactone cyclization condensation step is a polymerization reaction mixture itself obtained in the polymerization step or a solvent suitable for the cyclization condensation reaction after removing the solvent once. Means a mixture obtained by re-adding.

As a solvent which can be re-added at the time of the cyclization condensation reaction previously performed before the cyclization condensation reaction which used the devolatilization process simultaneously, it is not specifically limited, For example, aromatic hydrocarbons, such as toluene, xylene, ethylbenzene; Ketones such as methyl ethyl ketone and methyl isobutyl ketone; Chloroform, dimethyl sulfoxide, tetrahydrofuran; And the like. These solvents may be used alone or in combination of two or more. It is preferable to use the same kind of solvent as the solvent used in the polymerization step.

Examples of the catalyst to be added in the method (i) include esterification catalysts or transesterification catalysts, such as commonly used X-toluenesulfonic acid, basic compounds, organic carboxylates, carbonates, and the like. It is preferable to use the above-mentioned organophosphorus compound. Although the addition time of a catalyst is not specifically limited, For example, you may add in the beginning of reaction, you may add in the middle of reaction, may add in both of them, and the addition amount of a catalyst is not specifically limited, For example, with respect to the mass of the polymer (a), Preferably it is 0.001-5 mass%, More preferably, it is 0.01-2.5 mass%, More preferably, it is 0.01-1 mass%, Especially preferably, it is 0.05-0.5 mass %to be. The heating temperature and the heating time of the method (i) are not particularly limited, but for example, the heating temperature is preferably room temperature to 180 ° C, more preferably 50 to 150 ° C, and the heating time is preferably 1 to 20 hours, More preferably, it is 2 to 10 hours. If the heating temperature is less than room temperature or the heating time is less than 1 hour, the cyclization condensation reaction rate may decrease. On the contrary, when heating temperature exceeds 180 degreeC or heating time exceeds 20 hours, coloring and decomposition | disassembly of resin may arise.

Method (ii) can heat the polymerization reaction mixture obtained in the polymerization process as it is, for example, using a pressure resistant kettle type reactor or the like. Although the heating temperature and heating time of the method (ii) are not specifically limited, For example, heating temperature becomes like this. Preferably it is 100-180 degreeC, More preferably, it is 100-150 degreeC, and heating time becomes like this. 20 hours, More preferably, it is 2 to 10 hours. If heating temperature is less than 100 degreeC, or a heating time is less than 1 hour, the cyclization condensation reaction rate may fall. On the contrary, when heating temperature exceeds 180 degreeC or heating time exceeds 20 hours, coloring and decomposition | disassembly of resin may arise. In either method, there is no problem even if it is pressurized depending on the conditions.

In the cyclization condensation reaction performed before the cyclization condensation reaction using the devolatilization process at the same time, even if a part of the solvent is volatilized naturally during the reaction, there is no problem.

The mass reduction rate in the range of 150-300 degreeC in the dynamic TG measurement at the end of the cyclization condensation reaction performed beforehand before the cyclization condensation reaction which used the devolatilization process simultaneously, ie, just before the devolatilization process starts, preferably Is 2% or less, more preferably 1.5% or less, and more preferably 1% or less. If the mass reduction rate exceeds 2%, even if the cyclization condensation reaction is carried out simultaneously with the devolatilization step, the cyclization condensation reaction rate may not rise to a sufficiently high level, and the physical properties of the resulting lactone ring-containing polymer may deteriorate. . Moreover, when performing said cyclization condensation reaction, you may coexist other thermoplastic resins in addition to a polymer (a).

Cyclocondensation reaction in which the hydroxy group and the ester group present in the molecular chain of the polymer (a) obtained in the polymerization step are subjected to cyclization condensation reaction beforehand to raise the degree of cyclization condensation reaction to some extent, and then the cyclization condensation reaction using the devolatilization step simultaneously is performed. In the case of the above, the polymer obtained in the cyclization condensation reaction carried out in advance (the polymer in which at least part of the hydroxy group and the ester group in the molecular chain are subjected to cyclization condensation reaction) and a solvent are subjected to the cyclization condensation reaction simultaneously using the devolatilization step simultaneously. The devolatilization step may be introduced, followed by other treatments such as isolating the polymer (a polymer in which at least a portion of the hydroxy group and the ester group present in the molecular chain are subjected to cyclization condensation reaction) and then adding the solvent again. You may introduce into the cyclization condensation reaction used simultaneously.

The devolatilization step is not limited to the end of the cyclization condensation reaction.

≪2-hydroxymethylacrylic acid ester≫

The 2-hydroxymethylacrylic acid ester of the present invention is a 2-hydroxymethylacrylic acid ester represented by the following formula (2), characterized in that the turbidity after a heating test at 90 ° C. for 2 hours is 0.05 or less:

Where

R ⁴ and R ⁵ independently of one another represent a hydrogen atom or an organic moiety having 1 to 20 carbon atoms. In addition, the organic residue may contain an oxygen atom.

The 2-hydroxymethylacrylic acid ester of the present invention preferably has a turbidity after a heat test at 90 ° C. for 2 hours, preferably 0.02 or less, and more preferably 0.01 or less.

Here, the measurement of turbidity shall be performed as follows. First, 10 g of 2-hydroxymethylacrylic acid ester is placed in a glass screw tube having a capacity of 20 ml, 500 ppm of hydroquinone monomethyl ether is added as an polymerization inhibitor, and the lid is covered. This screw tube is put into a 90 degreeC thermostat, and the heating test is performed for 2 hours. After 2 hours, the screw tube was taken out, cooled to room temperature, and the absorbance (turbidity) of the target product was set at a wavelength of 400 nm at a spectrophotometer (UV-1650PC, manufactured by Shimadzu Corporation) with a zero absorbance in pure water. Measure

Hereinafter, the manufacturing method and purification method of 2-hydroxymethylacrylic acid ester represented by said Formula (2) are demonstrated.

The 2-hydroxymethylacrylic acid ester represented by the above formula (2) is reacted with an acrylic acid ester represented by the following formula (4) and an aldehyde compound in the presence of a tertiary amine compound and water sufficient to form an aqueous phase at the end of the reaction. By making it can be prepared:

Where

R ⁴ represents a hydrogen atom or an organic residue having 1 to 20 carbon atoms. In addition, the organic residue may contain an oxygen atom.

As acrylic acid ester represented by said Formula (4), For example, (a) Acrylic acid whose substituent represented by R <^4> is a hydrogen atom; (b) alkyl acrylate esters in which the substituent represented by R ⁴ is an alkyl group having 1 to 18 carbon atoms, for example methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-acrylate Butyl, n-octyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, stearyl acrylate and the like; (c) acrylic acid cycloalkyl esters in which the substituent represented by R ⁴ is a cycloalkyl group having 3 to 10 carbon atoms, such as cyclopentyl acrylate and cyclohexyl acrylate; (d) Acrylic acid aryl ester whose substituent represented by R <^4> is an aryl group, for example, phenyl acrylate, o-methoxyphenyl acrylate, p-methoxyphenyl acrylate, p-nitrophenyl acrylate, o-methylphenyl acrylate, p-methylphenyl acrylate And pt-butylphenyl acrylate. Among these acrylic esters, methyl acrylate, ethyl acrylate, n-butyl acrylate and 2-ethylhexyl acrylate are particularly preferable.

As an aldehyde type compound, The compound containing an aldehyde group; Trioxane; Paraacetaldehyde; And oxymethylene compounds represented by the following formula (5):

Where

Y represents a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms,

p represents the integer of 1-100.

Moreover, in said Formula (5), when the substituent represented by Y is a C3-C10 cycloalkyl group, the cycloalkyl group may contain another substituent further.

Examples of the compound containing an aldehyde group include formaldehyde, acetaldehyde, propionaldehyde, butylaldehyde, valericaldehyde, isobutylaldehyde, pivalaldehyde, cyclohexylaldehyde, cyclohexenealdehyde, benzaldehyde, aldehyde, aldehyde, aldehyde, and the like. Etc. can be mentioned.

As an oxymethylene compound represented by said Formula (5), the density | concentration of 20-50 mass% aqueous solution (hydrated formaldehyde) of formaldehyde, paraformaldehyde which is a polymer (dimer-100-mer) of formaldehyde, formaldehyde, for example Methanol aqueous solution of 20-50 mass%, etc. are mentioned.

Among these aldehyde compounds, a 20-50 mass% aqueous solution of acetaldehyde, paraformaldehyde, formaldehyde, and an aqueous methanol solution having a concentration of formaldehyde of 20-50 mass% are particularly preferable. An aldehyde type compound may be used independently or may use 2 or more types together.

By reacting the acrylic acid ester represented by the formula (4) and the aldehyde compound, the 2-hydroxymethylacrylic acid ester represented by the formula (2) can be obtained. In the formula (2), the substituent represented by R ⁵ is a substituent derived from an aldehyde compound.

As a tertiary amine compound used as a catalyst in the said reaction, For example, Trialkylamine, such as trimethylamine, triethylamine, tri-n-propylamine, and triisopropylamine; N, N-dimethylethylamine, N, N-dimethylpropylamine, N, N-dimethylisopropylamine, N, N-dimethylbutylamine, N, N-dimethylisobutylamine, N, N-dimethyl-t- N, N-dimethylalkylamine, such as butylamine and N, N-dimethyl (trimethylsilyl) amine; N, N-diethylalkylamine, such as N, N-diethylmethylamine, N, N-diethylpropylamine, N, N-diethylisopropylamine; Etc. can be mentioned. These tertiary amine compounds can be used individually or in combination of 2 or more types. Among these tertiary amine compounds, compounds having a relatively high solubility in water are preferable, and N-methylalkylamine (N-methyl compound having a boiling point at ordinary pressure of 100 ° C. or less and having at least one N-methyl group) ) Is more preferable, N, N-dimethyl alkylamine having a boiling point at normal pressure of 100 ° C. or lower, and having two N-methyl groups is more preferable, and trimethylamine is most preferred.

Although the tertiary amine compound can be used in various states, such as a liquid phase and a gas phase, it is preferable to use it as 5-80 mass% aqueous solution, and it is more preferable to use it as 20-60 mass% aqueous solution. By using the tertiary amine compound in the form of an aqueous solution, handling at the start of the reaction and at the time of the reaction becomes easy, and handling in the case of recovering and reusing the tertiary amine compound after the reaction is also facilitated.

The molar ratio (acrylic acid ester / aldehyde compound represented by the formula (4)) between the acrylic acid ester and the aldehyde compound represented by the formula (4) is not particularly limited, but is at least 2 or more, more preferably 2.5 to 15 More preferably, it exists in the range of 2.5-8. When this molar ratio is less than 2, the generation | occurrence | production of the impurity derived from an aldehyde type compound increases, the selectivity of the 2-hydroxymethylacrylic acid ester represented by said Formula (2) falls, and the refinement requires much time and effort. There may be cases.

The molar ratio (tertiary amine compound / aldehyde compound) between the tertiary amine compound and the aldehyde compound is not particularly limited, but is preferably 0.01 to 2, more preferably 0.02 to 1, more preferably 0.05 to It is in the range of 0.8. When this molar ratio is less than 0.01, the improvement of reaction rate is not recognized, the formation of a side reaction product increases, and the selectivity of the 2-hydroxymethylacrylic acid ester represented by said Formula (2) may fall. Conversely, when this molar ratio exceeds 2, depending on the reaction conditions, hydrolysis of the 2-hydroxymethylacrylic acid ester represented by the acrylic acid ester represented by the above formula (4) or the product of the above formula (2) may occur. have.

The acrylic acid ester and the aldehyde compound represented by the formula (4) are reacted in the presence of sufficient water to form an aqueous phase at the end of the reaction. Preferably, the reaction solution (reaction system) forms a two-phase system of the organic phase and the water phase at the start of the reaction, at the time of the reaction, and at the end of the reaction, and reacts in the presence of an amount of water in which the reaction can proceed. The organic phase is substantially a mixture of an insoluble compound in water, that is, an acrylic acid ester represented by the above formula (4) as a raw material, a 2-hydroxymethylacrylic acid ester represented by the above formula (2) as a product, a solvent described later, and the like. Means.

The usage-amount of water is not specifically limited, For example, the kind (property), combination, usage-amount of an acrylic acid ester, an aldehyde type compound, a tertiary amine compound, and a solvent represented by said Formula (4); The property of 2-hydroxymethylacrylic acid ester represented by formula (2) obtained; Reaction conditions such as reaction temperature; In consideration of the above, it can be appropriately set to an optimum amount. Specifically, in the case of using methyl acrylate as the acrylate ester represented by the formula (4), using paraformaldehyde as the aldehyde compound, and using trimethylamine as the tertiary amine compound, However, water can be added so that the quantity of water with respect to the total amount of methyl acrylate and paraformaldehyde becomes about 2-40 mass%. By adding such an amount of water, the reaction solution forms a two-phase system of an organic phase and an aqueous phase through the start of the reaction, the reaction, and the end of the reaction, and the reaction proceeds efficiently.

At the time of reaction, insoluble in water can be used in order to form an organic phase as needed. The kind of solvent is especially so long as it is a compound which melt | dissolves the acrylic acid ester, the aldehyde type compound represented by said formula (4), the 2-hydroxymethylacrylic acid ester represented by said formula (2), etc., and is inactive with respect to reaction. It is not limited. Although the usage-amount of a solvent is not specifically limited, For example, the kind (property), combination, and usage-amount of an acrylic ester, an aldehyde compound, a tertiary amine compound, and a solvent which are represented by said Formula (4); The property of 2-hydroxymethylacrylic acid ester represented by formula (2) obtained; Reaction conditions such as reaction temperature; In consideration of the above, it can be appropriately set to an optimum amount. The solvent may be used alone or in combination of two or more. Moreover, it can also be used as a solvent by using the acrylic ester represented by the said Formula (4) very much.

Although reaction conditions, etc. at the time of performing the said reaction are not specifically limited, The acrylic acid ester represented by the said Formula (4) which is a raw material, and the 2-hydroxymethylacrylic acid ester represented by said Formula (2) which is a product are in a molecule | numerator. Since it has a polymerizable double bond, it has a property which is easy to superpose | polymerize. Therefore, when reacting the acrylate ester and the aldehyde compound represented by the formula (4), it is preferable to add a polymerization inhibitor (or polymerization inhibitor) or molecular oxygen to the reaction system in order to suppress the polymerization of these compounds. Do.

Although it does not specifically limit as a polymerization inhibitor, For example, quinones, such as hydroquinone, methyl hydroquinone, t-butyl hydroquinone, 2, 4- di- t-butyl hydroquinone, and 2, 4- dimethyl hydroquinone. ; Amine compounds such as phenothiazine; Phenols such as 2,4-dimethyl-6-t-butylphenol, 2,4-di-t-butylphenol and p-methoxyphenol; Etc. can be mentioned. These polymerization inhibitors can be used alone or in combination of two or more. Although the addition amount of a polymerization inhibitor is not specifically limited, For example, it can make it the ratio with respect to the acrylic ester represented by said formula (4) in 0.001-1 mass%.

As molecular oxygen, for example, air or a mixed gas of molecular oxygen and nitrogen may be used. In this case, it is possible to stir or blow a gas containing molecular oxygen (so-called bubbling) in order to contain molecular oxygen in the reaction solution, that is, the organic phase or the aqueous phase. And in order to fully suppress superposition | polymerization, it is preferable to use a polymerization inhibitor and molecular acid �� in combination.

Although reaction temperature is not specifically limited, In order to suppress superposition | polymerization, Preferably it is 10-150 degreeC, More preferably, it is 40-100 degreeC, More preferably, it exists in the range of 40-80 degreeC. When reaction temperature is less than 10 degreeC, since reaction rate becomes slow, reaction time may become too long and the 2-hydroxymethylacrylic acid ester represented by said Formula (2) may not be manufactured efficiently. On the contrary, when reaction temperature exceeds 150 degreeC, superposition | polymerization cannot be suppressed and hydrolysis of the acrylic acid ester represented by said Formula (4) may occur.

The reaction time can be appropriately set according to the reaction temperature or the kind (property), combination, amount of use, etc. of the acrylate, aldehyde compound, tertiary amine compound, and solvent represented by the formula (4) so as to complete the reaction. have. Therefore, although reaction time is not specifically limited, About 0.5 to 10 hours are enough. In addition, the reaction pressure is not particularly limited, and may be any of normal pressure (for example, atmospheric pressure), reduced pressure, and pressurization.

After completion of the reaction, a predetermined operation such as liquid separation is performed to separate the reaction solution into an organic phase and an aqueous phase. If necessary, after washing the organic phase sufficiently with water, the acrylic ester represented by the unreacted formula (4) and the solvent are separated and recovered by fractional distillation. Then, the mixture is refluxed at a predetermined temperature and subjected to heat treatment, followed by rectification, whereby 2-hydroxymethylacrylic acid ester represented by the above formula (2) with high purity can be easily obtained. Generally, although there are a trace amount, the 2-hydroxymethylacrylic acid ester represented by the said Formula (2) which is a preparation obtained by making the acrylic acid ester represented by the said Formula (4) react with an aldehyde type compound contains several by-products. It is. And some of the by-products are impurities with a small difference in boiling point with the 2-hydroxymethylacrylic acid ester represented by said Formula (2) which is a target object.

Impurities to be heat-treated, that is, impurities having a small difference in boiling point from the 2-hydroxymethylacrylic acid ester represented by the above formula (2), are acetal compounds contained in the 2-hydroxymethylacrylic acid ester represented by the above formula (2). to be. As this acetal compound, when the target object is 2-hydroxymethyl acrylate, ethyl 2-ethoxy methoxymethyl acrylate etc. are mentioned, for example.

Since the acetal compound has a small difference in boiling point from the 2-hydroxymethylacrylic acid ester represented by Formula (2), which is the target product, separation by distillation is difficult in that state. However, as a result of intensive research by the present inventors, it has been found that the acetal compound is easily changed to a compound having a higher boiling point than the 2-hydroxymethylacrylic acid ester represented by the formula (2) by heat treatment.

The temperature which heat-processes 2-hydroxymethylacrylic acid ester represented by said Formula (2) which is a preparation is the temperature at which the acetal compound contained in it changes into a compound of high boiling point, and with respect to the bottom (bottom) temperature at the time of rectification, If it is in the range of -10 to 30 ° C, white foreign matter does not occur during storage of the obtained 2-hydroxymethylacrylic acid ester represented by the formula (2). The heat treatment temperature is preferably within the range of 0 to 25 ° C with respect to the bottom temperature at the time of rectification, and more preferably within the range of 10 to 20 ° C with respect to the bottom temperature at the time of rectification in order to efficiently process. When heat processing temperature is lower than -10 degreeC with respect to the bottom temperature at the time of rectification, a white foreign material may become easy to generate | occur | produce during storage of the obtained 2-hydroxymethylacrylic acid ester represented by Formula (2). Moreover, since 2-hydroxymethylacrylic acid ester represented by said Formula (2) has a polymerizable double bond in a molecule | numerator, it has the property which is easy to superpose | polymerize. For this reason, when heat processing temperature is higher than 30 degreeC with respect to the bottom temperature at the time of rectification, superposition | polymerization may not be suppressed.

In addition, it is preferable to carry out in a vacuum state or a boiling state at the time of heat processing. The 2-hydroxymethylacrylic acid ester represented by the above formula (2) is boiled out, but is cooled in the condenser and returned to the distillation apparatus. About the vacuum degree at this time, it may be the pressure boiling at the temperature within the range of -10-30 degreeC with respect to the bottom temperature at the time of rectification.

The heat treatment time can be appropriately set according to the heat treatment temperature and is not particularly limited, but is usually in the range of 0.5 to 5 hours.

Moreover, since 2-hydroxymethylacrylic acid ester represented by said Formula (2) has the property which is easy to superpose | polymerize, in order to suppress that this compound superposes | polymerizes at the time of heat processing, it is a polymerization inhibitor (polymerization inhibitor) and a molecule | numerator. Preference is given to adding phase oxygen.

Although it does not specifically limit as a polymerization inhibitor, The polymerization inhibitor mentioned above is mentioned as a polymerization inhibitor which can be used when making the acrylate ester and the aldehyde type compound represented by said Formula (4) react. The polymerization inhibitor may be used alone or in combination of two or more. Although the addition amount of a polymerization inhibitor is not specifically limited, For example, the ratio with respect to the 2-hydroxymethylacrylic acid ester represented by the said Formula (2) which is a preparation can be made into the range of 0.01-1 mass%.

As molecular oxygen, for example, air or a mixed gas of molecular oxygen and nitrogen may be used. In this case, a gas containing molecular oxygen may be blown into the reaction solution, that is, the organic phase or the aqueous phase (so-called bubbling). And in order to fully suppress superposition | polymerization, it is preferable to use a polymerization inhibitor and molecular oxygen together.

Thus, when refine | purifying the 2-hydroxymethylacrylic acid ester represented by the said Formula (2) which is a preparation obtained by making the acrylic acid ester represented by the said Formula (4) react with an aldehyde type compound, about the bottom temperature at the time of rectification, After performing a heat treatment at a temperature within the range of -10 to 30 ° C, rectification can yield a 2-hydroxymethylacrylic acid ester represented by Formula (2) of high purity. The acetal compound which is an impurity with a small difference in boiling point with the 2-hydroxymethyl acrylic acid ester represented by the said Formula (2) which is a target object by the said heat processing has a higher boiling point than the 2-hydroxymethylacrylic acid ester represented by said Formula (2). Changes in the compound. At this time, since a non-point component also arises, by heat-processing at high temperature before rectification, the component which becomes a factor of cloudiness at the time of rectification can be removed. For this reason, the high quality 2-hydroxymethylacrylic acid ester represented by Formula (2) can be obtained in high yield.

As described above, in the production of the lactone ring-containing polymer, when a 2-hydroxymethylacrylic acid ester represented by the above-mentioned formula (2) of high quality is used as a monomer and t-amyl peroxide is used as a polymerization initiator, Generation of the polymer gel in the lactone ring-containing polymer can be suppressed very effectively.

`` Use and Molding of Lactone Ring Polymer ''

The lactone ring-containing polymer of the present invention is not only excellent in transparency and heat resistance, but also has desired characteristics such as low colorability, mechanical strength and molding processability, and is particularly a molding material having few foreign substances and difficult to gel. desirable. The lactone ring-containing polymer of the present invention is useful for optical parts such as a light guide, an optical lens, an optical film, an optical prism, an optical disc, and the like. Of these optical parts, a light guide, an optical lens, and an optical film are particularly preferable. Do.

The lactone ring containing polymer of this invention can be shape | molded in various shapes according to a use. Usually, the lactone ring-containing polymer of the present invention is formed by heating and granulating, for example, into a molding material such as pellets, and then secondary molded into various shapes. As a shape which can be shape | molded, a film, a sheet, a plate, a disk, a block, a ball, a lens, a rod, a strand, a cord, etc. are mentioned, for example. As a shaping | molding method, it can select suitably according to a shape from a conventionally well-known shaping | molding method, It does not specifically limit.

Hereinafter, the optical film which is an especially preferable use is taken as an example, and the method of manufacturing an optical film from the lactone ring 특히 containing polymer of this invention is demonstrated in detail.

<Production of Optical Film>

In order to manufacture an optical film from the lactone ring-containing polymer of the present invention, the raw material is pre-blended in a conventionally known mixer such as Omni-Mixer, for example, and the resulting mixture is subjected to extrusion kneading. In this case, the mixer used for extrusion kneading is not specifically limited, For example, conventionally well-known mixers, such as an extruder, such as a single screw extruder and a twin screw extruder, and a pressurized kneader, can be used.

As a film shaping | molding method, conventionally well-known film shaping | molding methods, such as the solution casting method (solution casting method), the melt-extrusion method, the calender method, the compression molding method, are mentioned, for example. Among these film forming methods, a solution cast method (solution casting method) and a melt extrusion method are particularly preferable.

As a solvent used for the solution casting method (solution casting method), For example, aromatic hydrocarbons, such as benzene, toluene, xylene; Aliphatic hydrocarbons such as cyclohexane and decalin; Esters such as ethyl acetate and butyl acetate; Ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; Alcohols such as methanol, ethanol, isopropanol, butanol, isobutanol, methyl cellosolve, ethyl vertical solver and butyl cellosolve; Ethers such as tetrahydrofuran and dioxane; Halogenated hydrocarbons such as dichloromethane, chloroform and carbon tetrachloride; Dimethylformamide; Dimethyl sulfoxide; Etc. can be mentioned. These solvents may be used alone or in combination of two or more.

As an apparatus for performing the solution casting method (solution casting method), a drum type casting machine, a band type casting machine, a spin coater, etc. are mentioned, for example.

Examples of the melt extrusion method include a T-die method, an inflation method, and the like. The molding temperature at that time can be appropriately adjusted according to the glass transition temperature of the film raw material, and is not particularly limited. Preferably it is 150-350 degreeC, More preferably, it is 200-300 degreeC.

When film-forming by the T-die method, a T die is formed in the front-end | tip of a well-known single screw extruder or a twin screw extruder, the film extruded to the film form can be wound up, and a roll-shaped film can be obtained. At this time, it is also possible to uniaxially stretch by adjusting the temperature of a winding roll suitably and extending | stretching in an extrusion direction. Moreover, simultaneous biaxial stretching, sequential biaxial stretching, etc. can also be performed by extending | stretching a film in the direction perpendicular | vertical to an extrusion direction.

The film composed of the lactone ring-containing polymer of the present invention may be an unstretched film or a stretched film. In the case of a stretched film, it may be a uniaxial stretched film or a biaxial stretched film. In the case of a biaxially oriented film, it may be a simultaneous biaxially oriented film or a sequential biaxially oriented film. In the case of biaxial stretching, the mechanical strength is improved and the film performance is improved. The lactone ring 는 containing polymer of this invention can be extended | stretched by mixing other thermoplastic resins, the increase of retardation can be suppressed, and the film which maintained optical isotropy can be obtained.

It is preferable that extending | stretching temperature is near the glass transition temperature of the lactone ring containing polymer which is a film raw material, Specifically, Preferably, it is (glass transition temperature -30 degreeC)-(glass transition temperature +100 degreeC), More preferably, Glass transition temperature -20 DEG C) to (glass transition temperature +80 DEG C). When extending | stretching temperature is less than (glass transition temperature -30 degreeC), sufficient draw ratio may not be obtained. On the contrary, when the stretching temperature is higher than the glass transition temperature (+ 100 ° C), a polymer may flow (flow), which may make it impossible to perform stable stretching.

The draw ratio defined by the area ratio is preferably in the range of 1.1 to 25 times, more preferably 1.3 to 10 times. If the draw ratio is less than 1.1 times, it may not be connected to the improvement of toughness due to stretching. On the contrary, when the draw ratio is more than 25 times, the effect as much as the draw ratio is raised may not be recognized.

The stretching speed is in one direction, preferably in the range of 10 to 20,000% / min, more preferably in the range of 100 to 10,000% / min. If the stretching speed is less than 10% / min, it takes time to obtain a sufficient stretching ratio, and the manufacturing cost may become expensive. On the contrary, when the stretching speed exceeds 20,000% / min, crushing of the stretched film may occur.

Moreover, in order to stabilize the optical isotropy and a mechanical characteristic, the film comprised from the lactone ring containing polymer of this invention can be heat-treated (annealed) etc. after an extending | stretching process. The heat treatment conditions can be appropriately selected similarly to the heat treatment conditions for the conventionally known stretched film, and are not particularly limited.

The film composed of the lactone ring-containing polymer of the present invention is preferably 5 to 200 m, more preferably 10 to 100 m. If the thickness is less than 5 µm, not only the strength of the film is lowered, but also the crimp may be large when the durability test is performed by adhering to another component. On the contrary, when thickness exceeds 200 micrometers, not only transparency of a film falls but also moisture permeability becomes small, and when the water-based adhesive agent is used at the time of adhering to another component, the drying speed of the water which is the solvent may become slow.

The film composed of the lactone ring 유 -containing polymer of the present invention preferably has a wetting tension on the surface of 40 mN / m or more, more preferably 50 mN / m or more, and more preferably 55 mN / m or more. If the surface wetting tension is at least 40 mN / m or more, the adhesive strength between the film composed of the lactone ring-containing polymer of the present invention and other components is further improved. In order to adjust the surface wetting tension, for example, corona discharge treatment, ozone spray, ultraviolet irradiation, flame treatment, chemical treatment, and other conventionally known surface treatment can be performed.

The film comprised by the lactone ring containing polymer of this invention may contain various additives. As an additive, For example, antioxidant, such as a hindered phenol type, phosphorus type, a sulfur type; Stabilizers such as light stabilizers, weather stabilizers, and heat stabilizers; Reinforcing materials such as glass fibers and carbon fibers; Ultraviolet absorbers such as phenyl salicylate, (2,2'-hydroxy-5-methylphenyl) benzotriazole and 2-hydroxybenzophenone; Near infrared absorbers; Flame retardants such as tris (dibromopropyl) phosphate, triallyl phosphate, and antimony oxide; Antistatic agents such as anionic, cationic and nonionic surfactants; Coloring agents such as inorganic pigments, organic pigments, and dyes; Organic fillers or inorganic fillers; Resin modifiers; Plasticizers; slush; Antistatic agent; Etc. can be mentioned.

Preferably the content rate of the additive in the thermoplastic resin film which has a lactone ring 유 containing polymer as a main component is 0-5 mass%, More preferably, it is 0-2 mass%, More preferably, it is 0-0.5 mass%.

(Example)

Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not restrict | limited by the following example of course, It is also possible to change suitably and to implement in the range which may be suitable for the meaning of the previous and the later. However, they are all included in the technical scope of the present invention.

First, the evaluation method of a lactone ring containing polymer is demonstrated.

<Polymerization reaction rate, polymer composition analysis>

The reaction rate at the time of a polymerization reaction and the content rate of the specific monomer unit in a polymer were computed by measuring the quantity of the unreacted monomer in the obtained polymerization reaction mixture using gas chromatography (GC17A, Shimadzu Corporation make).

<Dynamic TG>

The polymer (or polymer solution or pellet) is first dissolved or diluted in tetrahydrofuran, added to excess hexane or methanol to reprecipitate, and the removed precipitate is vacuum dried (1.33 hPa (1 mmHg), 80 ° C). , 3 hours or more) to remove volatile components and the like, and the obtained white solid resin was analyzed by the following method (dynamic TG method).

Measuring device: Differential parallax balance (Thermo Plus 2 TG-8120 Dynamic TG, manufactured by Rigak Co., Ltd.)

Measurement condition: Sample amount 5-10 mg

Heating rate: 10 ℃ / min

Atmosphere: nitrogen flow 200 ml / min

Method: Stepwise isothermal control method (control at mass reduction rate value of 0.005% / s or less within the range of 60 ° C to 500 ° C)

Lactone Currency Exchange Rate

For example, in the case of polymer compositions obtained from methyl methacrylate and methyl 2-hydroxymethyl acrylate, the mass reduction is initiated in the dynamic TG measurement, based on the amount of mass reduction that occurs when all hydroxy groups are de-alcoholized as methanol. The de-alcohol reaction rate can be calculated from the mass reduction by the de-alcohol reaction up to 300 ° C. before the decomposition of the polymer starts at 150 ° C. before the decomposition.

That is, in the dynamic TG measurement of the polymer which has a lactone ring structure, the mass reduction rate is measured between 150 degreeC and 300 degreeC, and the measured value obtained is made into the measured mass reduction rate (X). On the other hand, from the composition of the polymer, the mass reduction rate (i.e., 100% dealcohol reaction in the composition) is assumed to be the alcohol in order that all the hydroxy groups included in the polymer composition are involved in the formation of the lactone ring. The mass reduction rate calculated on the assumption that it has occurred is called the theoretical mass reduction rate (Y). Moreover, the theoretical mass reduction rate (Y) can be computed more specifically from the molar ratio of the raw material monomer which has a structure (hydroxy group) which participates in the dealcoholization reaction in a polymer, ie, the content rate of the raw material monomer in the said polymer composition. have. These are the dealcohol formulas:

1- (Measured mass reduction rate (X) / theoretical mass reduction rate (Y))

Substituting in, and calculating the value and expressing it as a percentage (%), the de-alcohol reaction rate (lactone cyclization rate) can be obtained.

As an example, the content rate of the lactone ring structure in the pellet obtained in Example 1 mentioned later is calculated. When the theoretical mass reduction rate (Y) of this polymer is calculated, the molecular weight of methanol is 32, the molecular weight of 2-hydroxymethyl acrylate is 116, and the content rate (mass ratio) of the methyl 2-hydroxymethyl acrylate in the polymer is in terms of composition. Since it is 20.0 mass%, it becomes (32/116) x 20.0 mass%-5.52 mass%. In addition, the measured mass reduction rate (X) by dynamic TG measurement was 0.17 mass%. When these values are applied to the above-described de-alcohol formula, it becomes 1- (0.17 / 5.52)-0.969, so the de-alcohol reaction rate (lactone cyclization rate) is 96.9%.

<Weight average molecular weight>

The weight average molecular weight of the polymer was calculated by polystyrene conversion using a gel permeation chromatograph (GPC system, manufactured by Toso Corporation). The developing solution used chloroform.

Thermal Analysis of Polymers

The thermal analysis of the polymer was carried out using a differential scanning calorimeter (DSC-8230, manufactured by Rigaku Co., Ltd.) under conditions of a sample of about 10 mg, a heating rate of 10 ° C./min, and a nitrogen flow of 50 ml / min. In addition, glass transition temperature (Tg) was computed by the midpoint method based on ASTM-D-3418.

<Melt flow rate>

The melt flow rate was measured according to JIS-K6874 at a test temperature of 240 ° C. and a load of 10 kg.

Measurement of Melt Viscosity

The melt viscosity of the polymer was measured under the conditions of a temperature of 250 ° C., a load of 10 kgf / cm 2, and a die shape of 0.5 mmφ × 1 mm using a flow tester (CFT-500C, manufactured by Shimadzu Corporation).

<Content of polymer gel>

100 g of the polymer was dissolved in 500 ml of methyl ethyl ketone purified by microfiltration. The polymer solution obtained was passed through a membrane filter made of polytetrafluoroethylene having an average pore diameter of 1.0 mu m, and the polymer gel was filtered on a membrane filter. In the obtained polymer gel, the average particle diameter of 50 micrometers or more was counted visually under the microscope, and was shown as the number per 100 g of polymers.

Next, the synthesis example of 2-hydroxymethyl acrylate is demonstrated. Moreover, in the synthesis example 1, heat processing was performed at the temperature of 0-26.5 degreeC high with respect to the temperature in the distillation kettle at the time of fractional distillation, and high-purity 2-hydroxymethyl acrylate was obtained. In the synthesis example 2, the heat processing was performed at the temperature low at 2-30 degreeC with respect to the temperature in the distillation kettle at the time of fractional distillation, and methyl 2-hydroxymethyl acrylate of low purity was obtained.

`` Synthesis example 1 ''

2,066 g (24 moles) of methyl acrylate, an aldehyde compound as a acrylate ester represented by the formula (4) in a 3-liter four-necked flask equipped with a thermometer, a gas suction tube, a cooling tube, a stirring apparatus, and a wooden bath. As a tertiary amine compound, 195.8 g (6 mol) of 92 mass% paraformaldehyde as an aqueous solution was used. The ratio of p-methoxyphenol to methyl acrylate was 1,000 ppm. Thereafter, the reaction solution was stirred at 8O &lt; 0 &gt; C for 8 hours while inhaling air into the reaction solution.

After the reaction was completed, the reaction solution was transferred to a separating lot and separated into an organic phase and an aqueous phase. Next, 100 g of water was added to the organic phase and washed with water. After separating the organic phase and the aqueous phase, the organic phase was further washed with the same amount of water, and the organic phase and the washing liquid were separated.

The obtained organic phase was transferred to a 2-liter four-necked flask equipped with a thermometer, a gas suction tube, an air column distillation tube, an agitator, and an oil bath, 5 g of phenothiazine as a stabilizer was added, and the internal temperature was increased while inhaling air. Methyl acrylate was recovered at a pressure of 400-133 hPa (300-100 mmHg) while adjusting not to exceed 100 占 폚.

Next, the pressure was 40 hPa (30 mmHg), and heat treatment was performed while boiling at an internal temperature of 110 to 120 ° C. The boiled liquid was cooled with a condenser and returned to the flask.

After the heat treatment, fractional distillation of the organic phase was performed to obtain 418 g of methyl 2-hydroxymethyl acrylate, which is a fraction of tower top temperature 86 to 87 ° C./13.3 hPa (10 mmHg). The bottom temperature at the time of rectification at the time of obtaining this target object was 93.5-110 degreeC.

10 g of methyl 2-hydroxymethyl acrylate thus obtained was placed in a 20 ml glass screw tube, 500 ppm of hydroquinone monomethyl ether was added as an polymerization inhibitor, and the lid was covered. This screw tube was put into a 90 degreeC thermostat, and the heating test was performed for 2 hours. After 2 hours, the screw tube was taken out and cooled, and the absorbance (turbidity) of the target was adjusted in a state where the absorbance 0 was adjusted to pure water at a wavelength of 400 nm of the spectrophotometer (UV-1650PC, manufactured by Shimadzu Corporation). Measured. The turbidity of this target was 0.001.

This target product was stored at 40 ° C. for 3 months, but the target product was colorless and transparent, and no turbid foreign matter was generated.

`` Synthesis example 2 ''

The same operation as in Example 1 was performed until the step of recovering methyl acrylate. Thereafter, the pressure was 26.7 hPa (20 mmHg), and heat treatment was performed while boiling at an internal temperature of 100 to 110 ° C. The boiled liquid was cooled with a condenser and returned to the flask.

After the heat treatment, fractional distillation of the organic phase was performed to obtain 407 g of methyl 2-hydroxymethyl acrylate, which is a fraction of tower top temperature 105 to 106 ° C / 40 hPa (30 mmHg). The bottom temperature at the time of rectification at the time of obtaining this target object was 112-130 degreeC.

10 g of methyl 2-hydroxymethyl acrylate thus obtained was placed in a glass screw tube having a volume of 20 ml, 500 ppm of hydroquinone monomethyl ether as a polymerization inhibitor was added, and the lid was covered. This screw tube was put into a 90 degreeC thermostat, and the heating test was performed for 2 hours. After 2 hours, the screw tube was taken out and cooled, the wavelength of the spectrophotometer (UV-1650PC, manufactured by Shimadzu Corporation) was set to 400 nm, and the absorbance (turbidity) of the target was adjusted in a state where the absorbance was set to 0 with pure water. Measured. The turbidity of this target was 0.072.

Although this target object was stored at 40 degreeC for 3 months, it became cloudy white from February, and white precipitate generate | occur | produced after 3 months.

`` Example 1 ''

8,000 g of methyl methacrylate (MMA) and 2,000 g of 2-hydroxymethyl acrylate (MHMA; Synthesis example) in a 30 liter kettle type reactor equipped with a stirring device, a temperature sensor, a cooling tube, and a nitrogen introduction tube. Prepared at 1), 10,000 g of toluene was added thereto, and the mixture was heated to 105 ° C while passing nitrogen, and at the point of reflux, 10.0 g of t-amylperoxyisononanoate (lupazol 570, atopy) as a polymerization initiator. At the time of reflux, a solution composed of 20.0 g of t-amylperoxyisononanoate and 100 g of toluene was added dropwise over 2 hours while adding Nashishomi Co., Ltd. product. The solution polymerization was carried out at, and further aged for 4 hours.

10 g of stearyl phosphate / phosphate distearyl mixture (Phoslex A-18, manufactured by Sakai Chemical Co., Ltd.) was added to the obtained polymer solution and subjected to cyclization condensation reaction at about 90 to 110 ° C. for 5 hours under reflux. Was carried out. Subsequently, the obtained polymer solution was subjected to a vent type screw twin screw extruder having a barrel temperature of 260 ° C., a rotational speed of 100 rpm, a reduced pressure of 13.3 to 400 hPa (10 to 300 mmHg), a number of rear vents, and a number of fore vents (φ = 29.75 mm, L / D = 42) at a processing rate of 2.0 kg / h in terms of resin amount, and further extrusion of the cyclization condensation reaction and devolatilization in the extruder, thereby producing a lactone ring-containing polymer. A clear pellet was obtained.

With respect to the obtained lactone ring-containing polymer, dynamic TG was measured to detect a mass loss of 0.17% by mass. In addition, the lactone ring-containing polymer had a weight-average molecular weight of 147,700, a glass transition temperature of 130 ° C., a melt flow rate of 11.0 g / 10 min, a lactone cyclization rate of 97%, and a polymer gel content of 100 g of a two-lactone ring-containing polymer. . The results are shown in Table 1.

The pellet of the obtained lactone ring-containing polymer was kneaded in a twin screw extruder (φ = 29.75 mm, L / D = 30) at a barrel temperature of 270 ° C. and a rotational speed of 100 rpm. It remained as it was 100 g of dog / lactone ring containing polymers. The results are shown in Table 1.

It was 2,100 poise when the melt viscosity at 250 degreeC of the pellet of the obtained lactone ring # containing polymer was measured. Subsequently, after leaving the pellet of this lactone ring # containing polymer in the 280 degreeC oven for 30 minutes, the melt viscosity at 250 degreeC of the lactone ring # containing polymer was measured again, and it was 3,700 poise. The viscosity increase rate (after heating / before heating) was 1.76 from the melt viscosity before and after heating. The results are shown in Table 1.

`` Example 2 ''

8,000 g of methyl methacrylate (MMA), 2,000 g of methyl 2-hydroxymethyl acrylate (MHMA; Synthesis example) in a 30 L kettle-type reactor equipped with a stirring device, a temperature sensor, a cooling tube and a nitrogen introduction tube. Prepared in 2), 10,000 g of toluene and 5.0 g of n-dodecyl mercaptan were added thereto, and the mixture was heated to 100 ° C while passing nitrogen therethrough, and at the point of reflux, 10.0 g of t-amyl as a polymerization initiator. A solution consisting of 20.0 g of t-amyl peroxy isonanonoate and 100 g of toluene was added over 2 hours while adding peroxyisononanoate (lufazol 570, manufactured by Atopy Inosynato Co., Ltd.). While dripping, solution polymerization was performed at about 95-110 degreeC under reflux, and further aged for 4 hours.

10 g of stearyl phosphate / phosphate distearyl mixture (Phoslex A-18, manufactured by Sakai Chemical Co., Ltd.) was added to the obtained polymer solution and subjected to cyclization condensation reaction at about 90 to 110 ° C. for 5 hours under reflux. Was carried out. Subsequently, the obtained polymer solution was subjected to cyclization condensation reaction and devolatilization in an extruder in the same manner as in Example 1, and extruded to obtain a transparent pellet of a lactone ring-containing polymer.

The dynamic TG was measured about the obtained lactone ring containing polymer, and mass loss of 0.18 mass% was detected. The lactone ring-containing polymer had a weight-average molecular weight of 141,000, a glass transition temperature of 130 ° C., a melt flow rate of 13.0 g / 10 min, a lactone conversion rate of 97%, and a polymer gel content of 58 g / lactone ring-containing polymer 100 g. . The results are shown in Table 1.

In addition, when the pellets of the obtained lactone ring-containing polymer were kneaded under the same conditions as in Example 1, the content of the polymer gel was increased to 100 g of the 60-lactone ring-containing polymer. The results are shown in Table 1.

It was 2,050 poise when the melt viscosity at 250 degreeC of the pellet of the obtained lactone ring # containing polymer was measured. Subsequently, after leaving the pellet of this lactone ring # containing polymer in the 280 degreeC oven for 30 minutes, it was 3,800 poise when the melt viscosity at 250 degreeC of the lactone ring # containing polymer was measured again. The viscosity increase rate (after heating / before heating) was 1.85 from the melt viscosity before and after heating. The results are shown in Table 1.

`` Example 3 ''

8,000 g of methyl methacrylate (MMA), 2,000 g of 2-hydroxymethyl acrylate (MHMA); Synthesis Example 1 in a 30-liter kettle reactor with a stirrer, temperature sensor, cooling tube and nitrogen introduction tube Prepared), 10,000 g of toluene was added thereto, while nitrogen was passed through it, the temperature was raised to 105 ° C and refluxed, and 5.0 g of 1,1'-azobis (cyclohexane-1-carboni as a polymerization initiator) was added. Trilyl) (V-40, manufactured by Wako Pure Chemical Industries, Ltd.) and added with 10.0 g of 1,1'-azobis (cyclohexane-1-carbonitrile) and 100 g of toluene While the solution was added dropwise over 2 hours, solution polymerization was carried out at about 105 to 110 ° C. under reflux, and further aged for 4 hours.

10 g of stearyl phosphate / phosphate distearyl mixture (Phoslex A-18, manufactured by Sakai Chemical Co., Ltd.) was added to the obtained polymer solution and subjected to cyclization condensation reaction at about 90 to 110 ° C. for 5 hours under reflux. Was carried out. Subsequently, the obtained polymer solution was subjected to cyclization condensation reaction and devolatilization and extruded in an extruder in the same manner as in Example 1 to obtain a transparent pellet of a lactone ring-containing polymer.

The dynamic TG was measured about the obtained lactone ring containing polymer, and mass loss of 0.31 mass% was detected. This lactone ring-containing polymer had a weight-average molecular weight of 168,000, a glass transition temperature of 131 ° C, a melt flow rate of 7.2 g / 10 min, a lactone ring ratio of 94%, and a polymer gel content of 5 g / lactone ring-containing polymer 100 g. It was. The results are shown in Table 1.

Moreover, when the pellets of the obtained lactone ring containing polymer were kneaded under the same conditions as in Example 1, the content of the polymer gel was as it was in the state of 100 g of 5 pieces / lactone ring-containing polymer. The results are shown in Table 1.

It was 4,400 poise when the melt viscosity at 250 degreeC of the pellet of the obtained lactone ring containing polymer was measured. Subsequently, after leaving the pellet of this lactone ring # containing polymer in the 280 degreeC oven for 30 minutes, the melt viscosity at 250 degreeC of the lactone ring # containing polymer was measured again, and it was 8,000 poise. The viscosity increase rate (after heating / before heating) was 1.82 from the melt viscosity before and after heating. The results are shown in Table 1.

`` Example 4 ''

8,000 g of methyl methacrylate (MMA), 2,000 g of methyl 2-hydroxymethyl acrylate (MHMA; Synthesis example) in a 30 L kettle-type reactor equipped with a stirring device, a temperature sensor, a cooling tube and a nitrogen introduction tube. Prepared in 1), 10,000 g of toluene was added thereto, 12.0 g of dichlorotris (triphenylphosphine) ruthenium, 10.2 g of aluminum triisopropoxide, 4.7 g of 2,2'-dichloroacetophenone as a polymerization initiator. Was added. Under reflux, solution polymerization was carried out at about 105 to 110 ° C, and further aged for 24 hours.

The obtained polymer solution was added to excess hexane, the polymer powder was precipitated, and the precipitate was washed with hexane and water, followed by vacuum drying at 80 ° C and 1.33 hPa (1 mmHg) for 3 hours or more to remove volatile components and the like. It was.

The obtained polymer was again dissolved in toluene and made into a 50% solution. To this solution, 0.001 g of stearyl phosphate / phosphate distearyl mixture (Phoslex A-18, manufactured by Sakai Chemical Co., Ltd.) was added to 1 g of the polymer, and the mixture was refluxed at about 90 to 110 ° C. for 5 hours, Cyclic condensation reaction was performed. Subsequently, the obtained polymer solution was subjected to cyclization condensation reaction and devolatilization and extruded in an extruder in the same manner as in Example 1 to obtain a transparent pellet of a lactone ring-containing polymer.

About the obtained lactone ring 유 containing polymer, dynamic TG was measured and the mass loss of 0.22 mass% was detected. The lactone ring-containing polymer had a weight-average molecular weight of 72,000, a glass transition temperature of 130 ° C., a melt flow rate of 32.5 g / 10 min, a lactone cyclization rate of 96%, and a polymer gel content of 20 g / lactone ring-containing polymer 100 g. It was. The results are shown in Table 1.

In addition, when a pellet of the obtained lactone ring-containing polymer was kneaded under the same conditions as in Example 1, the content of the polymer gel was as it was in the state of 100 g of 20 pieces / lactone ring-containing polymer. The results are shown in Table 1.

It was 1,700 poise when the melt viscosity at 250 degreeC of the pellet of the obtained lactone ring containing polymer was measured. Subsequently, after leaving the pellet of this lactone ring # containing polymer in the 280 degreeC oven for 30 minutes, it was 2,500 poise when the melt viscosity at 250 degreeC of the lactone ring # containing polymer was measured again. The viscosity increase rate (after heating / before heating) was 1.47 from the melt viscosity before and after heating. The results are shown in Table 1.

`` Comparative Example 1 ''

8,000 g of methyl methacrylate (MMA), 2,000 g of methyl 2-hydroxymethyl acrylate (MHMA; Synthesis example) in a 30 L kettle-type reactor equipped with a stirring device, a temperature sensor, a cooling tube and a nitrogen introduction tube. Prepared in 2), 10,000 g of toluene and 5.0 g of n-dodecyl mercaptan were added thereto, and the mixture was heated to 100 ° C while passing nitrogen therethrough, and at the point of reflux, 10.0 g of t-butyl was obtained as a polymerization initiator. A solution consisting of 20.0 g of t-butylperoxy isopropyl carbonate and 100 g of toluene was added for 2 hours while adding peroxyisopropyl carbonate (Kayacarbon BIC-75, manufactured by Kayaku Akuzo Co., Ltd.). While dropping, the solution polymerization was carried out at about 95 to 110 ° C under reflux, and further aged for 4 hours.

10 g of stearyl phosphate / phosphate distearyl mixture (Phoslex A-18, manufactured by Sakai Chemical Co., Ltd.) was added to the obtained polymer solution, and a cyclization condensation reaction was performed at about 90 to 110 ° C. for 5 hours under reflux. Subsequently, the obtained polymer solution was subjected to cyclization condensation reaction and devolatilization in an extruder in the same manner as in Example 1, and extruded to obtain a transparent pellet of a lactone ring-containing polymer.

The dynamic TG was measured about the obtained lactone ring containing polymer, and the mass loss of 0.24 mass% was detected. In addition, the lactone ring-containing polymer had a weight-average molecular weight of 133,000, a glass transition temperature of 130 ° C., a melt flow rate of 11.3 g / 10 min, a lactone cyclization rate of 96%, and a polymer gel content of 130 g / lactone ring-containing polymer 100 g. It was. The results are shown in Table 1.

In addition, when the pellets of the obtained lactone ring-containing polymer were kneaded under the same conditions as in Example 1, the content of the polymer gel was increased to 100 g of the 380-lactone ring-containing polymer. The results are shown in Table 1.

It was 2,400 poise when the melt viscosity at 250 degreeC of the pellet of the obtained lactone ring # containing polymer was measured. Subsequently, after leaving the pellet of this lactone ring # containing polymer in the 280 degreeC oven for 30 minutes, it was 103,400 poise when the melt viscosity at 250 degreeC of the lactone ring # containing polymer was measured again. The viscosity increase rate (after heating / before heating) was 43.08 from the melt viscosity before and after heating. The results are shown in Table 1.

`` Comparative Example 2 ''

8,500 g of methyl methacrylate (MMA), 1,500 g of 2-hydroxymethyl acrylate (MHMA; synthesis) in a 30 liter kettle reactor with a stirrer, temperature sensor, cooling tube and nitrogen introduction tube Prepared in Example 2), 3,800 g of methyl isobutyl ketone (MIBK) and 950 g of methyl ethyl ketone (MEK) were added thereto, and the initial monomer concentration was 68%. 7.0 g of t-amyl-3 was used as a polymerization initiator. , 5,5-trimethylhexanoate (KayaesterAN, manufactured by Kayakuakuzo Co., Ltd.), at the same time, 7.0 g of t-amyl-3,5,5-trimethylhexanoate and 280 g of MIBK The solution consisting of and 70 g of MEK was added dropwise over 4 hours while solution polymerization was carried out at about 95 to 110 ° C. under reflux, and further aged for 4 hours. A mixed solvent (MIBK: MEK = 4: 1) was added at a rate of 2,500 g / h from 2 hours to 4 hours after the initiation of the polymerization so that the polymer concentration in the solution was 45% or less. It was dripped at the speed of / h.

0.005 g of stearyl phosphate / phosphate distearyl mixture (Phoslex A-18, manufactured by Sakai Chemical Co., Ltd.) was added to 1 g of the polymer component of the obtained polymer solution, and the mixture was refluxed under nitrogen while passing through nitrogen. Cyclization condensation reaction was performed at 80-100 degreeC for 5 hours. Subsequently, the obtained polymer solution was subjected to cyclization condensation reaction and devolatilization and extruded in an extruder in the same manner as in Example 1 to obtain a transparent pellet of a lactone ring-containing polymer.

The dynamic TG was measured about the obtained lactone ring 중합체 containing polymer, and the mass loss of 0.26 mass% was detected. The lactone ring-containing polymer had a weight-average molecular weight of 305,000, a glass transition temperature of 129 ° C, a melt flow rate of 0.5 g / 10 min, a lactone ring ratio of 95%, and a polymer gel content of 280 pieces / lactone ring-containing polymer 100 g. It was. The results are shown in Table 1.

In addition, when the pellets of the obtained lactone ring-containing polymer were kneaded under the same conditions as in Example 1, the content of the polymer gel was increased to 100 g of the 830-lactone ring-containing polymer. The results are shown in Table 1.

As can be clearly seen from Table 1, the lactone ring-containing polymers of Examples 1 and 2 were prepared using t-amyl peroxide as a polymerization initiator, and the lactone ring-containing polymer of Example 3 was prepared using an azo initiator. In addition, the lactone ring-containing polymer of Example 4 is produced using a living radical initiator, and since the molecular weight is all within a predetermined range, it shows a high lactone cyclization rate, high heat resistance, and a melt flow rate suitable for molding. It is very small in content of a polymer gel, and is especially preferable for an optical use.

In contrast, the lactone ring-containing polymer of Comparative Example 1 was prepared using a t-butyl peroxide as a polymerization initiator, although the molecular weight was within a predetermined range, and the lactone ring-containing polymer of Comparative Example 2 was a t-amyl Although it is manufactured using a peroxide as a polymerization initiator, since molecular weight is out of a predetermined range, it shows high lactone cyclization rate and heat resistance, but there is much content of a polymer gel, and it is not suitable especially for optical use.

The lactone ring-containing polymer of Example 1 prepared by using the high purity methyl 2-hydroxymethyl acrylate prepared in Synthesis Example 1 as a monomer and using a t-amyl peroxide as the polymerization initiator was synthesized in Synthesis Example 2 The content of the polymer gel is much smaller than that of the lactone ring-containing polymer of Example 2 prepared by using low purity methyl 2-hydroxymethyl acrylate prepared in the above and using t-amyl peroxide as a polymerization initiator. In the production of lactone ring-containing polymers, polymers in lactone ring-containing polymers are prepared by using 2-hydroxymethylacrylic acid ester purified by a specific method as a monomer and using t-amyl peroxide as a polymerization initiator. It has been shown that the generation of the gel can be suppressed very effectively.

As can be seen from Table 1, the lactone ring containing polymers of Examples 1 to 4 had a viscosity increase rate of 2.0 times or less after heating at 280 ° C. for 30 minutes for the reasons described above. Intermolecular crosslinking does not occur very much, and gelation is considered to be suppressed.

In contrast, the lactone ring-containing polymer of Comparative Example 1 was produced by using a t-butyl-type peroxide as a polymerization initiator or, when heated, the melt viscosity rapidly increased, and gelation was caused by branching or intermolecular crosslinking of the polymer chain. Is thought to occur.

In this way, in the production of the lactone ring-containing polymer, not from the t-butyl type peroxide used in the conventional production method, but from the polymer chain, such as t-amyl type peroxide, azo initiator, living radical initiator, and the like. By using a polymerization initiator having a low ability to extract hydrogen and producing so that the molecular weight is within a predetermined range, it can be seen that a lactone ring-containing polymer containing less foreign matter and less likely to gel.

According to the lactone ring-containing polymer of the present invention, since a specific polymerization initiator such as a t-amyl peroxide is used at the time of manufacture and the molecular weight is limited within a predetermined range, it is not only excellent in transparency and heat resistance, but also in mechanical strength, In addition to having desired characteristics such as molding processability, in particular, there are very few foreign matters (polymer gels), and it is difficult to cause gelation even when heat is applied during molding, for example, an excellent optical component can be provided.

The lactone ring-containing polymer of the present invention is not only excellent in transparency and heat resistance, but also has desired characteristics such as mechanical strength and molding processability, and is particularly small in foreign matter and difficult to gel, and thus can be widely used in optical applications. In particular, it makes a great contribution to the field related to optical materials.

Claims (6)

No content of polymer gel having an average particle diameter of 50 µm or more per 100 g of lactone ring-containing polymer or greater than 0 to 100, a weight average molecular weight of 50,000 to 170,000, Herein, the number of polymer gels having an average particle diameter of 50 µm or more is 100 g of a lactone ring-containing polymer dissolved in 500 ml of a solvent, followed by filtration with a filter having an average pore diameter of 1.0 µm and then a polymer gel having an average particle diameter of 50 µm or more remaining on the filter. Measured visually under a microscope; Lactone ring containing polymer characterized by having a lactone ring structure represented by following formula (1):

Where R ¹ , R ² and R ³ independently of one another represent a hydrogen atom or an organic moiety having 1 to 20 carbon atoms, The organic moiety may contain an oxygen atom. The lactone ring-containing polymer according to claim 1, wherein the rate of increase in viscosity after heating at 280 ° C. for 30 minutes is 0.8 to 2.0 times. delete A molding material formed by heating and granulating the lactone ring-containing polymer according to claim 1. An optical component selected from a light guide, an optical lens and an optical film formed from the molding material according to claim 4. As a 2-hydroxymethylacrylic acid ester used as a monomer for manufacturing the lactone ring containing polymer of Claim 1, and represented by following formula (2), 2-hydroxymethylacrylic acid ester characterized by a turbidity of 0 to 0.05 after a heat test at 90 ° C. for 2 hours:

Where R ⁴ and R ⁵ independently of each other represent a hydrogen atom or an organic moiety having 1 to 20 carbon atoms, The organic moiety may contain an oxygen atom.