Vinyl polymer, polymerizable composition, and method for producing vinyl polymer

Abstract

To provide a vinyl polymer with suppressed coloration, a method for producing the same, and a polymerizable composition usable in the production method.SOLUTION: A vinyl polymer contains a structure derived from a chain transfer agent (A) represented by the following formula (1) (where R' represents a hydrogen atom, a halogen atom, -OC(=O)R", -C(=O)NH2, -CN, -C(=O)OR" or an aryl group; Y represents -SO2R"; and each R" independently represents an alkyl group, a cycloalkyl group, an aryl group or a heterocyclic group) and a constituent unit derived from a vinyl monomer (B). A method for producing the vinyl polymer includes polymerizing the polymerizable composition containing the chain transfer agent (A), the vinyl monomer (B) and a polymerization initiator (C).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a vinyl polymer, a polymerizable composition, and a method for producing a vinyl polymer.

Background Art

[0002] In the fields of dicing related and adhesion such as adhesives, coating fields such as coating agents, inks and paints, and electronic material fields such as underfills, in order to meet various requirements such as improving material performance that can withstand the use environment, simplifying the manufacturing process, and saving energy, the development of materials, particularly polymer materials, has been carried out. When using a general polymer (chain polymer) material as an adhesive or a paint, the polymer is often dissolved in a solvent to reduce its viscosity for use. On the other hand, a multi-branched polymer has a lower viscosity compared to a chain polymer of the same molecular weight, so that a solvent is not required or only a small amount is needed, and it is expected to be effective in reducing harmful volatile organic compounds (VOCs) in paint and adhesive applications.

[0003] As a method for synthesizing such a multi-branched polymer, for example, a method using an addition-fragmentation chain transfer (AFCT) agent (Non-Patent Document 1) and a method using catalytic chain transfer with cobalt (Patent Document 1) are known. Although the vinyl polymers obtained by the production methods described in Patent Document 1 and Non-Patent Document 1 suggest the presence of a branched structure, the synthesis of high molecular weight polymers has not been achieved. Patent Documents 2 and 3 describe a production method capable of obtaining a vinyl polymer having a high molecular weight and a branched structure by appropriately designing the molecular structure of the AFCT agent.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Non-Patent Document

[0005]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the vinyl polymers obtained by the methods of Patent Document 2 or Patent Document 3 are colored, and thus there is a problem that they cannot be used in applications that require high transparency such as coating agents.

[0007] An object of the present invention is to provide a vinyl polymer with suppressed coloring. Another object of the present invention is to provide a method for producing the vinyl polymer and a polymerizable composition that can be used in such a production method.

Means for Solving the Problems

[0008] The present invention includes the following configurations. [1] A vinyl polymer containing a structure derived from a chain transfer agent (A) represented by the following formula (1) and a structural unit derived from a vinyl monomer (B) other than the chain transfer agent (A).

Chemical Formula

Advantages of the Invention

[0009] According to the present invention, there are provided a vinyl polymer with suppressed coloring, a method for producing the same, and a polymerizable composition used in the method for producing the vinyl polymer.

Modes for Carrying Out the Invention

[0010] In the present invention, the numerical range represented by "~" means a numerical range including the numerical values before and after "~" as the lower limit value and the upper limit value, respectively. "(Meth)acrylic" means acrylic or methacrylic. "(Meth)acrylate" means acrylate or methacrylate. "(Meth)acrylo" means acrylo or methacrylo. "Vinyl monomer" is a compound having a polymerizable double bond.

[0011] [Vinyl Polymer] The vinyl polymer according to the embodiment has a structure derived from a chain transfer agent (A) and a structural unit derived from a vinyl monomer (B) other than the chain transfer agent (A). Hereinafter, it will be described in order.

[0012] (Chain Transfer Agent (A)) The chain transfer agent (A) is a compound represented by the following formula (1).

[0013] [Chemical Formula]

[0014] In the formula (1), R' is a hydrogen atom, a halogen atom, -OC(=O)R", -C(=O)NH 2 , -CN, -C(=O)OR" or an aryl group. Y is -SO 2It is "R”. Each R” is independently an alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group.

[0015] Examples of the halogen atom in R’ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. As the halogen atom, a chlorine atom or a bromine atom is preferable. When R’ is a halogen atom, it shows an appropriate chain transfer constant value in step (i) described later.

[0016] Examples of the aryl group in R’ include aryl groups having 6 to 18 carbon atoms. Examples of the aryl group having 6 to 18 carbon atoms include a phenyl group, a benzyl group, and a naphthyl group. The aryl group may have a substituent. Examples of the substituent include an alkyl group, an aryl group, a carboxy group, an alkoxycarbonyl group, a carbamoyl group, a cyano group, a hydroxy group, an amino group, an amide group, a halogen atom, an allyl group, an epoxy group, an alkoxy group, and a group showing hydrophilicity or ionic property. Examples of the group showing hydrophilicity or ionic property include an alkali salt of a carboxy group, an alkali salt of a sulfoxy group, a poly(alkylene oxide) group such as a polyethylene oxide group and a polypropylene oxide group, and a cationic substituent such as a quaternary ammonium base.

[0017] Y is -SO 2 It is R”. In R’ and Y, each R” is independently an alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group.

[0018] Examples of the alkyl group in R” include linear or branched alkyl groups having 1 to 20 carbon atoms. Specific examples of the linear or branched alkyl group having 1 to 20 carbon atoms include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, t-butyl group, i-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, and icosyl group.

[0019] Examples of the cycloalkyl group in R” include cycloalkyl groups having 3 to 20 carbon atoms. Specific examples of the cycloalkyl group having 3 to 20 carbon atoms include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, and adamantyl group.

[0020] Examples of the aryl group in R” include aryl groups having 6 to 18 carbon atoms. Specific examples of the aryl group having 6 to 18 carbon atoms include phenyl group, benzyl group, and naphthyl group.

[0021] Examples of the heterocyclic group in R” include heterocyclic groups having 5 to 18 carbon atoms containing an oxygen atom, a nitrogen atom, or a sulfur atom as a heteroatom. Specific examples of the heterocyclic group include γ-lactone group, ε-caprolactone group, and morpholine group.

[0022] Note that the alkyl group, cycloalkyl group, aryl group, and heterocyclic group in R” may have a substituent. Examples of the substituent include an alkyl group, an aryl group, a carboxy group, an alkoxycarbonyl group, a carbamoyl group, a cyano group, a hydroxy group, an amino group, an amide group, a halogen atom, an allyl group, an epoxy group, an alkoxy group, and a group exhibiting hydrophilicity or ionic property. Examples of the group exhibiting hydrophilicity or ionic property include an alkali salt of a carboxy group, an alkali salt of a sulfoxy group, a poly(alkylene oxide) group such as a polyethylene oxide group and a polypropylene oxide group, and a cationic substituent such as a quaternary ammonium base.

[0023] As R” in R’, an alkyl group or a cycloalkyl group is preferable, an alkyl group is more preferable, a linear or branched alkyl group having 1 to 6 carbon atoms is further preferable, and a linear alkyl group having 1 to 6 carbon atoms is particularly preferable. As R” in Y, an aryl group is preferable, an aryl group having 6 to 18 carbon atoms is further preferable, and an aryl group having 6 to 10 carbon atoms is further preferable.

[0024] As the chain transfer agent (A), a 2-(arylsulfonylmethyl)acrylate ester in which R” in R’ is a linear alkyl group having 1 to 6 carbon atoms is preferable, a 2-(phenylsulfonylmethyl)acrylate ester in which R” in R’ is a linear alkyl group having 1 to 6 carbon atoms is more preferable, methyl 2-(phenylsulfonylmethyl)acrylate, ethyl 2-(phenylsulfonylmethyl)acrylate, and propyl 2-(phenylsulfonylmethyl)acrylate are further preferable, and methyl 2-(phenylsulfonylmethyl)acrylate is particularly preferable. These chain transfer agents (A) can be used alone or in combination of two or more.

[0025] (Other chain transfer agents) In the vinyl polymer according to the embodiment, other chain transfer agents may be used in combination with the chain transfer agent (A). That is, the vinyl polymer according to the embodiment may further have a structure derived from other chain transfer agents other than the chain transfer agent (A). As other chain transfer agents, a chain transfer agent in which a growing end radical of a polymer extracts a hydrogen atom in the chain transfer agent molecule to generate a radical is preferable, -OH, -SH, -C(=O)OH, -NH 2 , -NHR 1 , and -SO 3A chain transfer agent having at least one group selected from the group consisting of H is more preferable. However, the R 1 is an alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group.

[0026] Other chain transfer agents include mercapto group-containing chain transfer agents such as n-dodecyl mercaptan; secondary hydroxyl group-containing chain transfer agents such as isopropyl alcohol, and the like. Other chain transfer agents can be used alone or in combination of two or more.

[0027] (Vinyl monomer (B)) The vinyl monomer (B) is not particularly limited, but is a monomer other than the chain transfer agent (A), and a (meth)acrylate compound is preferable. Examples of the (meth)acrylate compound include alkyl (meth)acrylates having an alkyl group with 1 to 30 carbon atoms, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, glycidyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, ethoxyethoxyethyl (meth)acrylate, polyethylene glycol (meth)acrylate and its alkyl ether, benzyl (meth)acrylate, phenyl (meth)acrylate, 3-(triethoxysilyl)propyl (meth)acrylate, and 2-(dimethylamino)ethyl (meth)acrylate and its quaternary alkylammonium salt.

[0028] As the alkyl (meth)acrylate having an alkyl group with 1 to 30 carbon atoms, alkyl (meth)acrylates having a linear or branched alkyl group with 1 to 10 carbon atoms are preferable, alkyl acrylates having a linear or branched alkyl group with 1 to 10 carbon atoms are more preferable, alkyl acrylates having a linear alkyl group with 1 to 6 carbon atoms and alkyl acrylates having a branched alkyl group with 3 to 10 carbon atoms are particularly preferable, and n-butyl acrylate and 2-ethylhexyl acrylate are most preferable. These vinyl monomers (B) can be used alone or in combination of two or more.

[0029] The vinyl polymer according to the embodiment may contain a small amount of other structural units other than the structural units derived from the (meth)acrylate-based compound as long as the effects of the present invention are not impaired. The other structural units are not particularly limited as long as they are structural units derived from vinyl monomers capable of radical polymerization. Examples of the vinyl monomers capable of radical polymerization include styrene-based monomers such as (meth)acrylic acid, α-methylstyrene, vinyltoluene, and styrene; vinyl ether-based monomers such as methyl vinyl ether, ethyl vinyl ether, and isobutyl vinyl ether; fumaric acid, monoalkyl esters and dialkyl esters of fumaric acid; maleic acid, monoalkyl esters and dialkyl esters of maleic acid; itaconic acid, monoalkyl esters and dialkyl esters of itaconic acid; (meth)acrylonitrile, (meth)acrylamide, butadiene, isoprene, vinyl chloride, vinylidene chloride, vinyl acetate, vinyl ketone, vinyl pyridine, and vinyl carbazole. These vinyl monomers capable of radical polymerization can be used alone or in combination of two or more.

[0030] The vinyl monomer (B) is preferably used such that the ratio (mol%) of the total number of moles of acrylic acid and acrylate-based compounds to the total number of moles of the vinyl monomer (B) is 50 mol% or more. Thereby, a vinyl polymer in which x described later is 50 mol% or more can be obtained. The ratio (mol%) of the total number of moles of acrylic acid and acrylate-based compounds to the total number of moles of the vinyl monomer (B) is more preferably 60 mol% or more, and even more preferably 70 mol% or more.

[0031] The mass ratio represented by [Structure derived from chain transfer agent (A)] / [Constituent unit derived from vinyl monomer (B)] is preferably 0.0001 or more, more preferably 0.001 or more, and even more preferably 0.002 or more. The mass ratio represented by [Structure derived from chain transfer agent (A)] / [Constituent unit derived from vinyl monomer (B)] is preferably 0.1 or less. If the mass ratio is below the upper limit value, the vinyl polymer will have a high degree of branching. The preferable lower limit and upper limit of the mass ratio can be arbitrarily combined. For example, 0.0001 to 0.1 is preferable. The mass ratio is, for example, 1 It can be determined by 1H-NMR measurement. Specifically, it can be determined by using the integrated value of the peaks derived from the chain transfer agent (A) and the integrated value of the peaks derived from the vinyl monomer (B) and calculating their ratio.

[0032] The vinyl polymer according to the embodiment preferably has a structure represented by the following formula (2).

[0033]

Chemical formula

[0034] The meanings of the symbols in formula (2) are as follows. R and R 1 ~R n are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group. Z is a group derived from a radical polymerization initiator, a group derived from the chain transfer agent (A), or a group derived from another chain transfer agent. X 1 ~X n are each independently a hydrogen atom, a methyl group, or a structure represented by formula (3), and at least one of X 1 ~X n is a structure represented by formula (3). R n and X n in, n is a natural number from 2 to 10,000.

[0035] [Chemical formula]

[0036] The meanings of the symbols in formula (3) are as follows. R and R 1 ~R n are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group, Z is a group derived from a radical polymerization initiator, a group derived from a chain transfer agent (A), or a group derived from another chain transfer agent, and X 1 ~X n are each independently a hydrogen atom, a methyl group, or a structure represented by formula (3). In R n and X n , n is a natural number from 2 to 10,000.

[0037] R and R in formula (2) 1 ~R n and R in formula (3) 1 ~R n are independent of each other, and X in formula (2) 1 ~X n and X in formula (3) 1 ~X n are independent of each other.

[0038] Since at least one of X 1 ~X n in formula (2) is a structure represented by formula (3), the vinyl polymer according to the embodiment has a branched structure.

[0039] The fact that the vinyl polymer according to the embodiment has the structures represented by formulas (2) and (3) means that in the 1 1H-NMR measurement of the vinyl polymer according to the embodiment, there are peaks with chemical shift values of 5.5 to 5.6 ppm and 6.1 to 6.2 ppm, and 13 in the 13C-NMR measurement, it can be confirmed that there is a peak with a chemical shift value of 38 to 41 ppm. Here, 1In the 1H-NMR measurement, peaks with chemical shift values of 5.5 to 5.6 ppm and 6.1 to 6.2 ppm indicate the presence of terminal double bonds in the vinyl polymer according to the embodiment. Also, 13 In the 13C-NMR measurement, a peak with a chemical shift value of 38 to 41 ppm indicates that the vinyl polymer according to the embodiment has a branched structure represented by formula (3).

[0040] In the vinyl polymer according to the embodiment, as shown in formula (2), it is preferable that terminal double bonds are introduced. These terminal double bonds have polymerizability and are useful because a graft copolymer can be easily synthesized by copolymerizing with a vinyl monomer.

[0041] The vinyl polymer according to the embodiment preferably has structural units derived from (meth)acrylic acid or (meth)acrylate compounds, as shown in formulas (2) and (3).

[0042] In the vinyl polymer according to the embodiment, in formulas (2) and (3), when the ratio of the number of moles of hydrogen atoms to the total number of moles of hydrogen atoms and methyl groups contained in X 1 ~X n is defined as x, x is preferably 50 mol% or more, more preferably 60 mol% or more, still more preferably 70 mol% or more. When x is 50 mol% or more, the vinyl polymer according to the embodiment has a high degree of branching. Note that x is a value determined by the charging ratio of acrylic acid and acrylate compounds in the vinyl monomer (B) as a raw material.

[0043] The weight average molecular weight (Mw) of the vinyl polymer according to the embodiment is not particularly limited, but is preferably 20,000 to 700,000, more preferably 30,000 to 600,000, still more preferably 40,000 to 500,000, particularly preferably 40,000 to 400,000, and most preferably 40,000 to 350,000. By using such a vinyl polymer as a raw material, molded articles and coating films excellent in elastic modulus and mechanical strength can be obtained. The weight average molecular weight is a value calculated by converting the value measured by gel permeation chromatography (GPC) into standard polystyrene equivalents.

[0044] The vinyl polymer according to the embodiment described above has a structure derived from the chain transfer agent (A), that is, it is polymerized using the chain transfer agent (A), and thus coloring is suppressed. Therefore, it can also be suitably used in applications that require high transparency such as coating agents. The reason why coloring is suppressed by using the chain transfer agent (A) is not necessarily clear, but it is presumed that the radical species regenerated from the chain transfer agent is less likely to cause side reactions.

[0045] [Polymerizable Composition] The polymerizable composition according to the embodiment includes the chain transfer agent (A), the vinyl monomer (B), and the polymerization initiator (C), and may also contain a solvent as required. By subjecting the polymerizable composition according to the embodiment to polymerization, the vinyl polymer according to the above-described embodiment can be obtained.

[0046] (Polymerization Initiator (C)) The polymerization initiator (C) is not particularly limited, and conventionally known compounds can be used, but radical polymerization initiators are preferred. Examples of the radical polymerization initiator include azo-based radical polymerization initiators and peroxide-based radical polymerization initiators.

[0047] Specific examples of the azo-based radical polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), and 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile). Specific examples of the peroxide-based radical polymerization initiator include 2,4-dichlorobenzoyl peroxide, t-butyl peroxypivalate, o-methylbenzoyl peroxide, bis-3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, t-butyl peroxy-2-ethylhexanoate, cyclohexanone peroxide, benzoyl peroxide, methyl ethyl ketone peroxide, dicumyl peroxide, lauroyl peroxide, diisopropylbenzene hydroperoxide, t-butyl hydroperoxide, and di-t-butyl peroxide. The radical polymerization initiator may be used alone or in combination of two or more.

[0048] (Solvent) The solvent is not particularly limited. For example, alcohol solvents (such as methanol and ethanol), aromatic hydrocarbon solvents (such as toluene, ethylbenzene, xylene, and anisole), ketone solvents (such as acetone, methyl isobutyl ketone, and methyl ethyl ketone), and ester solvents (such as butyl acetate, ethyl acetate, and propylene glycol monomethyl ether acetate) can be mentioned. The solvent can be used alone or in combination of two or more.

[0049] In the conventional method, depending on the type of the solvent, the conversion rate of the monomer during polymerization may decrease, and it may be difficult to obtain a high molecular weight vinyl polymer. On the other hand, in the polymerizable composition according to the embodiment, by using the chain transfer agent (A), coloring can be suppressed, and furthermore, since the conversion rate during polymerization is high regardless of the solvent, a high molecular weight vinyl polymer can be obtained.

[0050] (Composition of the polymerizable composition) The content of the chain transfer agent (A) in the polymerizable composition is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 10 parts by mass, and even more preferably 1 to 10 parts by mass with respect to 100 parts by mass of the vinyl monomer (B). When the content of the chain transfer agent (A) is at least the lower limit value, a branched structure can be appropriately introduced into the resulting vinyl polymer. When the content of the chain transfer agent (A) is at most the upper limit value, properties such as the elastic modulus, mechanical strength, and durability of the vinyl polymer can be sufficiently obtained.

[0051] The content of the polymerization initiator (C) in the polymerizable composition is not particularly limited, but is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and still more preferably 0.1 to 1 part by mass with respect to 100 parts by mass of the vinyl monomer (B). When the content of the polymerization initiator (C) is within the above range, an appropriate polymerization rate can be obtained in step (i) described later.

[0052] The content of the solvent in the polymerizable composition is not particularly limited, but is preferably 0 to 300 parts by mass, more preferably 10 to 150 parts by mass, and still more preferably 20 to 111 parts by mass with respect to 100 parts by mass of the vinyl monomer (B). When the content of the solvent is within the above range, an appropriate polymerization rate can be obtained in step (i) described later, and the solution viscosity after the formation of the vinyl polymer is reduced, resulting in excellent handleability.

[0053] (Other additives) The polymerizable composition according to the embodiment may contain other additives. Examples of other additives include pigments, ultraviolet absorbers, mold release agents, defoaming agents, plasticizers, viscosity modifiers, and the like. Known compounds can be used as these additives.

[0054] [Method for producing vinyl polymer] The method for producing a vinyl polymer according to the embodiment includes the following step (i). Step (i): A step of subjecting a polymerizable composition containing a chain transfer agent (A), a vinyl monomer (B) other than the chain transfer agent (A), and a polymerization initiator (C) to polymerization. Hereinafter, step (i) will be described in detail.

[0055] <Step (i)> In step (i), a polymerizable composition containing a chain transfer agent (A), a vinyl monomer (B), and a polymerization initiator (C) is subjected to polymerization. The polymerizable composition may contain a solvent and other additives as necessary. According to the method for producing a vinyl polymer according to the embodiment, a vinyl polymer having a branched chain or a graft copolymer which is a vinyl polymer having a graft chain can be produced by the step (i).

[0056] As used herein, the “graft copolymer” is a polymer having one or more blocks connected as a side chain polymer structure to a main chain polymer structure. In a polymer having a branched chain, the structures of the main chain polymer and the side chain polymer may be different or the same. On the other hand, in a graft copolymer, the structures of the main chain polymer and the side chain polymer are different in the type (structure) of monomer units or different in composition or sequence distribution even if they are the same monomer units.

[0057] Conventional methods for producing graft copolymers include, for example, a method in which a macromonomer having a radically polymerizable double bond at the end is produced as a side chain polymer structure and then radically polymerized with a monomer that becomes a constituent unit of the main chain polymer, a method in which a main chain polymer having a reaction point and a macromonomer having a reaction point are produced in advance and then reacted with each other, and a method in which after producing the main chain polymer, a radical is generated on the main chain polymer using an initiator having a hydrogen abstraction ability, and a monomer that becomes a constituent unit of the side chain polymer is reacted to produce a side chain polymer structure. The “macromonomer” means a polymer having a radically polymerizable group or an addition-reactive functional group. All of these methods require two or more polymerization steps. In contrast, according to the method for producing a vinyl polymer according to the embodiment, a vinyl polymer having a branched chain or a graft chain can also be produced by only one polymerization step, that is, only by the step (i). The method for producing a vinyl polymer according to the embodiment may further include a polymerization step after the second step.

[0058] The polymerization method of the coincidence composition is not particularly limited, and for example, conventionally known polymerization methods such as bulk polymerization method, solution polymerization method, suspension polymerization method, emulsion polymerization method, etc. can be used. The polymerization reaction may be carried out in the presence of air, but from the viewpoint of the efficiency of radical polymerization, it is preferably carried out in an inert gas atmosphere such as nitrogen or argon. Although known methods are used as the method of carrying out in an inert gas atmosphere, for example, a method of blowing an inert gas into the polymerizable composition, a method of repeating freezing, degassing and melting can be used.

[0059] The polymerization temperature is not particularly limited, but from the viewpoint of the polymerization rate, 0 to 150 ° C is preferable, and 20 to 120 ° C is more preferable. The polymerization time is not particularly limited, but 0.5 to 48 hours is preferable, and 4 to 48 hours is more preferable.

[0060] From the viewpoint of improving the molecular weight and the degree of branching of the obtained vinyl polymer, the conversion rate of the vinyl monomer (B) in step (i) is preferably 85% or more, more preferably 90% or more, still more preferably 95% or more, and particularly preferably 98% or more. Here, the conversion rate (%) of the vinyl monomer (B) is determined from the measurement values of 1H-NMR measurement using a nuclear magnetic resonance apparatus (manufactured by JEOL Ltd., ECZ400S, 400 MHz) and using CDCl 3 as the measurement solvent. 1 Specifically, the conversion rate (%) of the vinyl monomer (B) can be calculated as the ratio of the integrated value of the peaks derived from the generated vinyl polymer to the sum of the integrated value of the peaks derived from the remaining vinyl monomer (B) and the amount of the generated vinyl polymer, using the integrated value of the peaks derived from the remaining vinyl monomer (B) and the integrated value of the peaks derived from the generated vinyl polymer.

[0061] The vinyl polymer obtained in step (i) may be used mainly as a vinyl polymer, or may be used as an additive for other resins. When used mainly as a vinyl polymer, it can be used as various molded articles such as sheets, films, various housings and covers, and light guides as melt-moldable molding materials. Further, it can be used as a paint or an adhesive by coating after dissolving in a solvent.

[0062] When using a vinyl polymer as an additive for other resins, examples of the resin as the main component include acrylic resins such as polymethyl methacrylate, polyolefins, polyamides, unsaturated polyesters, saturated polyesters such as polyethylene terephthalate and polybutylene terephthalate, polycarbonates, polystyrenes, ABS resins, AS resins, polyvinyl chlorides, polylactic acids, polyvinylidene fluorides, and the like. Functions that the vinyl polymer imparts to other resins include flexibility, toughness, impact resistance, weather resistance, processability, mold release property, scratch resistance, surface hardness, compatibility, crystal size control, ductility, and the like. Examples of methods for mixing with other resins include physical mixing, melt mixing, and methods of dissolving or dispersing before polymerization or curing.

Examples

[0063] Hereinafter, the present invention will be described more specifically by way of examples. However, the present invention is not limited to the examples described below, and various modifications are possible without departing from the gist of the present invention.

[0064] [Raw materials] Abbreviations of the raw materials used in the examples and comparative examples are shown below. (Chain transfer agent (A)) ASME: Methyl 2-(benzenesulfonylmethyl)acrylate (produced in Production Example 1)

[0065] (Other chain transfer agents) EBMA: Ethyl 2-(bromomethyl)acrylate (manufactured by Chemclear Co., Ltd.)

[0066] (Vinyl monomer (B)) EHA: 2-Ethylhexyl acrylate (manufactured by Mitsubishi Chemical Corporation) nBA: n-Butyl acrylate (manufactured by Mitsubishi Chemical Corporation)

[0067] (Polymerization initiator (C)) AIBN: 2,2’-Azobis(isobutyronitrile) (manufactured by FUJIFILM Wako Pure Chemical Corporation)

[0068] (Solvent) PGMEA: Propylene Glycol Monomethyl Ether Acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) MEK: 2-Butanone (manufactured by Nacalai Tesque, Inc.)

[0069] [Production Example 1: Synthesis of ASME] Into a 2.0 L separable flask, methyl methacrylate (48.06 g, 480.0 mmol) and methanol (252.8 g) were added. After cooling to 0 °C, iodine (144.2 g, 568.0 mmol) and sodium benzenesulfinate dihydrate (201.8 g, 1008 mmol) were added little by little, and the mixture was stirred at room temperature for 5 hours. Subsequently, dichloromethane (800.0 mL) was added for dilution, and saturated aqueous sodium carbonate solution (160.0 mL) and 5% aqueous sodium bisulfite solution (160.0 mL) were added. After liquid separation, 30.00 g of magnesium sulfate was added to the organic layer for drying, and then the solvent was distilled off. Subsequently, dichloromethane (280.0 mL) was added, and triethylamine (97.14 g, 960.0 mmol) was added dropwise over 30 minutes, and then the mixture was stirred at room temperature for 2 hours. Subsequently, after distilling off the solvent, column chromatography was performed using silica gel (3.000 kg) to obtain 61.00 g of white solid ASME.

[0070] [Measurement Method and Evaluation Method] <Weight-average Molecular Weight of Vinyl Polymer> The weight-average molecular weight of the vinyl polymer was measured using gel permeation chromatography (GPC) (HLC-8320 manufactured by Tosoh Corporation). After preparing a 0.2 mass% tetrahydrofuran solution of the vinyl polymer, 10 μL of the solution was injected into an apparatus equipped with columns manufactured by Tosoh Corporation (TSKgel SuperHZM-M (inner diameter 4.6 mm, length 15 cm), HZM-M (inner diameter 4.6 mm, length 15 cm), HZ-2000 (inner diameter 4.6 mm, length 15 cm), TSKguardcolumn SuperHZ-L (inner diameter 4.6 mm, length 3.5 cm)). Measurement was carried out under the conditions of a flow rate of 0.35 mL / min, an eluent of tetrahydrofuran (stabilizer BHT), and a column temperature of 40°C, and the weight-average molecular weight (Mw) was calculated in terms of standard polystyrene conversion.

[0071] <Conversion rate of vinyl monomer (B)> The conversion rate (%) of each vinyl monomer (B) was determined from the measurement values of 1H-NMR measurement using a nuclear magnetic resonance apparatus (ECZ400S, 400 MHz manufactured by JEOL Ltd.) with CDCl 3 used 1 Specifically, using the integrated value of the peaks derived from the remaining vinyl monomer (B) and the integrated value of the peaks derived from the produced vinyl polymer, the conversion rate was calculated as the ratio of the amount of the produced vinyl polymer to the sum of the amount of the remaining vinyl monomer (B) and the amount of the produced vinyl polymer.

[0072] <Coloring of vinyl polymer solution> The appearance of the vinyl polymer solution obtained in each example was visually evaluated. Those that were colorless and transparent were designated as "no coloring", and the others were designated as "with coloring".

[0073] [Example 1] (Preparation of vinyl polymer) To a Schlenk tube, 10.0 parts by mass of ASME as a chain transfer agent (A), 15 parts by mass of EHA as a vinyl monomer (B), 85 parts by mass of nBA, 0.31 parts by mass of AIBN as a polymerization initiator (C), 110.0 parts by mass of butyl acetate as a solvent, and a stirrer chip were added. The temperature was raised to 70 °C and stirred for 6 hours. Then, after cooling to room temperature, the obtained resin composition was recovered from the reaction vessel to obtain a vinyl polymer solution. Table 1 shows the conversion rate of the vinyl monomer (B) and the evaluation results of the obtained vinyl polymer.

[0074] [Examples 2 to 4, Comparative Examples 1 to 4] A polymerizable composition was prepared in the same manner as in Example 1 except that the amounts of the chain transfer agent (A), other chain transfer agents, vinyl monomer (B), polymerization initiator (C), and solvent were changed as shown in Table 1, and this was subjected to polymerization to obtain a vinyl polymer solution. Table 1 shows the results of evaluation in the same manner as in Example 1.

[0075]

Table 1

[0076] As shown in Table 1, in Examples 1 to 4, a colorless and transparent vinyl copolymer solution was obtained, indicating that the coloring of the resin could be suppressed. Since these vinyl polymers are not colored, they can be used in optical applications when applied to molded articles or coating films because they have no coloring and can achieve excellent handleability and physical properties such as low melt viscosity and solution viscosity derived from high branching degree, and thus are industrially useful. On the other hand, in Comparative Examples 1 to 4, since a chain transfer agent with a different structure was added instead of the chain transfer agent (A), coloring could not be suppressed despite having the same composition ratio as the vinyl copolymers of Examples 1 to 4. Coloring is not industrially preferable because it limits the use in optical applications.

Claims

1. A vinyl polymer comprising a structure derived from a chain transfer agent (A) represented by the following formula (1) and a constituent unit derived from a vinyl monomer (B) other than the chain transfer agent (A): 【Chemistry 1】 In formula (1), R' is a hydrogen atom, a halogen atom, -OC(=O)R", -C(=O)NH ２ , -CN, -C(=O)OR" or an aryl group. Y is -SO ２ R″. Each R″ is independently an alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group.

2. The vinyl polymer according to claim 1, wherein the mass ratio represented by [structure derived from the chain transfer agent (A)] / [structural unit derived from the vinyl monomer (B)] is 0.0001 to 0.

1.

3. 3. The vinyl polymer according to claim 1, which is a vinyl polymer having a branched structure.

4. A polymerizable composition comprising: a chain transfer agent (A) represented by the following formula (1); a vinyl monomer (B) other than the chain transfer agent (A); and a polymerization initiator (C). 【Chemistry 2】 In formula (1), R' is a hydrogen atom, a halogen atom, -OC(=O)R", -C(=O)NH ２ , -CN, -C(=O)OR" or an aryl group. Y is -SO ２ R″. Each R″ is independently an alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group.

5. A method for producing a vinyl polymer, comprising: a step (i) of subjecting a polymerizable composition containing a chain transfer agent (A) represented by the following formula (1), a vinyl monomer (B) other than the chain transfer agent (A), and a polymerization initiator (C) to polymerization: 【Chemistry 3】 In formula (1), R' is a hydrogen atom, a halogen atom, -OC(=O)R", -C(=O)NH ２ , -CN, -C(=O)OR" or an aryl group. Y is -SO ２ R″. Each R″ is independently an alkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group.

6. The method for producing a vinyl polymer according to claim 5, wherein the conversion rate of the vinyl monomer (B) in the step (i) is 85% or more.

7. The method for producing a vinyl polymer according to claim 5 or 6, wherein the content of the chain transfer agent (A) in the polymerizable composition is 0.01 to 10 parts by mass based on 100 parts by mass of the vinyl monomer (B).

8. The method for producing a vinyl polymer according to claim 5 or 6, wherein the vinyl polymer has a branched structure.

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