JP2005106591A - Analytical method for structural unit in acrylic resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for analyzing accurately a structural unit of a polymer, even in the case of a polymer of a (meth)acrylic ester containing an ester group derived from 1,4-butanediol or the like. <P>SOLUTION: This analytical method of the structural unit [1] in an acrylic resin is characterized as follows: the acrylic resin containing the structural unit [1] derived from a compound expressed by formula (1) is decomposed in the supercritical state in the presence of a lower alcohol; hereby, decomposed products including a cyclic ether expressed by formula (2) and diol expressed by formula (3) are produced; the cyclic ether (2) and the diol (3) in the products are isolated and quantitated; and the structural unit [1] in the acrylic resin is quantitated from the total quantity. Where, R1 is a hydrogen atom or a methyl group in formulas (1)-(3), and n is 4 or 5. A methylene group may be substituted by an oxygen atom, a sulfur atom, a carboxyl group, a sulfonyl group or a secondary amino group (-NH-), and the hydrogen atom in the methylene group may be substituted by a hydrocarbon group or an alkoxy group. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for analyzing a structural unit derived from a (meth) acrylic acid ester in an acrylic resin.

  A method for analyzing a structural unit of an acrylic resin containing a structural unit derived from a (meth) acrylic acid ester is reported in Patent Document 1. Specifically, by reacting an acrylic resin with a lower alcohol in a supercritical state, decomposing the ester group of (meth) acrylic acid ester into alcohol, and separating and quantifying the decomposed alcohol, (meth) acrylic A method for analyzing a structural unit derived from an acid ester is disclosed.

JP 2001-141725 A ([0058] to [0067])

The inventors analyzed an acrylic resin obtained by polymerizing butyl acrylate and 4-hydroxybutyl acrylate according to the method described in Patent Document 1. 4-hydroxybutyl acrylate has an ester group derived from 1,4-butanediol. The amount of 1,4-butanediol obtained by reacting the acrylic resin with a lower alcohol in a supercritical state is the amount of 1,4-butane to be given by the amount of 4-hydroxybutyl acrylate used for polymerizing the acrylic resin. The amount of 1,4-butanediol obtained by decomposition in a supercritical state is smaller than the amount of diol, and it is difficult to correctly quantify the structural unit derived from 4-hydroxybutyl acrylate. It became clear that.
An object of the present invention is to provide a method for accurately analyzing a structural unit of a (meth) acrylic acid ester polymer containing an ester group derived from 1,4-butanediol or the like. That is.

（式中、Ｒ_１は水素原子又はメチル基を表し、ｎは４又は５を表す。メチレン基は、酸素原子、硫黄原子、カルボキシル基、スルホニル基、２級アミノ基（-ＮＨ-）で置換されていてもよく、メチレン基の水素原子は、炭化水素基、アルコキシ基で置換されていてもよい。）
で表される化合物に由来する構造単位［１］を含有するアクリル樹脂を低級アルコール存在下、超臨界状態で分解させ、式（２）で表される環状エーテル及び式（３）で表されるジオールを含む分解生成物を生成したのち、該生成物中の環状エーテル（２）及びジオール（３）を分離、定量し、その合計量から該アクリル樹脂における構造単位［１］を定量することを特徴とするアクリル樹脂における構造単位［１］の分析方法である。

（式中、ｎ、メチレン基は、前記と同じ意味を表す。） The present invention relates to formula (1)

(In the formula, R ₁ represents a hydrogen atom or a methyl group, and n represents 4 or 5. The methylene group is substituted with an oxygen atom, a sulfur atom, a carboxyl group, a sulfonyl group, or a secondary amino group (—NH—)). The hydrogen atom of the methylene group may be substituted with a hydrocarbon group or an alkoxy group.)
An acrylic resin containing the structural unit [1] derived from the compound represented by the formula is decomposed in the supercritical state in the presence of a lower alcohol, and represented by the cyclic ether represented by the formula (2) and the formula (3). After generating a decomposition product containing a diol, the cyclic ether (2) and the diol (3) in the product are separated and quantified, and the structural unit [1] in the acrylic resin is quantified from the total amount. It is the analysis method of the structural unit [1] in the acrylic resin characterized.

(In the formula, n and a methylene group have the same meaning as described above.)

  Among them, when formula (1) is 4-hydroxybutyl acrylate and / or 4-hydroxybutyl methacrylate, formula (2) is tetrahydrofuran, and formula (3) is 1,4-butanediol, It is preferable because it can be quantified.

  In addition, when the supercritical state is a state obtained by heating at 270 to 350 ° C. for 2 to 6 hours under sealed conditions using methanol or ethanol as the lower alcohol, the structural unit [1] is surely cyclic. It is preferable because it decomposes into ether (2) and diol (3).

  Furthermore, the analysis method of the present invention can be applied to a reaction product comprising the acrylic resin and a crosslinking agent instead of the acrylic resin.

According to the present invention, a specific structural unit such as the structural unit [1] can be estimated for the acrylic resin containing the structural unit derived from the compound (1), and the content is accurately quantified. can do.
In the method of the present invention, the content of the structural unit [1] can be accurately quantified under a wide range of conditions in which the temperature condition in the supercritical state is maintained at about 270 to 400 ° C. for about 2 to 6 hours. it can.
Furthermore, the reaction product consisting of the acrylic resin and the crosslinking agent is difficult to analyze because it is three-dimensionally cross-linked and does not dissolve in the chromatographic solvent, but according to the present invention, it is included in the product. Structural units such as the structural unit [1] can be estimated, and the content can be accurately quantified.

The acrylic resin analyzed by this invention contains the structural unit [1] derived from the compound represented by Formula (1).
In the formula (1), R ₁ represents a hydrogen atom or a methyl group, and n represents 4 or 5. The methylene group may be substituted with an oxygen atom, a sulfur atom, a carboxyl group, a sulfonyl group, or a secondary amino group (—NH—). Specific examples of the case where the methylene group is substituted include products obtained by ester-linking diols such as diethylene glycol, 2,2′-thiodiethanol, and diethanolamine with acrylic acid or methacrylic acid. .
The hydrogen atom of the methylene group may be substituted with a hydrocarbon group or an alkoxy group. Here, examples of the hydrocarbon group include alkyl groups such as a methyl group and an ethyl group, and aromatic groups such as a phenyl group.

  As the formula (1), 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, 4-hydroxypentyl acrylate, 4-hydroxypentyl methacrylate and the like are preferable, and 4-hydroxybutyl acrylate and 4-hydroxybutyl methacrylate are particularly preferable. is there.

  The acrylic resin may contain a structural unit derived from a monomer having an olefinic double bond in the molecule, which is different from the structural unit derived from the compound represented by the formula (1). . Specifically, (meth) acrylic acid, (meth) acrylic acid alkyl ester, (meth) acrylic acid aralkyl ester, (meth) acrylic acid alkoxyalkyl ester, hydroxyalkyl (meth) acrylic acid different from formula (1) Examples include esters, cyanoacrylates, (meth) acrylamides, vinyl compounds, α-olefins, (meth) acrylonitrile, conjugated diene compounds, and the like.

Here, examples of (meth) acrylic acid include acrylic acid, methacrylic acid, and salts of these acids.
Examples of (meth) acrylic acid alkyl esters include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, iso-butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, iso-octyl acrylate, lauryl acrylate, and stearyl. Acrylic acid alkyl esters such as acrylate and cyclohexyl acrylate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, iso-octyl methacrylate, lauryl methacrylate, stearyl methacrylate And alkyl methacrylates such as cyclohexyl methacrylate It is possible.
Examples of (meth) acrylic acid aralkyl esters include benzyl acrylate and benzyl methacrylate.
Examples of the (meth) acrylic acid alkoxyalkyl ester include methoxymethyl acrylate, methoxymethyl methacrylate, methoxyethyl acrylate, methoxyethyl methacrylate, ethoxymethyl acrylate, and ethoxymethyl methacrylate.

（式中、Ｒ_２は水素原子又はメチル基を表し、ｍは１〜３又は６〜１２を表す。メチレン基は、酸素原子、硫黄原子、カルボキシル基、スルホニル基、２級アミノ基（-ＮＨ-）で置換されていてもよく、メチレン基の水素原子には、炭化水素基、アルコキシ基が置換されていてもよい。）
具体的には、２−ヒドロキシエチル（メタ）アクリレート、３−ヒドロキシプロピル（メタ）アクリレート、６−ヒドロキシヘキシル（メタ）アクリレートなどが挙げられる。 Specifically, the (meth) acrylic acid hydroxyalkyl ester different from the formula (1) represents a compound represented by the formula (4).

(In the formula, R ₂ represents a hydrogen atom or a methyl group, m represents 1 to 3 or 6 to 12. The methylene group represents an oxygen atom, a sulfur atom, a carboxyl group, a sulfonyl group, a secondary amino group (—NH -) May be substituted, and a hydrogen atom of a methylene group may be substituted with a hydrocarbon group or an alkoxy group.)
Specific examples include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 6-hydroxyhexyl (meth) acrylate.

Examples of cyanoacrylates include 1-cyanovinyl acetate, and examples of (meth) acrylamides include acrylamide, methacrylamide, N, N-dimethylaminopropylacrylamide, diacetone diamide, N, N- Examples include dimethylacrylamide, N, N-diethylacrylamide, and N-methylolacrylamide.
Examples of the vinyl compound include styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene, octylstyrene, fluorostyrene, chlorostyrene, and bromostyrene. , Styrene monomers such as dibromostyrene, iodostyrene, nitrostyrene, acetylstyrene and methoxystyrene, nitrogen-containing aromatic vinyl such as vinylpyridine and vinylcarbazole, vinyl esters such as vinyl acetate and vinyl propionate, vinyl chloride, etc. Is mentioned.
Examples of the α-olefin include ethylene, propylene, and 1-butene. Examples of the (meth) acrylonitrile include acrylonitrile and methacrylonitrile.
The conjugated diene compound is an olefin having a conjugated double bond in the molecule, and specific examples include isoprene, butadiene and chloroprene.

Examples of the method for producing an acrylic resin that can be analyzed by the method of the present invention include a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, and a suspension polymerization method. In the production of acrylic resin, a polymerization initiator is usually used. The polymerization initiator is used in an amount of about 0.001 to 5 parts by weight with respect to a total of 100 parts by weight of all monomers used for the production of the acrylic resin.
Examples of the polymerization initiator include a thermal polymerization initiator and a photopolymerization initiator. Examples of the photopolymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone. Can be mentioned. Examples of the thermal polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 1,1′-azobis (cyclohexane-1-carbonitrile). 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl-2,2′-azobis (2-methylpro) Azo-based compounds such as 2,2′-azobis (2-hydroxymethylpropionitrile); lauryl peroxide, tert-butyl hydroperoxide, benzoyl peroxide, tert-butyl peroxybenzoate, cumene hydroper Oxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, tert-butyl Organic peroxides such as ruperoxyneodecanoate, tert-butylperoxypivalate, (3,5,5-trimethylhexanoyl) peroxide; inorganic peroxides such as potassium persulfate, ammonium persulfate, and hydrogen peroxide Is mentioned. A redox initiator using a thermal polymerization initiator and a reducing agent in combination can also be used as the polymerization initiator.

As the method for producing the acrylic resin, the solution polymerization method is preferable. As a specific example of the solution polymerization method, the compound (1), a monomer having an olefinic double bond, and an organic solvent are mixed as necessary, and a thermal polymerization initiator is added under a nitrogen atmosphere. And a method of stirring at about 40 to 90 ° C., preferably about 60 to 80 ° C. for about 3 to 10 hours. Moreover, in order to control reaction, you may add the monomer and thermal-polymerization initiator to be used during superposition | polymerization, or after melt | dissolving in an organic solvent.
Examples of the organic solvent include aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; aliphatic alcohols such as n-propyl alcohol and isopropyl alcohol; methyl ethyl ketone and methyl isobutyl ketone. And ketones.

The method of the present invention can also be applied to a reaction product comprising the acrylic resin and a crosslinking agent.
Examples of the crosslinking agent include aromatic isocyanate-based crosslinking agents and aliphatic isocyanate-based crosslinking agents.
Specific examples of the aromatic isocyanate crosslinking agent include toluylene diisocyanate (TDI), dimer of 2,4-toluylene diisocyanate, naphthylene-1,5-diisocyanate (NDI), o-toluylene diisocyanate (NDI). , Diphenylmethane diisocyanate (MDI), triphenylmethane triisocyanate, polymethylene polyphenyl isocyanate, and the like.
Specific examples of the aliphatic isocyanate-based crosslinking agent include hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), hydrogenated xylene diisocyanate, and dicyclohexylmethane diisocyanate.
The exemplified isocyanate prepolymer, the exemplified isocyanate block, the exemplified prepolymer block, and the like can also be used as a crosslinking agent.
As described in the method described in the cross-linking agent handbook (Yamashita et al., Taiseisha Co., Ltd., issued on October 20, 1981), the reaction product is usually prepared using an acrylic resin and a cross-linking agent. What is necessary is just to mix.

This method is applicable even if the acrylic resin to be analyzed by the method of the present invention contains components other than the acrylic resin that do not affect the analysis of the structural unit.
Examples of the component that may be contained include fibrous reinforcing materials such as glass fibers, silica alumina fibers, alumina fibers, and carbon fibers, needle-shaped reinforcing materials such as aluminum borate whiskers and potassium titanate whiskers; glass beads Inorganic fillers such as silica, talc, mica, graphite, wollastonite, dolomite, aluminum powder, and iron powder remain inactive and remain intact during the decomposition reaction, so they do not affect the analysis results of this method. It may be.
In addition, even a component that is decomposed in a supercritical state is a component that may be contained in the acrylic resin if the decomposition product can be distinguished from the structural unit of the acrylic resin by chromatography described later. Specifically, mold release improvers such as fluororesins and metal soaps; colorants such as dyes and pigments; antioxidants; heat stabilizers; ultraviolet absorbers; antistatic agents; One or more agents having an external lubricant effect such as a fluorocarbon surfactant and a siloxane surface modifier, a polymerization accelerator, and a polymerization inhibitor may be contained.

（式中、ｎ、メチレン基は、前記と同じ意味を表す。）
そして、該分解生成物中の環状エーテル（２）及びジオール（３）を分離、定量し、その合計量から該アクリル樹脂における構造単位［１］を定量する。 Next, the analysis method of the present invention will be described.
First, an acrylic resin or reaction product to be analyzed is decomposed in a supercritical state in the presence of a lower alkyl alcohol. In the obtained decomposition product, the structural unit [1] gives a cyclic ether (2) and a diol (3) represented by the following formula.

(In the formula, n and a methylene group have the same meaning as described above.)
Then, the cyclic ether (2) and the diol (3) in the decomposition product are separated and quantified, and the structural unit [1] in the acrylic resin is quantified from the total amount.

  Here, the decomposition in the supercritical state will be described. The critical state means the following state. That is, the substance has three states of inherent gas, liquid, and solid, and further, there is a fluid phase that does not condense even when pressure is applied when the critical temperature is exceeded and the critical pressure is exceeded. This state is called a supercritical state. The fluid in such a state exhibits properties different from the normal properties of liquids and gases. Supercritical fluid density is close to liquid, viscosity is close to gas, thermal conductivity and diffusion coefficient are non-liquid solvents, showing intermediate properties of gas and liquid, low viscosity, high diffusivity Therefore, mass transfer is advantageous, and high heat transfer can be obtained because of high heat transfer. And the structural unit derived from Formula (1) gives cyclic ether (2) and diol (3) by coexisting with the lower alkyl alcohol of such a supercritical state.

  The lower alkyl alcohol used is an alkyl alcohol having about 1 to 3 carbon atoms, and specifically includes methanol, ethanol, n-propanol, and isopropanol, preferably methanol, ethanol, and isopropanol, particularly preferably. Are methanol and ethanol. Usually, one kind of lower alkyl alcohol is used for easy determination.

Next, the conditions of temperature and pressure at which the lower alkyl alcohol becomes supercritical will be specifically shown. When the lower alkyl alcohol is methanol, a supercritical state is reached when the temperature exceeds 240 ° C. and the pressure exceeds 8.0 MPa. When the lower alkyl alcohol is ethanol, a supercritical state is reached when the temperature exceeds 243 ° C. and the pressure exceeds 7.0 MPa. Furthermore, when the lower alkyl alcohol is isopropanol, a supercritical state is reached when the temperature exceeds 244 ° C. and the pressure exceeds 5.4 MPa. When the lower alkyl alcohol is n-propanol, a supercritical state is reached when the temperature exceeds 264 ° C. and the pressure exceeds 5.1 MPa.
The temperature and pressure range of the decomposition reaction must be a temperature and pressure range in which the lower alkyl alcohol used in the reaction becomes a supercritical fluid, and the (meth) acrylic acid ester is almost hydrolyzed, The temperature and pressure for forming the diol and cyclic ether are preferred. The specific temperature is usually about 270 to 400 ° C, preferably about 300 to 350 ° C.

About the pressure conditions which form diol and cyclic ether, since the cost of a reaction container will start when a pressure is too high, it is 35 MPa or less normally, Preferably, it is about 8-20 MPa.
Moreover, as time to form diol and cyclic ether, although it changes also with temperature, in the case of 300-350 degreeC, it is about 2 to 6 hours, for example.

Examples of methods for separating and quantifying the decomposition products include gas chromatography, liquid chromatography, supercritical fluid chromatography, gel permeation chromatography, ion exchange chromatography, and thin layer chromatography. Examples include a method in which each fraction is separated into cyclic ethers, diols, alcohols and the like by chromatographic methods such as, and each fraction is quantified.
The apparatus used for the chromatography method is preferably an apparatus that can be connected to a detector described later. Specifically, a gas chromatography method, a liquid chromatography method, and a gel permeation chromatography method are preferable, and a liquid chromatography method is particularly preferable.

Here, a method for quantifying an acrylic resin polymerized only from 4-hydroxybutyl acrylate (hereinafter sometimes referred to as 4HBA) and butyl acrylate (hereinafter sometimes referred to as BA) by a method called a corrected area percentage method. Illustrate. 4HBA is an ester reaction product of 1,4-butanediol and acrylic acid, and the structural unit derived from 4HBA is 1,4-butanediol diol (3) and tetrahydrofuran (hereinafter referred to as THF). Cyclic eel (2). BA is an ester reaction product of butanol and acrylic acid.
First, a sample having a known weight of 1,4-butanediol, tetrahydrofuran (hereinafter sometimes referred to as THF) and butanol is prepared, and the peak area of each fraction is read from the chromatogram of the sample. The relative sensitivity of each fraction is obtained from the weight ratio and the peak area of each fraction, and the sensitivity correction coefficient ratio, which is the ratio of the reciprocal of the relative sensitivity, is calculated. Separately, the decomposition product of the acrylic resin obtained in the supercritical state is measured by a chromatography method under the same conditions. The composition ratio of each fraction can be calculated by multiplying the composition ratio obtained from the peak area ratio of each fraction in the chromatogram of the obtained decomposition product by the sensitivity correction coefficient ratio.
Examples of other quantitative methods by chromatography include an absolute calibration curve method and an internal standard method.

  By connecting a detector to the above chromatography method apparatus, it is possible to identify alcohols derived from ester groups such as cyclic ether (2), diol (3) and alcohol. Examples of the detector include an ultraviolet absorption detector, a flame ionization (FID) detector, a mass spectrometry detector, a fluorescence detector, an NMR detector, an infrared spectroscopic (IR) detector, and a parallax refraction (RI) detector. A solvent evaporation type light scattering detector or the like is used. As detectors for gas chromatography methods, FID detectors and mass spectrometry detectors are used. As detectors for liquid chromatography methods and gel permeation chromatography methods, ultraviolet absorption detectors, mass spectrometry detectors, NMR detectors, RI Detectors, solvent evaporation type light scattering detectors, and supercritical fluid chromatography detectors are preferably FID detectors, mass spectrometry detectors, ultraviolet absorption detectors, NMR detectors, solvent evaporation type light scattering detectors. Used.

If each fraction separated by the chromatography method is a known fraction, it is detected by, for example, an ultraviolet absorption detector, an FID detector, a fluorescence detector, an RI detector, a solvent evaporation type light scattering detector, or the like. And the retention time of known fractions are identified. If it is an unknown fraction, the structure of the unknown fraction may be identified by a predetermined identification method of these detectors using, for example, a mass spectrometry detector, an NMR detector, an infrared spectroscopy (IR) detector, or the like. .
The detector is directly connected to the chromatographic apparatus for easy analysis, but the fraction eluted together with the mobile phase from the chromatographic apparatus is concentrated, or the obtained fraction is directly detected by the detector. Analysis can also be performed by the method.

  Furthermore, as described above, a sample containing an insoluble insoluble component such as a fibrous reinforcing material other than an acrylic resin, a needle-shaped reinforcing material, an inorganic filler, or a pigment in the acrylic resin to be analyzed is more than the above. When decomposing in a critical state and using a chromatographic method for analyzing the decomposition product, it is preferable to remove insolubles from the decomposition product by filtration, centrifugation, or the like.

Thus, since the structural unit [1] in the acrylic resin gives the cyclic ether (2) and the diol (3), and can be separated and quantified, the structural unit [1] in the acrylic resin can be obtained from the total amount thereof. Can be quantified.
Moreover, according to the method of the present invention, for example, even if a structural unit derived from an acrylate ester different from the formula (1) is contained in the acrylic resin, the content of the acrylate ester can be quantified. .
For example, as illustrated above, even when the structural unit derived from butyl acrylate is contained in the acrylic resin, the formulas (2) and (3) are generated from the structural unit derived from the formula (1). Since the corresponding butanol is produced from the structural unit derived from butyl acrylate, the content of the structural unit derived from butyl acrylate in the acrylic resin can be quantified by quantifying this.

  Hereinafter, the present invention will be described more specifically with reference to examples. In the examples, “parts” and “%” are based on weight unless otherwise specified.

(Acrylic resin production example 1)
99.9 parts of butyl acrylate (BA) and 0.1 part of 4-hydroxybutyl acrylate (4HBA) are mixed with ethyl acetate, and after nitrogen substitution, 0.1 part of 2,2-azobis (isobutyronitrile) After mixing, the mixture was stirred at 70 to 80 ° C. for 8 hours to obtain acrylic resin 1.

(Acrylic resin production examples 2 to 5)
Acrylic resins 2 to 5 were obtained in the same manner as in Production Example 1 except that the amounts of BA and 4HBA used were as described in Table 1. In Production Example 5, 4HBA is not used.

(Reaction Product Production Example 6)
After further mixing 0.5 parts of a polyisocyanate compound (trade name: Coronate L, manufactured by Nippon Polyurethane) with the acrylic resin 1 obtained in Production Example 1, the mixture is applied onto a polyethylene terephthalate sheet. The reaction product 6 was obtained by standing at 40 ° C. for 1 week.

(Production Examples 7 to 9 of reaction product)
The acrylic resin to be used is acrylic resin 2 in production example 7, acrylic resin 3 in production example 8,
In Production Example 9, reaction products 7 to 9 were obtained in the same manner as Production Example 6 except that acrylic resin 4 was used.

(Calculation example of sensitivity correction coefficient ratio of decomposition products)
About 1,500 mg of 1-butanol decomposed from BA, 1,4-butanediol decomposed from 4HBA, and tetrahydrofuran were weighed in a 50 ml volumetric flask and precisely weighed to make 50 ml with methanol to obtain Solution I. 10 ml of Solution I was accurately weighed with a whole pipette into a 50 ml volumetric flask, and made exactly 50 ml with methanol to obtain Solution II. 5 ml of Solution I was accurately weighed into a 50 ml volumetric flask with a whole pipette, and exactly 50 ml with methanol to make Solution III. 1 ml of Solution I was accurately weighed with a whole pipette into a 50 ml volumetric flask, and made exactly 50 ml with methanol to obtain Solution IV. The solutions I to IV were analyzed by gas chromatography, the peak area value of each component was read, the sensitivity correction coefficient per unit mass of each component was determined, the average value ratio was taken, and the sensitivity correction coefficient ratio was calculated ( Table 1).

(Example 1)
About 20 mg of acrylic resin 1 was put into a stainless steel pipe having a 1/4 inch diameter (6.35 mm diameter) and a length of 10 cm together with 0.4 ml of methanol, and sealed with a wedge type stopper. This was heated in an oven at 300 ° C. for 3 hours to obtain a uniform decomposition product. The obtained decomposition product was analyzed by gas chromatography under the following conditions to obtain a chromatogram (FIG. 1). The three main components detected are attributed to butanol, 1,4-butanediol and tetrahydrofuran (hereinafter sometimes referred to as THF). From these peak area values and the above factors, the respective weight ratios in the decomposition products are as follows: They were quantified as 99.89%, 0.07%, and 0.06%, respectively. When about 20 mg of different acrylic resins 1 were analyzed in the same manner, butanol, 1,4-butanediol and THF were 99.89%, 0.08% and 0.06%. The weight ratios of butanol, 1,4-butanediol and THF were 99.89%, 0.07% and 0.06%, respectively.
The structural unit derived from 4HBA is quantified to be 0.1%, which is the total amount of 1,4-butanediol and THF, and the structural unit derived from BA is 99.9% corresponding to butanol. And quantified.
These results were consistent with the amounts of 4HBA and BA used during manufacture.

(Gas chromatograph conditions)
Apparatus: GC6890 manufactured by Agilent
Column: J & W DB-WAX ID 0.25mmφ Length 30m Film thickness 0.25μm
Carrier gas: He 1ml / min
Oven temperature: 32 ° C (5min hold) → 240 ° C (10min hold), heating rate: 5 ° C / min
Vaporization chamber temperature: 250 ℃
Detector: FID
Injection method: Split method Split ratio 30: 1

(Examples 2-9)
Example 1 was repeated except that the acrylic resin used was 2-9.
Table 1 shows the weight ratio of each of butanol, 1,4-butanediol and THF (average value obtained by performing gas chromatography twice), and the quantification of structural units derived from 4HBA and structural units derived from BA. The results are listed.

(Examples 10 and 11)
The same procedure as in Example 1 was performed except that the supercritical state of the acrylic resin 1 was carried out at 300 ° C. for 5 hours (Example 10) and 350 ° C. for 3 hours (Example 11). The results are summarized in Table 1.

By utilizing the quantification method of the present invention, for example, acrylic resins and reaction products used in pressure-sensitive adhesives, adhesives, paints, thickeners, etc., in addition to (meth) acrylic acid alkyl esters and the like, structures Unit [1] can be analyzed accurately.
Thereby, various physical properties of the acrylic resin and the reaction product, and the types and compositions of these structural units can be compared and examined. Moreover, it can also analyze whether the manufactured acrylic resin and reaction product have a composition of a desired structural unit.

2 is a gas chromatogram of a decomposition product obtained by decomposing acrylic resin 1 in the supercritical state in the presence of methanol.

Explanation of symbols

1: Butanol (alcohol provided by structural unit derived from BA)
2: Tetrahydrofuran (cyclic ether (2) provided by a structural unit derived from 4HBA)
3: 1,4-butanediol (diol (3) provided by a structural unit derived from 4HBA)
4: Methanol (lower alkyl alcohol)

Claims (7)

Formula (1)

(In the formula, R ₁ represents a hydrogen atom or a methyl group, and n represents 4 or 5. The methylene group is substituted with an oxygen atom, a sulfur atom, a carboxyl group, a sulfonyl group, or a secondary amino group (—NH—)). The hydrogen atom of the methylene group may be substituted with a hydrocarbon group or an alkoxy group.)
An acrylic resin containing the structural unit [1] derived from the compound represented by the formula is decomposed in the supercritical state in the presence of a lower alcohol, and represented by the cyclic ether represented by the formula (2) and the formula (3). After generating a decomposition product containing a diol, the cyclic ether (2) and the diol (3) in the product are separated and quantified, and the structural unit [1] in the acrylic resin is quantified from the total amount. The analysis method of the structural unit [1] in the acrylic resin characterized.

(In the formula, n and a methylene group have the same meaning as described above.)   Formula (1) is 4-hydroxybutyl acrylate and / or 4-hydroxybutyl methacrylate, The analysis method of Claim 1 characterized by the above-mentioned.   The analytical method according to claim 1 or 2, wherein the formula (2) is tetrahydrofuran and the formula (3) is 1,4-butanediol.   The supercritical state is a supercritical state obtained by heating at 270 to 350 ° C for 2 to 6 hours under sealed conditions using methanol or ethanol as a lower alcohol. The analysis method according to any one of the above.   The method for separating and quantifying the cyclic ether (2) and the diol (3) in the product comprises a gas chromatography method, a liquid chromatography method, a supercritical fluid chromatography method, and a gel permeation chromatography method. The analysis method according to claim 1, wherein the analysis method is at least one chromatography method selected from the group consisting of:   The detector connected to the apparatus used for the chromatography method is an ultraviolet absorption detector, a flame ionization (FID) detector, a mass spectrometry detector, a fluorescence detector, an NMR detector, an infrared spectroscopy (IR) detector, 6. The analysis method according to claim 5, wherein the analysis method is at least one detector selected from the group consisting of a parallax refraction (RI) detector and a solvent evaporation type light scattering detector.   A reaction product comprising an acrylic resin containing the structural unit [1] and a cross-linking agent is decomposed in a supercritical state in the presence of a lower alcohol, and includes the cyclic ether (2) and the diol (3). An acrylic resin characterized in that after the product is formed, the cyclic ether (2) and the diol (3) in the product are separated and quantified, and the structural unit [1] in the acryl resin is quantified from the total amount. Of analyzing structural unit [1] in FIG.

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