JP2014101438A - Acetal compound and acetal polymer compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an acetal compound (monomer) and a polymer compound (polymer) of the same, which are derived from plant resources and easily decomposable and exhibit changes in hydrophilicity and hydrophobicity associated with decomposition and changes in solubility in water-based solutions.SOLUTION: Provided is an acetal compound having a structural unit represented by a general formula (1) or represented by a general formula (2).

Description

  The present invention relates to an acetal compound and an acetal polymer compound.

  In recent years, in preparation for the depletion of petroleum resources, research and development of organic compounds, plastics, pharmaceuticals, etc. using plant resources have been actively conducted.

  As an example, plants such as coffee beans, sweet potato leaves, mugwort, etc. contain a lot of polyphenols called chlorogenic acid, and quinic acid obtained by hydrolyzing chlorogenic acid is a variety of chemicals and pharmaceuticals. Application to such as is expected.

  Technologies for quinic acid include, for example, a method for producing a chlorogenic acid-containing product such as caffeoylquinic acid under a predetermined solvent condition for use in foods and pharmaceutical raw materials, and the efficiency of quinic acid. A method of purifying quinic acid for taking it out is disclosed (see, for example, Patent Documents 1 and 2).

  Quinic acid is a pentafunctional compound in which four hydroxyl groups and one carboxyl group are bonded to the cyclohexane ring. In the presence of a catalyst such as an acid catalyst, the hydroxyl group at the 3rd and 4th positions on the ring is acetalized to form the 1st position. It is known that the carboxyl group and the hydroxyl group at the 5-position can be easily converted into the following polyalicyclic compounds by esterification (lactonization).

Japanese Patent No. 4842680 Japanese Patent Laid-Open No. 11-140014

  As described above, although quinic acid has been studied for uses such as foods and pharmaceutical raw materials, it has not been sufficiently studied for application to chemical products. Therefore, by enabling the application of polyalicyclic compounds derived from compounds derived from plant resources such as quinic acid to various uses, for example, development as synthetic raw materials and various materials, it is possible to remove petroleum. Expected to be used as a material.

  The present invention has been made in view of the above, and is derived from a plant resource and is an acetal monomer which is an acetal monomer derived from a plant resource and exhibiting easily degradable, hydrophilicity / hydrophobicity change accompanying decomposition and solubility change in an aqueous solution. Compound, and acetal polymer compound derived from plant resources, having transparency, easy degradability, and relatively high glass transition temperature, and showing hydrophilicity / hydrophobicity change accompanying decomposition and solubility change in aqueous solution An object is to provide (acetal polymer) and to achieve the object.

Specific means for achieving the above object are as follows.
<1> An acetal compound (monomer) represented by the following general formula (1).
In the general formula (1), R ¹ represents a hydrogen atom or a methyl group. R ² and R ³ each independently represents a hydrogen atom, an alkyl group, or an aryl group, and R ² and R ³ may be linked to each other to form a ring.

<2> An acetal polymer compound (polymer) having a structural unit represented by the following general formula (2).
In the general formula (2), R ¹ represents a hydrogen atom or a methyl group. R ² and R ³ each independently represents a hydrogen atom, an alkyl group, or an aryl group, and R ² and R ³ may be linked to each other to form a ring.

  <3> The acetal polymer compound according to <2>, wherein the weight average molecular weight is 1000 to 200000.

  According to the present invention, an acetal compound that is an acetal monomer that is derived from a plant resource and exhibits easy degradability, a hydrophilicity / hydrophobicity change accompanying decomposition and a solubility change in an aqueous solution, and a plant resource An acetal polymer compound (acetal polymer) that is derived, has transparency, easily decomposable, and has a relatively high glass transition temperature, and exhibits changes in hydrophilicity and hydrophobicity due to decomposition and solubility in aqueous solutions. Is done.

It is a NMR chart of the acetal monomer M-1. It is a NMR chart of acetal type polymer P-1.

  Hereinafter, the acetal compound of the present invention will be described in detail. As an acetal compound, the first aspect of the present invention is an acetal monomer (monomer), and the second aspect of the present invention is an acetal polymer compound (polymer).

  In the present specification, a numerical range indicated using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively. In addition, the notation of a substituent such as an alkyl group is not limited to either an unsubstituted group or a group having a substituent unless otherwise specified, and may be an unsubstituted or substituted substituent. It means that.

  In the present specification, the expression “(meth) acryl” means either acrylic or methacrylic or both.

-Acetal monomer-
The 1st aspect which is an acetal type compound of this invention is a monomer (henceforth an acetal type monomer) represented by following General formula (1).

  The acetal monomer according to the first embodiment is a (meth) acrylic monomer having an acetal ring in the molecule. This monomer is significant in that it is derived from a compound derived from a plant resource that is not a fossil fuel (for example, quinic acid), and has an acetal ring and thus has an acid decomposition reaction. In addition, this monomer also has the property of exhibiting a remarkable change in solubility in an aqueous solution because an acetal group is removed by an acid to form a hydroxyl group.

In the general formula (1), R ¹ represents a hydrogen atom or a methyl group. R ² and R ³ each independently represents a hydrogen atom, an alkyl group, or an aryl group, and R ² and R ³ may be linked to each other to form a ring.

The alkyl group represented by R ² and R ³ may be unsubstituted or may have a substituent, and R ² and R ³ may be either the same group or different groups.
Examples of the alkyl group represented by R ² and R ³ include an alkyl group having 1 to 12 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an i-propyl group, a butyl group, a t-butyl group, A hexyl group etc. can be mentioned. Especially, a C1-C8 alkyl group is preferable, a C1-C4 alkyl group is more preferable, and especially a methyl group, an ethyl group, and a butyl group are suitable.

R ² and R ³ may be connected to each other to form a ring. When a ring is formed, a 5-membered ring or a 6-membered ring is preferable, and a 5-membered or 6-membered cyclo ring is more preferable. As examples of the cyclo ring, a cycloheptyl ring, a cyclohexyl ring and the like are preferable.

The aryl group represented by R ² and R ³ may be unsubstituted or have a substituent, and R ² and R ³ may be either the same group or different groups.
Examples of the aryl group represented by R ² and R ³ include an aryl group having 6 to 18 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthracenyl group. Among these, an aryl group having 6 to 12 carbon atoms is preferable.

Examples of the substituent when the group represented by R ^{1 to} R ³ in the general formula (1) is substituted include an alkyl group, an alkenyl group, and an aryl group.

Among the above, in general formula (1), R ¹ is a hydrogen atom or a methyl group, and both R ² and R ³ are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an aryl having 6 to 12 carbon atoms. Preferred when selected from the group

  Specific examples of the acetal monomer represented by the general formula (1) are shown below. However, the present invention is not limited to these specific examples.

As shown in the following reaction scheme 1, the synthesis of the acetal monomer of the present invention is carried out by using compound X, which is a polyalicyclic compound, as a raw material and reacting this compound with the following compound A in a predetermined solvent ( A compound represented by the general formula (1) can be generated by methacryloylation.
At this time, as compound X, IPQL (isopropylidene quinic acid lactone) where R ² = R ³ = methyl group may be used. In this case, for example, compounds such as the specific examples M-1 and M-3 described above can be synthesized.
Alternatively, this compound may be used by synthesizing a compound in which R ² and R ³ represent other groups other than a methyl group in advance by an acetal exchange reaction using an aldehyde compound, a ketone compound, or a dialkoxyalkane from IPQL. As the aldehyde compound, ketone compound and dialkoxyalkane at this time, those having a boiling point higher than that of acetone used for deriving IPQL from quinic acid are preferably used. In this case, for example, compounds in which at least one of R ² and R ³ is other than a methyl group, such as the specific examples M-2 and M-4 to M-6 described above, can be synthesized.
Examples of aldehyde compounds used at this time include monoaldehydes such as benzaldehyde, examples of ketone compounds include monoketones such as cyclopentanone and cyclohexanone, and examples of dialkoxyalkanes include dimethoxy compounds. Examples include propane, diethoxypropane, dimethoxypentane, diethoxypentane and the like.
In principle, it is also possible to synthesize directly from quinic acid by using these aldehyde compounds, ketone compounds and dialkoxyalkanes instead of acetone for quinic acid without going through IPQL. Aldehyde compounds, ketone compounds, and dialkoxyalkanes function as a reaction substrate and solvent, and are particularly advantageous when quinic acid is soluble in these compounds. From the viewpoint of reactivity, a method in which compound X is synthesized in advance by an acetal exchange reaction using the above aldehyde compound, ketone compound or dialkoxyalkane via IPQL is preferable. Since quinic acid is highly hydrophilic, a method of synthesizing via IPQL is preferred when a highly hydrophobic aldehyde compound or ketone compound is reacted to introduce a highly hydrophobic group.

In reaction scheme 1, ^R 2, ^{R 3} of ^{R 1,} and compounds wherein X in the compound A are respectively synonymous with ^{R 1,} R 2, ^{R 3} in the above general formula (1), preferred embodiments Is the same. Further, R ^A in Compound A each independently represents a hydroxyl group, a halogen atom (eg, chlorine atom, bromine atom), an alkoxy group, or the like. R ^{1 to} R ³ in the general formula (1) are as described above.

  The (meth) acryloylation reaction in which compound X and compound A are reacted is, for example, an inert solvent such as ethyl acetate, pyridine, dimethylacetamide, xylene, toluene, benzene, octane, isooctane, hexane, cyclohexane, or a mixed solution thereof. Among them, it is preferable to carry out in a temperature range of −5 ° C. to 100 ° C., more preferably in a temperature range of 10 ° C. to 70 ° C.

As compound A in Reaction Scheme 1, (meth) acrylic acid or a derivative thereof is used. (Meth) acrylic acid includes acrylic acid and methacrylic acid.
Examples of (meth) acrylic acid derivatives include halides of (meth) acrylic acid (eg: (meth) acrylic acid chlorides (eg (meth) acrylic acid chloride), (meth) acrylic acid bromides), (meta ) Acrylic acid salt and the like.

  Compound X can be synthesized by a conventionally known method. IPQL, which is an example of compound X, is a compound synthesized by, for example, mixing quinic acid and acetone and reacting them in the presence of a catalyst such as sulfuric acid. Although quinic acid has not been used in many ways to derive compounds that can be applied to food additives and chemical products, quinic acid can be acetalized and is suitable for the induction of compounds that are degradable by acids and the like. is there. Moreover, since an acetal group is removed by an acid or the like and a hydroxyl group (OH group) is easily generated, it is suitable for induction of a compound having excellent solubility in an aqueous solution.

  Confirmation that the compound represented by General formula (1) was synthesize | combined can be performed by NMR measurement.

-Acetal polymer compounds-
The 2nd aspect which is an acetal type high molecular compound of this invention is a polymer (henceforth acetal type polymer) which has at least the structural unit (repeating unit) represented by following General formula (2).

  The acetal polymer according to the second embodiment is a (meth) acrylic polymer containing a structural unit having a polyalicyclic skeleton in the side chain, and exhibits transparency due to the polyalicyclic structure. It has a high glass transition temperature (Tg). In addition, since this polymer has an acetal ring in the polymer side chain, it has decomposition reactivity with an acid or the like, and the acetal group is removed by an acid or the like to generate a hydroxyl group, thereby remarkably solubility in an aqueous solution. Also shows changes. In addition, in resist resin applications, the lactone skeleton not only contributes to the solubility in aqueous solutions, but also esters in alkaline solutions (e.g., developers) can be easily cut, so a significant improvement in developer solubility is expected. The pattern resolution can be improved.

In the general formula (2), R ¹ represents a hydrogen atom or a methyl group. R ² and R ³ each independently represents an alkyl group or an aryl group, and R ² and R ³ may be linked to each other to form a ring.
R ^{1, R 2} and ^{R 3} are each as ^R 1, ^{R 2} and ^{R 3} in the general formula described above (1) synonymous, preferable embodiments thereof are also the same. As for the substituent when the group represented by the general formula (2) R ¹ to R ³ in the is substituted, R ¹ to R ³ in the general formula described above (1) is substituted Examples of the substituent in the case are the same.

The acetal polymer compound of the present invention is a polymer having a plurality of structural units represented by the general formula (2), and the number n (integer) thereof is within the range of molecular weights described later depending on the application and purpose. What is necessary is just to select suitably.
In addition, the acetal polymer compound of the present invention may be a homopolymer composed only of the structural unit represented by the general formula (2), or the general formula (2) as long as the transparency and Tg are not impaired. It may be a copolymer having a structural unit derived from a monomer other than the structural unit represented by the general formula (2) together with the structural unit represented by 2).

Specific examples of “other monomers” for deriving other structural units other than the structural unit represented by the general formula (2) include monomers selected from the following monomer groups.
(1) Alkenes ethylene, propylene, 1-butene, isobutene, 1-hexene, 1-dodecene, 1-octadecene, 1-eicocene, hexafluoropropene, vinylidene fluoride, chlorotrifluoroethylene, 3,3,3- Trifluoropropylene, tetrafluoroethylene, vinyl chloride, vinylidene chloride, etc .;
(2) Dienes 1,3-butadiene, isoprene, 1,3-pentadiene, 2-ethyl-1,3-butadiene, 2-n-propyl-1,3-butadiene, 2,3-dimethyl-1,3 -Butadiene, 2-methyl-1,3-pentadiene, 1-phenyl-1,3-butadiene, 1-α-naphthyl-1,3-butadiene, 1-β-naphthyl-1,3-butadiene, 2-chloro -1,3-butadiene, 1-bromo-1,3-butadiene, 1-chlorobutadiene, 2-fluoro-1,3-butadiene, 2,3-dichloro-1,3-butadiene, 1,1,2- Trichloro-1,3-butadiene and 2-cyano-1,3-butadiene, 1,4-divinylcyclohexane and the like;

(3) Derivatives of α, β-unsaturated carboxylic acid (3a) Alkyl acrylates Methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate , Amyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, tert-octyl acrylate, dodecyl acrylate, phenyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, 2-bromoethyl acrylate, 4-chlorobutyl acrylate, 2-cyanoethyl acrylate, 2-acetoxyethyl acrylate, methoxybenzyl Chryrate, 2-chlorocyclohexyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, 2-methoxyethyl acrylate, ω-methoxypolyethylene glycol acrylate (number of added polyoxyethylene: n = 2 to 100), 3-methoxy Butyl acrylate, 2-ethoxyethyl acrylate, 2-butoxyethyl acrylate, 2- (2-butoxyethoxy) ethyl acrylate, 1-bromo-2-methoxyethyl acrylate, 1,1-dichloro-2-ethoxyethyl acrylate, glycidyl acrylate Such);
(3b) Alkyl methacrylates Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, amyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2 -Ethylhexyl methacrylate, n-octyl methacrylate, stearyl methacrylate, benzyl methacrylate, phenyl methacrylate, allyl methacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, cresyl methacrylate, naphthyl methacrylate, 2-methoxyethyl methacrylate, 3-methoxybutyl methacrylate, ω Methoxy polyethylene glycol methacrylate (number of added polyoxyethylene: n = 2-100), 2-acetoxyethyl methacrylate, 2-ethoxyethyl methacrylate, 2-butoxyethyl methacrylate, 2- (2-butoxyethoxy) ethyl methacrylate Glycidyl methacrylate, 3-trimethoxysilylpropyl methacrylate, allyl methacrylate, 2-isocyanatoethyl methacrylate, etc .;
(3c) Diesters of unsaturated polycarboxylic acids Dimethyl maleate, dibutyl maleate, dimethyl itaconate, dibutyl taconate, dibutyl crotonate, dihexyl crotonate, diethyl fumarate, dimethyl fumarate, etc .;
(3d) Amides of α, β-unsaturated carboxylic acid N, N-dimethylacrylamide, N, N-diethylacrylamide, Nn-propylacrylamide, N-tert-butylacrylamide, N-tert-octylmethacrylamide, N-cyclohexylacrylamide, N-phenylacrylamide, N- (2-acetoacetoxyethyl) acrylamide, N-benzylacrylamide, N-acryloylmorpholine, diacetone acrylamide, N-methylmaleimide and the like;

(4) Unsaturated nitriles Acrylonitrile, methacrylonitrile, etc .;
(5) Styrene and derivatives thereof Styrene, vinyl toluene, ethyl styrene, p-tert-butyl styrene, methyl p-vinyl benzoate, α-methyl styrene, p-chloromethyl styrene, vinyl naphthalene, p-methoxy styrene, p- Hydroxymethylstyrene, p-acetoxystyrene, etc .;
(6) Vinyl esters Vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl benzoate, vinyl salicylate, vinyl chloroacetate, vinyl methoxyacetate, vinyl vinyl acetate, etc .;
(7) Vinyl ethers Methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, tert-butyl vinyl ether, n-pentyl vinyl ether, n-hexyl vinyl ether, n-octyl vinyl ether, n-dodecyl Vinyl ether, n-eicosyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexyl vinyl ether, fluorobutyl vinyl ether, fluorobutoxyethyl vinyl ether, etc .; and (8) other polymerizable monomers N-vinyl pyrrolidone, methyl vinyl ketone, phenyl vinyl ketone, Methoxyethyl vinyl ketone, 2-vinyl oxazoline, 2-isopropenyl oxazoline, etc.

  When the acetal polymer of the present invention is a copolymer having a structural unit derived from another monomer, the ratio of the structural unit derived from the other monomer to the structural unit represented by the general formula (2) (other monomer / General formula (2)) is preferably in the range of 1/99 to 98/2.

Among the above, in general formula (2), R ¹ is a hydrogen atom or a methyl group, and both R ² and R ³ are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an aryl having 6 to 12 carbon atoms. Preferred is a case selected from a group.

  Although there is no restriction | limiting in particular as molecular weight of the acetal type polymer of this invention, From a viewpoint of a glass transition temperature, the range of 1000-200000 is preferable at a weight average molecular weight (Mw), The range of 3000-150,000 is more preferable, 50000- The range of 150,000 is more preferable.

  Mw is a value determined by gel permeation chromatography (GPC) using HLC-8220GPC (manufactured by Tosoh Corporation) and converted to polystyrene. For the measurement, three columns of TSKgeL Super HZM-H, TSKgeL Super HZ4000, TSKgeL Super HZ2000 (manufactured by Tosoh Corporation, 4.6 mm ID × 15 cm) were used as the column, and the mobile phase solvent was N-methylpyrrolidone (NMP), The standard sample is monodispersed polystyrene (manufactured by Tosoh Corporation), the sample concentration is 0.35% by mass, the column temperature is 140 ° C., and the flow rate is 0.35 mL / min.

The glass transition temperature (Tg) of the acetal polymer of the present invention can be appropriately selected depending on the application, but is preferably 10 ° C. to 250 ° C. in terms of moldability, heat resistance and handling. 30 to 180 degreeC is more preferable.
Tg is a value measured using a differential scanning calorimeter (DSC; DSC6100 manufactured by Seiko Instruments Inc.).

  Hereinafter, specific examples of the acetal polymer having the structural unit represented by the general formula (2) are shown. Although the compound of the specific example does not show molecular weight, it represents any compound that satisfies the above-mentioned range of Mw. However, the present invention is not limited to these specific examples.

  In the synthesis of the acetal polymer of the present invention, the compound represented by the general formula (1) is synthesized in the same manner as in the above reaction scheme 1, and then a polymerization initiator is dissolved in a solution obtained by dissolving the compound in a predetermined organic solvent. And a polymer having a repeating unit represented by the general formula (2) having an acetal ring in the side chain is produced by radical polymerization of the compound represented by the general formula (1).

In radical polymerization, known polymerization initiators such as radical thermal polymerization initiators and radical photopolymerization initiators can be used as the polymerization initiator. Among these, it is particularly preferable to use a radical thermal polymerization initiator. The radical thermal polymerization initiator is a compound that generates radicals when heated to a temperature equal to or higher than the decomposition temperature.
Examples of the radical thermal polymerization initiator include diacyl peroxide (acetyl peroxide, benzoyl peroxide, etc.), ketone peroxide (methyl ethyl ketone peroxide, cyclohexanone peroxide, etc.), hydroperoxide (hydrogen peroxide, tert-butyl hydro gen). Peroxide, cumene hydroperoxide, etc.), dialkyl peroxide (di-tert-butyl peroxide, dicumyl peroxide, dilauroyl peroxide, etc.), peroxyesters (tert-butyl peroxyacetate, tert-butyl peroxide) Oxypivalate), azo compounds (azobisisobutyronitrile, azobisisovaleronitrile, etc.), persulfates (ammonium persulfate, sodium persulfate) Um, such as potassium persulfate), and the like.
Such radical thermal polymerization initiators may be used alone or in combination of two or more.

  The radical polymerization method is not particularly limited, and an emulsion polymerization method, a suspension polymerization method, a bulk polymerization method, a solution polymerization method, and the like can be applied. The radical polymerization method is described, for example, in “Polymer Chemistry Experimental Method” edited by Polymer Society (Tokyo Kagaku Dojin, 1981).

  When the polymerization initiator is used, the amount of the polymerization initiator used is 0.1 to 20 with respect to the mass of the monomer to be polymerized (including at least the acetal monomer represented by the general formula (1) described above). % By mass is preferable, and 0.5 to 10% by mass is more preferable.

  Examples of preferable organic solvents for radical polymerization include alcohols such as isopropanol and butanol, ethers such as dibutyl ether, ethylene glycol dimethyl ether, tetrahydrofuran and dioxane, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, and ethyl acetate. And esters such as butyl acetate, amyl acetate and γ-butyrolactone, aromatic hydrocarbons such as benzene, toluene and xylene, dimethylacetamide, dimethylformamide and N-methylpyrrolidone. In addition, these organic solvents can be used individually by 1 type or in combination of 2 or more types. Furthermore, from the viewpoint of solubility of the monomer and the polymer to be produced, a water-mixed organic solvent in which water is used in combination with the above organic solvent is also applicable.

  The radical polymerization temperature is preferably in the range of 30 ° C to 170 ° C, more preferably in the range of 40 ° C to 150 ° C.

  Confirmation that the compound represented by the general formula (2) has been synthesized can be performed by NMR measurement.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist thereof. Unless otherwise specified, “part” is based on mass.

Example 1
<Synthesis of Compound (1)>
After putting 100 g of quinic acid and 2.5 L of acetone into a 3 L reaction vessel, 5 ml of sulfuric acid was added dropwise thereto, and 400 g of sodium sulfate was further added in quarters. Thereafter, heating under reflux was performed for 4 hours. Subsequently, 100 g of sodium sulfate was added, and the mixture was further reacted for 1 hour. After the reaction was completed, the temperature was lowered to room temperature, 200 ml of 9% by mass sodium bicarbonate solution was added thereto, and the mixture was stirred for 15 minutes, and then filtered to remove all the solvent. Subsequently, liquid separation was performed using ethyl acetate and brine, and the ethyl acetate layer was dried over magnesium sulfate, and then the solvent was distilled off again. In this way, 85 g of the following compound (1) was synthesized (yield: 77%).

<Synthesis of Monomer M-1>
21.4 g of compound (1) synthesized as described above and 100 ml of pyridine were placed in a reaction vessel, and after compound (1) was dissolved in pyridine, the mixture was cooled to 5 ° C. with ice. Next, 23 ml of methacrylic acid chloride was dropped into the reaction vessel. After completion of the dropwise addition, the temperature was returned to room temperature and reacted for 12 hours. After completion of the reaction, the reaction solution was separated using ethyl acetate and dilute aqueous hydrochloric acid, and neutralized with 9 mass% sodium bicarbonate water. Thereafter, the ethyl acetate layer was dried over magnesium sulfate, the solvent was removed, and 10 g of Compound M-1 was synthesized. The reaction scheme at this time is shown below.

The synthesized monomer M-1 was subjected to NMR measurement, and its NMR chart is shown in FIG. 1 (deuterated solvent: CDCl ₃ ).

(Example 2)
<Synthesis of Polymer P-1>
28 g of monomer M-1 synthesized in the same manner as in Example 1 and 48 g of propylene glycol monomethyl ether acetate (PGMEA) were placed in a reaction vessel, and monomer M-1 was dissolved in PGMEA. Further, “V-601” 0.6 g (manufactured by Wako Pure Chemical Industries, Ltd .; radical polymerization initiator) was added. And it was made to react under nitrogen stream at 90 degreeC for 3 hours, and 110 degreeC for 2 hours. After completion of the reaction, the reaction mixture was diluted with PGMEA, re-precipitated with methanol, and dried at 80 ° C. In this way, 21 g of polymer P-1 was synthesized. The reaction scheme at this time is shown below.

When the molecular weight of the synthesized polymer P-1 was measured by gel permeation chromatography (GPC) under the following conditions and calculated in terms of polystyrene, the weight average molecular weight (Mw) was 100,000.
<Condition>
・ GPC: HLC-8220GPC (manufactured by Tosoh Corporation)
Column: TSKgeL Super HZM-H, TSKgeL Super HZ4000, TSKgeL Super HZ2000 (manufactured by Tosoh Corporation, 4.6 mm ID × 15 cm) Mobile phase solvent: Tetrahydrofuran (THF)
Standard sample: monodisperse polystyrene (manufactured by Tosoh Corporation)
Sample concentration: 0.35% by mass
-Column temperature: 140 ° C
・ Flow rate: 0.35 mL / min

  It was 99 degreeC when the glass transition temperature (Tg) of the synthesize | combined polymer P-1 was measured using the differential scanning calorimeter (DSC) DSC6100 (made by Seiko Instruments Inc.).

Further, the polymer P-1, perform NMR measurements, shows the NMR chart in FIG. 2 (deuterated solvent: CDCl _3).

  Furthermore, the transparency of the polymer P-1 was evaluated by preparing a 30% propylene glycol monomethyl ether acetate (PGMEA) solution and visually observing it. As a result, there was no coloring or white turbidity, and good transparency was exhibited.

The acetal compound according to the present invention can be applied to transparent resins, resist compositions, biocompatible materials and the like in the optical field. For example, in a resist resin application, a significant improvement in developer solubility is expected due to generation of a hydroxyl group by removal of an acetal group by an acid.

Claims (3)

An acetal compound represented by the following general formula (1).

[R ¹ represents a hydrogen atom or a methyl group. R ² and R ³ each independently represents a hydrogen atom, an alkyl group, or an aryl group, and R ² and R ³ may be linked to each other to form a ring. ] An acetal polymer compound having a structural unit represented by the following general formula (2).

[R ¹ represents a hydrogen atom or a methyl group. R ² and R ³ each independently represents a hydrogen atom, an alkyl group, or an aryl group, and R ² and R ³ may be linked to each other to form a ring. ] The acetal polymer compound according to claim 2, which has a weight average molecular weight of 1,000 to 200,000.