JPH0212968B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to modified copolymers of ethylenically unsaturated compounds. Generally, it is well known that monomers such as ethylenically unsaturated compounds undergo considerable volume shrinkage during homopolymerization and copolymerization. For example, the volume shrinkage rates during polymerization of ethylene, acrylonitrile, methyl methacrylate, and styne are respectively 66.0%, 31.0%,
21.2% and 14.5%. If the volume shrinkage during polymerization is large, for example, when used as a forming material, dimensional accuracy may be lost, when used as a casting material, the cast product may be distorted due to shrinkage, or the adhesive strength with the mold may be reduced. There are problems such as gaps being created. In addition, when used as a paint, internal distortion may cause a decrease in adhesion to the coated plate and cause warping, and when used as an adhesive, internal distortion may cause a decrease in adhesive strength, warpage, deformation, etc. cause problems. Furthermore, it is also known that common crosslinkable polymers shrink when crosslinked and cured. Epoxy resins have a low shrinkage rate during crosslinking and curing due to ring opening of epoxy groups, so they are widely used in paints, adhesives, molded products that require dimensional accuracy, cast products, etc.
The shrinkage rate of epoxy resin varies somewhat depending on the type of crosslinking agent, curing time and temperature, but is about 1 to several percent (see Kobunshi, Vol. 27, February issue, 1978, pp. 108-111). Monomers that do not substantially shrink or preferably expand during polymerization or cross-linking of polymers are currently extremely popular as materials for manufacturing sophisticated equipment, such as strain-free composite materials, adhesives, and casting materials. It is valued and explored. As a result of intensive research to develop such a non-shrinkable polymer, the present inventors added a specific 2-(meth)allyloxymethyl-spiro-orthoester compound to a conventionally known ethylenically unsaturated compound. When a spiro-orthoester group is introduced into the ethylenically unsaturated compound by radical copolymerization, the resulting copolymer does not substantially shrink during crosslinking due to ring opening of the orthoester group. These findings led to the completion of the present invention. In this specification, (meth)allyl means allyl or methallyl, and (meth)allyloxy means allyloxy or methallyloxy. The copolymer provided by the present invention comprises one or more ethylenically unsaturated monomers and at least one compound represented by the following formula [] (hereinafter referred to as compound []). It can be produced by radical copolymerization, and the above-mentioned ethylenically unsaturated monomer and compound [ ] are obtained in the form of regular or irregular bonding. (Here, n represents an integer of 3 to 5, and R represents a hydrogen atom or a methyl group, respectively.) The present inventors have previously discovered the compound [ ], which undergoes not only cationic ring-opening polymerization but also radical polymerization. Having learned that this is the case, he has filed a patent application for the compound [], but as stated in the specification, the compound [] is γ-butyrolactone, δ-
It can be produced by an addition reaction between lactones selected from valerolactone and ε-caprolactone and (meth)allyl glycidyl ether. The reaction formula is shown below. (In the above formula, R is a hydrogen atom or a methyl group, and l is an integer of 3, 4 or 5. The same applies hereinafter.) When producing the compound [], (meth)allyl glycidyl ether and lactones, In a solvent such as methylene chloride or tetrahydrofuran, acids such as BF ₃ .Et ₂ O.SnCl ₄ , TiCl ₄ ,
It is desirable to carry out the reaction using an acid such as FeCl ₃ , p-toluenesulfonic acid, sulfuric acid, etc. as a catalyst.
There is no particular restriction on the reaction temperature, but it is generally 0°C to 60°C.
Do it with Furthermore, there are no particular restrictions on the molar ratio of (meth)allyl glycidyl ether/lactone, the catalyst concentration, and the amount of solvent used, but in general, the molar ratio of (meth)allyl glycidyl ether/lactone = 0.3.
~1.5, catalyst concentration 0.1~3wt% (relative to charged lactone +
Solvent), the amount of solvent used is 0.5 to 20 (weight ratio to lactone charged). The degree of progress of the reaction can be easily determined by analyzing the reaction solution using, for example, a gas chromatograph or a liquid chromatograph. The compound [] is separated and obtained from the reaction solution as follows. For example, an alkaline aqueous solution, such as an aqueous sodium hydroxide solution, is added to the reaction solution while cooling it with ice water, and after stirring and mixing, the mixture is separated into an aqueous layer and an organic layer. After repeating the above operation until the unreacted lactone compound in the organic layer is reduced to almost zero, the organic layer is reduced to 10%.
Wash with NaCl aqueous solution. Next, after dehydrating the organic layer with magnesium sulfate, low-boiling substances are first removed by atmospheric distillation, and the residue is distilled under reduced pressure to obtain the compound []. The ethylenically unsaturated compound from which the monomer unit A can be derived by radical copolymerization with the above compound [] is represented by (i) the following formula: (In the formula, R ₁ is hydrogen or an alkyl group, and R ₂ is -
CN, -COOR ₃ , -OCOR ₄ is phenyl or a phenyl group having alkyl, halogen or haloalkyl as a substituent, R ₃ is a substituted or unsubstituted alkyl, cycloalkyl or aryl group, and R ₄ is an alkyl group and (ii) anhydrides and esters of maleic, itaconic and citraconic acids and esters of fumaric acid. Specific examples of the compounds represented by [] above include the following compounds. Esters of acrylic acid and methacrylic acid, such as methyl, ethyl, propyl, butyl, benzyl, phenyl, cyclohexyl, phenoxyethyl, acetoxyethyl, hydroxyethyl, 2-ethylhexyl, esters of acrylic acid and methacrylic acid; styrene and styrene derivatives,
For example o-, m- or p-chlorostyrene, m-
or p-chloromethylstyrene, α-methylstyrene, etc.; vinyl acetate; acrylonitrile, methacrylonitrile. The radical copolymerization of the compound [] and the ethylenically unsaturated compound can be carried out by conventional radical polymerization means, such as ultraviolet rays, infrared rays, heat, electron beams, or microwaves. Incidentally, maleic anhydride or the like can be radically copolymerized with the compound [] without a catalyst to give the desired copolymer. In ultraviolet radical polymerization, a photoinitiator is usually used. Suitable photoinitiators include acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 4'-isopropyl-2-hydroxy-2
-Methylpropiophenone, 2-hydroxy-2
-Methylpropiophenone, 4,4'-bis(diethylamino)benzophenone, benzophenone,
Methyl-(0-benzoyl)-benzoate, 1
-Phenyl-1,2-propanedione-2-(0
-ethoxycarbonyl)-oxime, 1-phenyl-1,2-propanedione-2-(0-benzoyl)-oxime, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin octyl ether, Carbonyl compounds such as benzyl or diacetyl; anthraquinone or xanthone derivatives such as methylanthraquinone, chloroanthraquinone, chlorothioxanthone, 2-methyloxanthone or 2-i-propyloxanthone; diphenyl sulfide, diphenyl disulfide or dithio Sulfur compounds such as carbamates; α-chloromethylnaphthalene, anthracene, etc. When polymerizing using infrared rays, heat, or microwaves,
Any radical initiator that can generate radicals upon decomposition can be used. For example, di-tert-butyl peroxide,
Organic peroxides such as 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butyl hydroperoxide, tert-butylperoxybenzoate; 2,2'-azobisisobutyro Azo compounds such as nitrile; ammonium persulfate,
Persalts such as potassium persulfate can be used. Further, polymerization using ionizing radiation such as an electron beam is usually carried out without a catalyst. When a catalyst is used, the amount used is generally 0.01 to 10 wt%, preferably 0.1% based on the total amount of monomers.
~5wt% range. Radical polymerization proceeds even at room temperature when irradiated with ultraviolet rays or ionizing radiation, but in other cases it proceeds smoothly under heating or heating conditions. As the polymerization method, any of bulk, solution, suspension and emulsion polymerization can be employed, but bulk or solution polymerization is usually convenient. When using a solvent, for example, ethers such as dioxane, alicyclic hydrocarbons such as cyclohexane, aromatic hydrocarbons such as toluene and xylene, halogenated alkanes such as dichloroethylene, ketones such as methyl ethyl ketone, methyl isobutyl ketone, etc. Cellosolves such as methyl cellosolve and ethyl cellosolve are commonly used. The produced copolymer is prepared by dissolving it in a solvent in which the produced polymer is soluble, such as methylene chloride, dioxane, dimethylformamide, etc.
For example, the copolymer can be separated and purified by repeating several times the operation of adding the copolymer dropwise to a precipitation solvent such as n-hexane or methanol under stirring to precipitate the copolymer. In the modified copolymer of the present invention, the compound []
If the monomer unit derived from A is present in the copolymer at about 1 mol %, the volume shrinkage during crosslinking can be substantially improved. X and Y representing the mole fraction and the mole fraction of structural unit B, respectively, are such that Y/(X+Y) is 1/
It can be any ratio ranging from 100 to 99/100. However, even if the bicycloorthoester unit is present in an amount greater than 50 mol%, it will not only increase the cost but also lead to a decrease in water resistance.
The (X+Y) ratio needs to be in the range of 3/100 to 50/100. Moreover, the weight average molecular weight of the copolymer according to the present invention is
5 million to 5 million. Since the copolymer of the present invention has a volume-expandable spiro-orthoester group in the molecule, it exhibits the characteristic that there is virtually no volume change during crosslinking and curing, and physical properties such as heat resistance and solvent resistance are improved by crosslinking. Improved. Thus, the copolymer of the present invention eliminates the above-mentioned drawbacks associated with volumetric shrinkage, and can be used for paints with good adhesion that do not cause voids, adhesives that do not cause internal distortion, and composite materials and adhesives that require dimensional accuracy. Extremely useful for manufacturing mold materials, etc. For example, an excellent coating film can be obtained by dissolving the copolymer of the present invention in an appropriate solvent and applying it to a substrate surface, and curing the formed coating film by an appropriate crosslinking means. After injection, crosslinking can be performed to obtain improved molded articles. The copolymer of the present invention undergoes crosslinking according to a cationic polymerization mechanism, and has spiro-orthoester groups. (In the formula, n represents an integer of 3 to 5) becomes a crosslinked polymer through a ring-opening polymerization reaction. This crosslinking is usually initiated using a cationic polymerization catalyst. Examples of cationic polymerization catalysts used for this purpose include:
Lewis acids such as BF ₃ , FeCl ₃ , SnCl ₄ , SbCl ₃ , SbF ₃ , TiCl ₄ ; combinations of Lewis acids such as BF ₃ OEt ₂ , BF ₃ -aniline complex, etc. and compounds containing O, S, N, etc. Coordination compounds; examples include oxonium salts, diazonium salts, carbonium salts, halogen compounds, mixed halogen compounds, and perhalogen acid derivatives of Lewis acids. The amount of catalyst used is generally in the range of 0.001 to 10% by weight based on the copolymer to be crosslinked. There are no particular restrictions on polymerization temperature, but it is usually room temperature to 200℃.
It will be held in Further, crosslinking can also be carried out by irradiation with radiation such as electron beams and ultraviolet rays. In the case of ultraviolet irradiation, a cationic polymerization catalyst such as φ-N ⁺ ≡
Aromatic diazonium salts such as N・PF ⁶ ₋ , φ−N ⁺ ≡N・BF ⁴ ₋ ; aromatic halonium salts such as φ−I ⁺ −φ・BF ⁴ ₋ ;

Aromatic onium salts of Group A elements of the periodic table such as [Formula];

Aromatic onium salts of elements of group a of the periodic table, such as: ##STR1## may be used. The amount of catalyst used is generally in the range of 0.001 to 10% by weight based on the copolymer to be crosslinked. In the following examples, the specific gravity of the produced copolymer was measured by the following method. A sample was dissolved in a solvent such as dichloroethane, the solution was applied to a substrate, the solvent was gradually evaporated at room temperature, and then dried under reduced pressure to form a thin film of the copolymer. Using a density gradient tube method B type direct reading specific gravity measuring device (Shibayama Kagaku Kikai Seisakusho), a small piece of the above thin film degassed in a potassium carbonate aqueous solution was placed in a density gradient tube made of a potassium carbonate aqueous solution, and the measurement was carried out. . Furthermore, the average molecular weight of the produced copolymer was calculated as a polystyrene equivalent weight average molecular weight from high performance liquid chromatography (HLC) analysis. The measurement conditions are as follows. Apparatus: HLC-801A manufactured by Toyo Soda Kogyo Co., Ltd. Column: TSK gel-GMH 2 bottles eluent; Tetrahydrofuran flow rate: 1 ml/min Next, the present invention will be further explained by synthesis examples of compound [], working examples, and reference examples. do. Synthesis example of compound [] 1 180 g (1.58 mol) of ε-caprolactone and 300 ml of methylene chloride were placed in a 4-neck flask equipped with a stirrer, condenser, thermometer, and dropping funnel, and the solution in the pot was poured with ice water while stirring. After cooling to 5° C., 5 ml of BF ₃ .Et ₂ O was added. 150 g of allyl glycidyl ether and 150 ml of methylene chloride were charged into a dropping funnel, and the above allyl glycidyl ether mixture was added dropwise to the flask over about 2 hours while stirring. During the dropping, the temperature of the pot liquid was maintained at 10°C or less. After stirring at room temperature for 5 hours, 10 ml of triethylamine was added to neutralize the catalyst. Next, to remove unreacted ε-caprolactone, the reaction solution was cooled with ice water, and 200 ml of 10% NaOH aqueous solution was added.
was gradually added, and stirring was continued for 30 minutes after the addition was completed, and then the aqueous alkaline solution layer and the organic layer were separated. After repeating the washing operation with the above 10% NaOH aqueous solution twice on the separated organic layer, the organic layer was washed with 10% NaOH solution.
Washed with 300 ml of NaCl aqueous solution. The organic layer was dehydrated with magnesium sulfate, and then the solvent was removed by simple distillation at normal pressure. Next, distill under reduced pressure to obtain 2-allyloxymethyl-1,4,6-trioxaspiro[4,6] at a boiling point of 98℃/0.8mmHg.
117 g (yield: 39%) of undecane was obtained. Its physical property values are as follows. Specific gravity: 1.070 (25℃) Refractive index: n ²⁵ _D = 1.467 Boiling point: 98℃/0.8mmHg IR (infrared absorption spectrum)... (see Figure 7): 1645cm ^-1 (-CH=CH ₂ ) 955cm ^-1 , 1070cm ^-1 , 1130cm ^-1 (C-O-C) NMR (Nuclear Magnetic Resonance Spectrum) (in CDCl ₃ )...
...(See Figure 8) δ (ppm): 5.0 to 6.0 (3H, CH ₂ = CH -) 3.2 to 4.5 (9H, -O-CH ₂ -
×4, -CH-O-) 1.9~2.3 (2H,

[Formula]) 1.4-1.9 (6H, (-CH ₂ )- ₃ ) Synthesis example of compound [] 2 Into a four-neck flask equipped with a stirrer, condenser, thermometer, and dropping funnel, 150 g of γ-butyrolactone ( 1.742 mol) and 300 ml of methylene chloride
After cooling the pot liquid to 5°C with ice water while stirring, 5 ml of BF ₃ ·Et ₂ O was added. 165 g of allyl glycidyl ether and 150 ml of methylene chloride were placed in a dropping funnel, and the above allyl glycidyl ether mixture was added dropwise over about 2 hours while stirring the pot liquid. During the dropping, the solution was cooled with ice water to maintain the temperature of the pot liquid below 10°C. Thereafter, after stirring at room temperature for 5 hours, 10 ml of trielamine was added to neutralize the catalyst. Next, the reaction solution was cooled with ice water, and 200 ml of 10% NaOH aqueous solution was gradually added. After the addition was completed, stirring was continued for 30 minutes, and then the aqueous alkaline solution layer and the organic layer were separated. After repeating the above washing operation with 10% NaOH aqueous solution until no unreacted ε-caprolactone was detected in the separated organic layer by liquid chromatography (the number of washings was 2 times), the organic layer was washed 10%.
Washed with 300 ml of % NaCl aqueous solution. The organic layer was dehydrated with magnesium sulfate and then removed by simple distillation at normal pressure. Next, distill under reduced pressure to obtain the boiling point
2-Allyloxymethyl at 94℃/1.0mmHg
1,4,6-trioxaspiro[4,4]nonane
142g (yield: 49%) was obtained. Its physical property values are as follows. Γ specific gravity 1.090 (25℃) Γ refractive index n ²⁵ _D = 1.459 Γ boiling point 94℃/1.0mmHg ΓIR... (see Figure 9) 1645cm ^-1 (-CH=CH ₂ ) 955cm ^-1 , 1050cm ^-1 , 1130cm ^-1 (C-O-C) ΓNMR... (See Figure 10) δ (ppm); 5.0 to 6.0 (3H, CH ₂ = CH -), 3.3 to 4.6 (9H, -O-CH ₂ -
×4, -O-CH-), 1.8~2.3 (4H,

[Formula]) Example 1 Acrylonitrile 0.233g (4.38 mmol), 2
-Allyloxymethyl-1,4,6-trioxaspiro[4,6]undecane 2.0g (8.76 mmol)
and 64.7 mg of azobisisobutyronitrile (3 mol % of the polymerizable components) as a polymerization initiator were mixed and reacted in a sealed tube at 70° C. for 24 hours to obtain a pale yellow viscous substance. This product was dissolved in 10 ml of methylene chloride, and this was added dropwise to 200 ml of n-hexane with stirring to collect a precipitate. After repeating this purification operation once more, it was dried under reduced pressure to obtain a pale yellow solid with a yield of 30%. IR analysis of the obtained polymer revealed absorptions at 960 cm ^-1 and 1060 cm ^-1 characteristic of spiro-orthoester groups, and nitrile absorption at 2220 cm ^-1 (see Figure 1). Based on the elemental analysis values (nitrogen content 7.1%, oxygen content 17.2%), the copolymerization ratio in this polymer was determined to be 65.4% acrylonitrile and 2-allyloxymethyl-1,4,6-trioxaspiro[4,6 ] Undecane was 34.6%. The structure of this copolymer is represented by the following formula. (Here, Y/(X+Y)=0.346) The weight average molecular weight of this copolymer according to HLC analysis is 7000, and the specific gravity at 25°C is 1.176.
It was hot. Example 2 Methyl methacrylate 0.439 g (4.38 mmol), 2-allyloxymethyl-1,4,6-trioxaspiro[4,6]undecane 2.0 g (8.76
mmol) and 64.7 mg of azobisisobutyronitrile (3 mol% of the polymerizable components) as a polymerization initiator were mixed and reacted in a sealed tube at 70°C for 24 hours to obtain a viscous semi-solid product. Ta. This product was dissolved in 10 ml of methylene chloride, and this was added dropwise to 200 ml of n-hexane with stirring.
The resulting precipitate was collected. After repeating this purification operation, the yield was 20% as a result of drying at 60°C under reduced pressure.
%, a white solid polymer was obtained. IR analysis of the obtained polymer revealed absorptions at 960 cm ^-1 and 1140 cm ^-1 characteristic of spiro-orthoester groups (see Figure 2). In addition, the copolymerization ratio in this polymer is determined from the saponification value of the copolymer (500.9 mg-KOH/g), and the ratio of 2-allyloxymethyl-1,4,6-trioxas to 95 mol% of methyl methacrylate. It contained 5 mol% of pyro[4,6]undecane. In addition, the saponification value of the copolymer was determined by the following method. Copolymer 50mg, 0.1N sodium hydroxide standard aqueous solution 15ml and dimethylformamide (hereinafter
After putting 15ml (abbreviated as DMF) into a 100ml Erlenmeyer flask and attaching a Dimroth cooling tube,
Heat in a warm water bath at °C for 2 hours. After cooling to room temperature, 10 ml of 0.1N standard aqueous hydrochloric acid solution and 2 to 3 drops of phenolphthalein solution are added, followed by titration with N/100 standard aqueous hydrochloric acid solution, with the end point being the point at which the solution becomes colorless. As a control (blank), the result of carrying out the above operation without adding the copolymer is used.
This operation was repeated three times and averaged. The structure of this copolymer is represented by the following formula. (Here, Y/(X+Y)=0.05) The weight average molecular weight of this copolymer determined by HLC analysis was 23,000, and the specific gravity at 25°C was 1.206. Example 3 0.912 g (8.76 mmol) of styrene, 2.0 g (8.76 mmol) of 2-allyloxymethyl-1,4,6-trioxaspiro[4,6]undecane and azobisisobutyronitrile as a polymerization initiator.
86.3 mg (3 mol % of polymerizable components) were mixed and reacted in a sealed tube at 70° C. for 24 hours to obtain a viscous product. Dissolve this product in 10 ml of methylene chloride,
This was added dropwise to 200 ml of n-hexane with stirring to collect the precipitate. This purification operation was repeated once more and then dried under reduced pressure to obtain a white solid polymer with a yield of 28%. IR analysis of the obtained polymer revealed absorptions at 960 cm ^-1 and 1140 cm ^-1 characteristic of spiro-orthoester groups (see Figure 3). In addition, the copolymerization ratio of this polymer was determined by NMR analysis.
2-allyloxymethyl-1,4,6 for 90%
-Trioxaspiro[4,6]undecane was 10%. This ratio is δ=6.0~7.6ppm

It was calculated from [Formula] and the integral value of the peak of δ = 3.50 ppm (methylene at the 3rd and 7th positions of the spirooxoester). The structure of this copolymer is represented by the following formula. (Here, Y/(X+Y)=0.10) The weight average molecular weight of this copolymer determined by HLC analysis was 16,000. Moreover, the specific gravity at 25°C was 1.080. Example 4 0.859 g (8.76 mmol) of maleic anhydride and 2
-Allyloxymethyl-1,4,6-trioxaspiro[4,6]undecane 2g (8.76 mmol)
After dissolving 86.3 mg (3 mol% of polymerizable components) of azobisisobutyronitrile in 10 ml of 1,4-dioxane, the mixture was reacted in a sealed tube at 70°C for 24 hours. When the obtained reaction product was dropped into n-hexane, a white precipitate was generated. After repeating this purification operation, it was dried under reduced pressure to obtain a white powdery polymer with a yield of 91%. IR analysis of the obtained polymer revealed acid anhydride peaks at 1780 cm ^-1 and 1850 cm ^-1 . The copolymerization ratio of the polymer was determined by the same method as described in Example 2, that is, by adding a certain amount of the polymer in a DMF solution.
Hydrolysis was performed by adding a 0.1N aqueous sodium hydroxide solution, and excess sodium hydroxide was back-titrated with 0.1N hydrochloric acid to calculate the content of maleic anhydride residues. As a result, this copolymer with maleic anhydride and 2-allyloxymethyl-1,4,6
- It was found that it contains trioxaspiro[4,6]undecane in a 1:1 ratio. That is, the copolymer has the structure of the following formula. (Here, Y/(X+Y)=0.5) The weight average molecular weight of this copolymer was found to be about 4000 by HCL analysis. A solution of 0.1 g of the above copolymer dissolved in 0.2 ml of methylene chloride was added to a phosphoric acid-treated cold rolled steel plate (JIS G-3141
After coating SPCC BA#14X treatment) with a film thickness of 25μ,
As a result of hot air drying, a transparent coating film with good adhesion was obtained. This coating film was crosslinked by moisture in the air and was insoluble in methylene chloride. Example 5 Maleic anhydride 0.735 g (7.50 mmol), 2-
Allyloxymethyl-1,4,6-trioxaspiro[4,4]nonane 1.5 g (7.50 mmol) and azobisisobutyronitrile 37 mg (3 mol% of polymerizable components) were added to 10 ml of 1,4-dioxane. After dissolving, the mixture was reacted in a sealed tube at 70°C for 24 hours. When the obtained reaction product was dropped into n-hexane, a white precipitate was generated. After repeating this purification operation, it was dried under reduced pressure to obtain a white powdery polymer with a yield of 75%. By IR analysis of the obtained polymer
Acid anhydride peaks were observed at 1780 cm ^-1 and 1850 cm ^-1 . The copolymerization ratio of the polymer was determined in the same manner as in Example 4 by hydrolyzing the polymer with a 0.1N aqueous sodium hydroxide solution and back titrating excess sodium hydroxide with a 0.1N aqueous hydrochloric acid solution. As a result, maleic anhydride and 2-allyloxymethyl-1,4,6-trioxaspiro[4,4]
It was found that it contained nonane in a 1:1 ratio. That is, the copolymer has the structure of the following formula. (Here, Y/(X+Y)=0.50) The weight average molecular weight of this copolymer was found to be about 3500 by HCL analysis. Example 6 Vinyl acetate 0.377 g (4.38 mmol), acrylonitrile 0.233 g (4.38 mmol), 2-allyloxymethyl-1,4,6-trioxaspiro[4,
6] Undecane 2.0g (8.76 mmol) and azobisisobutyronitrile 86.3mg (polymerizable component 3)
mol %) were mixed and reacted in a sealed tube at 70° C. for 24 hours to obtain a pale yellow viscous product. This product was dissolved in 10 ml of methylene chloride, and the solution was added dropwise to 200 ml of n-hexane with stirring to remove the precipitate. After repeating this purification operation once more, it was dried at 60° C. under reduced pressure to obtain a pale yellow solid with a yield of 33%. IR analysis of the obtained polymer revealed absorptions at 960 cm ^-1 and 1060 cm ^-1 , which are characteristic of spiro-orthoester groups.
Absorption of 2220 cm ^-1 and 1740 cm characteristic of nitrile groups
Strong absorption of ester group (R-COO-) was observed in ^-1 (see Figure 4). The copolymerization ratio in this polymer and the acrylonitrile content are determined by elemental analysis (nitrogen content; 6.8
%), the vinyl acetate content was calculated from the saponification value (53.9 mg-KOH/g) in the same manner as in Example 2. As a result, the structure of this copolymer is represented by the following formula. [Here, X/(X+X'+Y)=0.56, X'/(X+
X'+Y)=0.11, Y/(X+X'+Y)=0.33] The weight average molecular weight of this copolymer was found to be 33,000 by HLC analysis. The specific gravity at 25°C was 1.152. Example 7 Acrylonitrile 0.398 g (7.50 mmol), 2
-Allyloxymethyl-1,4,6-trioxaspiro[4,4]nonane 1.50g (7.50 mmol) and azobisisobutyronitrile 74mg (3 mol% of polymerizable components) were mixed and placed in a sealed tube. 12 at 60℃
After reacting for some time, a pale yellow solid was obtained. This product was dissolved in 10 ml of methylene chloride, and this was added dropwise to 200 ml of n-hexane with stirring to collect a precipitate. This purification operation was repeated once more and then dried under reduced pressure to obtain a pale yellow solid with a yield of 60%. IR analysis of the obtained polymer showed absorption at 960 cm ^-1 and absorption at 2220 cm, which are characteristic of spiro-orthoester groups.
^-1 shows absorption of nitrile (see Figure 5). Based on the elemental analysis values (nitrogen content 7.7%, oxygen content 22.6%), the copolymerization ratio in this polymer was found to be 61.0% acrylonitrile and 2-allyloxymethyl-1,4,6-trioxaspiro[4, 4]
Nonane was 39.0%. The structure of this copolymer is represented by the following formula. (Here, Y/(X+Y) = 0.39) The weight average molecular weight of this copolymer according to HLC analysis is 10,000, and the specific gravity at 25°C is 1.160.
It was hot. Reference Example 1 100 mg of the copolymer obtained in Example 1 was dissolved in 22 ml of 1,1-dichloroethane, and 1.2 mg of BF ₃ ·Et ₂ O was added. This mixture was reacted at 70°C for 24 hours to obtain a pale yellow solid. The reactant was crosslinked and insoluble in methylene chloride. IR analysis of this cross-linked polymer revealed that 950cm ^-1 and 1140cm
^-1 absorption had almost disappeared. A new strong absorption of ester groups appeared at 1730 cm ^-1 (see Figure 6). The specific gravity of this crosslinked polymer at 25°C is 1.170
A volume expansion of 0.5% was observed due to crosslinking of the copolymer. Reference Example 2 100 mg of the copolymer obtained in Example 2 was dissolved in 2 ml of 1,1-dichloroethane, and 1.2 mg of BF ₃ ·Et ₂ O was added. This mixture was reacted at 70°C for 24 hours to obtain a white solid. The reactant was crosslinked and insoluble in methylene chloride. IR analysis of this crosslinked polymer revealed that the absorption at 960 cm ^-1 , which is characteristic of spiro-orthoester groups, had almost disappeared. The specific gravity of this crosslinked polymer at 25°C was 1.206, and the volumetric shrinkage of the copolymer due to crosslinking was almost zero. Reference Example 3 100 mg of the copolymer obtained in Example 3 was dissolved in 2 ml of 1,1-dichloroethane, and 1.2 mg of BF ₃ ·Et ₂ O was added. This mixture was reacted at 70°C for 24 hours to obtain a white solid. The reactant was crosslinked and insoluble in methylene chloride. IR analysis of this cross-linked polymer revealed that the absorption at 960 cm ^-1 characteristic of the spiro-ortho ester group almost disappeared, and a new absorption of the ester group appeared at 1730 cm ^-1 . Its specific gravity at 25℃ is
1.080, and the volume change due to crosslinking of the copolymer was almost zero. Reference Example 4 100 mg of the copolymer obtained in Example 6 was dissolved in 2 ml of 1,1-dichloroethane, and BF ₃ was added as an initiator.
1.2 mg of _Et2O was added. This mixture was reacted at 70°C for 24 hours to obtain a yellowish solid. The reactant was crosslinked and insoluble in methylene chloride. IR analysis of this crosslinked polymer revealed that the absorption at 960 cm ^-1 , which is characteristic of spiro-orthoester groups, had almost disappeared. Its specific gravity at 25°C was 1.148, and a volume expansion of 0.3% was observed due to crosslinking of the copolymer.

[Brief explanation of drawings]

Figures 1, 2, 3, 4, and 5 are infrared absorption spectra of the copolymers obtained in Example 1, Example 2, Example 3, Example 6, and Example 7, respectively. 6 is an infrared absorption spectrum diagram of the crosslinked copolymer obtained in Reference Example 1. Figure 7 shows 2-allyloxymethyl-1,4,6-trioxaspiro[4,6] obtained in Synthesis Example 1 of compound []
Figure 8 shows the IR spectrum of undecane, and Figure 8 shows the NMR spectrum of the same compound. Figure 9 shows the 2-allyloxymethyl- obtained in Synthesis Example 2 of compound [].
FIG. 10 is an IR spectrum diagram of 1,4,6-trioxaspiro[4,4]nonane and an NMR spectrum diagram of the same compound.

Claims (1)

[Scope of Claims] 1 Monomer unit A composed of at least one ethylenically unsaturated compound represented by the following (i) or (ii) and the structural unit B represented by the following formula (iii), Y/(X
+Y) = Ethylenically unsaturated compound having spiro-orthoester groups arranged in a regular or irregular manner at a mole fraction of 3/100 to 50/100 and having a weight average molecular weight in the range of 5 million to 5 million. modified copolymer. However, X is the mole fraction of A in the copolymer, and Y is the mole fraction of B in the copolymer. (In the formula, R ₁ is hydrogen or an alkyl group, and R ₂ is -
CN, -COOR ₃ , -OCOR ₄ is phenyl or a phenyl group having alkyl, halogen or haloalkyl as a substituent, R ₃ is a substituted or unsubstituted alkyl, cycloalkyl or aryl group, and R ₄ is an alkyl group ). (ii) Anhydrides or esters of maleic, itaconic or citraconic acids or esters of fumaric acid. (In the formula, n represents an integer of 3 to 5, and R represents a hydrogen atom or a methyl group.)