JPH0415204A - Maleic or fumaric diester derivative and polymer containing the same as monomer unit - Google Patents

Abstract

PURPOSE:To prepare the title deriv. giving a polymer excellent in physical and optical characteristics by introducing adamantane as an ester component into maleic or fumaric acid. CONSTITUTION:A maleic or fumaric diester wherein at least one of the two ester groups is an adamantly or lower alkyl-substd. adamantly ester group. The deriv. has a high radical-polymn. activity and gives a homo- or copolymer excellent in physical and optical characteristics. The polymer can be widely used as the material of a lens and an oxygen-enriching film utilizing its high oxygen transmissibility, and as other various functional materials.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a novel maleic acid diester or fumaric acid diester derivative, and a polymer containing the derivative as a monomer unit, which has excellent heat resistance and optical properties. It is related to.

[Prior Art] Maleic acid diester and fumaric acid diester are in a cis-trans isomer relationship with each other. Conventionally, these were thought to be difficult to homopolymerize due to steric hindrance of the two substituents. However, recent research by the present inventors has confirmed that fumaric acid diester can be easily polymerized in the presence of a radical polymerization initiator, and that the radical polymerizability increases as the ester substituent becomes bulkier. It has become clear [T,0tsu et al., Makr.
oa+o1. Chem.

Rapid, Coavun, 2.724 (198
1): Makroa+olChem,, 5upp1
．． , 12.133 (1985); Macroa, J.
+ol.

Sci,-Chem,, A25.537 (1!188
): Polym, Bul112, 449 (1984
) Such].

The resulting diester polymer is rigid because substituents are bonded to all carbons in the polymethylene main chain, has a high glass transition point (Tg) and melting point (Tm), and exhibits high orientation. Therefore, it is expected to be applied as a variety of functional polymers. In particular, fumaric acid diester polymers have excellent transparency, so they can be used in optical lenses, spectacle lenses, and high refractive index lenses.They also have excellent oxygen permeability, so they can be used in contact lenses and oxygen-enriched lenses. Practical use as membranes, etc. is progressing.

[Problems to be Solved by the Invention] Under these circumstances, the present inventors have actively conducted research with the aim of developing novel maleic acid and fumaric acid diester derivatives and polymers thereof with high functionality. The present invention was made as part of such research, and its purpose is to convert adamantane, a bulky alicyclic hydrocarbon that is chemically stable and has excellent heat resistance, into maleic acid and The object of the present invention is to provide a novel maleic acid or fumaric acid diester-based conductor that can be incorporated into fumaric acid as an ester component to provide a polymer with excellent physical and optical properties. In addition, another object of the present invention is to provide a composition containing these derivatives as a polymerization component or a copolymerization component.
The aim is to provide a polymer with excellent heat resistance, light transmittance, optical refractive index, impact resistance, etc.

[Means for Solving the Problems] The constitution of the present invention that can solve the above problems is such that at least one of the esters in the maleic acid diester or the fumaric acid diester is an adamantyl ester or a lower alkyl-substituted adamantyl ester. It has the following. These derivatives have excellent radical polymerization activity, and by homopolymerizing or copolymerizing them as monomer components, polymers with excellent physical and chemical properties can be obtained.

[Function] The maleic acid or fumaric acid diester conductor according to the present invention has, for example, the following general formula [A].

It is a novel compound represented by [B] and has one reactive 231 bond, and the polymer of the present invention has a monomer position represented by the following formula [C] in the molecule.

CH=C)I -C is an adamantyl group: lower alkyl-substituted adamantyl group; alkyl such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, isopropyl, t-butyl, t-amyl, etc. Representative examples include alicyclic groups such as cyclopropyl, cyclopentyl, cyclohexyl, and cyclonaphthyl; and aryl groups such as phenyl, hensyl, tolyl, xylyl, biphenyl, and naphthyl.

Among the maleic acid or fumaric acid diester derivatives represented by the above formulas [A] and [B], representative examples are as follows.

In the above formulas [A], [B], and [C], the substituent represented by R'R2 represents hydrogen or a lower alkyl group such as methyl or ethyl, and the type of substituent represented by R3 is not limited at all, but The general maleic acid or fumaric acid diester conductors as shown in (1) to (8) above are:
For example, it can be produced by reacting maleic anhydride or fumaric acid with adamantanol and an alcohol corresponding to the substituent R3 in the presence of a catalyst such as sulfuric acid or p-toluenesulfonic acid.

Hereinafter, typical manufacturing methods will be specifically explained.

(a) Synthesis of fumaric acid diadamantyl ester One equivalent of maleic anhydride and two equivalents of adamantanol were mixed with sulfuric acid or P-
When the reaction is carried out by heating in the presence of a catalyst such as 1-luenesulfonic acid, fumaric acid diadamantyl ester can be obtained. This reaction is carried out in a solvent such as toluene, benzene, or cyclohexane. The reaction is terminated when the theoretical amount of dehydration is reached, and after neutralization with an alkali, the formed precipitate is filtered off to obtain maleic acid diadamantyl ester. In addition, this maleic acid diadamantyl ester,
When the isomerization reaction is carried out using morpholine, fumaric acid diadamantyl ester can be obtained quantitatively in terms of Cx.

Incidentally, when 1 equivalent of fumaric acid and 2 equivalents of adamantanol are directly reacted according to the above reaction, fumaric acid diadamantyl ester can be obtained in a -stage reaction.

(b) Synthesis of asymmetric diester including adamantyl ester One equivalent of maleic anhydride and one equivalent of adamantanol are heated and reacted in the presence of a catalyst such as sulfuric acid or p-)-luenesulfonic acid to obtain a monoester, and further substituents When 1 equivalent of alcohol corresponding to R3 is added and the reaction is terminated when the theoretical amount of dehydration is reached, an asymmetric diester can be obtained. This reaction is carried out in a solvent such as toluene, benzene, or cyclohexane, and after the reaction is completed, it is neutralized with an alkali and the resulting precipitate is removed. When the 8 medium is distilled off under reduced pressure,
An asymmetric maleic diester is obtained.

When this is further subjected to an isomerization reaction using morpholine, the corresponding fumaric acid diester can be obtained almost quantitatively.

Incidentally, when 1 equivalent of fumaric acid is directly reacted with 1 equivalent of adamantanol and 1 equivalent of alcohol corresponding to substituent R3, an asymmetric diester can be obtained through a -stage reaction.

The maleic acid or fumaric acid diester-based talking conductor of the present invention can be produced, for example, by the method described above, but since the production method itself is not limited at all in the present invention, in addition to the method described above, various known methods can be used. Of course, it is also possible to manufacture it by applying it as appropriate, and all of these are included in the technical scope of the present invention.

Among the diester conductors obtained in this way, the unsaturated bonds in the fumaric acid diester conductors have radical polymerization activity, and the most practical ones are polymerizable monomers that utilize this polymerization activity. It is used as a.

That is, this fumaric acid diester derivative has, for example, 2.2
- Easily polymerizes in the presence of radical polymerization initiators such as acetophenones such as jetoxyacetophenone, peroxides such as benzoyl peroxide, and azo compounds such as azobisisobutyronitrile, and has high heat resistance and impact resistance. It provides a polymer with unique physical properties such as excellent properties, high light transmittance, high refractive index, low polymerization shrinkage rate, and hardness.

Of course, it is also possible to accelerate the polymerization reaction with heat or light. In particular, when this polymer is used as a plastic lens or other optical material, by adopting this photopolymerization method, it is possible to make a colorless and light-transmitting material. It's easy to get expensive things.

In addition to being able to be homopolymerized, this fumaric acid diester derivative can be used for various purposes and purposes by copolymerizing two or more of these derivatives or copolymerizing with copolymerizable monomers other than the birth conductor. Depending on the conditions, it is possible to obtain a polymer with further improved physical properties. The type of such copolymerizable monomer is not particularly limited, but when the resulting polymer is used as an optical material, preferred copolymerizable monomers include acrylic acid, methacrylic acid, their polymerizable derivatives, and styrene. Non-limiting examples include aromatic or aliphatic vinyl compounds such as , vinylcyclohexene and vinylnaphthalene, and monofunctional or polyfunctional molecules such as allyl alkyl ether.

The method of polymerization or copolymerization is not particularly limited either, and for example, bulk polymerization, emulsion polymerization, solution polymerization, ultraviolet polymerization, radiation polymerization, etc. can be appropriately employed.

The homopolymers or copolymers obtained by these methods are
It has a much higher melting point and decomposition temperature than conventional optical plastic materials, as well as a low polymerization shrinkage rate and a high optical refractive index, so it can be used alone or with other polymers. By combining and blending, it can be used as a material for optical members that utilize light transmission and reflection, such as various lenses such as eyeglasses, contact lenses, and camera lenses, prisms, and photosensitive materials for recording. Or gas content such as oxygen enrichment membrane jIll! It is extremely useful as a film.

The present invention will be specifically described below with reference to Examples, but the present invention is not limited by the Examples below.

[Example] In a 500 m1 glass colchen equipped with a water separator, 1
-Hydroxyadamantane 30.8g (0.2mo
l) and 9.8 g (0.1 mol) of maleic anhydride,
The reactor was charged with 250 ml of cyclohexane, and heated and stirred under reflux while being dehydrated in the presence of 1 g (0.01 mol) of concentrated sulfuric acid in a catalytic amount to proceed with the esterification reaction, and the reaction 2 was completed in about 8 hours.

After removing the solvent from the reaction product, column chromatography packed with activated alumina (developing agent: benzene)
and further purified with ethanol/benzene mixed solvent (5
Recrystallization by 1) gave diadamantyl maleate in a yield of 78%. mp: 146°C') l-NMR (CDC13, δ): 6.04 (
s, 2N, CH-), 2.17 (S, 18H, CH3C
H2), 1.63-1.71(m, 12H1CH
2)"C-NMR (CDCI, , δ) + 16
4.1(S), 130.0(d).

81.8(s), 41.3ft), 36.1(t), 3
0.9(d) IR spectrum Figure 1 Example 2 A glass colchen similar to that used in Example 1 was coated with 3,
5-dimethyl-1-hydroxyadamantane 36.4g
(0,2 mol) and maleic anhydride 9.8 g (0,
1 mol) was charged together with 250 ml of cyclohexane, and while being dehydrated in the presence of a catalytic amount of concentrated sulfuric acid 1 g (0.01 mol), the mixture was heated and stirred under reflux to proceed with the esterification reaction, and the reaction was completed in 8 hours. .

After removing the solvent from the reaction product, column chromatography packed with activated alumina (developing agent: benzene)
and further recrystallized from ethanol to obtain bis(3,5-dimethyl-1-adamantyl) maleate.
was obtained with a yield of 91%. mp: 84°C 'H-NMR (CDCh, δ): 6.02 (
s, 2) 1. CH@), 2.21-2.24 (m),
2.02(s), 1.76-1.78(m),
1.12-1.41(a+) ”C-NMR (CDC13, δ) + 164.1(
S), 130. [1(d)83.2(S), 50.5(
t), 47.2(t), 42.5(t).

39.6(t), 34.0(S), 31.1(d), 2
9.9(Q) IR spectrum: Figure 2.
78 mmol) and bis(3,5-dimethyl-1-adamantyl) maleate 3(Ig(68III
Iol), each equipped with a reflux condenser and a thermometer.
Pour 3 mL of cyclohexane into a flask and add 200 mL of cyclohexane.
ml and 5 ml of morpholine were added, and the mixture was heated under reflux for 15 hours.

After the reaction is complete, the solvent is removed and the precipitated white crystals are recrystallized with a mixed solvent of ethanol/benzene (4/1) or ethanol to give diadamantyl fumarate or bis(3,5-dimethyl-1-fumarate). adamantyl)
were obtained as white crystals.

Diadamantyl fumarate: approximately 100%, mp = 192°C 'H-NMR (CDCh, δ): 6.65 (
S, 2H, CH-), 2.18 (s, 6)1. C)
I), 2.14 (s, 12H, Cl42), 1.
63-1.70 (m, 12H1CH2) "C-NMR (CDCh, δ) + 164.1 (S
), 134. [1(d).

81.7(s), 41.2(t), 36.1ft)
, 3'0.8(d) IR spectrum: Figure 3 Bis(3,5-dimethyl-1-adamantyl) fumarate
: Approximately 100%, mp=70℃ 'H-NMR (CDCIs, δ): 6.02(
s, 2H, C) I-), 2.21-2.24(m),
2.02(s), 1.76-1.86(+o),
1.12 N1.41 (m), 0.88 (s, 6) 1
．． C) Is) 13C-NMR (CDCl2.δ):
164.1(S), t34. e(d).

83.2(S), 50.5(t), 47.2(t)
, 42.5 (t) 39.6 ft) , 34.0
(s), 31.1 (d), 29.9 (q)
IR Spectrum: Figure 4 Heaven! - # (500 m1 glass kolben with 5-way water separator, 1
-Hydroxyadamantane 15.4g (0.1mol)
or 3,5-dimethyl-1-hydroxyadamanta:/18.2 g (o, 1 mol) and fumaric acid 5
．． 8 g (0.05 mol) was charged together with 250 ml of benzene, and 0.7 g (0.007 mol) of concentrated sulfuric acid was added in a catalytic amount.
), the mixture was heated and stirred under reflux while being dehydrated to advance the esterification reaction, and the reaction was completed in about 15 hours.

After the reaction was completed, the mixture was neutralized with an aqueous sodium hydroxide solution (10%), the resulting precipitate was filtered off, and benzene was removed under reduced pressure. The obtained crude crystals were subjected to column chromatography packed with silica gel (developing agent: n-hexane/ether = 5/1
When separated and purified using a mixed solvent of 038mol: Yield 76t
)was gotten.

In a glass kolben of K Goryu 21, 1-hydroxyadamantane 250g (1.64 mmol), maleic anhydride 161g (1.64 mol), concentrated sulfuric acid (97k) 16
．． 5g (0,181ol) and benzene 500 II
The mixture was heated and stirred at reflux (85° C.) for 23 hours. After that, a water separator was installed and 52.5g of methanol (
1.54 mol) was added thereto, and the mixture was heated and stirred under reflux for 1 hour while dehydrating.

After the reaction was completed, the mixture was neutralized with an aqueous sodium hydroxide solution (10%), the resulting precipitate was filtered off, and the solvent was removed under reduced pressure. The obtained crude crystals were subjected to column chromatography packed with silica gel (developing agent: n-hexane/ether = 5/
1 mixed solvent) to give 1.18 g of adamantyl methyl maleate (
Yield: 45.7%) was obtained.

”C-NMR (CDCIs, δ)+165.6 (S)
, 163.9 (S).

131.8(d), 127.6(d), 82.3(
S), 51.9(Q)41J(t), 36.2(t
), 31.0 (d) IR spectrum: Fig. 5 Higashigogo 1 50 g (2 o.2 mol) of adamantyl methyl maleate obtained in Example 7 was placed in a glass colben, and Similarly, morpholine 1. The mixture was heated and stirred under reflux for 2 hours with Oml and 250 ml of cyclohexane. After the reaction was completed, the reaction mixture was treated in the same manner as in Example 3 to obtain 50 g of adamantyl methyl fumarate as a white crystalline solid.

"C-NMR (CDCI!, δ): 1B5.
5(S), 163.6(S).

136.0(d), 132.0(d), 81.9(s
), 52.2(q).

41.3ft), 36.2(t), 31.0(d)I
R spectrum: Figure 6 5 speed 19,1 and 1-hydroxyadamantane 152g (1a+ol)
, maleic anhydride 98 g (1 mol), concentrated sulfuric acid (97 g
U 9.5g (0.1mol), benzene 200ml
A monoesterification reaction was carried out in the same manner as in Example 7, except that 90 g (1.5 mol) of isopropyl alcohol was reacted with the monoester in the same manner as in Example 7. x38g (o, u: + mol) (yield: 4
Obtained 7.3U.

"C-NMR (CDCI, δ): 164.6 (
s), 163.8(s).

131.1(d), 128.5(d), 82.0(
s), 68.5(d) 41.2(t), 36.1(t
), 30.9(d), 21.7(Q) IR spectrum:
Figure 7: Adamantyl isopropyl maleate obtained above,
When isomerized using morpholine in the same manner as in Example 8,
A colorless transparent viscous liquid adamantyl isopropyl fumarate was obtained almost quantitatively.

13C-NMR ((:DCIs, δ); lδ4.5(S
), 183.7(S).

13s, 3(d), 132.9(d), 81.7(
S), u, e(d).

u, Nt), 36.1(t), 3o, 8(d),
21.7 (q) IR spectrum: Fig. 8 shows a plate ± 3.5-dimethyl-1-hydroxyadamantane 90 g
(0,5 mol), maleic anhydride 49 g (0,5 m0
1), concentrated sulfuric acid (97%) 4.5g (0,047mol)
A monoesterification reaction was carried out in the same manner as in Example 7 except that 200ml of benzene was used, and 25g of methyl alcohol (o, 5 II + ol
) was reacted in the same manner to obtain 69 g (0.24 mol) of colorless and transparent crystalline dimethyladamantyl methyl maleate.
) (Yield: Obtained 48 U.mp: 42-43℃"C
-NMR (CDC13, δ): 185.4 (S)
, 163.7(S).

1:H, 4(d), 127.7(d), 83.
4(s), 51.8(q).

50.4ft), 47.0(t), 42.4(t), 3
9.5(t).

33.9(s), 31.1(d), 29.8(q)IR
Spectrum: Figure 9 When dimethyladamantyl methyl maleate obtained above is isomerized using morpholine in the same manner as in Example 8, dimethyladamantyl fumarate is obtained as a colorless transparent viscous liquid.
Methyl was obtained almost quantitatively. bp: 142
~143°C 71 mmHg”C-NMR (CDCI,
δ): 164.9 (S), 163.1 (S).

x35. e(d), 131.9(dL 82.7(s
), 51.8(q).

50.3(t), 47.3(t), 47.0(t)
, 42.4(t) 39.5(t), 33.8(S)
, 31.0 (d), 29.8 (Q) IR spectrum: Figure 10 Azumaya 10 Yoshi dL Takumi 3.5-dimethyl-1-hydroxyadamantane 9o
g (o, 5 mol) Maleic anhydride 49 g (0
,5 mol), concentrated sulfuric acid (97U 4.5g (0,047
A monoesterification reaction was carried out in the same manner as in Example 7, except that 200 ml of benzene was used, and 30 g of isopropyl alcohol (0 mol) was added to the monoesterified product.
, 5 mol) was reacted in the same manner to obtain 61 g (0.19 mol) of dimethyladamantyl isopropyl maleate (yield: 3896) as a colorless transparent viscous liquid. , bp; 153~b'''C-NMR (CDCis, δ): 154
．． 5(s), 1δ3.8(s).

130.9(d), 128.6(d), 83.2(
s), 58.4(d).

50.4(t), 47.0ft), 42.4(t)
, 39.6ft).

33.9(S), 31.1(d), 29.8(Q)
, 21.7(Q) IR spectrum: Figure 11 When dimethyladamantyl isopropyl maleate obtained above is isomerized using morpholine in the same manner as in Example 8, dimethyladamantyl fumarate is obtained as a colorless transparent viscous liquid. Propyl was obtained almost quantitatively. bp:
144-144.5℃ 8mm) to Ig C-NMR (
CDCI3. δ) + 164.1(S), 183
．． 3(S).

135.0(d), 132.8(d), 82.7(
s), 68.3(d).

50.3(t), 47.0(t), 42.4(tl
, 39.5(t).

33.8(S), 31.0(d), 29.8(
Q), 21.6 (Q) IR spectrum: Figure 12 Example 15 (Production of polymer) Diadamantyl fumarate (DAdF) obtained in the previous example
, bis(3,5-dimethyl-1-adamantyl) fumarate (BDAdr), and bis(3,5-dimethyl-1-adamantyl) maleate (BDMAdM) were combined with various radical polymerization initiators [2,2°- Azobisisobutyronitrile (AIBN), 2,2'-azobisisobutyric acid dimethy7
Polymerization was carried out under various conditions in the presence of (MAIB), benzoyl peroxide (BPO), and di-tert-butyl peroxide (DtBpo), and the results shown in Table 1 were obtained.

The analysis results of Table 1 are shown below.

No. 1, 2: It is effective to perform solution polymerization at high temperature for DAdF, and when polymerizing DtBPO in toluene at 120°C, the polymerization reaction proceeds in a homogeneous system and a white powdery polymer is obtained. . As a result of GPC analysis, this polymer
It was confirmed that it has a molecular weight of about 10,000. In addition, after purification by reprecipitation method from benzene-ethanol, I
When the R spectrum was measured, the results shown in Figure 13 were obtained, showing the stretching vibration of the carbon-carbon double bond at 1660 cm-' and the carbon-hydrogen out-of-plane bending angle of the trans-1,2-substituted olefin at 996 cm-'. Absorption quickly disappears due to vibration.

The polymer was also subjected to thermogravimetric analysis (TGA) under a nitrogen stream for 10 minutes.
When the temperature was increased at a heating rate of ℃/min, the decomposition starting temperature was 273℃ and the maximum decomposition temperature was 33℃, as shown in Figure 14.
The residual weight at 7°C and 500°C was 13.796.

Figure 15 shows the 'H-NMR spectrum of poly(DAdF), and no absorption based on olefinic carbon (66,65) is observed, indicating that polymerization progresses due to double bond cleavage. It can be confirmed that

No. 3 to 5: BDMAdF can be polymerized in a high yield by performing bulk polymerization at 80° C. using BPO. In this case, as the polymerization progressed, the polymer precipitated and the polymerization system became non-uniform. Moreover, polymerization proceeds easily even at 60° C. in benzene, producing a polymer in high yield.

The IR spectrum of this polymer is as shown in FIG. 16, and it can be seen that the absorption based on double bonds disappears due to polymerization, as in the case of DAdF.

No, 8.7: BDMAdM does not polymerize at all under the same conditions as the fumarate (No, 6), but when morpholine, which is an isomerization catalyst to the trans isomer, is added to the polymerization system (No, 7), it easily polymerizes. The polymerization reaction proceeds.

6 (Production of copolymer) Radical copolymerization of methyl methacrylate (MMA) or adamantyl methacrylate (AMA) and fumaric acid diester was carried out using lauryl peroxide (0.4% by weight) as an initiator. It was done using TGA measurement results of the obtained copolymer and the obtained copolymer at 100°C
Table 2 summarizes the water absorption rates when heated at 1A (boiling water) for 1 hour.

Methacrylate and dimethyl fumarate also have poor compatibility;
Furthermore, although the decomposition temperature is low, it can be seen that when a fumarate compound into which an adamantyl group is introduced is copolymerized, the decomposition temperature increases and the water absorption resistance also improves.

Table 2 Example 17 (Production of copolymer) Dimethyl adamantyl acrylate (DAA) and dimethyl adamantyl alkyl fumarate were copolymerized. Polymerization was carried out by using a 100W high-pressure mercury lamp and injecting 0.5% by weight of 2.2-jetoxyacetophenone as a photopolymerization initiator into a mold made of two glass plates and a gasket. The polymer was photocured by irradiation with ultraviolet light for 3 minutes to obtain a colorless and transparent polymer.

The physical properties and optical properties of the obtained polymer are shown in Table 3, and the polymer of the present invention has a higher decomposition temperature and excellent water absorption resistance than the polymer of dimethyl adamantyl acrylate. It can be seen that the material has excellent refractive index and hardness.

Table 3 Polymer (A) Homopolymer of dimethyl adamantyl acrylate (B) Copolymer of dimethyl adamantyl acrylate 8170% by weight and dimethyl adamantyl methyl fumarate: 30 wt % (C) Dimethyl adamantyl acrylate 0[ i amount% and dimethyladamantyl isopropyl fumarate = 3
Copolymer with 0% by weight [Effect of the invention] The present invention is constructed as described above, and by introducing an adamantyl group or a lower alkyl-substituted adamantyl group into maleic acid or fumaric acid as an ester component, copolymerization is possible. It has now become possible to provide a new compound with properties. When these are monopolymerized or copolymerized with each other or with other polymers, they are rigid, have a high glass transition point (Tg) and melting point (Tm), are hard, and have excellent strength. It is possible to obtain a highly oriented polymer with excellent transparency and optical properties, and it is useful as a material for lenses such as optical lenses, eyeglass lenses, and high refractive index lenses. It can also be used as an oxygen-enriching film, and it can also be widely used as a variety of other functional materials.

[Brief explanation of drawings]

Figures 1 to 13 and 15 show IR of the compounds obtained in Examples.
Spectrum, Figure 14 is the TGA curve of poly(DAdF), Figure 16 is the TGA curve of poly(DAdF).

Claims (2)

[Claims] (1) A maleate diester or fumarate diester derivative, wherein at least one of the esters in the maleate diester or fumarate diester is an adamantyl ester or a lower alkyl-substituted adamantyl ester. (2) A polymer containing the maleic acid diester or fumaric acid diester described in claim (1) as a monomer unit.