JPH04103608A - Optical material - Google Patents

Abstract

PURPOSE:To provide the title material excellent in transparency, heat resistance, surface hardness and mechanical strength, consisting of an N-alicyclic alkyl- substituted maleimide/N-alkyl-substituted maleimide/olefin copolymer resin. CONSTITUTION:The objective material consisting of a resin 1X10<3> to 5X10<6> in weight-average molecular weight on a polystyrene basis where total units of formula I (R1 is CmH2m-1 alicyclic alkyl; (m) is 3-8) and second units of formula II (R2 is H2n+1 alkyl; (n) is 1-18) account for 50-98mol% of the entire polymer and third units of formula III (R3 is H or 1-8C alkyl; R4 and R5 are each 1-8C alkyl) of 50-2mol% of the entire polymer with the ratio, unit I/II=(1:99) to (100:0). The monomers for the units I and III are pref. N-cyclohexyl maleimide and isobutene, respectively; the monomer for the unit II is e.g. N-methyl maleimide.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is directed to an N-alicyclic alkyl-substituted maleimide/N-alkyl-substituted maleimide/olefin copolymer that has excellent transparency, heat resistance, surface hardness, and mechanical properties. This invention relates to optical materials with excellent optical strength.

(Prior Art) Conventionally, glass has generally been used as an optical material, but in recent years, transparent polymer materials have been used from the viewpoint of productivity, weight reduction, cost, etc.

In particular, polymethyl methacrylate (
(hereinafter abbreviated as PMMA) and polycarbonate (hereinafter abbreviated as PC) are used.

However, although PMMA has excellent optical properties, its glass transition temperature (Tg) is around 100° C., so its heat resistance is insufficient and its use is limited.

Although PC exhibits relatively high heat resistance with a Tg of around 150° C., it has problems such as low surface hardness and easy scratching, and further improvements in heat resistance are also required.

Since maleimide copolymers have high heat resistance, various studies have been made on them.

For example, a method of copolymerizing N-aromatically substituted maleimide with the above-mentioned methyl methacrylate,
71708 and JP 62-109811 disclose a method of copolymerizing a styrene resin with an N-aromatic substituted maleimide. Kaisho 61-27680
It is disclosed in Publication No. 7.

However, although the resins obtained by these methods have better heat resistance as the N-aromatically substituted maleimide content increases, they have problems such as brittleness, poor processability, and coloring, which limit their use as optical materials. I received it.

(Problems to be Solved by the Invention) An object of the present invention is to provide an optical material excellent in transparency, heat resistance, surface hardness, and mechanical strength.

(Means for solving the problem) As a result of intensive study in view of this problem, the inventors found that N-
The present inventors have discovered that an optical material comprising an alicyclic alkyl-substituted maleimide/N-alkyl-substituted maleimide/olefin copolymer achieves the above object, and has come to constitute the present invention.

That is, the present invention comprises the following constituent component (1) + (■
) or 50 to 98 mol% of the total polymer, component (II
I) is 50 to 2 mol% of the total, and the constituent component (I) is 50 to 2 mol% of the total.
)/(II) ratio is 1/99 to 10010,
Furthermore, the weight average molecular weight in terms of polystyrene is 1 x 103
The present invention relates to an optical material having excellent transparency, heat resistance, surface hardness, and mechanical strength, characterized by being made of a resin having a size of 5×10 6 or less.

(Here, R4 is an alicyclic alkyl group represented by C@H2Tl-1, and m is an integer of 3 to 8) (Here,
R2 is C1H2o. 1 is an alkyl group represented by n
represents an integer of 1 to 18) (wherein, R3 is hydrogen or an alkyl group having 1 to 8 carbon atoms, and R4 and R6 are hydrogen or an alkyl group having 1 to 8 carbon atoms.
-8 alkyl group) The above resin can be obtained, for example, by a radical copolymerization reaction of an N-alicyclic alkyl-substituted maleimide, an N-alkyl-substituted maleimide, and an olefin.

Examples of the N-alicyclic alkyl-substituted maleimide providing component (1) include N-cyclopropylmaleimide,
Examples include N-cyclobutylmaleimide, N-cyclobentylmaleimide, N-cyclohexylmaleimide, N-cyclooctylmaleimide, etc., and these can be used alone or in combination of two or more, but in particular N-
Cyclohexylmaleimide is preferred.

Examples of the N-alkyl-substituted maleimide providing the component (n) include N-methylmaleimide, N-ethylmaleimide, Nn-propylmaleimide, N-1-propylmaleimide, N-n-butylmaleimide, N-1
-Butylmaleimide, N-5-butylmaleimide, N-
t-butylmaleimide, N-n-pentylmaleimide,
Examples include N-n-hexylmaleimide, N-n-heptylmaleimide, N-n-octylmaleimide, N-laurylmaleimide, N-stearylmaleimide, and these may be used alone or in combination of two or more. can.

Examples of the olefins providing the component (m) include isobutyne, 2-methyl-1-butene, 2-methyl-1
-Pentene, 2-methyl-1-hexene, 1-methyl-
1-heptene, 1-isooctene, 2-methyl-1-octene, 2-ethyl-1-butene, 2-ethyl-1-
Pentene, 2-ethyl-1-hexene, 2-methyl-2
-butene, 2-methyl-2-pentene, 2-methyl-2
-hexene, etc., and these can be used alone or in combination of two or more, but isobutyne is particularly preferred.

Here, the content of structural units (I) + (II) is 50 to 98 mol%, preferably 50 to 90 mol% of the entire polymer.
, particularly preferably 50 to 80 mol%. 98 mol%
If it exceeds this, the resulting polymer tends to become brittle, which is undesirable.

In addition, the ratio of component (I)/(IT) is 1/99 ~
100'/0, preferably 10/90 to 90/10.

Further, if necessary, other vinyl monomers can be copolymerized within a range that does not impair the purpose of the present invention. Other vinyl monomers include styrene, α-methylstyrene, and vinyltoluene.

1.3-Butadiene, isoprene and their halogen-substituted derivatives, methyl methacrylate, ethyl methacrylate, propyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate.

Methacrylic esters such as benzyl methacrylate, acrylic esters such as methyl acrylate, ethyl acrylate, butyl acrylate, lauryl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, vinyl acetate, vinyl benzoate Vinyl esters such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, vinyl chloride, vinylidene chloride, maleic anhydride, N-phenylmaleimide, N-carboxylphenylmaleimide, acrylonitrile, ethylene,
Examples include compounds selected from propylene, 1-butene, and 1-hexene.

For polymerization of these monomers, any of known polymerization methods such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization can be employed.

Examples of the polymerization initiator include benzoyl peroxide, lauryl peroxide, octanoyl peroxide, acetyl peroxide, di-1-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, t-butyl peroxyacetate, and t-butyl peroxide. - organic peroxides such as butyl peroxybenzoate, 2.2'
-azobis(2,4-dimethylvaleronitrile), 2,
2°-azobis(2-butyronitrile), 2,2° −
Azo initiators such as azobisisobutyronitrile, dimethyl-2,2'-azobisisobutyrate, and 1,1'-azobis(cyclohexane-1-carbonitrile) can be used.

Solvents that can be used in the solution polymerization method include benzene, toluene, xylene, ethylbenzene, cyclohexane, dioxane, tetrahydrofuran, acetone, methyl ethyl ketone, ethyl acetate, dimethylformamide,
Examples include isopropyl alcohol and butyl alcohol.

The polymerization temperature can be appropriately set depending on the decomposition temperature of the initiator, but it is preferably carried out within the range of 40°C to 150°C for boat fishing.

The weight average molecular weight (M w ) of the produced resin can be determined by gel permeation chromatography (GPC). The molecular weight of the resin of the present invention is 1×103
More than 5x106, especially more than 1x104 and less than 5x105
The following are preferred. If the molecular weight exceeds 5 x 10', moldability will be poor, and if it is less than 1 x 103, problems such as brittleness of the resulting resin will occur.

Furthermore, if necessary, hindered phenol, a heat stabilizer such as an organic phosphate ester, a benzotriazole ultraviolet absorber, a hindered amine ultraviolet stabilizer, and various lubricants may be added to the resin obtained in the present invention. Good too.

Furthermore, it is also possible to mix and use other resins that are compatible with this.

Examples of methods for molding the resin of the present invention include common molding methods such as injection molding, extrusion molding, and compression molding.

The obtained molded product can be used in the fields of optical recording materials such as optical disks, optical lenses for cameras and videos, optical fibers, etc. (Example) The present invention will be explained below with reference to Examples. The present invention is not limited to the following examples.

The Tg of the produced polymer is DS manufactured by Seiko Electronics Co., Ltd.
Measurement was performed using C200 in nitrogen at a temperature increase rate of 10° C./ml.

The decomposition temperature (Td) of the produced polymer was determined at 40°C in nitrogen using TG/DTA200 manufactured by Seiko Electronics Co., Ltd.
The measurement was performed at a temperature increase rate of /min.

The molecular weight of the produced polymer was determined in terms of polystyrene using GPC (HLC-802A manufactured by Tosoh Corporation).

Light transmittance (ASTM 1746; 820 nm), bending strength (ASTM D790) and surface hardness (JIS
K5401) was evaluated using a 5CIX25XO, 8mm press piece.

Example 1 1g with stirrer, nitrogen inlet tube, thermometer and degassing tube
35. N-cyclohexylmaleimide in autoclave.
84g (0.20 mol), N-methylmaleimide 22
．． 20 g (Q, 2 Q moles), 0.40 g of 2.2'-azobisisobutyronitrile (AIBN) (
2,5 x 10-3 mol) and dioxane 800 ml)
After purging with nitrogen several times, 56.
10g (1.0 mol) was charged and the reaction was carried out at 60°C for 24 hours.

The reaction contents were poured into ethanol to precipitate the polymer. The obtained polymer was purified by reprecipitation with dioxane-ethanol, and then dried at 60°C under reduced pressure for 24 hours. The yield was 78.70g.

From the elemental analysis results and IH-NMR measurement results of the obtained polymer, N-methylmaleimide, N-
The ratio of cyclohexylmaleimide and isobutyne is 26
/26/48 mol%. Mw of the obtained polymer
was 159,000, Tg was 173°C, and Td was 404°C. A test piece was prepared by pressing the obtained polymer at 250° C. and 5 kg/cm 2 . The evaluation results are shown in Table 1.

Example 2 35.84 g of N-cyclohexylmaleimide (0,20
mole), N-methylmaleimide 22°20g (0,2
0 mol) instead of N-cyclohexylmaleimide 71
．． An N-cyclohexylmaleimide/isobutyne copolymer was synthesized according to Example 1 except that 68 g (0.40 mol) was used.

From the elemental analysis results of the obtained polymer, it was found that N in the polymer
-Cyclohexylmaleimide units were 52 mol%. The Mw of the obtained polymer was 170,000, and the Tg was 19.
0°C, Td was 411°C. The obtained polymer is 2
A test piece was prepared by pressing at 60"C and 5Kg/cm2. The evaluation results are shown in Table 1.

Comparative Examples 1 to 3 Test pieces of PMMA (manufactured by Mitsubishi Rayon), PC (manufactured by Teijin Kasei) and polystyrene (electrochemical type) were also prepared and evaluated in the same manner as in the examples. Table 1 shows the evaluation results.

(Effects of the Invention) The resin according to the present invention is useful as an optical material because it has excellent transparency, heat resistance, surface hardness, and mechanical strength.

Claims (1)

[Scope of Claims] Constituent components (I) + (II) shown below account for 50 to 98 mol% of the entire polymer, constituent component (III) accounts for 50 to 2 mol% of the entire polymer, and the structural units (I )/(II)
The ratio is 1/99 to 100/0, and the weight average molecular weight in terms of polystyrene is 1 x 10^3 or more 5 x 10
An optical material characterized by being made of a resin having a molecular weight of ^6 or less. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (Here, R_1 is an alicyclic alkyl group represented by C_m and H_2_m_-_1, and m is an integer from 3 to 8) ▲Mathematical formulas, chemical formulas , tables, etc. ▼ (II) (Here, R_2 is an alkyl group represented by C_nH_2_n_+_1, and n represents an integer from 1 to 18) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (III) (Here, , R_3 represents hydrogen or an alkyl group having 1 to 8 carbon atoms, R_4 and R_5 represent an alkyl group having 1 to 8 carbon atoms)