JPH0431408A - Transparent heat-resistant maleimide resin - Google Patents

Abstract

PURPOSE:To obtain a resin excellent in transparency and heat resistance by preparing a resin comprising structural units derived from N-ethylmaleimide and those derived from isobutene in a specified ratio and having a specified wt.-average mol.wt. in terms of PS. CONSTITUTION:A transparent heat-resistant resin comprising 50-98mol% structural units of formula I derived from N-ethylmaleimide and 50-2mol% structural units of formula II derived from isobutene and having a wt.-average mol.wt. in terms of PS of 1X10<3>-5X10<6> is prepd. The resin, excellent in transparency and heat resistance, is widely used for a molded article, sheet, film, etc.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to transparent heat-resistant resins.

The resin according to the present invention has excellent transparency and heat resistance, and can be used in a wide range of fields such as molded products, sheets, and films.

(Prior Art) As a conventional transparent resin, methacrylic resins containing methyl methacrylate as a main component are known and used in a wide range of applications. However, methacrylic resin
Due to its low heat distortion temperature, its applications are limited.

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 is disclosed in Japanese Patent Publication No. 43-9753 and Japanese Patent Application Publication No. 61-1417.
15, JP-A No. 61-171.708, and JP-A No. 62-109811 disclose a method of copolymerizing N-aromatically substituted maleimide with a styrene resin. Publication No. 61-7651
It is known from Japanese Patent Laid-Open No. 61-276807. However, the resins obtained by these methods are N
- The higher the aromatic substituted maleimide content, the better the heat resistance, but there are problems such as brittleness, poor processability, and coloring.

(Problems to be Solved by the Invention) An object of the present invention is to provide a resin with excellent transparency, heat resistance, and mechanical strength.

(Means for Solving the Problems) In view of this problem, the present inventors have made extensive studies and found that a transparent heat-resistant resin containing component (I) and component (II) in the main chain, in particular , component (I) is 50 to 98 mol% of the entire polymer, component (II) is 50 to 2 mol% of the entire polymer, and the weight average molecular weight in terms of polystyrene is 1 x 103 or more and 5 x 106 or less. The inventors have discovered that the characteristic transparent heat-resistant resin satisfies the above objectives, and have completed the present invention.

-HC-CH- H5 -CH2-C-? The compound providing H3 (II) component (1) is N-ethylmaleimide, and its content is 50 to 98 mol%, preferably 50 to 90 mol%, more preferably 50 to 85 mol% of the total polymer. It is mole%.

Furthermore, if the content of component (I) exceeds 98 mol%, the resulting polymer becomes brittle, which is not preferable.

The compound providing component (II) is isobutyne, and its content is from 2 to 50 mol%, preferably from 10 to 50 mol%, more preferably from 15 to 50 mol% of the total polymer.

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, vinyltoluene, 1°3-butadiene, isoprene and their halogen-substituted derivatives, methyl methacrylate, ethyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, and methacrylic acid. Methacrylic esters such as benzyl, acrylic esters such as methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, vinyl esters such as vinyl acetate, vinyl benzoate, Vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, vinyl chloride, vinylidene chloride, maleic anhydride, N-phenylmaleimide, N-carboxyphenylmaleimide, acrylonitrile, ethylene, propylene, 1-butene, 2-butene , and 1
-One or more compounds selected from 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, but solution polymerization is particularly preferred.

Examples of the polymerization initiator include benzoyl peroxide, lauryl peroxide, octanoyl peroxide, acetyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, t-butyl peroxyacetate, Organic peroxides such as t-butyl peroxybenzoate, or 2
,2-azobis-(2,4-dimethylvaleronitrile)
2.2′-Azobis=(2-butyronitrile), 2.2
°-Azobisisobutyronitrile, dimethyl-2,2'
Examples include azo initiators such as -azobisisobutyrate and 1,1'-azobis-(cyclohexane-1-carbonitrile).

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

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.

Here, the weight average molecular weight (M w ) of the resin produced is determined by gel permeation chromatography (GPC).
It can be found by The molecular weight of the resin of the present invention is preferably I x 10 3 or more and 5 x 10 6 or less, particularly I x 1 x 10 3 or more and 5 x 10 5 or less in terms of polystyrene. When the molecular weight exceeds 5 X i 06, moldability deteriorates, and when it is less than I X 103, problems such as the resulting resin being brittle occur.

In addition, the resin obtained in the present invention may contain hindered phenol, a heat stabilizer such as an organic phosphate ester, a benzotriazole ultraviolet absorber, a hindered amine ultraviolet stabilizer, various lubricants, various fillers, etc. as necessary. May be added.

(Effects of the Invention) The resin according to the present invention has excellent transparency and heat resistance, and is useful in a wide range of fields such as molded products, sheets, and films.

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

The glass transition temperature (Tg) of the produced polymer was determined by Co., Ltd.
Using Seiko Electronics DSC200, in nitrogen at 10°C.
The measurement was performed at a temperature increase rate of /min.

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 measured using gel permeation chromatography (GPC) HLC-8 manufactured by Tosoh Corporation.
It was determined by polystyrene conversion using 02A.

Example 1 1g with stirrer, nitrogen inlet tube, thermometer and degassing tube
62.5 g of N-ethylmaleimide in an autoclave (
0.5 mol), 2.2° -Azobisisobutyronitrile (AIBN) 0.8 g (5°0 1 g (1-,0 mol) was charged and the reaction was carried out at 60°C for 10 hours.

The reaction contents were poured into ethanol to precipitate the polymer. The obtained polymer was purified by reprecipitation with toluene-ethanol, and then dried at 60°C under reduced pressure for 24 hours. Yield is 8
It was 0.5g.

Elemental analysis results of the obtained polymer (C; 66°Ow t
%, H: 5.7 wt%, N: 7.8 wt%), the maleimide unit in the produced polymer was 52 mol%. The obtained polymer has a weight average molecular weight of jl (Mw) 0. 2xlO' Tg-125℃, Td
The temperature was -390°C. The obtained polymer was heated at 200°C for 5
A sheet with a thickness of lrnm was obtained by pressing at Kg/cm2. This sheet was colorless and transparent, and no coloration was observed.

Example 2 N-ethylmaleimide 62 was added to the reactor described in Example 1.
．． 5 g (0.5 mol), 0.8 g (5,0XIO-') of 2,2°-azobisisobutyronitrile (AIBN)
mol) and 800 mg of toluene and after purging several times with nitrogen, 28.1 g (0.5 mol) of isobutyne.
was charged and the reaction was carried out at 60°C for 8 hours.

The reaction contents were poured into ethanol to precipitate the polymer. The obtained polymer was purified by reprecipitation with toluene-ethanol, and then dried under reduced pressure at 60"C for 24 hours. The yield was 70.5 g.

Elemental analysis results of the obtained polymer (C, 64°6wt%
, H: 6.1 wt%, N: 8.4 wt%), the maleimide unit in the produced polymer was 60 mol%. The obtained polymer had a weight average molecular weight (Mw) of 32.1X1
0' Tg-14: 3°C, Td-407°C.

The obtained polymer was pressed at 200° C. and 5 kg/cm 2 to obtain a sheet with a thickness of 1 mm. This sheet was colorless and transparent, and no coloration was observed.

Example 3 N-ethylmaleimide 62 was added to the reactor described in Example 1.
．． 5 g (0.5 mol), 0.8 g (5,0XIO-') of 2.2'-azobisisobutyronitrile (AIBN)
After purging with nitrogen several times, 14.0 g (0.25 moles) of isobutyne was charged, and the reaction was carried out at 60° C. for 5 hours.

The reaction contents were poured into ethanol to precipitate the polymer. The obtained polymer was purified by reprecipitation with toluene-ethanol, and then dried at 60°C under reduced pressure for 24 hours. The yield is 4
It was 8.5g.

Elemental analysis results of the obtained polymer (C; 61° 1wt%
, H: 7.2 wt%, N: 9.8 wt%), the maleimide unit in the produced polymer was 80 mol%. The obtained polymer had a weight average molecular weight (Mw) of 22.6810
', Tg-193°C, Td-398°C. The obtained polymer was pressed at 250° C. and 5 kg/cm 2 to obtain a sheet with a thickness of 1 mm. This sheet was colorless and transparent, and no coloration was observed.

[Brief explanation of drawings]

FIG. 1 is an IR spectrum of the polymer obtained in Example 1.

Claims (1)

[Claims] (1) Component (I) is 50 to 98 mol% of the entire polymer, and component (II) is 50 to 2 mol% of the entire polymer
and the weight average molecular weight in terms of polystyrene is 1×10
A transparent heat-resistant resin characterized by having a size of ^3 or more and 5x10^6 or less. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II)