JPH0431407A - Transparent heat-resistant 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-methylmaleimide 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-methylmaleimide 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) Methacrylic resins containing methyl methacrylate as a main component have been known as transparent resins and are 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 Laid-open No. 61-1417.
15, JP-A No. 61-171.708, and JP-A No. 62109811, a method of copolymerizing N aromatic substituted maleimide with a styrene resin is disclosed in JP-A No. 47-6891, This method is known from Jikaima No. 61-76512 and Jikaima No. 61-276807. 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.

(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 (1) is 50 to 98 mol% of the entire polymer, component (n) 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 present inventors have discovered that a characteristic transparent heat-resistant resin satisfies the above objectives, and have completed the present invention.

-HC-CH- CH3 -CH2-C- CH.

(II) The compound providing component (I) is N-methylmaleimide, and as the N-alkyl substituent becomes a long chain, the heat resistance tends to decrease.

The content of component (1) is 50 to 98% of the total polymer.
It is mol%, preferably 50 to 90 mol%, more preferably 50 to 85 mol%. Furthermore, if the content of component (I) exceeds 98 mol%, the resulting polymer becomes brittle, which is not preferable.

The compound providing component (n) is isobutyne;
Its content is 2.-50 mol% of the total polymer, preferably 10 to 50 mol%, more preferably 15 to 50 mol%.

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, Methacrylic esters such as benzyl methacrylate, acrylic esters such as methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, vinyl esters such as vinyl acetate, vinyl benzoate, etc. 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), 22
'-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 I x 103 or more and 5 x 106 or less in terms of polystyrene,
In particular, I x 10' or more and 5 x 105 or less are preferred. When the molecular weight exceeds 5X106, moldability becomes poor, and when it is less than 1XIO3, 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 line stabilizer, various lubricants, and various fillers as necessary. etc. 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 manufactured by Tosoh Corporation.
-802A in terms of polystyrene.

Example 1 1g with stirrer, nitrogen inlet tube, thermometer and degassing tube
55.6 g of N-methylmaleimide in an autoclave (
0.5 mol), 2.2'-azobisisobutyronitrile (AIBN) 0.8 g (5°0XIO-3 mol)
After charging 800 m of dioxane and Q, and purging with nitrogen several times, 56.1 g (1.0 mol) of isobutyne 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 dioxane-ethanol, and then dried at 60°C under reduced pressure for 24 hours. Yield was 80.5g.

Elemental analysis results of the obtained polymer (C; 64°7wt
%, H: 7.8 wt%, N: 8.4 wt%), the maleimide unit in the produced polymer was 50 mol%. The obtained polymer has a weight average molecular fjk (Mw) of 1.6
．． 3X10' Tg-132°C, Td-397°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 2 N-methylmaleimide 55 was added to the reactor described in Example 1.
．． 6 g (0.5 mol), 0.8 g (5,0XIO-3) of 2,2°-azobisisobutyronitrile (AIBN)
mol) and 800 rydl of dioxane and after purging several times with nitrogen, 28. 1g (0,
5 mol) 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 dioxane-ethanol, and then dried at 60°C under reduced pressure for 24 hours. Yield was 70.5g.

Elemental analysis results of the obtained polymer (C; 62°3 w
t%, H; 7.2wt%, N
, 9, coWt9f1), the maleimide unit in the produced polymer was 58 mol%. The obtained polymer has a weight average molecular weight jl (Mw)1
2.2×10′ Tg-161°C, Td-401°C. The obtained polymer was heated at 200°C and 5Kg/cm2.
A sheet with a thickness of 1 mm was obtained by pressing with a press. This sheet C was colorless and transparent, and no coloring was observed.

Example 3 N-methylmaleimide 55 was added to the reactor described in Example 1.
．． 6 g (0.5 mol), 0.8 g (5,0XIO-3) of 2,2°-azobisisobutyronitrile (AIBN)
mol) and 800 mD of dioxane, and after flushing with nitrogen several times, 14.0 g of isobutyne (0.25 mD) was charged.
mol) 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 dioxane-ethanol, and then dried at 60°C under reduced pressure for 24 hours. Yield was 48.5g.

Elemental analysis results of the obtained polymer (C; 60°7 w
t%, H, 6.5wt%, N; 10.0wt%),
The maleimide unit in the produced polymer was 69 mol%.The resulting polymer had a weight average molecular weight (Mw) of 15
．． 4X10' Tg=190°C, Td-407°C. The obtained pot was heated at 230℃ and 5Kg/cm2.
A sheet with a thickness of 1 mm was obtained by pressing with a press. This sheet was colorless and transparent, and no coloration was observed.

Example 4 N-methylmaleimide 55 was added to the reactor described in Example 1.
．． 6 g (0.5 mol), 0.8 g (5,0XIO-3) of 2.2°-azobisisobutyronitrile (AIBN)
mol) and 800 mII of dioxane were charged, and after purging with nitrogen several times, 5.6 g (0.10 mol) of isobutyne was charged, and the reaction was carried out at 60°C for 3 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. Yield was 20.5g.

Elemental analysis results of the obtained polymer (C; 58°3 w
t%, H: 5.8 wt%, N: 10.9 wt%), the maleimide unit in the produced polymer was 80 mol%. The obtained polymer has a weight average molecular ffi (Mw)
Co-2,4X10' Tg-226℃, Td-411
It was ℃. The obtained polymer was heated at 280°C, 5Kg/c
A sheet with a thickness of 1 mm was obtained by pressing with m2. 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)