JPS63270712A - Heat-resistant resin composition - Google Patents

Abstract

PURPOSE:To form a heat-resistant resin composition useful for substrates of optical discs which can record, regenerate and erase by light, by blending a specific difunctional monoacryl monomethacrylate, an N-substituted maleimide compound, a polyfunctional (meth)acrylate, and a radical polymerization initiator. CONSTITUTION:The title composition is composed of a difunctional monoacryl monomethacrylate of formula I, an N-substituted maleimide compound of formula II (wherein R is cyclohexyl, lauryl, 2,6-diethylphenyl, o-chlorophenyl or phenyl), a polyfunctional (meth)acrylate for modifying viscosity and a radical polymerization initiator. It is preferred that the amount of the N-substituted maleimide compound of formula II is 40wt.% or less based on the amount of the total resin. At lest one radical polymerization initiator is used, and the amount of the initiator to be blended is 1wt.% or less based on the amount of the total resin.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heat-resistant resin composition mainly used as an optical disk substrate for recording, reproducing, and erasing using light.

2. Description of the Related Art In recent years, optical disks have attracted attention as memory devices for computers, and their practical use has been strongly desired.

Among these methods, the mainstream methods for forming disk substrates include injection molding using thermoplastic resins such as polycarbonate and PMMA, and forming grooves on glass or epoxy substrates using the 2P method. .

Furthermore, regarding the disk structure, conventional substrate materials have insufficient heat resistance, making writing difficult.

The powerful laser beam used during erasing instantly raises the temperature of the recording film to several hundred degrees, and the heat is transferred to the substrate through heat transfer.
Thermal deterioration and softening of the substrate itself, gas generation due to thermal decomposition, etc. occurred, and holes were formed in the recording film. To prevent this, attempts have been made to increase the heat resistance of the substrate by forming a heat insulating layer between the substrate and the recording film, but in this case the disk itself has a very complicated structure.

Problems to be Solved by the Invention However, in the above method, high pressure is applied to the molding resin in the injection acid type, which shortens the life of the stamper that transfers the grooves, and causes problems in the mold. Problems include that the flow of the resin causes molecular orientation, increasing birefringence, and that it is difficult to remove foreign matter mixed into the material.

On the other hand, in the 2P method, a glass substrate or epoxy substrate is certainly used, and the 2P material is injected onto it.

The 2P material body is a reactive liquid material to be cured;
Foreign matter in the material can be removed by cleaning or pupiling immediately before molding, but with glass substrates, the production tact and cost are high, and with epoxy substrates, the curing time of the epoxy resin is long (several hours to several hours). 10 hours) and poor mold releasability.

Furthermore, from the perspective of the disk configuration, thermoplastic resin, 2P,
The heat resistance of the material is insufficient, so it is necessary to form a heat insulating layer on the substrate or 2P, and then form a recording film on it to protect the substrate. This required time, and the disk structure was not suitable for mass production.

Therefore, the present invention aims to solve the above problems,
Consisting of a bifunctional monoacrylic monomethacrylate having an acryloyloxy group on one side and a methacryloyloxy group on the other, an N-substituted maleimide compound, a polyfunctional (meth)acrylate for viscosity adjustment, and one or more radical polymerization initiators. A heat-resistant resin composition is provided.

Means for Solving the Problems In order to solve the above problems, the heat-resistant resin composition of the present invention comprises bis(oxymethyl)tricyclo[6゜2
, 1, 02+6) decane monoacrylic monomethacrylate, an N-substituted maleimide compound represented by the general formula (n), a viscosity-adjusting polyfunctional (meth)acrylate, and one or more radical polymerization initiators. It is something.

Furthermore, the N-substituted maleimide compound represented by general formula (II) has N-cyclohexyl, N-cyclohexyl, N-substituted
The polyfunctional Solubility in (meth)acrylate compounds 9 Preferable in terms of mechanical strength, more preferably 6 to 30 wt of the total resin amount
It is better to be in the % range.

Polyfunctional (meth)acrylate for viscosity adjustment, 2.2
'-bis[4-(β-(meth)acryloyloxy)cyclohexylpropane, 2,2'-bis[4-(β-(
meth)acryloyloxyjetoxy)cyclohexylpropane, 1,4-bis((meth)acryloyloxymethyl)cyclohexane 1, trimethylolpropane tri(meth)acrylate, neopentyl glycol di(
It is preferable to use a single (meth)acrylic acid ester compound such as meth)acrylate, 1,6-hexanethiol di(meth)acrylate, diethylene glycol di(meth)acrylate, or a mixture thereof.

Polymerization methods include thermal polymerization, photopolymerization (ultraviolet (UV))
, polymerization using light, heat, etc. are all possible and are not particularly limited. Further, the polymerization initiator is not particularly limited as long as it is a radical initiator, and examples thereof include benzoyl peroxide, diisopropyl peroxycarbonate-1-, lauroyl peroxide, tert-butyl peroxy bivalate, etc. All known radical initiators such as peroxides, aso compounds such as azobisin butyronitrile, photosensitizers such as benzophenone, benzoin ethyl ether, benzyl, acetophenone, and anthraquinone, and sulfur compounds such as thioxanthone can be used. , may be used alone or in combination of two or more.

The amount of initiator is 1 wt% or less based on the total amount of resin per type, and the total amount of initiator is 0.0% based on the total amount of resin.
Used within the range of 01 to 6 wt%, more preferably 1
It is 0.1-0, swt% per seed. In addition, the polymerization temperature (
(including UV curing) preferably at 0 to 300°C.
Chill at 0-260°C.

The polymerization atmosphere can be carried out in air, in an inert gas, or in a vacuum, but in consideration of thermal decomposition, oxidation, etc. of the cured product, it is preferable to use both in an inert gas and a vacuum.

Function Since the present invention becomes a reactive liquid material with the above-described structure, foreign substances mixed in the material are removed by filtration, and the material is composed of a polyfunctional (meth)acrylate and an N-substituted maleimide compound. Therefore, compared to epoxy resin, the curing time can be significantly shortened (several hours → several seconds to several tens of minutes), and the mold releasability is also improved, making it possible to improve production takt time. There is no need to apply heavy pressure to flow the resin onto the stub bar for groove transfer, and only atmospheric pressure to minute pressure (I Ky/c4 or less) is required. This makes it suitable for workability in clean rooms, and it has also become possible to significantly extend the life of the stand bar. Furthermore, regarding the disk structure, the heat resistance of the disk substrate made of the heat-resistant resin composition of the present invention is significantly higher than that of conventional disk materials, so a heat insulating layer is formed on the substrate to protect the substrate. This eliminated the need for disk structures, resulting in improvements in productivity, cost reduction, and reliability.

Example Examples of the present invention will be described below.

Evaluation methods include thermogravimetry and differential thermal analysis (TG-D
TA), and the glass transition temperature (Tq) and thermogravimetry (T
Evaluation was made based on the temperature at which the weight decreased by 10 inches, 20%, and 60 inches according to G). In addition, as for optical properties, thickness 1
．． A flat plate of 6 gourds was made and evaluated by light transmittance (value at 810 nm) and birefringence (single pass).

This example has structural formula (I) containing bis(oxymethyl)tricyclo(5,2,1,02silo)decane monoacrylic monomethacrylate (hereinafter abbreviated as BTDMA, manufactured by Mitsubishi Yuka) and trimethylolpropane tricyclo(5,2,1,02silo)decane. Acrylate (hereinafter abbreviated as TMPTA, manufactured by Nippon Kayaku ■) was used, and N-cyclohexylmaleimide (CMIL N-laurylmaleimide (LMI), N-2,6-dinitylphenylmaleimide (DEPMI), N A predetermined amount of -o-chlorophenylmaleimide (CFx) and N-phenylmaleimide (PM) (manufactured by Oiri Chemical Industry Co., Ltd.) are blended together, and BPO (manufactured by NOF Corporation) as a radical polymerization initiator and Kosen Iigaaure 184 (manufactured by Ciba Geigy) was used as a sensitizing agent, and 80°C, 5°C was used as a precure.
0 minute or UV integrated light amount 10100O0〆1 (365n
150°C under a nitrogen flow (0.51/m1n) while vacuuming as a post-cure.
After 2 hours and 1 hour at 250'C, a cured product was obtained. still,
As the UV irradiation device, Jet Light (TL-3300) manufactured by Oak Seisakusho Co., Ltd. was used.

To evaluate warpage, fix one side of the flat plate on a fixed plate,
The height of the other end in the longitudinal direction from the fixed plate was measured as the amount of warpage.

○・・・・・・・・・0.2 fl or less △・・・・・・0.2 to 1 ×・・・・・・1111111 or more Judgment is Tg
) 250'C, temperature 360°C when weight loss is 10%
In the above, those with a cutlet amount of 0.2III11 or less were considered to be good products.

Table 1 shows the blending composition, and Table 2 shows the evaluation results of the cured product.

Table 1 Composition table Table 2 Evaluation results of cured product Effects of the invention As described above, the present invention provides bis(
oxymethyl) tricyclo(5,2,1,021']decane monoacrylic monomethacrylate and general formula (II
) By copolymerizing the N-substituted maleimide compound represented by () with a viscosity-adjusting polyfunctional (meth)acrylate using a radical polymerization initiator, heat resistance is significantly improved and birefringence is reduced to 0 to 3 nm. It was found that the disc molding process using Jin's material can be used as a material for optical disk substrates by ensuring a light transmittance of over 91%. It has become possible to create a disk substrate molding system in a small space. Furthermore, by taking advantage of the characteristics of the reactive liquid material and maintaining cleanliness, the amount of foreign matter mixed into the disk substrate can be reduced to less than that of a polycarbonate substrate, and the error rate can be reduced by more than an order of magnitude. In addition, as a result of considering the disk structure to take advantage of its high heat resistance, we were able to eliminate the heat insulating layer between the substrate and recording film that was previously required, resulting in a simpler structure and improved productivity.

It has become possible to create highly reliable and low-cost optical discs.

Claims (3)

[Claims] (1) General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ Bifunctional monoacrylic monomethacrylate,
General formula (II) ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼ R: N-substituted maleimide compound represented by {cyclohexyllauryl 2,6-diethylphenyl o-chlorophenylphenyl} and polyfunctional (meth)acrylate for viscosity adjustment and a radical polymerization initiator. (2) The main structure represented by general formula (I) is bis(oxymethyl)tricyclo[5,2,1,0^2^,^6]
Decane monoacrylic monomethacrylate, and
The heat-resistant resin composition according to claim 1, wherein the N-substituted maleimide compound represented by general formula (II) is 40 wt% or less of the total resin amount. (3) The heat-resistant resin composition according to claim 1, which contains at least one radical polymerization initiator, and the amount of each radical polymerization initiator is 1 wt% or less based on the total resin amount.