JP2003292545A - Polymerizable composition and cured material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cured material suitable as an optical plastic part having light weight, excellent transparency, high heat-resistance, low linear expansion coefficient, high mechanical strength, low water-absorption and low birefringence and provide a polymerizable composition to give the cured material. <P>SOLUTION: The polymerizable composition contains (A) at least one kind of bifunctional methacrylate selected from aliphatic bifunctional methacrylates of general formula [I] and (B) at least one kind of polyfunctional methacrylate selected from aliphatic polyfunctional methacrylates expressed by general formula [II]. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to optical members used in the fields of displays, optical communication, recording and energy, among them, display substrates such as LCDs, organic ELs, PDPs, touch panels, color filters, backlights and fronts. The present invention relates to a cured product suitable for a light guide plate such as a light and an optical substrate such as an optical disk substrate, an optical card substrate, and a solar cell substrate, and a curable composition as a raw material thereof.

[0002]

2. Description of the Related Art Conventionally, glass substrates have been used as display substrates for organic EL displays, liquid crystal displays, etc., but in recent years, plastic substrates have been used from the viewpoints of lightness, thinness, and resistance to cracking. The old display (plastic display) is drawing attention. Also, plastic displays are promising as next-generation displays such as flexible and electronic paper. These plastic displays include
A thin plastic substrate is needed. Already, plastic substrates are used in some mobile phone displays. However, due to the following points, a display having high definition and high reliability has not been obtained.

The heat resistance of plastic is less than 250.degree. The coefficient of linear expansion of plastic is one order higher than that of glass. The flexural modulus of plastic is smaller than that of glass by one order or more.

These problems cause problems when manufacturing a display using a plastic substrate regardless of the type of the display. The manufacturing of a liquid crystal display will be described below as an example.

Usually, ITO is crystallized in a temperature range of 200 ° C. or higher and its resistance value is lowered. Therefore, even a plastic substrate has a glass transition temperature of 250 ° C. or higher, preferably 300 ° C.
The above heat resistance is required. If the heat resistance of the plastic substrate is low, sufficient heating cannot be performed when forming the transparent electrode on the substrate, and therefore the resistance value of the transparent electrode such as ITO cannot be lowered. If the resistance of the transparent electrode does not decrease,
It is not possible to form an electric circuit having a conductivity required for display or a large-sized display. Further, the plastic substrate is required to have a heat resistance of 250 ° C. or higher in order to endure a heating process in cell assembly such as firing of a polyimide alignment film and curing of a sealant.

A material having a large linear expansion coefficient greatly expands and contracts due to a temperature change. Ordinary plastics are mainly composed of carbon-carbon bonds and have a linear expansion coefficient of 70.
ppm (7 × 10 ⁻⁵ / ° C.), and for a 300 mm long substrate, if the temperature rises by 1 ° C., the length of the substrate becomes 21 μm.
m becomes longer. The positional accuracy in the substrate plane in the liquid crystal cell assembly process is about 15 μm for the color STN LCD and TF.
In the T-type LCD, a numerical value of several μm is required regardless of whether it is monochrome or color. In particular, the patterning of electrodes by photolithography is a process that requires the most positional accuracy, but it is extremely difficult to keep the substrate temperature constant because this exposure process involves heat generation, and therefore the temperature of all process steps for liquid crystal cell assembly is very high. Is difficult to control within a range of ± 1 ° C. As described above, when the size of the plastic substrate is 300 mm square or more, the ordinary plastic having a linear expansion coefficient of 70 ppm cannot ensure the required positional accuracy, and thus a high-definition color image cannot be provided. In order to satisfy the required performance of the positional accuracy, the coefficient of linear expansion needs to be 60 ppm or less in the case of a substrate of 300 mm square. recently,
Considering productivity, substrate size is 500mm square, 1000mm
Since the area is square mm and the area is gradually increasing, it is more and more difficult to use the conventional plastic substrate.

Further, the expansion and contraction of the plastic resulting from this linear expansion is due to the exposure process for forming the color filter,
The quality is deteriorated in all processes that require high positional accuracy, such as the cell bonding process.

Even if the heat resistance of the plastic substrate is improved and it becomes possible to form an ITO film at 200 ° C. or higher, if the plastic substrate has a large linear expansion coefficient, the substrate will largely warp after the film formation. . Specifically, when heated to a high temperature, the plastic substrate expands considerably according to its linear expansion coefficient. When an inorganic material such as ITO is deposited in this stretched state and returns to room temperature, the plastic shrinks greatly, while the inorganic material having a low linear expansion shrinks only slightly. As a result, the formed plastic substrate is largely warped in a convex shape with the ITO side as the upper surface. It is difficult to assemble a display with a large warped substrate. Further, the stress strain generated at this time causes cracks in the inorganic film, which is a cause of lowering the reliability of the display.

Further, when the flexural modulus is small, the warpage after the film formation by heating is more remarkable. To reduce warpage,
Plastics with higher flexural modulus are needed. However, even if the flexural modulus is increased to the same level as glass,
If the difficulty of cracking, which is the characteristic of plastic, is impaired,
Since the advantage of using a plastic substrate is lost, there is a demand for a material having a good balance of flexural modulus and flexural strength.

JP-A-9-152510 discloses a resin obtained by polymerizing and curing a composition comprising a bis (meth) acrylate compound having a tricyclo [5.2.1.0 ^2,6 ] decane skeleton and a mercapto compound. However, the linear expansion coefficient in the temperature range of 25 ° C. to 250 ° C. exceeds 70 ppm, and there is a problem that the linear expansion coefficient is large.

Further, JP-A-10-255555 discloses that a composition comprising a (thio) carbamic acid ester or a mixture of a (thio) carbamic acid ester and a (meth) acrylic acid ester or a styrene derivative is polymerized and cured. Although a plastic member made of the above resin has been proposed, the bending elastic modulus is 4000 MPa, which is sufficient, but there is a problem that the linear expansion coefficient is large.

Further, as a plastic having a reduced linear expansion coefficient, a highly cross-linked resin such as a polyimide resin, a resin mixed with a nano-sized inorganic filler, a resin such as a silicone resin having a bond other than a carbon-carbon bond, and the like have been proposed. However, there are problems such as not being colorless, lacking transparency, and having a large specific gravity.

[0013]

SUMMARY OF THE INVENTION The present invention has solved the above-mentioned problems and has a high heat resistance, a low linear expansion coefficient, and a high bending elastic modulus.
The purpose of the present invention is to provide an optical plastic member having high bending strength and a raw material thereof.

[0014]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a compound having an aliphatic skeleton and two (meth) acrylate groups and an aliphatic skeleton are used. By using a polymerizable composition containing a compound having 3 or more (meth) acrylates, a cured product having high heat resistance, low linear expansion coefficient, high bending elastic modulus, and high bending strength is obtained. The present invention was found to be achieved.

That is, the gist of the present invention resides in a polymerizable composition containing the following components (A) and (B). Component (A): At least one bifunctional methacrylate selected from the aliphatic bifunctional methacrylates represented by the general formula [I].

[0016]

[Chemical 3]

(In the formula, A represents an aliphatic hydrocarbon residue having 1 to 8 carbon atoms which may have ether oxygen and / or hydroxyl group.)

Component (B): At least one polyfunctional methacrylate selected from the aliphatic polyfunctional methacrylates represented by the general formula [II].

[0019]

[Chemical 4]

(In the formula, D represents an aliphatic hydrocarbon residue having 1 to 8 carbon atoms which may have an ether oxygen and / or a hydroxyl group, and n represents an integer of 3 to 8.)

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Component (A): At least one bifunctional methacrylate selected from the aliphatic bifunctional methacrylates represented by the general formula [I].

[0022]

[Chemical 5]

In the formula, A is a C 1-8 optionally having an ether oxygen and / or a hydroxyl group, preferably C 2
~ 6 aliphatic hydrocarbon residues are shown. If the carbon number is too large, heat resistance and flexural modulus decrease. It preferably represents an aliphatic hydrocarbon residue which may have ether oxygen, particularly preferably an aliphatic hydrocarbon residue. Examples of the aliphatic hydrocarbon include a saturated hydrocarbon residue such as an alkyl residue and an unsaturated hydrocarbon residue such as an olefin residue, a diene residue and an acetylene residue, but an alkyl residue is preferable. The aliphatic hydrocarbon may be cyclic or chain.

Ether oxygen means a --C--O--C-- bond, and the hydrocarbon residue represented by A usually has a --C--O--C-- bond of 4 or less, preferably 2 or less. May be. The hydrocarbon residue represented by A may have a hydroxyl group of usually 4 or less, preferably 2 or less. Particularly preferred is an aliphatic hydrocarbon group having no ether oxygen or hydroxyl group. In addition, the carbon number of the hydrocarbon residue represented by A shows the total carbon number of the hydrocarbon residue represented by A.

Specific examples of the aliphatic bifunctional methacrylate compound represented by the general formula [I] include ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate and 1,3-butanediol. Dimethacrylate, 1,6-hexanediol dimethacrylate, 2-hydroxy-1,3-dimethacryloyloxypropane and the like can be mentioned, preferably,
Neopentyl glycol dimethacrylate is used. These may be used alone or in combination of two or more.

Component (B): At least one polyfunctional methacrylate selected from the aliphatic polyfunctional methacrylates represented by the general formula [II].

[0027]

[Chemical 6]

In the formula, D is a carbon number of 1 to 8 which may have an ether oxygen and / or a hydroxyl group, preferably 2 carbon atoms.
~ 6 aliphatic hydrocarbon residues are shown. If the carbon number is too large, heat resistance and flexural modulus decrease. It preferably represents an aliphatic hydrocarbon residue which may have ether oxygen, particularly preferably an aliphatic hydrocarbon residue. Examples of the aliphatic hydrocarbon include a saturated hydrocarbon residue such as an alkyl residue and an unsaturated hydrocarbon residue such as an olefin residue, a diene residue and an acetylene residue, but an alkyl residue is preferable. The aliphatic hydrocarbon may be cyclic or chain.

Ether oxygen means a --C--O--C-- bond, and the hydrocarbon residue represented by D has --C--O--C-- bond, usually 4 or less, preferably 2 or less. May be. The hydrocarbon residue represented by D may have a hydroxyl group of usually 4 or less, preferably 2 or less. Particularly preferred is an aliphatic hydrocarbon group having no ether oxygen or hydroxyl group.

The carbon number of the hydrocarbon residue represented by D means the total number of carbon atoms of the hydrocarbon residue represented by D. n
Is 3-8, preferably 3-6, particularly preferably 3-4,
It is more preferably 3.

Specific examples of the aliphatic polyfunctional methacrylate compound represented by the general formula [II] include trimethylolpropane = trimethacrylate and pentaerythritol =
Examples thereof include trimethacrylate and pentaerythritol = tetramethacrylate, and trimethylolpropane = trimethacrylate is preferably used. These may be used alone or in combination of two or more.

The inventors of the present invention have found that a cured product obtained by using only the component (A) has a high linear expansion coefficient and causes film cracking or large warpage when an inorganic film is laminated. Since only B) forms a highly crosslinked structure, curing shrinkage during molding is large, and it is difficult to obtain a plate-shaped cured product having a practical size. Even if a cured product is obtained, it is confirmed that the highly cross-linked structure lowers the bending strength, so there is a high risk of cracking during the work, and these components (A) and (B) should be used in combination. According to the above, it has been found that it is possible to balance the performance of the obtained cured product with high heat resistance, low linear expansion coefficient, high bending elastic modulus, and high bending strength. In particular, it has been found that by using the component (A) and the component (B) together, higher flexural modulus and flexural strength than the individual cured products can be exhibited.

Further, in the present invention, since an aliphatic hydrocarbon group is selected as A in the general formula [I] and D in the general formula [II], the molecular orientation derived from the aromatic ring generated at the time of molding is determined. Since it can be excluded, a cured product having a small birefringence, that is, a small optical distortion can be provided. The polymerizable composition of the present invention comprises a component (A) which is at least one kind of bifunctional methacrylate selected from the aliphatic bifunctional methacrylates represented by the general formula [I], and a fat represented by the general formula [II]. To 100 parts by weight in total of the component (B) which is at least one polyfunctional methacrylate selected from the group polyfunctional methacrylates,
The amount of the component (A) is usually 10 parts by weight or more, preferably 15 parts by weight or more, particularly preferably 20 parts by weight or more, and usually 9 parts by weight or more.
0 parts by weight or less, preferably 85 parts by weight or less, particularly preferably 80 parts by weight or less, and the component (B) is usually 1 part by weight.
It is 0 part by weight or more, preferably 15 parts by weight or more, particularly preferably 20 parts by weight or more, and usually 90 parts by weight or less, preferably 85 parts by weight or less, particularly preferably 80 parts by weight or less. If the amount of the component (A) is too large, the heat resistance is not sufficient and the linear expansion coefficient is large, and if it is too small, the bending strength decreases. Further, if the amount of the component (B) is too large, the flexural strength will decrease, and if it is too small, the effect of reducing the linear expansion coefficient will not be sufficient.

The method for producing the compounds represented by the general formulas [I] and [II] is not particularly limited, and may be, for example, Maruzen, Shin Jikken Kagaku Koza, 14 from the starting polyol. , Synthesis and Reactions of Organic Compounds (II) p.
It can be carried out according to the general ester production method described in 1002-1008, p.1017-1021, etc. For example, in the esterification reaction of a polyol and methacrylic acid, usually 1.0 to 1.3 equivalents of methacrylic acid are used with respect to 1 equivalent of the polyol, and as a catalyst, for example, sulfuric acid, hydrochloric acid, phosphoric acid,
Boron fluoride, P-toluenesulfonic acid, benzenesulfonic acid, cation-type ion exchange resin, etc. are used, usually in the presence of a solvent such as toluene, benzene, heptane or hexane.
It can be carried out while distilling off water produced by the reaction.

In the transesterification reaction between the polyol and the methacrylic acid ester, methyl methacrylate is generally used in an amount of usually 1.0 to 5.0 equivalents per equivalent of the polyol, and the catalyst is, for example, sulfuric acid or P-. Toluenesulfonic acid, tetrabutyl titanate, tetraisopropyl titanate, potassium butoxide, etc.
It can be carried out in the presence of a solvent such as benzene, heptane or hexane while distilling off the methanol produced by the reaction. In this reaction, as a polymerization inhibitor, for example, hydroquinone, hydroquinone monomethyl ether, phenothiazine, copper salt or the like can be used.

The polymerizable composition of the present invention preferably contains a mercapto compound [component (C)]. The mercapto compound acts as a chain transfer agent having a thiol group, and by blending the component (C), when a methacrylate compound composed of a mixed composition of the component (A) and the component (B) is polymerized and cured, A cured product with little optical distortion can be obtained. The component (C) is preferably a polyfunctional mercapto compound having two or more thiol groups in the molecule, particularly preferably the general formulas [III], [IV] and [V].
A compound selected from is used. These mercapto compounds can improve mechanical strength such as bending strength without significantly impairing the heat resistance of the obtained cured product.

[0037]

[Chemical 7]

[R ¹ represents —CH ₂ — or —CH ₂ CH ₂ —, and R ² has 2 carbon atoms which may contain ether oxygen.
Represents a hydrocarbon residue of -15, and a represents an integer of 2-6. ]

The mercapto compound represented by the general formula [III] is a divalent to hexavalent thioglycolic acid ester or thiopropionic acid ester. Specific examples of the compound represented by the general formula [III] include pentaerythritol tetrakis (β-thiopropionate), pentaerythritol tetrakis (β-thioglycolate), trimethylolpropane tris (β-thiopropionate). ),
Trimethylolpropane tris (β-thioglycolate), diethylene glycol bis (β-thiopropionate), diethylene glycol bis (β-thioglycolate, dipentaerythritol hexakis (β-thiopropionate), dipentaerythritol hexa Kiss (β-thioglycolate) and the like, and preferably,
Pentaerythritol tetrakis (β-thiopropionate) and pentaerythritol tetrakis (β-thioglycolate) are used.

[0040]

[Chemical 8]

[X is HS- (CH ₂ ) _b- (CO)-(O
_{CH 2 CH 2) d - (} CH 2) c - indicates, b and c are each independently an integer of 1 to 8, d is an integer of 0 to 2. ]

The mercapto compound represented by the general formula [I] is a ω-SH group-containing triisocyanurate. Specific examples of the compound represented by the general formula [I] include, for example,
Tris [2- (β-thiopropionyloxy) ethyl] triisocyanurate, Tris [2- (β-thioglyconyloxy) ethyl] triisocyanurate, Tris [2-
(Β-thiopropionyloxyethoxy) ethyl] triisocyanurate, tris [2- (β-thioglyconyloxyethoxy) ethyl] triisocyanurate, tris [2- (β-thiopropionyloxy) propyl] triisocyanurate, Examples thereof include tris [2- (β-thioglyconyloxy) propyl] triisocyanurate, and preferably tris [2- (β-thiopropionyloxy) ethyl] triisocyanurate.

[0043]

[Chemical 9]

[R ³ and R ⁴ each independently have 1 to 3 carbon atoms.
Is an alkylene group, and e and f are each independently 0.
Or an integer of 1, and g is an integer of 1 or 2. ]

The mercapto compound represented by the general formula [I] is an α, ω-SH group-containing compound. Specific examples of the compound of the general formula [I] include benzene dimercaptan, xylylene dimercaptan, 4,4′-dimercapto diphenyl sulfide and the like.

The blending ratio when the component (C) is used is
The total of the components (A), (B) and (C) is 10
When the amount is 0 parts by weight, the total amount of the component (A) and the component (B) is usually 70 parts by weight or more, preferably 80 parts by weight or more, particularly preferably 85 parts by weight or more, usually 9
It is 9.9 parts by weight or less, preferably 99 parts by weight or less, particularly preferably 95 parts by weight or less. The component (C) is usually 0.1 part by weight or more, preferably 1 part by weight or more, particularly preferably 5 parts by weight or more, usually 30 parts by weight or less, preferably 20 parts by weight, particularly preferably 15 parts by weight or less. Is the range. If the proportion of the mercapto compound as the component (C) is too large, the heat resistance of the cured resin may decrease.

The polymerizable composition of the present invention may contain auxiliary components other than the component (A), the component (B) and the component (C) within a range not impairing the gist of the present invention. Examples of the auxiliary component include a radical-polymerizable component (A), a monomer other than the component (B), a radical polymerization initiator, an antioxidant, an ultraviolet absorber, an ultraviolet stabilizer, a dye and pigment, and a filler. .

Monomers other than the radically polymerizable component (A) include, for example, methyl methacrylate, 2-hydroxyethyl methacrylate, phenyl methacrylate,
Benzyl methacrylate, 2,2-bis [4- (β-methacryloyloxyethoxy) phenyl] propane,
Methacrylate compounds such as 2,2-bis [4- (β-methacryloyloxyethoxy) cyclohexyl] propane and 1,4-bis (methacryloyloxymethyl) cyclohexane, styrenes such as styrene, chlorostyrene, divinylbenzene and α-methylstyrene. Examples include similar compounds.

These radical-polymerizable monomers are usually added in a proportion of 30 parts by weight or less based on 100 parts by weight of the total of the components (A) and (B). Examples of the radical polymerization initiator include a thermal polymerization initiator and a photopolymerization initiator. Specific examples of the thermal polymerization initiator include benzoyl peroxide, diisopropyl peroxycarbonate, t-
Butyl peroxy (2-ethyl hexanoate) etc. are mentioned.

Specific examples of the photopolymerization initiator include benzophenone, benzoin methyl ether, benzoin propyl ether, diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2,6-dimethylbenzoyldiphenylphosphine oxide, 2,4,6-.
Trimethylbenzoyldiphenylphosphine oxide and the like can be mentioned. Preferred are 2,4,6-trimethylbenzoyldiphenylphosphine oxide and benzophenone.

Even if these polymerization initiators are used alone, 2
You may use together 1 or more types. When the thermal polymerization initiator is added, the addition amount is usually 0.1% with respect to 100 parts by weight of the monomer.
It is 1 part by weight or more, preferably 0.3 part by weight or more, and usually 2 parts by weight or less, preferably 1 part by weight or less. If the addition amount of the thermal polymerization initiator is too large, the birefringence of the cured product may increase and the hue may deteriorate.

When the photopolymerization initiator is added, the addition amount is
It is usually 0.01 part by weight or more, preferably 0.02 part by weight or more, and usually 1 part by weight or less, preferably 0.5 part by weight or less, relative to 100 parts by weight of the monomer. If the amount of the photopolymerization initiator added is too large, not only the polymerization will rapidly proceed and the birefringence will increase, but also the hue may deteriorate. On the other hand, if the amount is too small, the composition may not be sufficiently polymerized.

The polymerizable composition of the present invention is polymerized after being shaped. The polymerization can be performed by a known method. A method in which a thermal polymerization initiator that generates radicals by heating is added to the polymerizable composition in advance, and the mixture is heated to polymerize (hereinafter sometimes referred to as "thermal polymerization"), and the polymerizable composition is previously exposed to ultraviolet rays or the like. A method in which a photopolymerization initiator that generates a radical by an active energy ray is added and polymerization is performed by irradiating with an active energy ray (hereinafter sometimes referred to as "photopolymerization") can be mentioned, but the birefringence is reduced. For this purpose, photopolymerization is preferred.

The amount of active energy rays to be irradiated is arbitrary within the range where the photoinitiator generates radicals, but when the amount is extremely small, the heat resistance of the cured product due to incomplete polymerization,
If the mechanical properties are not sufficiently expressed and, on the contrary, if the amount is extremely excessive, deterioration of the cured product due to light such as yellowing occurs. Therefore, it may be 200 to 200 depending on the composition of the monomer and the type and amount of the photoinitiator.
Ultraviolet rays of 400 nm are preferably irradiated in the range of 0.1 to 200J. Specific examples of the lamp to be used include a metal halide lamp and a high pressure mercury lamp.

For the purpose of promptly completing the curing by polymerization, photopolymerization and thermal polymerization may be carried out simultaneously. Specifically, the polymerizable composition and the entire mold are usually heated in the range of 30 to 300 ° C. to cure at the same time as the irradiation with the active energy ray. Moreover, you may heat the obtained hardening body after photopolymerization. Thereby, the completion of the polymerization reaction and the internal strain generated during the polymerization can be reduced. The heating temperature is appropriately selected according to the composition of the cured product and the glass transition temperature, but is usually preferably a temperature near the glass transition temperature or lower. If the heating temperature is too high, the hue of the cured product may deteriorate.

When the cured product of the present invention is used as an optical plastic member, it is usually formed into a film, sheet or plate having a thickness of 0.01 to 4 mm, preferably 0.1 to 1 mm. By providing, if necessary, one or more layers selected from the group consisting of a gas barrier layer, a cured coating layer and a conductive film on at least one surface of a cured product formed into a film, sheet or plate, liquid crystal or It can be an optical plastic member suitable for each application such as a touch panel.

The cured product of the present invention has a light transmittance in the visible light region, which is an index of transparency, of usually 80 or more, preferably 85% or more, and usually 95% or less, which is excellent in transparency.
The cured product of the present invention has a glass transition point, which is an index showing heat resistance, of usually 250 ° C. or higher, preferably 300 ° C. or higher, and shows high heat resistance.

The cured product of the present invention has a linear expansion coefficient of usually 50 ppm or less, preferably 48 ppm or less in the temperature range of 25 ° C. to 100 ° C. The coefficient of linear expansion in the temperature range from 25 ° C to 200 ° C is usually 60 ppm or less, preferably 55 ppm or less.

The cured product of the present invention has a bending strength of usually 90 MPa or more, preferably 100 MPa or more in a bending test of a plastic of JIS K7171 standard.
Flexural modulus is usually 3500 MPa or more, preferably 38
It is at least 00 MPa. Since it is preferable that the bending strength and the bending elastic modulus are large, there is no particular upper limit, but it is preferable that both the bending strength and the bending elastic modulus are in the above-mentioned ranges.
The cured product of the present invention usually has a birefringence of 0.1 to 2 nm and exhibits low birefringence. The cured product of the present invention is JIS K 5
The water absorption rate according to 400 is 2% or less, preferably 1% or less, which shows low water absorption.

The cured product of the present invention can be suitably used for various optical applications such as an optical plastic substrate such as an LCD substrate, a touch panel, an optical disk substrate and a solar cell substrate, and an optical plastic member such as a lens.

[0061]

According to the present invention, light weight and excellent transparency,
A cured product having high heat resistance, low linear expansion, high mechanical strength, low water absorption and low birefringence, which can be suitably used for an optical plastic member, and a polymerizable composition providing the same are obtained. .

[0062]

EXAMPLES The contents and effects of the present invention will be described below in more detail with reference to Examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. In the following, "part" means "part by weight". The plates and the plastic laminates obtained in Examples and Comparative Examples were evaluated by the following methods.

(1) Formability: Visual inspection. (2) Appearance: visually. (3) Heat resistance: Using a test piece having a thickness of 30 mm × 3 mm × 1 mm, TMA120 manufactured by Seiko Denshi KK was used to pull the glass transition point Tg by a pulling method TMA, and a distance between fulcrums was 20 mm.
It was measured at a load of 1 g and a heating rate of 5 ° C./min.

(4) Coefficient of linear expansion: 30 mm × 3 mm × 1
Using a mm-thick test piece, Seiko Denshi Co., Ltd. TMA1
20 by pulling method TMA, load 1g, temperature rising rate 5 ° C
/ Min, it measured in the measurement temperature range 25 ° C-400 ° C. At this time, it was calculated from the difference between the test piece lengths at 25 ° C and 100 ° C. Further, it was calculated from the difference between the test piece lengths at 25 ° C and 200 ° C.

(5) Bending strength: 25 mm × 80 mm × 1
Shimadzu autograph AG using mm-thick test piece
Distance between fulcrums at -5kNE: 20mm, 0.5mm / mi
A bending test was performed at n to measure the bending strength. (6) Flexural modulus: Shimadzu autograph AG-5kNE using a test piece of 25 mm x 80 mm x 1 mm thickness
A bending test was performed at a distance between fulcrums of 20 mm and 0.5 mm / min to measure the bending elastic modulus.

Example 1 85 parts by weight of a mixed composition obtained by mixing neopentyl glycol dimethacrylate and trimethylolpropane trimethacrylate in a weight ratio of 3: 1, pentaerythritol tetrakis (β-thiopropionate) 15 Parts, 0.1 part of 2,4,6-trimethylbenzoyldiphenylphosphine oxide (“Lucirin TPO” manufactured by BASF) as a photopolymerization initiator, and 0.1 part of benzophenone were uniformly stirred and mixed, and then defoamed to form a composition. I got a thing.

Using this composition as a spacer, the thickness is 1 m.
liquid into a mold of optically polished glass using a silicon plate of m,
Ultraviolet rays were irradiated for 5 minutes between the metal halide lamps having an output of 80 W / cm, which were 40 cm above and below the glass surface. After UV irradiation, the mold was released and heated at 150 ° C. for 1 hour to obtain a cured product. Table 1 shows the physical properties of the cured product.

Example 2 A cured product was obtained in the same manner as in Example 1 except that the mixing ratio of neopentyl glycol dimethacrylate and trimethylolpropane trimethacrylate was 1: 1. Table 1 shows the physical properties of the cured product.

Example 3 A cured product was obtained in the same manner as in Example 1 except that the mixing ratio of neopentyl glycol dimethacrylate and trimethylolpropane trimethacrylate was 1: 3. Table 1 shows the physical properties of the cured product.

[Example 4] The mixing ratio of neopentyl glycol dimethacrylate and trimethylolpropane trimethacrylate was set to 1: 1 and tris [2- (β- was used instead of pentaerythritol tetrakis (β-thiopropionate). A cured product was obtained in the same manner as in Example 1 except that thiopropionyloxy) ethyl] triisocyanurate was used. Table 1 shows the physical properties of the cured product.

[Example 5] 90 parts by weight of a mixed composition in which neopentyl glycol dimethacrylate and trimethylolpropane trimethacrylate were mixed in a ratio of 1: 1, tris [2- (β-thiopropionyloxy) ethyl] triisocyanurate A cured product was obtained in the same manner as in Example 1 except that 10 parts were used. Table 1 shows the physical properties of the cured product.

Comparative Example 1 A cured product was obtained in the same manner as in Example 1 except that only neopentyl glycol dimethacrylate was used instead of the mixture of neopentyl glycol dimethacrylate and trimethylolpropane trimethacrylate. Table 1 shows the physical properties of the cured product.

[Comparative Example 2] A cured product was obtained in the same manner as in Example 1 except that only trimethylolpropane trimethacrylate was used instead of the mixture of neopentyl glycol dimethacrylate and trimethylolpropane trimethacrylate. Table 1 shows the physical properties of the cured product.

Comparative Example 3 Bis (hydroxymethyl) was used instead of the mixture of neopentyl glycol dimethacrylate and trimethylolpropane trimethacrylate.
A cured product was obtained in the same manner as in Example 1 except that tricyclo [5.2.1.0 ^2,6 ] decane dimethacrylate was used. Table 1 shows the physical properties of the cured product.

[Comparative Example 4] Table 1 shows the physical properties of a commercially available 1 mm-thick polycarbonate plastic sheet (trade name: Panlite, manufactured by Teijin Ltd.).

[0076]

[Table 1]

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Mikio Suzuki             8-3-1 Chuo, Ami-cho, Inashiki-gun, Ibaraki Prefecture             Within Mitsubishi Chemical Corporation F-term (reference) 4F071 AA33X AA76 AA80 AA86                       AF17 AF20 AF29 AH12 BA01                       BB01 BC01 BC03                 4J100 AL62P AL63Q AL66P AL67Q                       BA02P BA02Q BA03P BA03Q                       BA08Q CA04 DA25 DA48                       DA49 DA62

Claims (10)

[Claims] 1. A polymerizable composition comprising the following components (A) and (B): Component (A): at least one bifunctional methacrylate selected from the aliphatic bifunctional methacrylates represented by the general formula [I] (In the formula, A represents an aliphatic hydrocarbon residue having 1 to 8 carbon atoms which may have an ether oxygen and / or a hydroxyl group.) Component (B): Aliphatic Formula [II] At least one polyfunctional methacrylate selected from polyfunctional methacrylates (In the formula, D represents an aliphatic hydrocarbon residue having 1 to 8 carbon atoms, which may have an ether oxygen and / or a hydroxyl group.
Represents an integer of 3 to 8. ) 2. The composition contains 10 to 90 parts by weight of the component (A) and 90 to 10 parts by weight of the component (B) based on 100 parts by weight of the total of the components (A) and (B). The curable composition according to claim 1. 3. A cured product, which is obtained by polymerizing the polymerizable composition according to claim 1 or 2, and has a glass transition temperature of 250 ° C. or higher. 4. The linear expansion coefficient in the temperature range from 25 ° C. to 100 ° C. is 50 ppm or less, and the linear expansion coefficient in the temperature range from 25 ° C. to 200 ° C. is 60 p.
It is below pm, The hardened | cured material of Claim 3 characterized by the above-mentioned. 5. The cured product according to claim 3, which has a bending strength of 90 MPa or more and a bending elastic modulus of 3500 MPa or more in a bending test of a plastic of JIS K7171 standard. 6. A glass transition temperature of 250 ° C. or higher,
The linear expansion coefficient in the temperature range from 25 ° C. to 100 ° C. is 50 ppm or less, and the bending elastic modulus is 3500 in the bending test of the plastic of JIS K7171 standard.
A transparent resin cured product having a pressure of at least MPa. 7. The cured product according to claim 6, which has a linear expansion coefficient of 60 ppm or less in a temperature range of 25 ° C. to 200 ° C. 8. The cured product according to claim 6, which has a bending strength of 90 MPa or more. 9. An optical plastic member comprising the cured product according to any one of claims 3 to 8. 10. The optical plastic member according to claim 9, which is a substrate for a display.