JPH09302176A - Methyl methacrylate-styrene copolymer resin composition sheet - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] A thermoplastic resin composition sheet having excellent appearance properties, dimensional stability, mechanical properties, excellent antistatic properties that prevent dust from adhering, and excellent optical properties with little coloring. I will provide a. SOLUTION: Methyl methacrylate-styrene copolymer resin 100 parts by weight, alkylbenzene sulfonic acid lithium salt 0.5 to 3 parts by weight and aliphatic amide 0.03 to 0.
A thermoplastic resin composition sheet having a thickness of 3.2 mm or less, which comprises 8 parts by weight and is extruded in a sheet shape from an extruder through a sheet forming die.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a methyl methacrylate-styrene copolymer resin composition sheet having excellent antistatic properties, appearance properties, optical properties, mechanical properties and dimensional stability. Specifically, for example, methyl methacrylate-styrene copolymer suitable for optical sheets such as Fresnel lenses and lenticular lenses used for projection television screens, and also suitable for electronic / electrical device material sheets that do not like dust and the like. The present invention relates to a resin composition sheet.

[0002]

2. Description of the Related Art Optical sheets used in projection televisions, etc., when fitted into a television even if the sheet is thinned, in order to increase the screen size and increase the sharpness of images.
Rigidity and dimensional stability are required so as not to bend. In general, optical sheets for televisions and the like are required to have light diffusing properties in order to widen the viewing angle and make it easier to see a bright image, and in particular, to satisfy this requirement, a sheet having a high refractive index is preferably used. . Also, in order to faithfully project colors, coloring by heat is avoided. Acrylic resin (hereinafter sometimes referred to as PMMA) sheets or polycarbonate resin (hereinafter sometimes referred to as PC) sheets have been used as conventional sheets used for these applications. However, in the case of the PMMA sheet, although the rigidity is high, the dimensional stability is poor due to the high water absorption, and the refractive index is low at 1.49. Further, in the case of the PC sheet, on the contrary, the water absorption rate is low, so that the dimensional stability is good and the refractive index is as high as 1.59, but the rigidity is low and there is a problem of bending. In view of these, the present inventors have conducted various studies as an optical sheet, and as a result, have found that a methyl methacrylate-styrene copolymer resin (hereinafter sometimes referred to as MS) sheet has dimensional stability due to high rigidity and low water absorption. , And the refractive index has an appropriate value of 1.52 to 1.54, and it was found that it is preferable as an optical sheet.
However, the optical sheet is required to have not only the above-mentioned physical properties but also antistatic property in order to prevent deterioration of transparency due to adhesion of dust to the surface of the sheet. On the other hand, various methods for making a thermoplastic resin antistatic have been disclosed so far. For example, Japanese Patent Publication No. 1-3741
No. 4 discloses a method in which an alkyl sulfonic acid alkali metal salt is kneaded into a thermoplastic resin as an antistatic agent, but in this case, since the compatibility between MS and the sulfonate is poor, the sheet may be damaged. Defects such as linear fog occur,
There is a problem that not only transparency is not obtained but also the antistatic property is partially insufficient. In addition, JP-A-3-4344
No. 0 discloses a method of blending PMMA with a sulfonic acid metal salt such as aromatic sulfonic acid and polyether, and JP-A-1-197552 describes blending of PMMA with a sulfonic acid metal salt and glycerin fatty acid ester. Although the respective methods have been disclosed, in this case, although the appearance defect and the antistatic property can be improved, there are problems such as coloring due to heat.

[0003]

DISCLOSURE OF THE INVENTION As a result of studies to improve the drawbacks of these conventional methods, the present inventors have found that an alkylbenzene sulfone represented by the following general formula (I) is used for a methyl methacrylate-styrene copolymer resin. By blending a specific amount of lithium acid salt and fatty acid amide,
It has been found that an optical sheet having excellent antistatic properties and appearance properties as well as excellent optical properties with a low degree of coloring, mechanical properties and dimensional stability can be obtained. Specifically, the addition of the fatty acid amide improves the dispersibility of the alkylbenzene sulfonic acid lithium salt in the MS resin and improves the antistatic property. Furthermore, since the fatty acid amide exerts its effect even in a small amount, not only the coloring itself is small, but also the effect of suppressing the coloring of the antistatic agent can be obtained. Also,
It has been found that by adding a specific amount of specific inorganic fine particles as a light diffusing agent, optical properties suitable for optics can be obtained without impairing transparency. The present invention has been completed based on such findings.

[0004]

[Means for Solving the Problems] That is, the present invention provides (1) at least (A) methyl methacrylate monomer 8
0 to 30% by weight, vinyl-based monomer copolymerizable therewith 0
Of 20 to 70% by weight and a monomer mixture of 20 to 70% by weight of a styrene monomer, a methylmethacrylate-styrene copolymer resin (B) an alkylbenzene sulfone represented by the following general formula (I). Acid lithium salt and (C) fatty acid amide as constituent components, and (A),
The components (B) and (C) are blended in amounts of 100 parts by weight, 0.5 to 3 parts by weight and 0.03 to 0.8 parts by weight, respectively, and extruded into a sheet form from an extruder through a sheet forming die. Methyl methacrylate-styrene copolymer resin composition sheet,

[0005]

Embedded image (In the general formula (I), R ¹ represents an alkyl group having 8 to 16 carbon atoms) (2) (A) has a weight ratio of the methyl methacrylate monomer to the styrene monomer of 75:25 to. It is a methylmethacrylate-styrene copolymer resin of 50:50 (methylmethacrylate unit: styrene unit) and has a weight average molecular weight of 240,000 or less and a refractive index of 1.52.
1.54, flexural modulus 36000-40000 kg /
cm ² and a water absorption of 0.15 to 0.25% (1) a methyl methacrylate-styrene copolymer resin composition sheet, (3) as a component (B), in the general formula (I) The ratio of the lithium sulfonate represented and the solvent component is 6 by weight.
(1) A methylmethacrylate-styrene copolymer resin composition sheet according to (1), which is obtained by using a liquid component consisting of 0:40 to 90:10, (4) The solvent component comprises alcohol having 1 to 4 carbon atoms and water. And the weight ratio of alcohol to water is 60:40.
The methylmethacrylate-styrene copolymer resin composition sheet according to claim 4, which is ˜90: 10, and (5) the methylmethacrylate-styrene copolymer resin composition sheet is used as at least one substrate of a screen constituent lens for a projection television. Claims 1-4
A methyl methacrylate-styrene copolymer resin composition sheet according to any one of items 1 to 4 above is provided.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. In the methyl methacrylate-styrene copolymer resin composition sheet of the present invention, the methyl methacrylate-styrene copolymer resin as the component (A) is 80 to 30% by weight of a methyl methacrylate monomer, and a vinyl-based monomer which is copolymerizable therewith. Body 0 to 20% by weight, styrene monomer 20 to 7
0% by weight, preferably methyl methacrylate monomer 7
It is obtained by copolymerizing a monomer mixture of 5 to 50% by weight and a styrene monomer of 25 to 50% by weight. Vinyl-based monomers copolymerizable with the methyl methacrylate monomer include acrylic acid ester-based monomers such as methyl acrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, and butyl methacrylate. And vinyl cyanide monomers such as methacrylic acid ester-based monomers, acrylonitrile and methacrylonitrile, acrylic acid and methacrylic acid, among which methyl acrylate is preferred. Examples of the styrene-based monomer include styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, chlorostyrene, and bromostyrene, and among them, styrene and α-methylstyrene are preferable.

In order to produce this methyl methacrylate-styrene copolymer resin, methyl methacrylate and styrene may be mixed and copolymerized in a proportion corresponding to the proportion of each monomer unit. When the copolymer resin is obtained, the proportion of the monomer of methyl methacrylate is 30% by weight or more.
When it is less than 1, mechanical properties such as strength and bending strength are deteriorated,
On the other hand, the methyl methacrylate monomer blending ratio is 8
If it exceeds 0% by weight, the refractive index of the obtained resin may decrease, and it may be difficult to produce pellets. Also,
The weight average molecular weight of the methyl methacrylate-styrene copolymer resin which is the component (A) is 100,000 to 240000 from the viewpoint of extrusion kneading property and physical properties, and preferably 120.
It is 000-200000. The weight average molecular weight of the methyl methacrylate-styrene copolymer resin is 100,000 to 240,000 also from the viewpoint of obtaining a suitable melt viscosity under molding temperature conditions when a sheet is molded by extrusion molding using this methyl methacrylate-styrene copolymer resin.
It is preferred that Further, the methyl methacrylate-styrene copolymer resin as the component (A) has a refractive index of 1.51 to 1.56, preferably 1.52 to 1.5.
4. Flexural modulus of 34,000 to 40,000 kg / cm ²
And the water absorption is 0.15 to 0.25%. The monomer blending ratio of the methyl methacrylate and styrene is selected so that the refractive index, the bending elastic modulus and the water absorption of the methyl methacrylate-styrene copolymer resin which is the component (A) fall within the above range, The composition sheet of the present invention using the component (A) is preferred for use in various optical devices. The refractive index, flexural modulus and water absorption rate defined in the present invention are measured as follows, for example.
The refractive index is measured by bringing a contact liquid into contact with the above-mentioned resin, which is a substance to be tested, and transmitting light having a specific wavelength. The flexural modulus is measured by using a tensilon or the like after leaving a molded plate immediately after resin molding under a constant temperature and humidity for a certain period of time. Further, the water absorption rate is measured from the difference in weight before and after water immersion, in which a molded plate immediately after resin molding is immersed in water at a constant temperature for a certain period of time. Next, the lithium salt of alkylbenzene sulfonic acid, which is the component (B) in the composition of the present invention, is represented by the following formula (I).

[0008]

Embedded image (In the general formula (I), R ¹ represents an alkyl group having 8 to 16 carbon atoms) Specific examples of the (B) lithium salt of alkylbenzenesulfonic acid in the present invention include lithium dodecylbenzenesulfonic acid salt and octylbenzenesulfone. Examples thereof include lithium acid salts. These lithium sulfonic acid salts may be mixed in a solid state, but since they are hard and hygroscopic in themselves, when mixed with the component (A) and the like, a liquid component containing a solvent is added. It is preferable to keep. As for the ratio of the liquid component, the weight ratio of the alkylbenzene sulfonic acid lithium salt and the solvent is preferably 60:40 to 90: 10% by weight, and particularly preferably 70:30 to 85: 15% by weight. When the concentration of the lithium salt of alkylbenzene sulfonic acid is within the above range, the solvent can be easily removed with an extruder and the extrusion stability can be kept good. Examples of the solvent component of the present invention include a mixture of a lower alcohol having 1 to 4 carbon atoms and water, and among them, a mixture of isopropyl alcohol and water is preferable.
The weight ratio of isopropyl alcohol and water is 60: 40-
90:10, especially 70:30 to 80:20 is preferable,
When the solvent component is within the above range, it is preferable in terms of dissolution of the lithium sulfonate salt, viscosity of the lithium sulfonate solution, dispersibility and extrusion stability. In the composition sheet of the present invention, the compounding ratio of (B) lithium salt of alkylbenzene sulfonic acid is 0.5 to 3 parts by weight, preferably 100 parts by weight of methyl methacrylate-styrene copolymer resin which is the component (A). Is 0.8-2
Parts by weight. If the compounding ratio of the lithium alkylbenzene sulfonate is less than 0.5 parts by weight, a sufficient antistatic effect cannot be obtained. If the amount exceeds 3 parts by weight,
It is not preferable because the obtained sheet may have decreased transparency or coloring.

The fatty acid amide which is the component (C) used in the present invention is an amide and / or bisamide of a higher fatty acid. Specific examples of the (C) fatty acid amide in the present invention include ethylene bis stearamide, oleic acid amide, stearic acid amide, N, N'-methylene bis stearamide, methylol stearamide, and the like. -Bis stearamide is preferably used. These may be used alone or as a mixture of two or more kinds. In the composition sheet of the present invention,
The mixing ratio of the (C) fatty acid amide is 0.03 to 0.8 parts by weight, preferably 0.0 to 100 parts by weight of the methyl methacrylate-styrene copolymer resin which is the component (A).
5 to 0.5 parts by weight. If the blending ratio of the fatty acid amide is less than 0.03 parts by weight, the dispersibility is insufficient, resulting in poor appearance and insufficient antistatic property. Above 0.
On the other hand, if it exceeds 8 parts by weight, the fatty acid amide is excessive and the appearance is poor and the transparency is lowered, which is not preferable.

In the present invention, optical properties suitable for optics can be provided by blending a specific amount of a light diffusing agent. Glass beads are preferable as the light diffusing agent, and fine light diffusing characteristics cannot be obtained with fine particles of other inorganic compounds. At that time, the glass beads have a particle size of 3 to 1
At least 80% by weight, preferably 90% by weight or more, having a thickness of 5 μm is 1 to 300 g / in the composition sheet.
m ² , preferably containing 5-200 g / m ² ,
It is preferable for using the composition sheet of the present invention in various optical instruments. The particle size of the glass beads used in the present invention is at least 80% by weight in the range of 3 to 15 μm. Particle size of glass beads is 3μ
When it is at least m, good transparency can be obtained, and when the particle size is 15 μm or less, good light diffusivity can be obtained. In particular, an optical sheet used for a projection television screen or the like must have both a high total light transmittance and a good light diffusivity, and has a particle size of 3 to 1
If less than 80% by weight of 5 μm, it may not be possible to obtain preferable optical properties. Therefore, as the glass beads, those having a particle size other than 3 to 15 μm, for example, those having a particle size of 1 to 3 μm and 15 to 25 μm may be contained within a range not exceeding 20% by weight. The glass beads are contained in the composition sheet in an amount of 1 to 300 g / m ² , preferably 5 to 200 g / m ² . Content is 1g / m above
If it is less than ² , the light diffusion is insufficient, and the above 300g
If it exceeds / m ² , the transparency is lowered, which is not preferable. In the composition sheet, the glass beads may be dispersed in a sheet having a single layer, or may be dispersed in at least one layer in a multilayer sheet having two or more layers.

When the sheet of the methyl methacrylate-styrene copolymer resin composition of the present invention is used as an optical sheet used in a screen for a projection television,
The sheet thickness is 0.8 to 10 mm, preferably 1.
It is desirable that it is 0 to 5.0 mm. When the sheet thickness is within the above range, the rigidity of the sheet can be maintained and the production is easy, which is preferable. The thinner the sheet thickness, the brighter it becomes. However, if it is less than 0.8 mm, the mechanical strength of the sheet becomes insufficient, and bending occurs.
If it exceeds m, the production may be difficult. The methyl methacrylate-styrene copolymer resin composition sheet of the present invention contains various stabilizers such as antioxidants, ultraviolet absorbers, and light stabilizers, pigments and dyes, in addition to glass beads as a light diffusing agent. Various additives such as flame retardants, fillers and lubricants, organic or inorganic light diffusing agents, rubbery impact modifiers or other synthetic resins can be blended and used. In preparing the composition sheet of the present invention, a conventionally known method may be adopted, and the composition sheet is obtained by stirring and mixing with a mixer such as dry blend or super mixer, and then melt-kneading with an extruder or the like. The methyl methacrylate-styrene copolymer resin composition sheet according to the present invention is manufactured by supplying the raw material from a hopper, guiding it between a screw and a heating cylinder, heating, melting, and transporting to the tip while kneading. Shaped and extruded into a sheet with a die attached to the part, then this is polished roll,
Pick it up with pinch rolls. Such a methyl methacrylate-styrene copolymer resin composition sheet of the present invention has excellent antistatic properties and appearance properties, and also has excellent optical properties, mechanical properties, and dimensional stability. It is a product sheet. In addition, the evaluation of the above-mentioned characteristics is performed by, for example, visually comparing a blank sheet as a standard with respect to appearance characteristics, and with a transmission method using a color difference meter for yellowness as a Y method.
Compare the I value, etc., for the surface resistivity value, after leaving the molded plate after molding under constant conditions, measure the resistance value with a minute ammeter etc., for the total light transmittance and cloud value, etc. It can be carried out by measuring with.

[0012]

EXAMPLES The present invention will be described in detail below with reference to examples. The evaluation was based on the following method. (1) Appearance characteristics were visually evaluated by using a blank sheet (sheet made of only synthetic polymer) as a standard. O marks indicate the case where it is transparent and has no cloudiness, sink marks, or linear cloudiness, and X marks indicate the case where there is cloudiness, sink marks, or lines. (2) The total light transmittance, haze value and yellowness (YI value) are all light transmission color difference meters (model: CO, manufactured by Nippon Denshoku Industries Co., Ltd.).
H-300A) was used and measured according to JIS-K7105. (3) The surface resistivity of the molded plate was 23 ° C. immediately after molding.
After leaving it in a constant temperature room with 50% humidity for 24 hours, with an R-12704 digital ultra-high resistance / micro ammeter manufactured by Advantest,
It was measured according to JIS-K6911. (4) The half-value angle was measured using an automatic goniophotometer GONIOPHOTOMETER manufactured by Murakami Color Research Laboratory.

Examples 1 to 5 Methylmethacrylate-styrene copolymer resin (weight average molecular weight 150 obtained by copolymerizing a monomer mixture consisting of 64% by weight of methyl methacrylate and 36% by weight of styrene)
000 pellets), a liquid component consisting of lithium salt of dodecylbenzene sulfonic acid / IPA / water (80/15/5% by weight), and ethylene bis stearamide.
Pellets were produced by blending in the proportions shown in Tables 1 and 2, mixed with stirring with a super mixer, and melt-kneaded and extruded at a resin temperature of 230 ° C. by a twin screw extruder with a vent of 45 mmφ. Then, a test piece was prototyped at a resin temperature of 235 ° C. with a vented sheet extruder of 65 mmφ, and each physical property value was measured. The measurement results are shown in Tables 1 and 2.

Example 6 Methyl methacrylate-styrene copolymer resin used in Example 1, lithium dodecylbenzene sulfonate, ethylene bis stearamide, and particle size 3 to 1
An average particle diameter of 5 μm containing 80% by weight or more
7 μm glass beads (manufactured by Toshiba Ballotini Co., Ltd., trade name: EMB-10) were mixed in the proportions shown in Table 2 to prepare test pieces in the same manner as in Example 1, and the respective physical property values were measured. It was measured. The measurement results are shown in Table 2.

Example 7 The methyl methacrylate-styrene copolymer resin used in Example 1, lithium dodecylbenzenesulfonate, ethylene bis stearamide, and a particle size of 3 to 1
An average particle size of 10 including 5 wt.
~ 12μm glass beads (Toshiba Ballotini Co., Ltd.)
Manufacture, trade name: EMB-20) was mixed in the proportions shown in Table 2, and a test piece was produced as a trial in the same manner as in Example 1.
Each physical property value was measured. The measurement results are shown in Table 2.

Examples 8 and 9 The methyl methacrylate-styrene copolymer resin used in Example 1, the lithium salt of dodecylbenzene sulfonic acid, and barium sulfate or calcium carbonate as a light diffusing agent were mixed in the proportions shown in Table 3. Then, a test piece was manufactured as in Example 1, and the respective physical property values were measured. The measurement results are shown in Table 3.

Comparative Example 1 A test piece was prepared in the same manner as in Example 1 except that the methyl methacrylate-styrene copolymer resin used in Example 1 and the lithium salt of dodecylbenzenesulfonic acid were mixed in the proportions shown in Table 3. Was prototyped and each physical property value was measured. The measurement results are shown in Table 3.

Comparative Example 2 Except that the methyl methacrylate-styrene copolymer resin used in Example 1, the lithium salt of dodecylbenzene sulfonic acid and the monoglyceride stearate were mixed in the proportions shown in Table 3, In the same manner, test pieces were manufactured as prototypes and the respective physical property values were measured. The measurement results are shown in Table 3. Comparative Examples 3 and 4 Example 1 except that the methyl methacrylate-styrene copolymer resin used in Example 1, the lithium salt of dodecylbenzenesulfonic acid, and ethylene bis stearamide were blended in the proportions shown in Table 4. Prototype test pieces were prepared in the same manner as above, and the respective physical property values were measured. Table 4 shows the measurement results.

[0019]

The antistatic resin composition of the present invention has excellent appearance properties, dimensional stability, mechanical properties, excellent antistatic properties that prevent dust from adhering, and excellent optical properties with little coloring. I have.

[0020]

[Table 1] Table 1 Example 1 Example 2 Example 3 Composition (parts by weight) MS 100 100 100 DBSL 0.8 1.0 2.0 EBSA 0.15 0.15 0.15 Thickness (mm) 2.9 2.9 2.9 Appearance characteristics ○ ○ ○ Yellowness (YI value) ) 1.1 1.1 1.2 Surface resistivity (Ω) 2 × 10 ¹⁰ 1 × 10 ¹⁰ 8 × 10 ⁹ Total light transmittance (%) 92 92 91 Haze value (%) 0.3 0.3 0.5 MS: Methyl methacrylate-styrene copolymer resin DBSL: Dodecylbenzenesulfonic acid lithium salt EBSA: Ethylene bis stearamide

[0021]

[Table 2] Table 2 Example 4 Example 5 Example 6 Example 7 Compounding composition (parts by weight) MS 100 100 100 100 DBSL 1.0 1.0 1.0 1.0 EBSA 0.05 0.3 0.15 0.15 Glass beads <g / m ² > − − 1.0 <20> 10 <136> Thickness (mm) 2.9 2.9 1.8 1.2 Appearance characteristics ○ ○ ○ ○ Yellowness (YI value) 1.1 1.2 − − Surface resistivity (Ω) 4 × 10 ¹⁰ 1 × 10 ¹⁰ 3 × 10 ¹² 5 × 10 ¹² Total light transmittance (%) 92 92 87 85 Haze value (%) 0.3 0.4 − − Half-value angle (°) − − 1.54 11

[0022]

[Table 3] Table 3 Comparative Example 1 Comparative Example 2 Example 8 Example 9 Composition (parts by weight) MS 100 100 100 100 DBSL 1.0 1.0 1.0 1.0 EBSA − − 0.15 0.15 SMG − 0.5 − − Barium sulfate <g / m ² > − − 0.3 <6> − Calcium carbonate <g / m ² > − − − 1.0 <17> Thickness (mm) 1.5 2.9 1.8 1.5 Appearance characteristics ○ ○ ○ ○ Yellowness (YI value) 1.3 1.3 − − Surface specific Resistance value (Ω) 8 × 10 ¹³ 1 × 10 ¹¹ 3 × 10 ¹² 2 × 10 ¹² Total light transmittance (%) 92 92 91 75 Haze value (%) 0.3 0.3 − − Half-value angle (°) − − 1.2 1.2 SMG: monoglyceride stearate

[0023]

Table 4 Table 4 Comparative Example 3 Comparative Example 4 blend composition (parts by weight) MS 100 100 DBSL 1.0 7.0 EBSA 1.0 0.15 SMG - - Barium sulfate <g / m ^2> - - Calcium carbonate <g / m ^2> - - Thickness (mm) 1.5 1.5 Appearance characteristics × × Yellowness (YI value) − − Surface resistivity (Ω) − − Total light transmittance (%) − − Haze value (%) − − Half value angle (°) − −

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Claims (5)

[Claims] 1. A unit amount comprising at least 80 to 30% by weight of (A) methyl methacrylate monomer, 0 to 20% by weight of vinyl monomer copolymerizable therewith, and 20 to 70% by weight of styrene monomer. A methylmethacrylate-styrene copolymer resin obtained by copolymerizing a mixture of polymers, (B) a lithium salt of alkylbenzene sulfonic acid represented by the following general formula (I), and (C) a fatty acid amide as constituent components, A), (B) and (C) components are mixed in amounts of 10 each
A methyl methacrylate-styrene copolymer resin composition sheet produced as 0 parts by weight, 0.5 to 3 parts by weight, and 0.03 to 0.8 parts by weight, and extruded in a sheet shape from an extruder through a sheet forming die. Embedded image (In the general formula (I), R ¹ represents an alkyl group having 8 to 22 carbon atoms) 2. In (A), the weight ratio of the methyl methacrylate monomer to the styrene monomer is 75:25 to 50:50.
(Methyl methacrylate unit: styrene unit) methyl methacrylate-styrene copolymer resin having a weight average molecular weight of 240,000 or less and a refractive index of 1.
52-1.54, flexural modulus 36000-40000
kg / cm ² and a water absorption rate of 0.15 to 0.25
% Of the methyl methacrylate-styrene copolymer resin composition sheet according to claim 1. 3. A liquid component having a weight ratio of the lithium sulfonate represented by the general formula (I) to the solvent component of 60:40 to 90:10 as the component (B). The methylmethacrylate-styrene copolymer resin composition sheet according to claim 1, which is used. 4. The methyl methacrylate according to claim 3, wherein the solvent component comprises alcohol having 1 to 4 carbon atoms and water, and the weight ratio of the alcohol to water is 60:40 to 90:10. -Styrene copolymer resin composition sheet. 5. The methyl methacrylate-styrene copolymer resin composition sheet according to claim 1, wherein the methyl methacrylate-styrene copolymer resin composition sheet is used as at least one substrate of a screen constituent lens for a projection television. .