JP2019119853A - Resin composition - Google Patents

Abstract

To obtain a resin composition having excellent flowability and strength with low birefringence.SOLUTION: A resin composition contains a polymer (A) containing a methacrylate monomer unit of 50 mass% or more and a maleimide monomer unit of 8 mass% or less, and a phenoxy resin (B).SELECTED DRAWING: None

Description

  The present invention relates to a resin composition.

Conventionally, acrylic resins have small birefringence and are widely used for optical applications as compared with other resins, but in recent years, with the development of optical devices, birefringence is required to be closer to zero. Along with this, conventionally, attempts have been made to control optical performance such as retardation by using, for example, an acrylic resin having a ring structure in its main chain (see Patent Document 1).
However, an acrylic resin having a ring structure in its main chain is brittle due to its rigidity, and for example, when it is formed into a film, cracks occur, and the strength as a formed product is poor.
As a method of improving the strength of acrylic resin, it is generally mentioned to increase the molecular weight, but since acrylic resin having a ring structure in the main chain has a higher viscosity than general acrylic resin, from the viewpoint of molding processability, It is not practical to further increase the molecular weight of such resins.
In addition, although copolymerization of styrene for controlling polymerization in acrylic resin has been conventionally performed, since the styrene monomer unit has a large intrinsic birefringence, the birefringence of the resin is possible even if a small amount is added. In particular, in the case of a thick-walled molded piece, a high phase difference appears.

International Publication No. 2011/149088

A resin or resin composition having excellent optical properties is inferior in strength and flowability to general acrylic resins due to its structure, and in particular, the strength is improved while maintaining the flowability, and the optical properties are also excellent. Resins and resin compositions are being sought.
The present invention has been made in view of the above problems, and it is an object of the present invention to obtain a low birefringence resin composition excellent in flowability and strength by controlling optical characteristics from an entirely new approach.

  As a result of intensive studies to solve the above problems, the present inventors designed the low birefringence by using styrene and a phenoxy resin with high intrinsic birefringence as a polymer, thereby providing high fluidity and strength. It has been found that a resin composition can be obtained which is well-balanced, and the present invention has been completed.

That is, the present invention is as follows.
[1]
A polymer (A) containing 50% by mass or more of a methacrylate ester monomer unit and 8% by mass or less of a maleimide monomer unit, and a phenoxy resin (B), Resin composition.
[2]
The resin composition according to [1], wherein the polymer (A) contains a copolymer (A1) containing a methacrylic acid ester monomer unit and an aromatic vinyl monomer unit.
[3]
The resin composition as described in [2] whose content X (mass%) of the said aromatic vinyl-type monomer unit is 1 mass% or more and 20 mass% or less in the said copolymer (A1).
[4]
The resin composition as described in [2] or [3] whose polymer (A) is a copolymer (A1) containing a methacrylic acid ester monomer unit and an aromatic vinyl-type monomer unit.
[5]
The resin composition in any one of [2]-[4] whose content Y (mass%) of the said phenoxy resin (B) in the said resin composition is 30 mass% or less.
[6]
The polymer (A) further includes a polymer (A2) containing 85% by mass or more of a methacrylic acid ester monomer unit,
The polymer (A) contains more than 0% by mass and 20% by mass or less of the polymer (A1), and 75% by mass or more and 98% by mass or less of the polymer (A2),
The resin composition as described in [2] or [3].
[7]
When the content of the polymer (A1) in the resin composition is α (%),
The content X (mass%) and the content Y (mass%),
0.7 ××× (α / 100) <Y <0.7 ××× (α / 100) +15
The resin composition in any one of [1]-[6] which satisfy | fills.
[8]
The polymer (A) is the polymer (A2),
Said content Y (mass%) is 2 mass% or more and 10 mass% or less,
The resin composition as described in [1].
[9]
In the polymer (A2), the content of the methacrylic acid ester monomer is 89% by mass to 99% by mass, and the content of the acrylic acid ester monomer is 1% by mass to 11% by mass [ The resin composition as described in 8].
[10]
The resin composition in any one of [1]-[9] whose absolute value of in-plane phase difference and thickness direction retardation which were measured using the injection molding piece with a thickness of 4 mm is 20 nm or less in all.
[11]
The Charpy impact strength measured without a notch using a strip-shaped molded piece having a thickness of 4 mm and a width of 10 mm is 20 kJ / m ² or more,
The melt flow rate at a load of 3.8 kg and 230 ° C measured according to JIS K 7210 is 1.5 g / 10 min or more
The resin composition in any one of [1]-[10].
[12]
The resin composition in any one of [1]-[11] whose 3% weight loss temperature in 10 degreeC / min temperature rising conditions is 300 degreeC or more in nitrogen atmosphere.
[13]
A residue containing a polymer (A) mainly composed of methyl methacrylate monomer units and a phenoxy resin (B), and heated to 400 ° C. under a nitrogen atmosphere at a temperature rising condition of 10 ° C./min. The resin composition in any one of [1]-[12] whose amount Z% and content Y% of a phenoxy resin (B) satisfy | fill the relationship of Z> Y.
[14]
The absolute value of the in-plane retardation measured at an arbitrary thickness and converted to a thickness of 100 μm is 1 nm or less,
The Charpy impact strength measured without a notch using a strip-shaped molded piece having a thickness of 4 mm and a width of 10 mm is 20 kJ / m ² or more,
The melt flow rate at a load of 230 ° C is 1.5 g / 10 min or more, measured according to JIS K 7210, 3.8 kg
Resin composition.
[15]
The injection molding using the resin composition as described in [1]-[14].

  According to the present invention, it is possible to provide a low birefringence resin composition excellent in flowability and strength.

Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail, but the present invention is not limited to the following description, and within the scope of the gist thereof Various modifications are possible.
In addition, the thing of the structural unit which comprises a copolymer is called "-monomer unit" below. Moreover, the thing of the constituent material of this "-monomer unit" may abbreviate | omit a "unit", and may only describe it as "-monomer."

The resin composition of the present embodiment may contain a copolymer (A) containing a methacrylic acid ester monomer unit and a phenoxy resin (B), and may optionally contain an additive.
More specifically, the resin composition of the present embodiment contains a polymer (A) containing 50% by mass or more of a methacrylic acid ester monomer unit and 8% by mass or less of a maleimide monomer unit, And phenoxy resin (B).

  According to the resin composition of the present embodiment, a low birefringence resin composition excellent in flowability and strength, for example, there is no limitation on the molding conditions by excellent flowability and strength, ie, a thick-walled molded body It is possible to provide a resin composition which has a small phase difference even if it is present, and does not cause problems such as cracking even if it is a thin-walled molded product.

(Polymer (A))
A polymer (A) contains 50 mass% or more of methacrylic acid ester monomer units, and contains 8 mass% or less of maleimides monomer units.
The polymer (A) in one aspect of this embodiment may include a copolymer (A1) containing a methacrylic acid ester monomer unit and an aromatic vinyl monomer unit. In this case, the polymer (A) may be made of the above-mentioned copolymer (A1).
In addition, the polymer (A) in the one aspect may further include the polymer (A2) containing the copolymer (A1) and containing 85% by mass or more of a methacrylic acid ester monomer unit.
Moreover, the polymer (A) in another aspect of the present embodiment may be made of the above-mentioned polymer (A2).

  The content X (mass%) of the aromatic vinyl monomer unit in the copolymer (A1) containing methyl methacrylate monomer unit and the aromatic vinyl monomer unit is 1% by mass or more It is preferable that it is 50 mass% or less, and the content of the aromatic vinyl monomer unit in the polymer (A2) containing 85 mass% or more of methacrylic acid ester monomer units is less than 1 mass%. Is preferred.

  The content of the specific monomer unit in the polymer (A) may be the content of the specific monomer unit in the resin when the polymer (A) is a single resin, and the polymer When (A) is a mixed resin of two or more types, the content of the specific monomer unit in the mixed resin may be used.

(Copolymer (A1))
As one preferable example of the copolymer (A) of the present embodiment, a copolymer (A1) containing a methacrylic acid ester monomer unit and an aromatic vinyl monomer unit can be mentioned.
When using a copolymer (A1) as a main component in a resin composition (D), 80 mass% or more is preferable, and, as for content of the methacrylic acid ester monomer unit in a copolymer (A1), 82 mass is preferable. % Or more is more preferable, and 85 mass% or more is more preferable.
When using a copolymer (A1) as a main component in a resin composition (D), as content X (mass%) of the aromatic vinyl monomer unit in a copolymer (A1), an aromatic vinyl is mentioned If the content of the monomer unit is increased, the control of birefringence of the resin composition becomes difficult, so 20 mass% or less is preferable, 18 mass% or less is more preferable, and 15 mass% or less is more preferable. In addition, from the viewpoint of improving strength and fluidity, the content X is preferably 1% by mass or more, more preferably 3% by mass or more, and still more preferably 5% by mass or more.

(Polymer (A2))
Moreover, the polymer (A2) which contains 85% or more of methacrylic acid ester monomer units is mentioned as one of the preferable examples of the copolymer (A) of this embodiment. The polymer (A2) may be a polymer containing 89 to 99% by mass of methacrylic acid ester monomer units and 1 to 11% by mass of acrylic acid ester monomer units.
When using a polymer (A2) as a main component in a resin composition (D), 75 mass% or more and 98 mass% or less of a polymer (A2), and also 0 mass% or more 20 mass% of said copolymers (A1) It is preferable to contain below.
When using a polymer (A2) as a main component in a resin composition (D), content X (mass%) of the aromatic vinyl monomer unit in copolymer (A1) is 1 mass% or more, 50 % Or less is preferred. 10 mass% or more and 45 mass% or less are more preferable, and 20 mass% or more and 40 mass% or less are preferable.

  Hereinafter, the monomer units contained in the polymer (A) will be described.

・・・・・（１） [Methacrylic acid ester monomer unit]
As a methacrylic acid ester monomer unit (X) (Hereinafter, it may describe as (X) monomer unit.) Which is a repetition derived from a methacrylic acid ester monomer, it shows by the following general formula (1). Monomer units are preferably used.

... (1)

In the general formula (1), R ¹ represents a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, and the alkyl group may be substituted by, for example, a hydroxyl group. R ¹ is preferably a methyl group.
R ² represents a group having 1 to 3 carbon atoms, preferably a hydrocarbon group having 1 to 3 carbon atoms, and the hydrocarbon group may be substituted by, for example, a hydroxyl group. R ² is preferably a linear or branched hydrocarbon group having 1 to 3 carbon atoms, more preferably a linear or branched saturated hydrocarbon group having 1 to 3 carbon atoms.

・・・・・（２） The monomer forming the methacrylic acid ester monomer unit (X) represented by the general formula (1) is not particularly limited, but a methacrylic acid ester monomer represented by the following general formula (2) It is preferred to use.

... (2)

In the general formula (2), R ¹ represents a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, and the alkyl group may be substituted by, for example, a hydroxyl group. R ¹ is preferably a methyl group.
R ² represents a group having 1 to 3 carbon atoms, preferably a hydrocarbon group having 1 to 3 carbon atoms, and the hydrocarbon group may be substituted by, for example, a hydroxyl group. R ² is preferably a linear or branched hydrocarbon group having 1 to 3 carbon atoms, more preferably a linear or branched saturated hydrocarbon group having 1 to 3 carbon atoms.

As specific examples of such monomers, methyl methacrylate, ethyl methacrylate, propyl methacrylate and isopropyl methacrylate are preferable from the viewpoints of heat resistance, handleability and optical properties, and from the viewpoint of keeping Tg high, methyl methacrylate is preferable. Ethyl methacrylate is preferred, and methyl methacrylate is preferred from the viewpoint of availability and the like.
The methacrylic acid ester monomers may be used alone or in combination of two or more.

[Aromatic vinyl monomer unit]
Examples of the aromatic vinyl monomer unit include styrene, α-methylstyrene, methoxystyrene, vinyl toluene and the like, with styrene being preferred.
The aromatic vinyl monomer units may be used alone or in combination of two or more.

The copolymer (A) may contain other monomer units in addition to methyl methacrylate monomer units.
Examples of other monomer units include acrylic acid ester monomer units, unsaturated carboxylic acid anhydrides monomer units, maleimides monomer units, other vinyl compound monomer units, and the like.

Examples of unsaturated carboxylic acid anhydrides include maleic anhydride and itaconic anhydride.
When a maleic anhydride monomer unit is contained in the copolymer (A), as the content in the copolymer (A), from the viewpoint of strength, fluidity, and compatibility with the phenoxy resin (B) 12 mass% or less is preferable, 5 mass% or less is more preferable, and 2 mass% or less is more preferable.

Maleimides include N-substituted maleimides such as maleimide, N-methyl maleimide, N-ethyl maleimide, N-phenyl maleimide, N-cyclohexyl maleimide and the like.
In the present embodiment, the content of the maleimide monomer unit in the copolymer (A) is 8% by mass or less.
When the copolymer (A) contains a maleimide monomer unit, the content in the copolymer (A) is preferably 5% by mass or less from the viewpoint of strength and fluidity. 3 mass% or less is more preferable, 1 mass% or less is further preferable, 0.1 mass% or less is still more preferable, and it is especially preferable not to contain.

The other vinyl compounds are not particularly limited as long as the effects of the present invention can be achieved, but preferred examples include acrylic esters.
Examples of acrylic esters include methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, cyclohexyl acrylate, phenyl acrylate, acrylic acid (2-ethylhexyl), Acrylic acid (t-butylcyclohexyl), benzyl acrylate, acrylic acid (2,2,2-trifluoroethyl) and the like are preferable, and from the viewpoint of handling and availability, methyl acrylate, ethyl acrylate, acrylic Propyl acid, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate and the like are more preferable, and methyl acrylate is particularly preferable.
Further, compounds other than acrylic acid esters are not limited to the following examples, but, for example, α, β-unsaturated acids such as acrylic acid and methacrylic acid; maleic acid, fumaric acid, itaconic acid, cinnamon Unsaturated group-containing divalent carboxylic acids such as acids and their alkyl esters; o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 3,4- Styrenic monomers such as dimethylstyrene, 3,5-dimethylstyrene, p-ethylstyrene, m-ethylstyrene, о-ethylstyrene, p-tert-butylstyrene, isopropenylbenzene (α-methylstyrene); 1 -Vinyl naphthalene, 2-vinyl naphthalene, 1,1-diphenyl ethylene, isopropenyl toluene, isopropenyl ether Aromatic vinyl compounds such as benzene, isopropenyl propyl benzene, isopropenyl butyl benzene, isopropenyl pentyl benzene, isopropenyl hexyl benzene, isopropenyl octyl benzene; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; acrylamide, methacrylamide and the like Amides of ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, etc. Acrylic acid at both terminal hydroxyl groups of ethylene glycol or its oligomers Or those esterified with methacrylic acid; neopentyl glycol di (meth) acrylate, di (meth) acrylate etc. Obtained by esterifying hydroxyl groups of acrylic acid with acrylic acid or methacrylic acid; those obtained by esterifying polyhydric alcohol derivatives such as trimethylolpropane and pentaerythritol with acrylic acid or methacrylic acid; and polyfunctional monomers such as divinyl benzene etc. Be
The above-mentioned acrylic acid ester and compounds other than acrylic acid ester may be used alone or in combination of two or more kinds.
The content of the above-mentioned other vinyl compound monomer units constituting the copolymer (A) in the copolymer (A) may be 0.1 to 20% by mass, preferably 1.0 to 15 It is mass%, More preferably, it is 1.5-12 mass%, More preferably, it is 2.0-10 mass%.

Hereinafter, the characteristics of the above-mentioned methacrylic resin will be described.
When the polymer (A) is one kind of resin, it may be a characteristic of the resin, and when the polymer (A) is a mixed resin of two or more kinds, it may be a characteristic of the mixed resin.

<Weight-average molecular weight (Mw) of copolymer (A)>
The weight average molecular weight (Mw) of the copolymer (A) contained in the resin composition of the present embodiment will be described.
The copolymer (A) preferably has a weight average molecular weight (Mw) of 50,000 to 300,000 measured by GPC (gel permeation chromatography).
In order to obtain excellent strength, the weight average molecular weight (Mw) of the methacrylic resin (A) is preferably 50000 or more, more preferably 60000 or more, still more preferably 70000 or more, still more preferably 80000 or more, 90000 or more Is even more preferred.
In addition, in order for the resin composition to exhibit good fluidity, the weight average molecular weight (Mw) of the copolymer (A) is preferably 300000 or less, more preferably 250,000 or less, and more preferably 230000 or less, 210000 or less is still more preferable, and 180000 or less is still more preferable.
When the weight average molecular weight of the copolymer (A) is in the range of 50,000 to 300,000, balance between strength and fluidity can be achieved, and good molding processability is maintained. Furthermore, as described later in this embodiment, by using the phenoxy resin (B) in combination with the copolymer (A), the strength and the flowability can be highly balanced, and a resin composition having a good handling property during molding and processing The thing is obtained.
The weight average molecular weight (Mw) of the copolymer can be measured by gel permeation chromatography (GPC), and specifically, it can be measured by the method described in the examples described later.
Specifically, a calibration curve is prepared from elution time and weight average molecular weight using a standard methacrylic resin which is known as a monodispersed weight average molecular weight in advance and available as a reagent, and an analysis gel column in which high molecular weight components are eluted first. Then, based on the calibration curve obtained subsequently, the weight average molecular weight (Mw) of the predetermined measurement target copolymer can be determined. The weight average molecular weight (Mw) is defined as the average of the molecular weight by weight fraction.

  Hereinafter, the method for producing the copolymer (A) will be described.

The copolymer (A) contained in the resin composition of the present embodiment can be polymerized by any method of bulk polymerization, solution polymerization, suspension polymerization method or emulsion polymerization method, preferably bulk polymerization, solution polymerization, It is a suspension polymerization method, more preferably a suspension polymerization method.
The polymerization temperature may be appropriately selected according to the polymerization method, but is preferably 50 ° C. or more and 100 ° C. or less, and more preferably 60 ° C. or more and 90 ° C. or less.

When producing a copolymer (A), you may use a polymerization initiator.
The polymerization initiator is not limited to the following, but when radical polymerization is carried out, for example, di-t-butyl peroxide, lauroyl peroxide, stearyl peroxide, benzoyl peroxide, t-butyl peroxy Neodecanate, t-butylperoxypivalate, dilauroyl peroxide, dicumyl peroxide, t-butylperoxy-2-ethylhexanoate, 1,1-bis (t-butylperoxy) -3, Organic peroxides such as 3,5-trimethylcyclohexane and 1,1-bis (t-butylperoxy) cyclohexane, azobisisobutyronitrile, azobisisovaleronitrile, 1,1-azobis (1-cyclohexane Carbonitrile), 2,2'-azobis-4-methoxy-2,4-azobis General radical polymerization initiators of azo type such as isobutyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, 2,2'-azobis-2-methylbutyronitrile and the like can be mentioned. One of these may be used alone, or two or more of them may be used in combination.
These radical initiators and a suitable reducing agent may be combined and used as a redox initiator.
These radical polymerization initiators and / or redox initiators are used in the range of 0 to 1 parts by mass with respect to 100 parts by mass of the total amount of all monomers used in the polymerization of the copolymer (A). In general, the temperature can be selected appropriately in consideration of the temperature at which the polymerization is performed and the half life of the polymerization initiator.

When a bulk polymerization method or a suspension polymerization method is selected as a polymerization method of the copolymer (A), polymerization may be performed using a peroxide type polymerization initiator from the viewpoint of preventing coloring of the methacrylic resin. preferable.
Examples of the peroxide-based polymerization initiator include, but are not limited to, lauroyl peroxide, decanoyl peroxide, and t-butylperoxy-2-ethylhexanoate. Peroxide is more preferred.
When the copolymer (A) is polymerized by solution polymerization at a high temperature of 90 ° C. or more, a peroxide having a 10-hour half-life temperature of 80 ° C. or more and soluble in the organic solvent used It is preferable to use an azobis initiator or the like as a polymerization initiator.
Examples of the peroxide and azobis initiator include, but are not limited to, for example, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, cyclohexane peroxide, 2 Examples include 5-dimethyl-2,5-di (benzoylperoxy) hexane, 1,1-azobis (1-cyclohexanecarbonitrile), 2- (carbamoylazo) isobutyronitrile and the like.

When manufacturing a copolymer (A), you may control the molecular weight of a copolymer (A) in the range which does not impair the objective of this invention.
The method for controlling the molecular weight of the copolymer (A) is not limited to the following. For example, a chain transfer agent such as alkyl mercaptans, dimethylacetamide, dimethylformamide, triethylamine, dithiocarbamates, triphenyl There is a method of controlling molecular weight by using an iniferter such as methylazobenzene or tetraphenylethane derivative. Moreover, it is also possible to adjust molecular weight by adjusting the addition amount of these.
As the chain transfer agent, alkyl mercaptans are preferable from the viewpoint of handleability and stability, and the alkyl mercaptans are not limited to the following, for example, n-butyl mercaptan and n-octyl mercaptan , N-dodecyl mercaptan, t-dodecyl mercaptan, n-tetradecyl mercaptan, n-octadecyl mercaptan, 2-ethylhexyl thioglycolate, ethylene glycol dithio glycolate, trimethylol propane tris (thioglycoat), pentaerythritol tetrakis (thio glycolate) Etc.).
These can be added as appropriate depending on the molecular weight of the target copolymer (A), but generally, the total amount of all monomers used in the polymerization of the copolymer (A) is 100. It is used in the range of 0.001 to 5 parts by mass with respect to the parts by mass.
Further, as other molecular weight control methods, methods of changing polymerization methods, methods of adjusting polymerization initiator, amount of chain transfer agent, iniferter, etc. described above, methods of changing various polymerization conditions such as polymerization temperature, etc. may be mentioned. .
These molecular weight control methods may use only one type of method, or two or more types of methods may be used in combination.

  In the present embodiment, the content of the copolymer (A) in the resin composition is preferably 70% by mass or more, more preferably 80% by mass or more, and still more preferably 85% by mass or more.

・・・・・（３） (Phenoxy resin (B))
The phenoxy resin of this embodiment has, for example, a constitutional unit represented by the following formula (3). The phenoxy resin which has a structural unit shown to Formula (3) can be manufactured by the dehydrochlorination reaction of bisphenol A and epichlorohydrin.

... (3)

  The weight average molecular weight of the phenoxy resin (B) is preferably greater than 5,000, more preferably 10,000 or more, and still more preferably 20,000 or more. Moreover, it is preferable that it is smaller than 150,000, 120000 or less is more preferable, and 100,000 or less is more preferable.

  The phenoxy resin (B) can be produced by a known method. The method of producing the phenoxy resin is generally solution polymerization.

  The resin composition (D) of the present invention is a resin composition containing the above-mentioned polymer (A) and a phenoxy resin (B). Here, as the polymer (A), the polymers (A1) and (A2) may be used alone, or (A1) and (A2) may be used simultaneously. In controlling the optical characteristics, it is important to set the ratio of (A1), (A2), and (B) within a specific range.

  In the embodiment, in the case of the one embodiment in which the copolymer (A1) is contained in the polymer (A), the phenoxy resin (B It is preferable that it is 30 mass% or less, 20 mass% or less is more preferable, and 15 mass% or less is more preferable. Further, in order to control birefringence and obtain a resin composition excellent in fluidity and strength, the content Y is preferably 5% by mass or more, more preferably 7% by mass or more, and further preferably 8% by mass or more .

When the polymer (A) contains the copolymer (A1), the content of the styrene monomer unit in the copolymer (A1) is X mass%, and the content of the phenoxy resin in the resin composition When the amount is Y% by mass and the content of the polymer (A1) in the resin composition is α (%), 0.7 ××× (α / 100) <Y <0.7 × X × ( It is preferable to satisfy α / 100) +15, and 0.7 × X × (α / 100) +3 <Y <0.7 × X × (α / 100) +10 is more preferable, and 0.7 × X × (α /100)+4<Y<0.7×X×(α/100)+8 is more preferable.
When X and Y fall within the above range, a resin composition having a small retardation and not limited to molding conditions is easily obtained.

In particular, when the polymer (A) is the copolymer (A1), the content of the styrene monomer unit and the phenoxy resin is reduced in order to reduce the retardation of the molded article using the resin composition. By setting the ratio to a specific ratio, it is possible to cancel the negative retardation derived from the styrene monomer unit and the positive retardation derived from the phenoxy resin to lower birefringence. Furthermore, it has been found that by satisfying the following conditions, a resin composition having excellent strength and fluidity can be obtained while realizing low birefringence. That is, when the content of the styrene monomer unit in the copolymer (A1) is X mass% and the content of the phenoxy resin in the resin composition is Y mass%, 0.7 × X <Y <0. It is preferable to satisfy 7 × X + 15, more preferably 0.7 × X + 2 <Y <0.7 × X + 12, and still more preferably 0.7 × X + 4 <Y <0.7 × X + 10.
When X and Y fall within the above range, a resin composition having a small retardation and not limited to molding conditions is easily obtained.

  In this embodiment, in the case of the above another embodiment in which the polymer (A) is the polymer (A2), the content Y of the phenoxy resin (B) in the resin composition is 2% by mass or more and 10% by mass or less Is preferred. The content Y is more preferably 8% by mass or less, further preferably 7% by mass or less, and preferably 3% by mass or more to control birefringence and obtain a resin composition excellent in fluidity and strength. 4 mass% or more is preferable.

  That is, by adjusting the content of the polymer (A1) and the content X of styrene units in the polymer (A1) according to the content Y of the phenoxy resin (B), it has necessary strength and fluidity. Resin compositions can be designed. When the amount of the phenoxy resin (B) is particularly small, the composition can be designed without containing the polymer (A1). The smaller the content Y of the phenoxy resin (B), the easier it is to control birefringence, and the resin composition obtained is also dominated by the characteristics of the acrylic resin, while the greater the content Y of the phenoxy resin, the more fluid There is a tendency that a resin composition excellent in strength and strength can be obtained.

(Additive)
The additive optionally used is not particularly limited as long as the effects of the present invention can be obtained, and may be appropriately selected according to the purpose.
The content of the additive in the resin composition is not particularly limited, but may be 5% by mass or less, preferably 3% by mass or less, and more preferably 2% by mass or less.

  Hereinafter, the characteristics of the methacrylic resin composition will be described.

<Strength>
The resin composition of the present embodiment preferably has a Charpy impact strength of 20 kJ / m ² or more, preferably 22 kJ / m ² or more, measured without a notch using a strip-shaped molded piece having a thickness of 4 mm and a width of 10 mm. Is more preferred. With the above range, practically sufficient strength can be obtained.
In addition, about the Charpy impact strength, it can measure by the method as described in the Example mentioned later.
<Flowability>
The resin composition of the present embodiment preferably has a melt flow rate of 1.5 g / 10 min or more at a load of 3.8 kg and 230 ° C. measured according to JIS K 7210, and is 1.8 g / min or more It is more preferable that Thereby, problems such as cracking do not occur at the time of production of a thin-walled injection molded product, and stable production can be performed.
In addition, about a melt flow rate, it can measure by the method as described in the Example mentioned later.

<Phase difference>
In the resin composition of the present embodiment, the absolute value of the in-plane retardation (Re) measured to a thickness of 100 μm is measured at a thickness of 100 μm in order to reduce birefringence as a molding, and the thickness is 100 nm or less. Is more preferably 2 nm or less, still more preferably 1 nm or less.
In addition, the absolute value of the thickness direction retardation (Rth) measured with a molded product having an arbitrary thickness and converted to a thickness of 100 μm is preferably 5 nm or less, more preferably 2 nm or less, still more preferably 1 nm or less .
Generally, in a thick-walled molded piece, a high phase difference is easily developed, and therefore, it is preferable that the absolute value of the phase difference is small even in the case of a thick-walled piece.
In the present embodiment, it is preferable that both the in-plane retardation (Re) and the thickness direction retardation (Rth) measured using an injection-molded piece having a thickness of 4 mm be 40 nm or less, and more preferable. Is 20 nm or less, more preferably 10 nm or less. Thereby, a molded object with small optical distortion can be obtained regardless of molding conditions.
The absolute value of the in-plane retardation (Re) and the absolute value of the thickness direction retardation (Rth) can be measured by the method described in the examples described later.

Transparency
The total light transmittance in the resin composition of the present embodiment may be appropriately optimized according to the application, but when used in applications where transparency is required, the total light in a thickness of 4 mm from the viewpoint of visibility The transmittance is preferably 85% or more. More preferably, it is 88% or more, further preferably 89% or more, and particularly preferably 90% or more.
Although it is preferable that the total light transmittance be high, in practical use, if it is 80% or more, sufficient visibility can be secured.
In addition, a total light transmittance can be measured by the method as described in the Example mentioned later, for example.

<Glass transition temperature>
The glass transition temperature of the methacrylic resin of the present embodiment is preferably 100 ° C. or more, more preferably 103 ° C. or more, still more preferably 105 ° C. or more, particularly preferably 110 ° C., from the viewpoint of obtaining sufficient heat resistance. It is above.
In addition, a glass transition temperature can be measured by a midpoint method based on ASTM-D-3418, and specifically, it can be measured by the method as described in the Example mentioned later, for example.

<Heat resistance>
The 3% weight loss temperature of the methacrylic resin composition of the present embodiment under a nitrogen atmosphere at a temperature rising condition of 10 ° C./min is preferably 300 ° C. or more, more preferably 310 ° C. or more, still more preferably 320 ° C or more.
In addition, 3% weight loss temperature can be measured by the method as described in the Example mentioned later, for example.

Regarding the methacrylic resin composition of the present embodiment, the residual amount Z (mass%) and the content Y of the phenoxy resin (B) when the temperature is raised to 400 ° C. under a nitrogen atmosphere and temperature rising conditions of 10 ° C./min. It is preferable that (mass%) satisfy the relationship of Z> Y, and it is preferable that Z> 1.5 × Y, and more preferably Z> 2 × Y.
In addition, residual amount Z can be measured by the method as described in the Example mentioned later, for example.

Hereinafter, the manufacturing method of the resin composition of this embodiment is described.
The methacrylic resin composition is obtained by mixing and kneading the copolymer (A), the phenoxy resin (B), and, if necessary, the various additives described above.
For example, it can manufacture by knead | mixing using kneading machines, such as an extruder, a heating roll, a kneader, a roller mixer, and a Banbury mixer. In particular, kneading with a twin-screw extruder is preferable from the viewpoint of productivity.
The kneading conditions may be appropriately determined depending on the purpose and application.

(1) Measurement of Weight Average Molecular Weight (Mw) The weight average molecular weight (Mw) of each resin of the copolymer obtained in the production example described later was measured using the following apparatus and conditions.
・ Measurement device: Tosoh company make, gel permeation chromatography (HLC-8320GPC)
·Measurement condition:
Column: One TSKguard column SuperH-H, two TSKgel SuperHM-M, and one TSKgel SuperH2500 were sequentially connected in series and used. In this column, high molecular weight elutes quickly and low molecular weight elutes slowly.
Developing solvent: tetrahydrofuran, flow rate: 0.6 mL / min, 0.1 g / L of 2,6-di-t-butyl-4-methylphenol (BHT) was added as an internal standard.
Detector: RI (differential refraction) detector Detection sensitivity: 3.0 mV / min Column temperature: 40 ° C
Sample: 0.02 g resin in 20 mL solution of tetrahydrofuran Injection amount: 10 μL
Standard samples for calibration curve: The following 10 types of polymethyl methacrylate (PMMA Calibration Kit M-M-10, manufactured by Polymer Laboratories) having known monodispersed weight peak molecular weight and different molecular weight were used.
Weight peak molecular weight (Mp)
Standard sample 1 1,916,000
Standard sample 2 625, 500
Standard sample 3 298, 900
Standard sample 4 138, 600
Standard sample 5 60, 150
Standard sample 6 27,600
Standard sample 7 10, 290
Standard sample 8 5,000
Standard sample 9 2,810
Standard sample 10 850
Under the above conditions, the RI detection intensity relative to the elution time of the resin was measured.
The weight average molecular weight (Mw) of the resin was determined based on the area area in the GPC elution curve and the calibration curve of the third approximation.

(2) Analysis of structural unit of copolymer (A)>
About the copolymer obtained by the below-mentioned manufacture example, the structural unit was identified by < ¹ > H-NMR measurement, and its abundance (mass%) was computed.
The measurement conditions of ¹ H-NMR measurement are as follows.
Device: JEOL-ECA 500
Solvent: CDCl ₃ -d ₁ (deuterated chloroform)
Sample: 15 mg of the copolymer (A) was dissolved in 0.75 mL of CDCl ₃ -d _{1 to} prepare a measurement sample.

(3) Charpy impact strength (kJ / m ² )
About the resin composition obtained by the below-mentioned test example and a comparative example, it conforms to JIS K 7111-1 using a Charpy impact tester apparatus (made by Toyo Seiki Co., Ltd.) and is a strip-shaped molding piece 4 mm thick and 10 mm wide Notched Charpy impact test was carried out using About a strip-shaped molding piece, using a molding machine made by Toshiba Machine Co., Ltd. EC-100SX, cut into a dumbbell shape at a molding machine setting temperature of 230 ° C. and a mold temperature of 70 ° C. Created.

(4) Melt flow rate (g / 10 min)
About the resin composition obtained by the below-mentioned test example and comparative example, according to JIS K 7210 using a melt indexer (made by Toyo Seiki Co., Ltd.), after heating for 2 minutes at 230 ° C., melt flow at 3.8 kg load The rate was measured.

(5) Measurement of retardation (5-1) Measurement of retardation in 100 μm thickness conversion <in-plane retardation (Re)>
The in-plane phase difference (Re) of the resin composition obtained by the below-mentioned test example and comparative example measures the phase difference (nm) in wavelength 550nm by a rotation analyzer method using Otsuka Electronics RETS-100. The obtained value (nm) was converted to a thickness of 100 μm and used as a measured value.
The absolute value (| Δn |) of birefringence and the in-plane retardation (Re) have the following relationship.
Re = | Δn | × d
(D: thickness of sample)
The absolute value (| Δn |) of birefringence is a value shown below.
| Δn | = | nx-ny |
(Nx: refractive index in the stretching direction, ny: refractive index in the plane perpendicular to the stretching direction)

<Thickness direction retardation (Rth)>
The thickness direction retardation (Rth) obtained in the test example and the comparative example described later is measured using a retardation measurement apparatus (KOBRA-21ADH) manufactured by Oji Scientific Instruments Co., Ltd. to measure the retardation (nm) at a wavelength of 589 nm. The obtained value (nm) was converted to a thickness of 100 μm and used as a measured value.
The absolute value (| Δn |) of birefringence and the thickness direction retardation (Rth) have the following relationship.
Rth = | Δn | × d
(D: thickness of sample)
The absolute value (| Δn |) of birefringence is a value shown below.
| Δn | = | (nx + ny) / 2-nz |
(Nx: refractive index in the stretching direction, ny: refractive index in the plane perpendicular to the stretching direction, nz: refractive index in the thickness direction perpendicular to the stretching direction, out of plane)

  Here, in an ideal sample which is completely optically isotropic in all three-dimensional directions, the in-plane retardation (Re) and the thickness direction retardation (Rth) are both zero.

(5-2) Measurement of Retardation of 4 mm Thickness Injection Molded Piece The resin composition obtained in the test example and comparative example described later is put into an injection molding machine, and an injection molded piece of 80 mm in length, 10 mm in width and 4 mm in thickness Was produced.
The in-plane retardation (Re) and the thickness direction retardation (Rth) were measured in the same manner as (5-1) described above except that the sample used for measurement of retardation was the above injection molded piece. .

(6) Measurement of total light transmittance The total light transmittance (%) is measured according to the ISO 13468-1 standard using the injection-molded piece produced in (5-2) described above, and the transparency is It is an index.

(7) Injection molding stability Using a molding machine of EC-100SX manufactured by Toshiba Machine Co., Ltd. using a resin composition obtained in the test examples and comparative examples described later, a molding machine set temperature is 280 ° C., for 30 seconds. A flat plate of 1 mm in thickness was manufactured under molding cycle conditions. Among the 20 shots, those with cracks of the molded piece three or more times were evaluated as “x”, those with one or more and two times or less were evaluated as “Δ”, and those with no cracks were evaluated as “o”.

(8) Glass transition temperature About the resin composition obtained by the below-mentioned Example and comparative example, it measures based on ASTM-D-3418 using a thermal analyzer (Diamond DSC made by Perkin Elmer). The glass transition temperature (° C.) was calculated by the midpoint method. The evaluation results are shown in Table 1.

(9) TGA Measurement Using 10 mg of the resin composition obtained in the test examples and comparative examples described below, using EVO II TG-DTA + SL manufactured by Rigaku Corporation, under a nitrogen atmosphere (100 mL / min), 10 ° C./min The 3% weight loss temperature (° C.) and the 400 ° C. temperature rising residue amount (mass%) under the temperature rising conditions of
More specifically, the temperature is raised from room temperature at 20 ° C./min, held at 50 ° C. for 10 minutes, raised at 20 ° C./min, held at 100 ° C. for 5 minutes, and then 10 ° C./min at 400 ° C. The temperature at which the 3% weight decreases is taken as the 3% weight loss temperature (° C), and the mass of the residue at 400 ° C rises by 400 ° C as a percentage of the mass of the sample before holding at 100 ° C. It was set as the amount of residue (mass%).

(10) Silver evaluation at the time of high temperature injection molding Using a molding machine of EC-100SX manufactured by Toshiba Machine Co., Ltd. using a resin composition obtained in the test example and comparative example described later, molding machine set temperature 280 ° C. 30 A flat plate of 1 mm in thickness was produced under molding cycle conditions of seconds. Of the 20 shots, those with three or more occurrences of silver were evaluated as “x”, those with one or more and two or less times were rated as “Δ”, and those without occurrence of silver were evaluated as “o”.

(11) Light Leakage in Crossed Polarizing Plate The 4 mm-thick injection-molded piece prepared in (5-2) above is set between two polarizing plates, and the light leakage occurs when the polarizing plates are placed orthogonally. Those with very little “A”, those with a thin white line seen along the flow direction of the resin “O”, those with a clear white line in the flow direction “A”, Molded pieces The thing which the whole became white blur was evaluated as "x".

[Production Examples 1 to 12]
The polymerization of the copolymers of Production Examples 1 to 12 was carried out by a suspension polymerization method.
First, 2 kg of water, 65 g of calcium phosphate tribasic, 39 g of calcium carbonate and 0.39 g of sodium lauryl sulfate were charged into a 5 L container equipped with a stirrer, and the mixture was stirred and mixed to prepare a suspension mixture.
Next, 25 kg of water was charged into a 60 L reactor and the temperature was raised to 80 ° C. to prepare for suspension polymerization. After confirming that the temperature reached 80 ° C. and becoming constant temperature, raw materials of the type listed in Table 1 as polymerization raw materials, lauroyl peroxide as an initiator, n-octyl mercaptan as a chain transfer agent, and the suspension mixture The whole was charged into a 60 L reactor and stirred.
Thereafter, suspension polymerization is carried out while maintaining about 80 ° C. After confirming the exothermic peak, the temperature is raised to 92 ° C. at a rate of 1 ° C./min, and then the temperature of 92 ° C. to 94 ° C. is maintained for 60 minutes, After cooling to 50 ° C., 20 mass% sulfuric acid was added to dissolve the suspending agent.
Next, the polymerization reaction solution was taken out of the 60 L reactor and sieved by a 1.68 mm sieve to remove large aggregates, and then the aqueous layer and the solid were separated in a Buchner funnel to obtain a beaded polymer. .
The beaded polymer was washed 5 times with about 20 L of distilled water on a Buchner funnel and then dried in a steam oven to obtain polymer microparticles corresponding to Production Examples 1-12.
The composition of the polymer determined by NMR was as described in Table 1.

[Comparative Production Example 1]
Comparative Production Example 1 was produced by a solution polymerization method.
432.3 kg of methyl methacrylate (MMA), 33.0 kg of N-phenylmaleimide (PMI), in a 1 m ³ reaction kettle equipped with a stirring device equipped with paddle blades, a temperature sensor, a cooling pipe, and a nitrogen introducing pipe. 84.7 kg of N-cyclohexyl maleimide (CMI), 450.0 kg of meta-xylene, and 0.045 kg of n-octyl mercaptan were charged and dissolved to prepare a raw material solution. The mixture was heated to 125 ° C. with stirring while passing nitrogen through it.
Separately, an initiator feed solution was prepared by mixing 0.23 kg of Perhexa C-75 and 1.82 kg of meta-xylene.
When the raw material solution reached 127 ° C., the feed (addition) of the initiator feed liquid (polymerization initiator mixed liquid) was started with the profiles of (1) to (6).
(1) 0.0 to 0.5 hours: feed rate 1.00 kg / hour (2) 0.5 to 1.0 hours: feed rate 0.50 kg / hour (3) 1.0 to 2.0 hours: Feed rate 0.42 kg / hour (4) 2.0 to 3.0 hours: Feed rate 0.35 kg / hour (5) 3.0 to 4.0 hours: Feed rate 0.14 kg / hour (6) 4. 0 to 7.0 hours: Feed rate 0.13 kg / hour The initiator is fed over a total of 7 hours (B time = 7 hours), and then the reaction is continued for another 1 hour, and 8 hours from the start of the initiator addition The polymerization reaction was carried out until later.
The internal temperature was controlled at 127 ± 2 ° C. during the polymerization reaction. When the polymerization conversion ratio of the obtained polymerization liquid was measured, it was 93.7 mass% of MMA units, 95.5 mass% of PMI units, and 91.2 mass% of CMI units. As a whole, the polymerization conversion was 93%.
The polymerization solution obtained above is subjected to a degassing treatment at a rate of 10 kg / hour in terms of resin amount at 140 rpm and using a φ 42 mm degassing extruder with 1 fore vent and 1 back vent, and the resin pellet of Comparative Production Example 1 Obtained.
The weight average molecular weight of the obtained pellet was 180,000, and the glass transition temperature was 135 ° C.
The composition determined by NMR was 79% by mass of MMA unit, 6% by mass of PMI unit, and 15% by mass of CMI unit.

[Comparative production example 2]
Comparative Production Example 2 was produced by a suspension polymerization method.
First, 2 kg of water, 65 g of calcium phosphate tribasic, 39 g of calcium carbonate and 0.39 g of sodium lauryl sulfate were charged into a 5 L container equipped with a stirrer, and the mixture was stirred and mixed to prepare a suspension mixture.
Next, 25 kg of water was charged into a 60 L reactor and the temperature was raised to 80 ° C. to prepare for suspension polymerization. After confirming that the temperature reached 80 ° C. and becoming a constant temperature condition, raw materials of the type and blending described in Table 1 as polymerization raw materials, lauroyl peroxide as initiator, and n-octyl mercaptan as chain transfer agent are added, The total amount of suspending agent was charged into a 60 L reactor and stirred.
Thereafter, suspension polymerization is carried out while maintaining about 80 ° C., and after confirmation of the exothermic peak, the temperature is raised to 92 ° C. at a rate of 1 ° C./min, and then the temperature of 92 ° C. to 94 ° C. is maintained for 60 minutes. After cooling to 50 ° C., 20% by mass sulfuric acid was added to dissolve the suspending agent.
Next, the polymerization reaction solution was taken out of the 60 L reactor and sieved by a 1.68 mm sieve to remove large aggregates, and then the aqueous layer and the solid were separated in a Buchner funnel to obtain a beaded polymer. .
The beaded polymer was washed 5 times with about 20 L of distilled water on a Buchner funnel and then dried in a steam oven to obtain polymer microparticles corresponding to Comparative Production Example 2.

[Examples 1 to 14, Comparative Examples 1 to 4]
The copolymers obtained in Production Examples 1 to 7 and Comparative Production Examples 1 and 2 were melt-kneaded using a twin-screw extruder according to the composition shown in Table 2, and the above physical properties were evaluated.
As a phenoxy resin, PKHH (Mw: 52000) manufactured by Inchem was used.

  The results of the physical property evaluation for each example and each comparative example are shown in Table 2.

As shown in Table 2, when the content of styrene and phenoxy resin satisfy a specific range, even if it is a thick-walled molded product of 4 mm, it shows low retardation, and the molding stability in thin wall is also good. Met.
Those containing maleimide had poor mold stability due to lack of strength and fluidity.

[Examples 15 to 57]
In these examples, the following were used as the polymer (A1) in addition to the above-mentioned Production Example polymers.
Nippon Steel Corp. MS-750LF (styrene content X = 25%)
Nippon Steel Corp. MS-600 (styrene content X = 40%)
The above physical properties of the copolymer obtained in Production Examples 8 to 12, MS-750LF MS-600, and phenoxy resin PKHH are melt-kneaded using a twin-screw extruder according to the compositions in Table 3 and Table 4. Evaluation was carried out.
As a phenoxy resin, PKHH (Mw: 52000) manufactured by Inchem was used.

  Tables 3 and 4 show the results of physical property evaluation for each example and each comparative example.

The present invention can provide a resin composition which has sufficient optical properties for practical use and is excellent in the balance between strength and fluidity.
The resin composition of the present invention is used for household goods, office automation equipment, AV equipment, for battery electrical equipment, lighting equipment, tail lamps, meter covers, headlamps, light guiding rods, automotive parts such as lenses, housing applications, sanitary ware substitutes, etc. Light guide plate, diffuser plate, polarizing plate protective film, quarter wave plate, 1 used for displays such as liquid crystal display, plasma display, organic EL display, field emission display, rear projection television, head-up display etc. / 2 wavelength plate, viewing angle control film, retardation film such as liquid crystal optical compensation film, display front plate, display substrate, lens, transparent substrate such as touch panel, transparent substrate used for decoration film etc. and solar cell, light Communication system, optical switching system, optical measurement system In beam field of the waveguide, a lens, an optical fiber, the coating material of the optical fiber, LED lenses, as a lens cover or the like, there is industrial applicability.

Claims (15)

  A polymer (A) containing 50% by mass or more of a methacrylate ester monomer unit and 8% by mass or less of a maleimide monomer unit, and a phenoxy resin (B), Resin composition.   The resin composition according to claim 1, wherein the polymer (A) contains a copolymer (A1) containing a methacrylic acid ester monomer unit and an aromatic vinyl monomer unit.   The resin composition of Claim 2 whose content X (mass%) of the said aromatic vinyl-type monomer unit is 1 mass% or more and 20 mass% or less in the said copolymer (A1).   The resin composition according to claim 2 or 3, wherein the polymer (A) is a copolymer (A1) containing a methacrylic acid ester monomer unit and an aromatic vinyl monomer unit.   The resin composition as described in any one of Claims 2-4 whose content Y (mass%) of the said phenoxy resin (B) in the said resin composition is 30 mass% or less. The polymer (A) further includes a polymer (A2) containing 85% by mass or more of a methacrylic acid ester monomer unit,
The polymer (A) contains more than 0% by mass and 20% by mass or less of the polymer (A1), and 75% by mass or more and 98% by mass or less of the polymer (A2),
The resin composition according to claim 2 or 3. When the content of the polymer (A1) in the resin composition is α (%),
The content X (mass%) and the content Y (mass%),
0.7 ××× (α / 100) <Y <0.7 ××× (α / 100) +15
The resin composition as described in any one of Claims 1-6 which satisfy | fills. The polymer (A) is the polymer (A2),
Said content Y (mass%) is 2 mass% or more and 10 mass% or less,
The resin composition according to claim 1.   In the polymer (A2), the content of the methacrylic acid ester monomer is 89% by mass to 99% by mass, and the content of the acrylic acid ester monomer is 1% by mass to 11% by mass. Item 9. The resin composition according to Item 8.   The resin composition as described in any one of Claims 1-9 whose absolute value of in-plane phase difference and thickness direction phase difference which were measured using the injection molding piece with a thickness of 4 mm is 20 nm or less in all. The Charpy impact strength measured without a notch using a strip-shaped molded piece having a thickness of 4 mm and a width of 10 mm is 20 kJ / m ² or more,
The melt flow rate at a load of 3.8 kg and 230 ° C measured according to JIS K 7210 is 1.5 g / 10 min or more
The resin composition as described in any one of Claims 1-10.   The resin composition according to any one of claims 1 to 11, wherein a 3% weight loss temperature under a nitrogen atmosphere at a temperature rising condition of 10 ° C / min is 300 ° C or higher.   The residual amount Z (mass%) when the temperature is raised to 400 ° C. under a nitrogen atmosphere and temperature rising conditions of 10 ° C./min, and the content Y (mass%) of the phenoxy resin (B) has a relationship of Z> Y. The resin composition as described in any one of Claims 1-12 which satisfy | fills. The absolute value of the in-plane retardation measured at an arbitrary thickness and converted to a thickness of 100 μm is 1 nm or less,
The Charpy impact strength measured without a notch using a strip-shaped molded piece having a thickness of 4 mm and a width of 10 mm is 20 kJ / m ² or more,
The melt flow rate at a load of 230 ° C is 1.5 g / 10 min or more, measured according to JIS K 7210, 3.8 kg
Resin composition. An injection-molded article using the resin composition according to any one of claims 1 to 14.