KR101045126B1 - Optical Films and Process for Production Thereof - Google Patents

Abstract

In the present invention, when the glass transition temperature is 110 ° C. or more and 200 ° C. or less, and the shear rate is 100 (1 / s), the acrylic resin having a viscosity of 250 Pa · s or more and 1000 Pa · s or less at a resin temperature of 270 ° C. is a barrier-flight type. By using an extruder composed of a screw or a screw including a mixing section, by setting the temperature of the cylinder and the die of the extruder to a temperature of less than +145 ℃ glass transition temperature of the acrylic resin to form an acrylic resin according to the melt extrusion method . Thereby, it provides the optical film and manufacturing method which have few impurities, and are excellent in a physical property and an appearance.

Description

Optical Films and Process for Production Thereof

TECHNICAL FIELD The present invention relates to an optical film and a method for manufacturing the same, and more particularly, to an optical film with a small amount of foreign matter and a method for producing the same.

Acrylic resin represented by polymethyl methacrylate (hereinafter referred to as "PMMA") is an optically isotropic material having excellent optical performance, high light transmittance, low birefringence, and low retardation, and has been applied to various optical materials. . Recently, as flat displays, infrared sensors, and optical waveguides such as liquid crystal displays, plasma displays, organic EL displays, and the like progress, demands for heat resistance of optically transparent polymer materials are increasing. I'm asking.

As the acrylic resin having heat resistance (hereinafter referred to as "heat resistant acrylic resin"), a lactone ring-containing polymer (for example, Patent Documents 1 and 2) obtained by performing a lactone cyclization condensation reaction of a polymer having a hydroxyl group and an ester group in a molecular chain , 3 and 4) and maleimide copolymers obtained by copolymerizing maleimides (see Patent Document 5, for example). When these heat-resistant acrylic resins are molded into a melt-extruded film by an extruder, a single screw extruder is generally used.

Patent Document 1: Japanese Patent Application Laid-Open No. 2000-230016

Patent Document 2: Japanese Patent Application Laid-Open No. 2001-151814

Patent Document 3: Japanese Patent Application Laid-Open No. 2002-120326

Patent Document 4: Japanese Patent Application Laid-Open No. 2002-254544

Patent Document 5: Japanese Patent Application Laid-Open No. 09-324016

However, the extrudable melt viscosity of these heat-resistant acrylic resins is higher than that of general acrylic resins, and in order to bring the resin closer to the temperature at which the resin decomposes, many impurities such as carbides due to resin deterioration have been generated. In addition, when the temperature is lowered to reduce impurities, there is a problem that a lot of fisheye (fisheye) is generated due to melting of the resin. In other words, when molding a heat-resistant acrylic resin into a melt-extruded film (hereinafter referred to as an "optical film"), even when melted at high temperatures or melted at low temperatures, foreign substances such as impurities and fisheye adversely affect the appearance and physical properties of the film. Because of this, it was not possible to obtain an optical film excellent in both appearance and properties.

The present invention has been made in view of the above-described problems, and an object thereof is to provide an optical film having a low content of foreign substances, excellent physical properties and an appearance, and a method of manufacturing the same.

As described above, in the prior art, an optical film excellent in both appearance and physical properties could not be obtained. Thus, the inventors have diligently studied to maintain the temperature of some materials of the extruder below a certain temperature by using a barrier flight type screw or a mixing section as a screw of the extruder. By this, sufficient plasticization and kneading can be performed at low temperature, and further, the inventors have found that the remaining amount of deteriorated foreign matter has been reduced, and thus, the present invention has been completed.

In other words, the optical film according to the present invention has a viscosity at a resin temperature of 270 ° C. of 250 Pa · s or more when the glass transition temperature is 110 ° C. or more and 200 ° C. or less, and the shear rate is 100 (1 / s). It is an optical film provided with acrylic resin of 1000 Pa * s or less, The said optical film is characterized by the impurity content of 10 piece / m <^2> or less.

According to the said structure, since the optical film of this invention is 110 degreeC or more and 200 degrees C or less, acrylic resin has sufficient heat resistance. Furthermore, when the shear rate is 100 (1 / s), the viscosity of the acrylic resin at the resin temperature of 270 ° C is 250 Pa.s or more and 1000 Pa.s or less, which is sufficient for formation of an optical film according to a method such as melt extrusion. Mechanical strength. Therefore, the optical film excellent in the physical property can be provided.

Moreover, since the said optical film has very little impurity content of 10 pieces / m <^2> or less, it can be said that decomposition degradation of the acrylic resin which is a raw material is very small. Therefore, since the coloring etc. resulting from the decomposition degradation of acrylic resin are extremely few, the optical film excellent also in an external appearance can be provided.

Moreover, as for the optical film of this invention, it is more preferable that volatile organic substance content is 1000 ppm or less. Volatile organic substances are caused by partial degradation of an acrylic resin, which adversely affects the appearance of the optical film, but according to the above constitution, the optical film having excellent appearance can be provided because the content of volatile organic matter is very small.

Moreover, it is preferable that the optical film of this invention contains the polymer in which the said acrylic resin has a lactone ring structure. Since the polymer having a lactone ring structure has a high cyclization condensation reaction rate, it is possible to prevent bubbles or silver streaks from being mixed into the molded article. Moreover, it has high heat resistance resulting from a lactone ring structure. Therefore, the optical film which is more excellent in external appearance and heat resistance can be provided.

In the manufacturing method of the optical film of the present invention, the extrusion and the barrier flight-type screw is used to set the temperature of the cylinder and die of the extruder to a temperature below the glass transition temperature of the acrylic resin + 145 ° C and melt extrusion method. It is characterized by molding an acrylic resin.

According to the said structure, since melt extrusion is performed using a barrier flight type screw, excessive shearing is not added to an acrylic resin, resin temperature can be kept low and sufficient melt kneading can be performed. Moreover, since the temperature of the cylinder and die of this extruder is set to the temperature of less than +145 degreeC of glass transition temperature of acrylic resin, it can melt-extrude and can prevent overheating of resin. Therefore, it is possible to melt-extrude acrylic resin at low temperature and to obtain an optical film with few impurities.

In the method for producing an optical film of the present invention, the extrusion and mounting of a screw including a mixing section sets the temperature of the cylinder and die of the extruder to a temperature of less than 145 ° C. in the glass transition temperature of the acrylic resin, and the melt extrusion method. According to the present invention, acrylic resins are molded.

According to the above configuration, since melt extrusion is performed using a screw including a mixing section as in the case of using a barrier flight type screw, sufficient melt kneading can be maintained while the resin temperature is kept low without excessive shearing on the acrylic resin. Can be done. In addition, since the temperature of the cylinder and die of the extruder is set to a temperature of less than the glass transition temperature of the acrylic resin + 145 ° C, extrusion of the melt can be prevented. Therefore, it is possible to melt-extrude acrylic resin at low temperature, and to obtain an optical film with few impurities.

Moreover, in the manufacturing method of the optical film of this invention, it is preferable that the said extruder attaches the polymer filter whose filtration precision is 25 micrometers or less.

Since the extruder contains the polymer filter, it is possible to remove the foreign matter contained in the acrylic resin with high accuracy.

In the method for producing an optical film of the present invention, it is preferable that the extruder is provided with a volatile matter removing means, and the volatile matter removing means sucks decomposition gas generated by melt kneading of the acrylic resin.

According to the above structure, since the volatile matter removing means is capable of suctioning off the decomposition gas generated by melt kneading of the acrylic resin, it is possible to suppress an increase in moisture or residual volatile matter contained in the optical film. Therefore, more excellent optical film can be obtained.

Moreover, it is preferable that the optical film of this invention was manufactured by the manufacturing method of the optical film which concerns on this invention. Moreover, in the manufacturing method of the optical film of this invention, it is preferable that the said optical film is an optical film which concerns on this invention.

1 is a side view showing an embodiment of a barrier flight type screw.
FIG. 2 is a side view schematically showing the configuration of an extruder equipped with a barrier flight type screw in one embodiment. FIG.
3 is a side view showing one embodiment of a screw including a mixing section.

Although the present invention will be described in detail below, the scope of the present invention is not limited to these descriptions, and the present invention may be appropriately modified without departing from the spirit of the present invention in addition to the following examples.

[One. Optical film of this invention]

The optical film of the present invention has an acrylic system having a viscosity of 250 Pa · s or more and 1000 Pa · s or less at a resin temperature of 270 ° C. when the glass transition temperature is 110 ° C. to 200 ° C. and the shear rate is 100 (1 / s). It is an optical film which has resin, and the said optical film is impurity content 10 piece / m <^2> .

First, the said acrylic resin is demonstrated.

(1.acrylic resin)

The acrylic resin used in the present invention is a resin obtained by polymerizing acrylic acid, methacrylic acid and derivatives thereof as a main component, and its derivatives are not particularly limited as long as the effects of the present invention are not impaired, and known methacrylic acid thermoplastic resins are known. It is available. For example, general formula (1)

[Formula 1]

(Herein, R ¹ and R ² each independently represent a hydrogen atom or an organic residue having 1 to 20 carbon atoms. Specific examples of the organic residue include a linear, split or cyclic alkyl group having 1 to 20 carbon atoms. As a specific example of the compound (monomer), acrylic acid, methacrylic acid, and its derivative (s) which have a structure shown in ()), methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, and n-butyl (meth) acrylate T-butyl (meth) acrylate, n-hexyl (meth) acrylate, 2-chloroethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, (meth) acrylic acid 2, 3, 4, 5, 6-pentahydroxyhexyl, (meth) acrylic acid 2, 3, 4, 5-tetrahydroxypentyl, etc. are mentioned. Only one type of these may be used, or two or more types may be used together. Especially, methyl (meth) acrylate is the most preferable at the point which is excellent in thermal stability.

In addition, methacryl-based thermoplastic resins may be copolymerized with N-substituted maleimides such as phenyl maleimide, cyclohexyl maleimide, and methyl maleimide from the viewpoint of heat resistance, and in molecular chains (also referred to as in the main skeleton of the polymer or in the main chain). Lactone ring structure, glutaric anhydride structure, glutarimide structure, or the like may be introduced.

Especially, the structure which does not contain a nitrogen atom is preferable at the point which a film is hard to color (yellowing). Moreover, it is preferable to have a lactone ring structure in a principal chain from the point which is easy to express correct birefringence (exact phase difference). Although about 4-8 membered ring may be sufficient about the lactone ring structure in a principal chain, it is more preferable that it is a 5-6 membered ring from a structure safety, and 6-membered ring is especially preferable. Thus, when the lactone ring structure in a main chain is a 6-membered ring, the structure shown by following General formula (2) and Unexamined-Japanese-Patent No. 2004-168882 etc. are mentioned, The synthesis | combination of the polymer before introduce | transducing a lactone ring structure into a main chain is carried out. Prior to the general formula (2), a polymer having a high polymerization yield, a polymer having a high content of a lactone ring structure, and a polymer having a high polymerization yield can be easily obtained at a high polymerization yield, and have good copolymerizability with (meth) acrylic acid esters such as methyl methacrylate. It is preferable that it is a structure shown by ().

Moreover, these acrylic resin may have the unit which copolymerized the other monomer component copolymerizable in the range which does not lose heat resistance. Specific examples of the other monomer components that can be copolymerized include aromatic vinyl monomers such as styrene and α-methylstyrene, mitoryl monomers such as acrylonitrile, and vinyl esters such as vinyl acetate.

The weight average molecular weight of the acrylic resin is preferably in the range of 1,000 or more and 2,000,000 or less, more preferably in the range of 5,000 or more and 1,000,000 or less, still more preferably in the range of 10,000 or more and 500,000 or less, very preferably 50,000 or more. It is in the range of 500,000 or less.

It does not specifically limit as a method of manufacturing the said acrylic resin, What is necessary is just to superpose | polymerize the monomer composition containing a (meth) acrylic acid ester using a conventionally well-known method.

The polymerization temperature and polymerization time vary depending on the type of monomer (monomer composition) used, the ratio of use, and the like. Preferably, the polymerization temperature is in the range of 0 ° C to 150 ° C, and the polymerization time is in the range of 0.5 to 20 hours. More preferably, polymerization temperature exists in the range of 80 degreeC or more and 140 degrees C or less, and polymerization time exists in the range of 1 hour or more and 10 hours or less.

In the case of the polymerization form using a solvent, a polymerization solvent is not specifically limited, Especially aromatic hydrocarbon solvents, such as toluene, xylene, ethylbenzene; Ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; Ether solvents such as tetrahydroplan; These may be mentioned, Only one type of these may be used and two or more types may be used together. When producing a lactone ring-containing polymer to be described later, it is preferable that the boiling point is within a range of 50 ° C. or more and 200 ° C. or less since the residual volatilization of the lactone ring-containing polymer that can be finally obtained increases if the boiling point of the solvent used is too high. .

In the case of a polymerization reaction, you may add a polymerization initiator as needed. The polymerization initiator is not particularly limited, but for example cumene hydroperoxide, diisopropylbenzene hydroperoxide, di-t-butyl peroxide, lauroyl peroxide, benzoyl peroxide, t-butyl peroxyisopropyl carbonate organic peroxides such as t-amyl peroxy-2-ethylhexanoate; Azo compounds, such as 2, 2- azobis (isobutyronitrile), 1, 1- azobis (cyclohexanecarbonitrile), 2, 2- azobis (2, 4- dimethylvaleronitrile); These may be mentioned, These may use only one type and may use two or more types together. What is necessary is just to set the usage-amount of a polymerization initiator suitably according to the combination of monomers, reaction conditions, etc. which are employ | adopted, and are not specifically limited.

In the case of polymerization, in order to inhibit gelation of the reaction solution, it is preferable to suppress the concentration of the polymer produced in the polymerization reaction mixture to be 50% by weight or less. Specifically, when the concentration of the polymer produced in the polymerization reaction mixture is more than 50% by weight, it is preferable to add the polymerization solvent to the polymerization reaction mixture appropriately and to suppress it to 50% by weight or less. The concentration of the polymer produced in the polymerization reaction mixture is more preferably 45% by weight or less, even more preferably 40% by weight or less. In addition, when the concentration of the polymer in the polymerization mixture is too low, the productivity is lowered, so that the concentration of the polymer in the polymerization mixture is preferably 10% by weight or more, more preferably 20% by weight or more.

It does not specifically limit as a form which adds a polymerization solvent suitably to a polymerization reaction mixture, A polymerization solvent may be added continuously or a polymerization solvent may be added intermittently. In this way, by inhibiting the concentration of the polymer produced in the polymerization reaction mixture, it is possible to more sufficiently inhibit the gelation of the reaction solution, and in particular, the hydroxyl group and the ester group of the molecular chain in order to improve the heat resistance by increasing the lactone ring-containing mixture Even if the compounding is increased, gelation can be sufficiently suppressed.

The polymerization solvent to be added may be a solvent of the same kind as the solvent used in the initial preparation process of the polymerization reaction or may be a different kind of solvent. However, it is preferable to use the same solvent as the solvent used in the initial operation of the polymerization reaction. Moreover, one type of solvent may be sufficient as the superposition | polymerization solvent to clean, and two or more types of mixed solvent may be sufficient as it.

In the polymerization reaction mixture obtained at the end of the polymerization reaction, a solvent other than the polymer usually obtained is contained. When the said polymer is made into the lactone ring containing polymer mentioned later, it is not necessary to remove a solvent completely and to obtain a polymer in a solid state, but it is preferable to carry out the lactone cyclization condensation process which follows after the solvent containing state. In addition, if necessary, after obtaining in a solid state, you may re-add the solvent suitable for the following lactone cyclization condensation process.

Although the color of the acrylic resin obtained by the polymerization reaction is not particularly determined, it is suitable for the transparent and low yellowing not to lose the original characteristics of the acrylic resin. For example, the acrylic resin has a haze value of 3 or less, more preferably 2 or less, and most preferably 1 or less. Moreover, the YI (yellow index) value of the molded object is 10 or less, Preferably it is five or less.

(2. Lactone ring-containing polymer)

Since the acrylic resin has high transparency, heat resistance, optical properties, and the like, and can sufficiently exhibit characteristics for various optical uses, a lactone ring structure according to intramolecular cyclization reaction is introduced into a copolymer of (meth) acrylic acid ester. It is preferable to have what is called a lactone ring containing polymer, and it is very preferable to have it as a main component. "Main component" means that it contains 50 weight% or more with respect to the total weight of acrylic resin. Although it does not specifically limit as a lactone ring containing polymer, Preferably, it has a lactone ring structure represented by following General formula (2).

[Formula 2]

(In formula, R <^3> , R <^4> , R <^5> represents an organic residue of C1-C20 each independently, or an organic residue may contain an oxygen atom.)

The content of the lactone ring structure represented by the general formula (2) in the lactone ring-containing polymer structure is preferably 4% by weight or more and 90% by weight or less, more preferably 10% by weight or more and 70% by weight or less, even more preferably 10 It is at least 60% by weight, particularly preferably at least 10% by weight and at most 50% by weight. When the said content rate is less than 5 weight%, heat resistance, solvent resistance, and surface hardness may become inadequate and it is unpreferable. Moreover, when the said content rate is more than 90 weight%, moldability may fall and it is unpreferable.

The lactone ring-containing polymer may have a structure other than the lactone ring structure represented by General Formula (2). Although it does not specifically limit as structures other than the lactone ring structure represented by General formula (2), For example, (meth) acrylic acid ester is selected from the hydroxyl group containing monomer, unsaturated carboxylic acid, and the monomer represented by following General formula (3) at least. The polymer structural unit (repeated structural unit) which superposes | polymerizes and forms one type is preferable.

[Formula 3]

Wherein R ⁶ represents a hydrogen atom or a methyl group, X represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group, an -OAc group, a -CN group, a -CO-R ⁷ group, or a -COR ⁸ group Ac group represents an acetyl group, R ⁷ and R ⁸ represents a hydrogen atom or an organic residue having 1 to 20 carbon atoms.)

In the lactone ring-containing polymer, the content of the structure other than the lactone ring structure represented by the general formula (2) is preferably 10% by weight or more in the case of the polymer structural unit (repeated structural unit) formed by polymerizing (meth) acrylic acid ester. Within the range of 95 weight% or less, More preferably, in the range of 10 weight% or more and 90 weight% or less, More preferably, in the range of 40 weight% or more and 90 weight% or less, Especially preferably, 50 weight% or more and 90 weight% It is in the range of% or less.

In addition, in the case of the polymer structural unit (repeated structural unit) which superposes | polymerizes and forms a hydroxyl-containing monomer, the content rate of structures other than the lactone ring structure represented by General formula (2) becomes like this. Preferably it is 0 to 30 weight% of range More preferably in the range of 0% by weight to 20% by weight, still more preferably in the range of 0% by weight to 15% by weight, particularly preferably in the range of 0% by weight to 10% by weight to be.

Moreover, in the case of the polymer structural unit (repeated structural unit) which superposed | polymerized and formed the unsaturated carboxylic acid, the content rate of structures other than the lactone ring structure represented by General formula (2) becomes like this. Preferably it is 0 to 30 weight% of range. More preferably in the range of 0% by weight to 20% by weight, even more preferably in the range of 0% by weight to 15% by weight, particularly preferably in the range of 0% by weight to 10% by weight. .

Moreover, in the case of the polymer structural unit (repeated structural unit) which superposes | polymerizes and forms the monomer represented by General formula (3), the content rate of structures other than the lactone ring structure represented by General formula (2) becomes like this. Within the range of weight% or less, More preferably, in the range of 0 weight% or more and 20 weight% or less, More preferably, In the range of 0 to 15 weight%, Especially preferably, 0 to 10 weight% It is in the following ranges.

Although the manufacturing method of a lactone ring containing polymer is not specifically limited, Preferably, after obtaining a polymer which has a hydroxyl group and an ester group in a molecular chain by a superposition | polymerization process, a lactone ring structure is introduce | transduced into a polymer by heat-processing the said polymer. It can obtain by carrying out lactone ring condensation reaction.

The high heat resistance is imparted to the polymer by forming the lactone ring structure in the polymer chain (in the polymer backbone). If the reaction rate of the cyclization condensation reaction leading to the lactone ring structure is insufficient, the heat resistance may not be sufficiently improved, the condensation reaction may occur during molding by the heat treatment during molding, or the alcohol formed may be present in the molded article as foam or silver streaks. It is not desirable because there is.

It does not specifically limit about the method of heat-processing the said polymer for lactone ring condensation reaction, A well-known method can be used. For example, the polymerization reaction mixture containing the solvent obtained by the polymerization process may be heat-treated as it is. Moreover, heat processing can also be performed using a ring-closure catalyst in presence of a solvent as needed. Moreover, it is also possible to heat-process using the heating furnace, a reaction apparatus, the extruder with a devolatilization system, etc. which have a vacuum apparatus or a devolatilization apparatus for removing volatile matter.

When carrying out a cyclization condensation reaction, another acrylic resin can coexist in addition to the said polymer. In the case of the cyclization condensation reaction, an esterification catalyst or a transesterification catalyst such as p-toluenesulfonic acid, which is generally used as a catalyst for cyclization condensation reaction, may be used, if necessary, and acetic acid, propionic acid, benzoic acid, acrylic acid, methacrylic acid, and the like. The organic carboxylic acids of can also be used as a catalyst. As indicated in Japanese Patent Application Laid-Open No. 61-254608 or Japanese Patent Application Laid-Open No. 61-261303, basic compounds, organic carbonates, carbonates and the like can also be used.

When carrying out cyclization condensation reaction, it is preferable to use an organophosphorus compound as a catalyst. By using an organophosphorus compound as a catalyst, it is possible to improve the cyclization condensation reaction rate and to significantly reduce the coloring of the obtained lactone ring-containing polymer. Moreover, by using an organophosphorus compound as a catalyst, it is possible to suppress the molecular weight fall which may occur when using the devolatilization process mentioned later, and can provide outstanding mechanical strength.

As organophosphorus compounds which can be used as a catalyst in the cyclization condensation reaction, for example, alkyl (aryl) aphosphonic acids such as methyl phosphonic acid, ethyl phosphonic acid, and phenyl aphosphonic acid (however, these are tautomers) Alkyl (aryl) phosphinic acid) and diesters or monoesters thereof; Dialkyl (aryl) phosphinic acids such as dimethylphosphinic acid, diethylphosphinic acid, diphenylphosphinic acid, phenylmethylphosphinic acid and phenylethylphosphinic acid and esters thereof; Alkyl (aryl) phosphonic acids such as methyl phosphonic acid, ethyl phosphonic acid, trifluoro methyl phosphonic acid and phenyl phosphonic acid and their diesters or monoesters; Alkyl (aryl) aphosphinic acids and esters thereof such as methyl aphosphinic acid, ethyl aphosphinic acid and phenyl aphosphinic acid; Phosphite diesters or monoesters such as methyl phosphite, ethyl phosphite, phenyl phosphite, dimethyl phosphite, diethyl phosphite, diphenyl phosphite, trimethyl phosphite, triethyl phosphite and triphenyl phosphite; Methyl phosphate, ethyl phosphate, 2-ethylhexyl phosphate, isodecyl phosphate, lauryl phosphate, stearyl phosphate, isostearyl phosphate, phenyl phosphate, dimethyl phosphate, diethyl phosphate, di-2-ethylhexyl phosphate, diiso phosphate Decyl, dilauryl phosphate, distearyl phosphate, diisostearyl phosphate, diphenyl phosphate, trimethyl phosphate, triethyl phosphate, triisodecyl phosphate, trilauryl phosphate, tristearyl phosphate, triisostearyl phosphate Phosphoric acid diesters such as triphenyl or monoesters or triesters; Mono, di or trialkyl (aryl) such as methyl phosphine, ethyl phosphine, phenyl phosphine, dimethyl phosphine, diethyl phosphine, diphenyl phosphine, trimethyl phosphine, triethyl phosphine and triphenyl phosphine Phosphine; Alkyl (aryl) halogen phosphines such as methyl dichlorophosphine, ethyl dichlorophosphine, phenyldichlorophosphine, dimethylchlorophosphine, diethylchlorophosphine and diphenylchlorophosphine; Methyl phosphine, ethyl phosphine oxide, phenyl phosphine oxide, dimethyl oxide phosphine, diethyl phosphine oxide, diphenyl phosphine oxide, trimethyl phosphine oxide, triethyl phosphine oxide, triphenyl phosphine oxide, etc. Monooxide, di or trialkyl (aryl) phosphine; Halogenated tetraalkyl (aryl) phosphoniums such as tetramethyl phosphonium chloride, tetraethyl phosphonium chloride and tetraphenyl phosphonium chloride; And the like. Among these, due to its high catalytic activity and low colorability, alkyl (aryl) aphosphonic acid, phosphite diester or monoester, phosphate diester or monoester, alkyl (aryl) phosphonic acid are preferable, and allyl (aryl) aphosphonic acid, Phosphoric acid diesters or monoesters, phosphoric acid diesters or monoesters are more preferred, and alkyl (aryl) aphosphonic acid, phosphoric acid diesters or monoesters are very preferred. Only one type may be used for these organophosphate compounds, and they may use two or more types together.

The amount of the catalyst used in the cyclization condensation reaction is not particularly limited, but is preferably in the range of 0.001 to 5% by weight, more preferably in the range of 0.01 to 2.5% by weight, still more preferably 0.01 to the polymer. It is in the range of -1 weight%, Very preferably, it is in the range of 0.05 to 0.5 weight%. If the amount of the catalyst is less than 0.001% by weight, it may not be possible to sufficiently improve the reaction rate of the cyclization condensation reaction, while if the amount of the catalyst is more than 5% by weight, it may cause coloration or melt molding by crosslinking the polymer. Because it is not desirable.

The addition time of a catalyst is not specifically limited, It may add in the initial stage of reaction, may add in the middle of reaction, or may add both time mentioned above.

It is preferable to perform a cyclization condensation reaction in presence of a solvent, and to also use the devolatilization process at the time of cyclization condensation reaction. In this case, the form which combines the devolatilization process over the whole cyclization condensation reaction, and the form which does not use the devolatilization process in the whole process of a cyclization condensation reaction, but also only in a part of process is mentioned. In the method of using the devolatilization step, the reaction equilibrium is advantageous to the production side because the alcohol produced by condensation in the condensation cyclization reaction is forcibly removed and removed.

The devolatilization process refers to a process of removing by-product alcohol, if necessary, under reduced pressure heating conditions according to a cyclization condensation reaction leading to a volatile component such as a solvent and a residual monomer and a lactone ring structure. If this removal process is not sufficient, the remaining volatile matter in the produced resin will increase, resulting in problems such as coloring due to deterioration at the time of production, molding defects such as foam or silver streak, and the like.

In the case of using the devolatilization process as a whole through the cyclization condensation reaction, the apparatus to be used is not particularly limited, but in order to implement the present invention more effectively, a devolatilization device or a vented extruder comprising a heat exchanger and a devolatilization tank, and the devolatilization device And it is preferable to use what arrange | positioned the said extruder in series, and it is more preferable to use the devolatilization apparatus or vent type extruder which consists of a heat exchanger and a devolatilization tank.

When using the devolatilization apparatus which consists of the said heat exchanger and a devolatilization tank, the reaction process temperature is preferable in the range of 150-350 degreeC, and more preferable in the range of 200-300 degreeC. If the reaction treatment temperature is lower than 150 ° C., the cyclization condensation reaction may be insufficient to increase the remaining volatile content. If the reaction treatment temperature is higher than 350 ° C., coloring or decomposition may occur.

In the case of using the devolatilization device comprising the heat exchanger and the devolatilization tank, the pressure during the reaction treatment is preferably in the range of 931 to 1.33 hPa (700 to 1 mmHg), and more preferably in the range of 798 to 66.5 hPa (600 to 50 mmHg). If the pressure is higher than 931 hPa, there is a problem that volatile components including alcohol are likely to remain. If the pressure is lower than 1.33 hPa, industrial implementation is difficult.

In the case of using the vented extruder, any one or several vents may be used, but it is preferable to have several vents.

The reaction treatment temperature at the time of using the said vent type extruder is preferable in the range of 150-350 degreeC, and more preferable in the range of 200-300 degreeC. If the temperature is lower than 150 ° C., the cyclization condensation reaction may be insufficient to increase the remaining volatile content. If the temperature is higher than 350 ° C., coloring or decomposition may occur.

The pressure at the time of reaction treatment in the case of using the said vent type extruder is preferable in the range of 931-11.3 hPa (700-1 mmHg), and more preferable in the range of 798-13.3 hPa (600-10 mmHg). If the pressure is higher than 931 hPa, there is a problem that volatile components including alcohol are likely to remain. If the pressure is lower than 1.33 hPa, industrial implementation is difficult.

In addition, in the case of using the devolatilization process throughout the cyclization condensation reaction, the physical properties of the lactone ring-containing polymer obtained under strict heat treatment conditions may deteriorate as described later. It is preferable to carry out using a catalyst of, using a vented extruder or the like under mild conditions as possible.

In addition, in the case of using the devolatilization process throughout the cyclization condensation reaction, the polymer obtained in the polymerization process is preferably introduced into the cyclization condensation reaction system together with the solvent, in which case, once again, such as a vented extruder, It can also be passed through the reactor system.

The devolatilization step may not be used throughout the course of the cyclocondensation reaction, but may be used only in a part of the process. For example, the apparatus from which the polymer is produced is heated again, and if necessary, a part of the devolatilization step is combined to advance the cyclization condensation reaction to some extent, and then a cyclization condensation reaction is also completed to simultaneously complete the reaction. It is a form to let.

In the form that combines the devolatilization process throughout the above-mentioned cyclization condensation reaction, for example, when the polymer is heat treated at a high temperature of about 250 ° C. or higher using a twin screw extruder, the cyclization condensation reaction depends on the difference in thermal history. Before this occurs, some decomposition and the like may occur, and the physical properties of the obtained lactone ring-containing polymer may deteriorate. Therefore, if the cyclization condensation reaction is carried out to some extent before the cyclization condensation reaction that combines the devolatilization process at the same time, the reaction conditions in the second half can be alleviated, and the deterioration of the physical properties of the obtained lactone ring-containing polymer can be suppressed. It is preferable because there is.

In a particularly preferred embodiment, the devolatilization step is started over time from the start of the cyclization condensation reaction, that is, the cyclization condensation reaction rate is raised to some extent by the cyclization condensation reaction of the hydroxyl group and the ester group present in the molecular chain of the polymer obtained in the polymerization step in advance. Then, the form which takes the cyclization condensation reaction which combined the devolatilization process simultaneously is mentioned. Specifically, for example, using a cauldron-type reactor in advance in the presence of a solvent to proceed the cyclization condensation reaction to a certain reaction rate, and then a devolatilization device consisting of a reactor equipped with a devolatilizer, for example, a heat exchanger and a devolatilizer The form which completes a cyclization condensation reaction with a vent type extruder etc. is mentioned preferably. Especially in this form, it is more preferable that the catalyst for cyclization condensation reaction exists.

As described above, the cyclization condensation reaction rate is raised to some extent by the cyclization condensation reaction of hydroxyl groups and ester groups present in the molecular chain of the polymer obtained in the polymerization step, followed by the cyclization condensation reaction using a devolatilization process simultaneously. It is a preferable form in the state which obtained a polymer. This form also increases the cyclization condensation reaction rate, further increases the glass transition temperature, thereby obtaining a lactone ring-containing polymer excellent in heat resistance. In this case, as a criterion of the cyclization condensation reaction rate, in the dynamic TG measurement shown in the examples, the weight loss ratio between 150 and 300 ° C is preferably 2% or less, more preferably 1.5% or less, and even more preferably 1 Less than or equal to

The reactor that can be employed in the cyclization condensation reaction performed in advance before the cyclization condensation reaction simultaneously using the devolatilization process is not particularly limited, but preferably, a devolatilization device composed of an autoclave, a kiln-type reactor, a heat exchanger, and a devolatilization tank can be used. Moreover, the vent type extruder suitable for the cyclization condensation reaction which combined the devolatilization process simultaneously can also be used. More preferably, it is an autoclave, a kiln type reactor. However, even when using a reactor such as a vented extruder, the venting conditions are not relaxed or vented, or the temperature conditions, barrel conditions, screw shapes, screw operating conditions, etc. are adjusted, such as reaction conditions in an autoclave or kiln type reactor. It is possible to perform a cyclization condensation reaction in a state.

In the case of the cyclization condensation reaction which is performed in advance before the cyclization condensation reaction which simultaneously uses the devolatilization step, the method comprising (i) adding a catalyst and heating the mixture containing the polymer and the solvent obtained in the polymerization step preferably (ii) The method of heat-reacting with a catalyst and the method of performing electricity (i) or (ii) under pressurization are mentioned.

In addition, the "mixture containing a polymer and a solvent" used in a cyclization condensation reaction in a lactone cyclization condensation process can also use the polymerization reaction mixture obtained by the polymerization process as it is, and after removing a solvent, the solvent suitable for cyclization condensation reaction is added again. It means you can.

Although it does not specifically limit as a solvent which can be re-added at the time of the cyclization condensation reaction previously performed before the cyclization condensation reaction which combined the devolatilization process simultaneously, For example, aromatic hydrocarbons, such as toluene, xylene, ethylbenzene; Ketones such as methyl ethyl ketone and methyl isobutyl ketone; Although chloroform, DMSO, tetrahydrofran, etc. are also good, Preferably it is a solvent of the same kind as the solvent which can be used at a superposition | polymerization process.

Examples of the catalyst added in the method (i) include esterification catalysts or transesterification catalysts such as p-toluenesulfonic acid, basic compounds, organic carbonates, carbonates, and the like, which are generally used. Preference is given to using one organophosphorus compound.

The addition time of a catalyst is not specifically limited, It may add in the initial stage of reaction, may add in the middle of reaction, or may add both time mentioned above. The amount of the catalyst to be added is not particularly limited, but is preferably in the range of 0.001 to 5% by weight, more preferably in the range of 0.01 to 2.5% by weight, still more preferably 0.01 to 0.1, based on the weight of the weight. It is in the range of weight%, Very preferably in the range of 0.05 to 0.5 weight%. The heating temperature and the heating time of the method (i) are not particularly limited, but the heating temperature is preferably at least room temperature, more preferably at least 50 ° C., and the heating time is preferably in the range of 1 to 20 hours, more Preferably it is in the range of 2 to 10 hours. If the heating temperature is low or the heating time is short, the cyclization condensation reaction rate is lowered, which is not preferable. If the heating time is too long, coloring or decomposition of the resin may occur, which is not preferable.

As said method (ii), the method of heating the polymerization reaction mixture obtained at the superposition | polymerization process using a pressure-resistant kiln etc. as it is, etc. are mentioned, for example. As heating temperature, Preferably it is 100 degreeC or more, More preferably, it is 150 degreeC or more. As heating time, Preferably it is in the range of 1 to 20 hours, More preferably, it is in the range of 2 to 10 hours. If the heating temperature is low or the heating time is short, the cyclization condensation reaction rate is lowered, which is not preferable. If the heating time is too long, coloring or decomposition of the resin may occur, which is not preferable.

There is no problem even if it is pressurized depending on conditions with said method (i) and (ii). In addition, in the cyclization condensation reaction which is performed before the cyclization condensation reaction which combines the devolatilization process at the same time, there is no problem even if a part of the solvent volatilizes naturally during the reaction.

At the end of the cyclization condensation reaction, which is carried out before the cyclization condensation reaction in combination with the devolatilization step, that is, the weight loss rate between 150 and 300 ° C. of the dynamic TG measurement immediately before the initiation of the devolatilization step is preferably 2% or less. Preferably 1.5% or less, and even more preferably 1% or less. When the weight reduction rate is higher than 2%, even if the cyclization condensation reaction that simultaneously uses the devolatilization step is carried out, the cyclization condensation reaction rate does not rise to a sufficiently high level, and there is a possibility that the physical properties of the resulting lactone ring-containing polymer are lowered. In addition, when performing said cyclization condensation reaction, another thermoplastic resin can coexist in addition to a polymer.

As another thermoplastic resin, the thermoplastic resin thermodynamically compatible with a lactone ring containing polymer is preferable. For example, a copolymer containing a vinyl cyanide monomer unit and an aromatic vinyl monomer unit, specifically, an acrylonitrile-styrene copolymer, polyvinyl chloride resin, or methacrylic acid ester containing 50% by weight or more And polymers.

Among them, the acrylonitrile-styrene copolymer is excellent in compatibility, among other things, and a transparent molded article can be obtained without losing heat resistance. The thermodynamic compatibility of the lactone ring-containing polymer and other thermoplastic resins can be confirmed by measuring the glass transition point of the thermoplastic resin composition obtained by mixing them. Specifically, it can be said that the glass transition point measured by the differential scanning calorimetry is thermodynamically compatible with only one point being observed for the mixture of the lactone ring-containing polymer and other thermoplastic resins.

As other thermoplastic resins, when an acrylonitrile-styrene copolymer is used, the method of polymerizing a lactone ring-containing polymer and an acrylonitrile-styrene copolymer may be emulsion polymerization, suspension polymerization, solution polymerization, or bulking. Although a legal method etc. can be used, what was obtained by the solution polymerization method or the bulk polymerization method from the transparency and optical performance viewpoint of the optical film obtained is preferable.

In the case of the embodiment in which the hydroxyl group and the ester group present in the molecular chain of the polymer obtained in the polymerization step are subjected to cyclization condensation reaction in advance to raise the degree of cyclization condensation reaction to some extent, followed by the cyclization condensation reaction using a devolatilization step simultaneously. You may perform the cyclization condensation reaction which combined the devolatilization process simultaneously, without separating the polymer obtained by the cyclization condensation reaction (polymer which the hydroxyl group and ester group which exist in the molecular chain are cyclized condensation reaction), and a solvent. In addition, if necessary, a cyclization that simultaneously uses a devolatilization process after separating the polymer (a polymer in which at least a portion of the hydroxyl groups and ester groups present in the molecular chain are subjected to cyclization condensation reaction) and then adding the solvent again. You may perform a condensation reaction.

The devolatilization step is not limited to being completed at the same time as the cyclization condensation reaction, and may be completed over time from the end of the cyclization condensation reaction.

As described above, the lactone ring-containing polymer preferably uses a catalyst during the cyclization condensation reaction. However, if the catalyst remains in the resin, an unreacted ring-forming unit (that is, is not yet Alcohol may be generated by transesterification of an active hydrogen such as a hydroxyl group of a unit that does not form a ring or a small amount of water present in the system with an alkylester group, and foaming may occur. In order to prevent this foaming phenomenon, it is preferable to mix | blend a deactivator.

In general, when the catalyst used in the cyclization condensation reaction is an acidic substance, a neutral substance may be used to neutralize the catalyst remaining after the reaction. Therefore, when the catalyst used for the cyclization condensation reaction is an acidic substance, a basic substance is preferably used as a deactivator. The basic paper is not particularly limited as long as it does not generate a substance that inhibits the physical properties of the resin composition during thermal processing. For example, a metal carboxylate, a metal complex, a metal oxide, etc. are mentioned.

<Deactivator>

For example, when a lactone ring-containing polymer is used as the methacrylic acid resin, as described above, in the lactone cyclization condensation step, the hydroxyl group and the ester group present in the molecular chain of the polymer undergo cyclization to cause a de-alcohol reaction, which is a kind of transesterification. Thus, a lactone ring structure is formed in the molecular chain of the polymer (in the main skeleton of the polymer). In general, when the catalyst used for transesterification is an acidic substance, a basic substance may be used to neutralize the catalyst remaining after the reaction.

Therefore, the deactivator used in this case is a basic substance, and is not particularly limited as long as it does not generate a substance that inhibits the resin composition during thermal processing. For example, metal compounds such as metal salts, metal complexes and metal oxides may be used. Can be mentioned.

The metal constituting the metal compound is not particularly limited as long as it does not impair the physical properties of the resin composition or the like and does not cause environmental pollution at the time of disposal. Examples thereof include alkali metals such as lithium, sodium, and potassium; Alkaline earth metals such as magnesium, calcium, strontium and barium; Positive substances such as zinc, aluminum, tin and lead; zirconium; And the like.

Of these metals, typical metal elements are preferred in view of low coloration of the resin, alkaline earth metals and amphoteric metals are particularly preferred, and calcium, magnesium and zinc are most preferred. The metal salt is preferably a metal salt of an organic acid in view of dispersibility to a resin and solubility in a solvent, and very preferably a metal salt of an organic carboxylic acid, an organic phosphate compound and an acidic organic sulfur compound. The organic carboxylic acid constituting the metal salt of the organic carboxylic acid is not particularly limited, but for example, formic acid, acetic acid, propionic acid, butyric acid, gil acetic acid, hexane, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, and laurin Acids, myristic acid, palmitic acid, stearic acid, fehenic acid, tridecanoic acid, pentadecanoic acid, heptadecanoic acid, lactic acid, malic acid, citric acid, oxalic acid, malonic acid, succinic acid, fumaric acid, maleic acid, adipic acid, etc. Can be mentioned.

The organophosphorus compounds constituting the metal salt of organophosphoric acid include alkyl (aryl) phosphonic acids such as methyl aphosphonic acid, ethyl aphosphonic acid, and phenyl aphosphonic acid (however, these may be alkyl (aryl) phosphinic acids which are phase variants). And monoesters or diesters thereof; Dialkyl (aryl) phosphinic acids and esters thereof such as dimethyl phosphinic acid, diester phosphinic acid, diphenylphosphinic acid, phenylmethylphosphinic acid and phenylethylphosphinic acid; Alkyl (aryl) phosphonic acids such as methyl phosphonic acid, ethyl phosphonic acid, trifluoromethyl phosphonic acid and phenyl phosphonic acid, and monoesters or diesters thereof; Alkyl (aryl) aphosphinic acids and esters thereof such as methyl aphosphinic acid, ethyl aphosphinic acid and phenyl aphosphinic acid; Phosphite monoesters, diesters or triesters such as methyl phosphite, ethyl phosphite, phenyl phosphite, dimethyl phosphite, diethyl phosphite, diphenyl phosphite, trimethyl phosphite and triethyl phosphite; Methyl phosphate, ethyl phosphate, 2-ethylhexyl phosphate, octyl phosphate, isodecyl phosphate, lauryl phosphate, stearyl phosphate, isostearyl phosphate, phenyl phosphate, dimethyl phosphate, diethyl phosphate, di-2-ethylhexyl phosphate, Diisodecyl phosphate, dilauryl phosphate, distearyl phosphate, diisostearyl phosphate, diphenyl phosphate, trimethyl phosphate, triethyl phosphate, triisodecyl phosphate, trilauryl phosphate, tristearyl phosphate, triiso phosphate Phosphoric acid monoesters, diesters or triesters such as aryl and triphenyl phosphate; Mono-di- or tri-alkyl such as methylphosphine, ethylphosphine, phenylphosphine, dimethylphosphine, diethylphosphine, diphenylphosphine, trimethylphosphine, triethylphosphine, triphenylphosphine ( Aryl) phosphine; Alkyl (aryl) halogen phosphines such as methyl dichlorophosphine, ethyl dichlorophosphine, phenyldichlorophosphine, dimethylchlorophosphine, diethylchlorophosphine and diphenylchlorophosphine; Methyl phosphine, ethyl phosphine oxide, phenyl phosphine oxide, dimethyl oxide phosphine, diethyl phosphine oxide, diphenyl phosphine oxide, trimethyl phosphine oxide, triethyl phosphine oxide, triphenyl phosphine oxide, etc. Mono-, di- or tri-alkyl (aryl) phosphines; Halogenated tetraalkyl (aryl) phosphoniums such as tetramethyl phosphonium chloride, tetraethyl phosphonium chloride and tetraphenyl phosphonium chloride; And the like.

Examples of the acidic organic sulfur compound constituting the metal salt of the acidic organic sulfur compound include p-toluenesulfonic acid, methanesulfonic acid, benzenesulfonic acid, xylenesulfonic acid, and dodecylbenzenesulfonic acid. Although it does not specifically limit as an organic component in a metal complex, Acetyl acetone etc. are mentioned.

On the other hand, when the catalyst used for transesterification is a basic substance, what is necessary is to deactivate the catalyst which remains after reaction using acidic substances, such as an organic phosphate compound, for example. In any case, these deactivators may be used alone or in combination of two or more. In addition, a deactivator can add any form, such as a solid, a powder, a granule, a dispersion, a suspension, and aqueous solution, and is not specifically limited.

On the other hand, when the catalyst used for transesterification is a basic substance, what is necessary is to deactivate the catalyst which remains after reaction using acidic substances, such as an organophosphorus compound, for example. In any case, these deactivators may be used alone or in combination of two or more. In addition, a deactivator can add any form, such as a solid, a powder, a granule, a dispersion, a suspension, and aqueous solution, and is not specifically limited.

What is necessary is just to adjust suitably the compounding quantity of a deactivator according to the usage-amount of the catalyst used for the cyclization condensation reaction, and it is not specifically limited. For example, it is preferably 10 ppm or more and 10,000 ppm or less, more preferably 50 ppm or more and 5,000 ppm or less, even more preferably 100 ppm or more and 3000 ppm or less based on the mass of the lactone-containing polymer. When the said compounding quantity is less than 10 ppm, use of a deactivator becomes inadequate, and foaming may generate | occur | produce at the time of heating, and it is unpreferable. If the amount exceeds 10,000 ppm, the use of the deactivator is saturated and at the same time, the deactivator is used more than necessary, which is not preferable because the manufacturing price may increase.

The deactivator may be added at any time after the lactonation structure is formed. For example, a method of adding a lactone ring-containing polymer, a deactivator, and other components at the same time by adding at a predetermined stage during the production of the lactone ring-containing polymer and then kneading the same by heating and melting; A method of preparing a lactone ring-containing polymer and then adding a deactivator, and simultaneously kneading the lactone ring-containing polymer, deactivator, and other components by heating and melting; Lactone ring-containing polymers, other components and the like are heated and melted, and a quencher, other components and the like are added and kneaded therein; And the like.

The lactone ring-containing polymer preferably has a weight average molecular weight of 1,000 or more and 2,000,000 or less, more preferably 5,000 or more and 1,000,000 or less, even more preferably 10,000 or more and 500,000 or less, and very preferably 50,000 or more and 500,000 or less.

The lactone ring-containing polymer preferably has a weight loss rate of 1% or less, more preferably 0.5% or less, even more preferably 0.3% or less between 150 and 300 ° C in the dynamic TG measurement.

Since the lactone ring-containing polymer has a high cyclization condensation reaction rate, it is possible to avoid the drawback of bubbles or silver streaks in the molded article after molding. In addition, the lactone ring-containing polymer obtained has sufficiently high heat resistance in order to sufficiently introduce the lactone ring structure into the polymer by a high cyclization condensation reaction rate.

In the thermogravimetric analysis (TG), the lactone ring-containing polymer preferably has a 5% weight reduction temperature of 280 ° C or higher, more preferably 290 ° C or higher, even more preferably 300 ° C or higher. In thermogravimetric analysis (TG), the 5% weight loss temperature is an indicator of thermal stability, and if it is less than 280 ° C, there is a fear that sufficient thermal stability cannot be exhibited.

The total amount of residual volatile matter contained in the lactone ring-containing polymer is preferably 5,000 ppm or less, more preferably 2,000 ppm or less. When the total amount of residual volatile matter is more than 5,000 ppm, it may cause the molding defect, such as coloring, foaming, or silver streaks due to deterioration or the like during molding.

The lactone ring-containing polymer preferably has a total light transmittance of 85% or more, more preferably 88% or more, even more preferably 90% or more, as measured by a method according to ASTM-D-1003 of a molded article obtained by injection molding. to be. The total light transmittance is a criterion for transparency, and if it is less than 85%, the transparency is lowered and there is a possibility that it cannot be used for the intended purpose.

(3. Physical properties of optical film)

The optical film of the present invention has an acrylic system having a viscosity of 250 Pa · s or more and 1000 Pa · s or less at a resin temperature of 270 ° C. when the glass transition temperature is 110 ° C. to 200 ° C. and the shear rate is 100 (1 / s). It is an optical film which has resin, and the said optical film is content of impurity 10 pieces / m <^2> or less.

In general, when a glass material is in a low temperature glass state and in a high temperature supercooled liquid state, a material capable of becoming a glass is bounded by a narrow temperature range inherent to the material, such as a coefficient of thermal expansion, electrical conductivity, viscosity, and the like. Other physical quantity changes rapidly. The glass transition temperature refers to the temperature zone at this boundary, the temperature at which polymer molecules begin microbrown movement.

There are various measuring methods for the glass transition temperature. In this specification, the differential scanning calorimeter (DSC) defines the temperature required by the midpoint method according to ASTM-D-3418. The optical film of the present invention has an acrylic resin having a glass transition temperature of 110 ° C. or more and 200 ° C. or less, and the acrylic resin is generally recognized as a heat-resistant acrylic resin among those skilled in the art.

If the glass transition temperature is higher than 200 ° C., the flowability of the molten resin is poor, so that molding of the film is difficult. Glass transition temperature becomes like this. Preferably it is 115 degreeC or more and 180 degrees C or less, More preferably, it is 120 degreeC or more and 160 degrees C or less.

In the case where the shear rate is 100 (1 / s), the acrylic resin needs to have a viscosity of 250 Pa · s or more and 1000 Pa · s or less at a resin temperature of 270 ° C. Shear velocity also refers to a change in flow rate based on the positional difference in the direction perpendicular to the wall when the flow of fluid follows the wall. The shear rate is usually at its maximum on the wall and lowers as it falls off the wall. In addition, a shear rate of 100 (1 / s) is the center of the speed normally acting in an extruder.

The acrylic resin preferably has a viscosity of 300 Pa · s or more and 2000 Pa · s or less when the resin temperature is 250 ° C. when the shear rate is 100 (1 / s).

Moreover, it does not specifically limit as a method of measuring the said viscosity, It can measure using a conventionally well-known rheometer etc.

The optical film which concerns on this invention contains the said acrylic resin. As a component which can be contained other than the said acrylic resin, polymers (other polymer) other than an acrylic resin, other additives, etc. are mentioned.

As another polymer, For example, olefin type polymers, such as polyethylene, a polypropylene, an ethylene propylene copolymer, and a poly (4-methyl-1- pentene); Halogen-containing polymers such as vinyl chloride and vinyl chloride resin; Acrylic polymers such as polymethyl methacrylate; Styrene-based polymers such as polystyrene, styrene-methyl methacrylate copolymer, styrene-acrylonitrile copolymer, and acrylonitrile-butadiene-styrene block copolymer; Polyesters such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate; Polyamides such as nylon 6, nylon 66 and nylon 610; Polyacetals; Polycarbonate; Polyphenylene oxide; Polyphenylene sulfide; Polyether ether ketone; Polysulfones; Polyethersulfone; Polyoxybenzylene; Polyamideimide; Rubber polymers such as ABS resin and ASA resin containing polybutadiene rubber and acrylic rubber; And the like.

The content ratio of the other polymer in the optical film is preferably 0% by weight or more and 50% by weight or less, more preferably 0% by weight or more and 40% by weight or less, still more preferably 0% by weight or more and 30% by weight. Very preferably, they are 0 weight% or more and 20 weight% or less.

As said other additive, For example, antioxidant, such as a hindered phenol type, phosphorus type, sulfur type; Stabilizers such as light stabilizers, weather stabilizers and thermal stabilizers; Reinforcing materials such as glass fibers and carbon fibers; Ultraviolet absorbers such as phenylsaltylate, (2, 2'-hydroxy-5-methylphenyl) benzotriazole and 2-hydroxybenzophenone; Near infrared absorbers; Flame retardants such as tris (dibromopropyl) phosphate, triaryl phosphate and antimony oxide; Antistatic agents such as anionic, cationic and nonionic surfactants; Coloring agents such as inorganic pigments, organic pigments, and dyes; Organic pyramids and inorganic pyramids; Resin modifiers; Organic fillers and inorganic fillers; Plasticity; Lubricant; Antistatic agent; Flame retardant; And the like.

The content ratio of the other additives in the optical film is preferably 0% by weight or more and 5% by weight or less, more preferably 0% by weight or more and 2% by weight or less, still more preferably 0% by weight or more and 0.5% by weight. It is as follows.

It is preferable to melt-knead the said other polymer and additive with an acryl-type resin before forming a film.

The optical film has an impurity content of 10 pieces / m ² or less. Examples of the impurity include carbides (so-called " carbon foreign matters &quot;) generated by acrylic resin being partially overheated and deteriorated during melt kneading of raw materials in the manufacturing process of the optical film.

Content of the impurity in an optical film can be measured by the method according to the external appearance observation method of JISK6718, for example. Specifically, it can be measured by first visually inspecting an optical film under scattered light and visually counting an impurity of 20 µm or more under a microscope having a magnification of 20 to 100 times. Since the optical film of the present invention has a very small content of impurities of 10 / m ² or less, the optical film is excellent in physical properties such as glass transition temperature and viscosity and excellent in appearance.

In one embodiment, it is preferable that content of volatile organics of the optical film of this invention is 1000 ppm or less, and it is more preferable that it is 600 ppm or less. The volatile organics are mainly as small as possible when the resin is pushed out of the extruder into the atmosphere, accumulate in the dice, and because they are discontinuously transferred to the film surface, thereby deteriorating the appearance, it is preferable to use as little as possible. In addition, since the volatile organic substance may bleed out at the time of preservation or use of an optical film, and may damage the external appearance of an optical film, it is preferable that it is as little as possible. The optical film of this embodiment has an excellent appearance since the content of volatile organic matter is small as described above.

The volatile organic matter is caused by partial decomposition degradation of the acrylic resin as a raw material, and is likely to occur when the acrylic resin is molded at a high temperature of + 145 ° C or higher. As a volatile organic substance, (meth) acrylic acid ester, such as methyl methacrylate, is mentioned, for example. The method for measuring the content of volatile organics is not particularly limited. For example, it can measure using conventionally well-known methods, such as gas chromatography.

Although the optical film of this invention can be shape | molded by shaping | molding methods, such as a melt extrusion method, a melt cast method, a calender method, and a compression molding method, Preferably it is manufactured by the manufacturing method of the optical film which concerns on this invention. . Then, the manufacturing method of the optical film which concerns on this invention is demonstrated next.

[2. Manufacturing Method of Optical Film]

In the method for producing an optical film according to the present invention, a barrier flight type screw or a screw including a mixing section is used, and the temperature of the cylinder and the die of the extruder is less than the glass transition temperature of the acrylic resin + 145 ° C. It demonstrates by temperature and is a method of shape | molding acrylic resin by melt extrusion method.

The " barrier flight type screw " is a thermoplastic resin kneading screw rotatably disposed in a cylinder, and having a main flight for discharging the solid resin pellets supplied into the cylinder into a molten state through a semi-melt state, between the main flights. An auxiliary flight for dividing the gap portion is formed in at least one portion of the gap portion formed at. The "barrier flight type screw" is also used as an alias, such as "double flight type screw", "damflight type screw", etc. In this specification, "barrier flight type screw" shall also include the screw of the said alias.

1 is a side view showing an embodiment of a barrier flight type screw. In FIG. 1, the barrier flight type screw 1 has the main flight 2 and the auxiliary flight 3, and is comprised from the supply part 4, the melt promotion part 5, and the measurement part 6. As shown in FIG. The primary flight 2 is usually formed in one spiral successively from the screw base side rather than directly below the hopper to the end of the screw which is the end of the screw from which the molten resin is sent. (3) is helically formed continuously in at least one part of the clearance part formed between the main flights 2 so that the clearance part may be divided into 2 parts.

The L / D of the barrier flight type screw 1 (L represents the cylinder length of the extruder, D represents the inner diameter of the cylinder) is not particularly limited, but is preferably 10 or more and 100 or less and 20 or more in order to obtain sufficient plasticization or kneading state. 50 or less are more preferable, and 25 or more and 40 or less are the most preferable. If L / D is 10 or less, it is difficult to obtain sufficient plasticization or kneading state, and if it is 100 or more, excessive shear heating may be applied to the resin and the resin may decompose.

The supply part 4 is a stable supply and preheating of the raw material, and a groove having an appropriate depth is selected according to the type of raw material. The melt promotion part 5 is a part which arrange | positions the auxiliary flight 3 which is smaller about 1-3 mm diameter than the outer diameter of the main flight 2 between the main flights 2. The depth of the groove is deep so that excessive shear is not applied to the molten resin, and the resin temperature can be kept low, so that the desired temperature can be easily set. In addition, the depth of the solid groove decreases and becomes shallow to the extent that the resin does not block at the end portion thereof. The L / D of the melting accelerator 5 is not particularly limited, but is preferably about 10 to 15 for non-vented screws and about 5 to 10 for vent screws.

3 is a side view showing one embodiment of a screw including a mixing section. In FIG. 3, the mixing section screw (a) has a main flight (b) and a mixing section (c), and is composed of a supply section (d), a melting accelerator (e), and a metering section (f). The main flight (b) is usually composed of one in a row from the end of the screw machine to the start of the mixing section rather than the portion just below the hopper. Moreover, it is formed continuously in a spiral form from the mixing section end part (the front end side of the measurement part f) to the screw front end part which is the end of the side from which the resin of the screw melt is sent. In addition, depending on the structure of the mixing section, a spiral section may be formed continuously in the whole including the mixing section.

A screw including a mixing section is a screw in which a mixing section portion c, which is an element for completely plasticizing and melting, is inserted as part of the screw, and the resin is dispersed and mixed by being efficiently sheared in the mixing section portion c. In FIG. 3, although the mixing section part c is drawn with the dashed-dotted line, if it has the said use, it is not specifically limited. As an example of the mixing section mechanism of the mixing section part c, a dalmedia type, a full ted type, a pin type, a Murdock type, a Gregory type, a unimelt type, etc. are mentioned.

The L / D of the screw including the mixing section, the supply portion, the melting accelerator, the depth of the groove, and the like may be the same as the barrier flight type screw. The L / D of the mixing section part c is not particularly limited but is preferably about 1 to 10. It is also possible to combine barrier flight type screws with screws with mixing sections.

The metering section 6 is a boost and homogeneous ripening part. It is preferable that L / D is about 4-5. In the case where the barrier flight type screw illustrated in FIG. 1 is used, when the vent part (volatile removal means) 12, which will be described later, is provided in the extruder 100, the vent part (volatile removal means) 12 is melt-promoted (4). It is preferable to install so as to be located at the rear part of the) and in front of the metering part (6).

Next, the manufacturing method of the optical film of this invention is demonstrated, referring FIG. FIG. 2 is a side view showing an outline of the configuration of an extruder equipped with a barrier fly screw in one embodiment. FIG. In FIG. 2, the extruder 100 includes a vari-flight screw 1, a cylinder 10, a temperature unit 11, a vent section (a volatile removal water) 12, a hopper 13, a die 14, a gear. The pump 15 and the filter 16 are included. Instead of the barrier flight type screw 1, it is also possible to use a screw a comprising the mixing section shown in FIG.

The material of the member constituting the extruder 100 is not particularly limited, and steel of SCM system, stainless steel of SUS system, or the like can be used. In addition, the surface of the barrier flight type screw 1, the cylinder 10, and the die 14 is plated with chromium, nickel, titanium, or the like, and the TiN, TiAIN, TiCN, CrN, DLC, etc., by PVD (Physical Vapor Deposition) method. It is preferable to use a film having a coating such as (diamond-shaped carbon), a thermal sprayed tungsten carbide or other ceramic, a nitrided surface, or the like. Such surface treatment is preferable in that a uniform melt state of the resin can be obtained because the coefficient of friction with the resin becomes small.

The barrier flight type screw 1 is configured to be rotatable in the cylinder 10. The pellets of the acrylic resin supplied to the extruder 100 are preferably preheated at an appropriate temperature of not more than Tg before being put into the hopper 13 or in the hopper 13. By preheating the resin, the molding temperature can be lowered, which enables more stable molding and at the same time prevents the generation of impurities. If the preheating temperature is lower than 40 ℃, there is no effect of preheating. If the preheating temperature is higher than the resin Tg, the resin pellets may be fused and solidified in the hopper.

In addition, it is preferable to dry the resin for the purpose of removing moisture, oxygen, remaining monomers, remaining solvent, etc. contained in the resin, and inert gas circulation such as dehumidifying dryer, vacuum dryer, nitrogen, etc. together with the preliminary heating. It is preferable to dry using a type | mold dryer. It is also preferable to dry in the hopper 13.

In the method of the present invention, it is preferable to heat-melt the resin in the cylinder 10 and the hopper 13 in which the barrier-flighted screw 1 is inserted and in the absence of oxygen, and to replace it with an inert gas such as nitrogen gas. It is preferable. For example, it is implemented by introducing nitrogen gas into the lower part of the hopper 13. By maintaining the state without oxygen, generation | occurrence | production of an impurity in a film can be further prevented.

Pellets of the acrylic resin supplied from the hopper 13 into the cylinder 10 are discharged toward the front of the cylinder 10 (leftward in the drawing) by the rotation of the barrier-flighted screw 1, and then in a solid state to a semi-melt state. Change, and also change from the semi-melt state to the molten state. In addition, the hopper 13 may be equipped with cooling means, such as a water cooling jacket, in order to prevent the bridge | crosslinking of acrylic resin. They can also be applied to screws with mixing sections.

In this process, in the region where the barrier-flighted screw 1 is formed, the completely molten resin does not shear, and simply passes through the gap between the vertex of the auxiliary flight 3 and the inner wall of the cylinder 10. It is transferred to the groove of the screw end of the groove divided into two. And since this melted melt is kneaded by kneading the melted melt and the melted melt discharged in the groove of the screw tip sheared, the film is free of impurities such as burnt foreign substances, fish eye, silver streak, etc. You can get The acrylic resin is melt kneaded by going through this process.

In addition, when a screw with a mixing section is attached, the resin melted is dispersed and mixed completely by high shear in the mixing section, and the melt extrusion is performed, so that the acrylic resin (without raising the temperature to a high temperature) is a low resin. Uniform dispersion is carried out at the temperature, and sufficient melt kneading can be performed. As a result, the same results as in the barrier flight type screw can be obtained.

Moreover, when making the optical film of this invention contain the other polymer and other additive which were already demonstrated, it is preferable to melt-knead these polymers and an additive with an acryl crab resin.

The power per unit time required for the extruder 100 is a value (kwhr / kg) obtained by dividing the power (kw) required to rotate the barrier-flighted screw 1 by the extrusion amount (kg / hr) per unit time. The larger this number is, the higher the efficiency is plasticized. The numerical value varies depending on the viscosity and molecular weight of the acrylic resin to be used, the number of exchange of the screw 1 and the temperature of the cylinder 10, but the range is preferably 0.1 kwhr / kg or more and 0.4 kwhr / kg. If the value is lower than 0.1 kwhr / kg, it is not preferable because sufficient plasticization may not be performed. If the value is higher than 0.4 kwhr / kg, the decomposition of the resin may be promoted by shear heating by the rotation of the screw. .

Although the number of axes of the extruder is not particularly limited, it may be either a single screw extruder or a double screw extruder. However, when a twin screw extruder is used, it is easy to plasticize or knead, but a single extruder is preferable because excessive shear heat is applied to the resin. .

The temperature of the cylinder 10 and the die 14 needs to be less than +145 degreeC of the glass transition temperature of acrylic resin, Preferably it is 220 degreeC or more and 300 degrees C or less, More preferably, it is 240 degreeC or more and 280 degrees C or less. Most preferably, they are 250 degreeC or more and 275 degrees C or less. In addition, it is preferable to set the temperature of the gear pump 15 and the filter 16 in the same manner as the temperatures of the cylinder 10 and the die 14.

At a temperature of +145 DEG C or higher of the acrylic resin, the acrylic resin of the raw material is partially decomposed and deteriorated, so that volatile organic matters are easily generated. On the other hand, if the melt viscosity of the resin is increased below 220 ° C, higher power than necessary or L / D necessary for plasticization may be required, which may adversely affect productivity. If the temperature exceeds 300 ° C, the resin may decompose.

The temperature control unit 11 is for adjusting the temperature of the cylinder 10, the die 14, the gear pump 15 and the filter 16. As the temperature control unit 11, a conventionally known temperature control system combining a heater such as an air cooler, a water cooler, an oil cooler, and a heater such as an electric heating heater can be used, and the temperature can be adjusted using a conventionally known temperature control module. Just do it. In FIG. 2, the temperature control unit 11 adjusts the temperature of the cylinder 10, the die 14, the gear pump 15, and the filter 16, but is not limited thereto. ), Each of the dice 14, the gear pump 15 and the filter 16 may have a separate temperature unit.

The die | dye 14 is a type | mold provided in the exit of an extruder, in order to shape | mold the acrylic resin discharged | emitted from an extruder to a fixed shape continuously in the case of extrusion and shaping | molding. Before supplying the melt-kneaded acrylic resin to the ice 14, it is preferable to use the filter 16 because foreign matter is removed with high accuracy. It is preferable that it is a polymer filter as the filter 16, The polymer filter is what laminated | stacked and sintered metal fiber, and it is preferable to have a three-dimensional network structure. For example, a ribbed filter can be used. It is preferable that the opening of the filter 16 is 25 micrometers or less, and it is more preferable that it is 15 micrometers or less.

[Polymer filter]

As said polymer filter, it is preferable that the filtration degree exists in the range of 1 micrometer or more and 25 micrometers or less, It is more preferable to exist in the range which is 1 micrometer or more and 15 micrometers or less, It is still more preferable to exist in the range which is 1 micrometer or more and 10 micrometers or less. In addition, when the filtration residence time is long, the plastic resin or the like tends to be heated and deteriorated, which may cause an increase in foreign matters. Moreover, when the filtration degree exceeds 25 micrometers, since it becomes easy to mix a foreign material, it is unpreferable.

The polymer filter is not particularly limited as long as it is a polymer filter having a filtration degree within the above range, and a conventionally known polymer filter can be used. As said polymer filter, a rib disk type polymer filter, a pack disk filter, a cylindrical filter, a candle type filter, etc. can be mentioned, for example. Among these, since the filtration area is large and the pressure loss is small even when high-viscosity resin is filtered, a ribdest type polymer filter is more preferable.

In the case where the polymer filter is a rib disc type polymer filter, the filter may include a material sintered from a metal fiber nonwoven fabric, a material sintered from a metal powder, a laminate of several gold meshes, or the like. Among these, those made of a material obtained by sintering a metal fiber nonwoven fabric are more preferable.

Since the filtration area with respect to the resin throughput per hour in the said polymer filter is suitably selected according to extrusion amount, it is not specifically limited, For example, it can be 0.001-0.15 m <^2> / (kg / h).

In the filtration of the polymer filter, the temperature inside the polymer filter is preferably the same as the temperature of the cylinder and the dice.

The method of discharging the acrylic resin melted by the extruder from the die 14 is not particularly limited, and can be performed using a conventionally known apparatus such as the gear pump 15. The gear pump 15 prevents fluctuations in the extrusion amount, is effective in reducing pressure fluctuations from the extruder outlet to the dies 14, and can prevent thickness flaws in the longitudinal direction of the film. Although the position in which the gear pump 15 is installed is not particularly limited, it is preferable that the gear pump 15 is located at the side of the barrier flight type screw 1 (screw 1 with mixing section) rather than the filter 16 as shown in FIG. Thereby, discharge of acrylic resin can be performed smoothly.

The acrylic resin discharged from the die 14 can be cooled and solidified on a casting drum (not shown) to form a film. It does not specifically limit as the die | dye 14, A conventionally well-known thing can be used. For example, a manifold dry, a fishtail die, a coat hanger die, etc. can be used.

In the case where the molten resin extruded from the die 14 is cooled and solidified on the casting drum, as the method of bringing the casting drum and the film into close contact with each other, the electrostatic pinning method, the touch roll method, the air knife method, the air nozzle method, the air chamber method, the back up The chamber method, sleeve method, etc. can be enumerated, and an optimal method is selected rather than the thickness of the target film.

It is preferable to perform various surface treatments on the cooling roll surface for solidifying the film extruded from the die 14 similarly to the surface of the cylinder 10, the die 14, and the like. These surface treatments prevent adhesion of the extruded film to the roll surface, thereby preventing the occurrence of thickness irregularities of the film, increasing the degree of cooling roll surface, and being hard to be damaged due to the high surface hardness, and even if the film is continuously produced. It is preferable at the point that it can stabilize and maintain the film surface grade, and can produce a film with no thickness spot.

The film may be used as a stretched film by stretching. There is no restriction | limiting in the extending | stretching method, A conventionally well-known extending | stretching method, for example, the longitudinal stretch which extends | stretches in the longitudinal direction of a film using the circumferential speed difference between rollers, and both ends of a film are grasped by tenter creep etc., and the width direction of a film The method of transverse axial stretching extended | stretched by and the sequential biaxial stretching which combines these can be used. In this case, longitudinal stretching and horizontal axis stretching may be performed only once, and multistage stretching of two or more stages may be performed. Moreover, simultaneous biaxial stretching which extends | stretches longitudinal and lateral simultaneously can be used.

As extending | stretching temperature, it is preferable that it is -5 degreeC or more and 50 degrees C or less as a glass transition temperature of acrylic resin, It is preferable that they are 0 degreeC or more and 40 degrees C or less, It is more preferable that they are 5 degreeC or more and 30 degrees C or less. Moreover, it is preferable that it is 1.1 times or more and 5 times or less as a thinning ratio, It is more preferable that it is 1.2 times or more and 3.5 times or more, It is more preferable that it is 1.5 times or more and 2.5 times or less.

The vent part (volatile volatile removal means) 12 can effectively remove and remove decomposed gases such as volatile organic matter and water generated in the cylinder 10 generated by melt kneading of the acrylic resin under reduced pressure. As the pressure reduction degree of the vent part (volatile removal means) 12, the range of 0.13 hPa or more and 931 hPa or less (0.1 mmHg or more and 700 mmHg or less) is more preferable. When the pressure is higher than 931 hPa, residual volatiles in the molten resin, monomer components generated by resin decomposition, and the like tend to remain. Moreover, when it is lower than 0.13 hPa, there exists a problem that industrial implementation becomes difficult.

The position at which the vent section (volatile removal means) 12 is provided is not particularly limited. However, since the decomposition gas generated during melt kneading is effectively removed, the position after the melting of the resin is preferably completed. In FIG. 2, the vent part (volatile removal means) 12 is a rear part of the melting promotion part 5 demonstrated in FIG. 1, and is provided so that it may be located in the whole of the metering part 6. As shown in FIG. The number of the vent portions (volatile removal means) 12 is not particularly limited, and may be one or plural. The vent in the "vented extruder" described in the section of the cyclization condensation reaction also performs the same function as the vent portion (volatile removal means) 12.

When the volatile organic substance is extruded from the die 14 into the atmosphere, it is rapidly released from the pressure, so that it adheres to the die 14 and produces a so-called net wood. This mesh is discontinuously transferred to the film surface and damages the appearance of the film. Since the compressor 100 is equipped with the vent part (volatile removal means) 12, since the decomposition gas, such as a volatile organic substance, can be removed effectively, the optical film excellent in external appearance can be manufactured.

In the present specification, the "optical film" is intended to include a film or a sheet. Although the film thickness of the said optical film is not specifically limited, It is preferable that they are 1 micrometer or more and 10 mm or less, It is more preferable that they are 5 micrometers or more and less than 500 micrometers, It is more preferable that they are 10 micrometers or more and less than 200 micrometers. Since the optical film with a film thickness of thinner than 1 micrometer is bad in intensity | strength, it is unpreferable, and breaking etc. arise easily when extending | stretching. On the other hand, when the film thickness is thicker than 10 mm, it is not preferable because molding is difficult.

In addition, this invention is not limited to each structure demonstrated above, Various changes are possible within the range shown in a claim, and also about embodiment obtained by combining suitably the technical means respectively disclosed by different embodiment of this invention, It is included in the technical scope.

Example

Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited to these. In addition, for convenience, "mass part" is simply referred to as "part" and "liter" is simply described as "L".

[Polymerization Reaction Rate, Polymer Composition Component]

The reaction rate at the time of the polymerization reaction and the content rate of the specific monomer unit in the polymer were determined by measuring the amount of unreacted monomer in the obtained polymerization reaction mixture using gas chromatography (manufactured by Dokjin Co., Ltd., device name: GC17A).

[Dynamic TG]

The polymer (or polymer solution or pellet) is first dissolved or diluted in tetrahydrofuran, and excess nucleose or metaol is added to metaol to reprecipitate, and the extracted precipitate is vacuum dried (1 mmHg (1.3 hPa), 80 ° C., 3 Time or more), volatile components and the like were removed, and the obtained white solid resin was analyzed by the following method (dynamic TG method).

Measuring device: Thermo Plus2 TG-8120 Dynamic TG (manufactured by Rigak Co., Ltd.)

Measurement Condition: Sample Name 5-10mg

Temperature rise rate: 10 ℃ / min

Atmosphere: Nitrogen Flow 200ml / min

Method: Phased isothermal control method (control at weight loss rate 0.005% / sec or less between 60 ℃ -500 ℃)

[Ratio of de-alcohol reaction rate and lactone ring structure]

First, based on the weight loss generated when all hydroxyl groups are de-alcoholized from methanol from the polymer retaining obtained by polymerization, and from 150 ° C. before the reduction of the weight in the dynamic TG measurement to 300 ° C. before the decomposition of the polymer starts. Dealcohol reaction rate was calculated | required from the weight loss by dealcoholization reaction.

That is, in the dynamic TG measurement of a polymer having a lactone ring structure, the weight loss rate is measured between 150 ° C. and 300 ° C., and the obtained measured weight loss rate is (X). On the other hand, from the composition of the polymer, all the hydroxyl groups contained in the polymer composition become alcohol because of the formation of the lactone ring, and the theoretical weight loss rate assuming that the alcohol is de-alcoholized (that is, 100% de-alcohol reaction occurred on the composition) Assume that the weight reduction rate calculated assuming that f is Y (Y). In addition, the theoretical weight loss rate (Y) can be computed more specifically from the molar ratio of the raw material monomer which has a structure (hydroxyl group) which participates in the dealcoholization reaction in a polymer, ie, the content rate of the electrical raw material monomer in a heading polymer composition. These values (X, Y) are calculated from the alcoholic formula:

1- (Measured weight loss rate (X) / theoretical weight loss rate (Y))

Substituting for to obtain its value and expressing it in% yields a de-alcohol reaction rate.

As an example, in the pellet obtained in Production Example 1 described later, the proportion of the lactone ring structure is calculated. When the theoretical weight loss rate (Y) of this polymer is obtained, the molecular weight of methanol is 32, the molecular weight of methyl 2- (hydroxymethyl) acrylate is 116, and the content rate of the polymer of methyl 2- (hydroxymethyl) acrylate ( Weight ratio) is 20 weight &

On the other hand, the measured weight loss amount (X) by dynamic TG measurement was 0.15 weight%. Substituting these values in the dealcohol calculation formula yields 1- (0.15 / 5.52) ≒ 0.973, so the dealcohol reaction rate is 97.3%.

Thus, only a predetermined lactone cyclization is carried out for this dealcohol reaction rate, and the content (weight ratio) in the copolymerization composition of the raw material monomer having a structure (hydroxy group) related to the lactone ring ring is multiplied by the dealcoholization reaction rate, and the lactone ring unit The content ratio of the structure of can be calculated.

In the case of Example 1, the content of the 2- (hydroxymethyl) acrylate in the copolymer is 20% by weight, the calculated de-alcohol reaction rate is 97.3% by weight, and the molecular weight is 116 2- (hydroxymethyl) acrylate Since the food content of the lactone cyclic structural unit produced when condensed with this methyl methacrylate is 170, the content rate of the lactone ring in this copolymer is 28.5 (20.1 X 0.973 X 170/116) weight%.

[Weight Average Molecular Weight]

The weight average molecular weight of a polymer was calculated | required by polystyrene conversion of GPC (the East-West company GPC system). The developing solution used chloroform.

[Thermal Analysis of Resin]

The thermal analysis of the acrylic resin was performed using DSC (Ricak Co., Ltd., apparatus name: DSC-8230) on the conditions of about 10 mg of samples, the temperature increase rate of 10 degree-C / min, and nitrogen flow 50 cc / min. In addition, glass transition temperature (Tg) was calculated | required by the midpoint method according to ASTM-D-3418.

[Melt Floworate]

Melt flow rate was measured by test temperature 240 degreeC and load 10 kg based on JIS-K7210.

Melt Viscosity

The melt viscosity of the pellet of the sufficiently dry acrylic resin was measured using the capillary rheometer RH10 made by Borin Instit.

[Determination of MMA Residual Component in Optical Film]

The film was dissolved in dimethylacetamide to prepare a 10% by mass solution, and diphenyl carbonate was quantified by gas chromatography as an internal table.

[b value]

The b value of the film for optics was measured using (color difference meter ND-1001DP by Nippon Denki KK).

The value "b" indicates the value of b ^{* in terms} of color in accordance with JIS Z8729, and was determined by an average value of 10 points measured by superimposing the optical film with a ratchet white plate.

[Production Example 1]

136 kg of methyl methacrylate (MMA), 34 kg of 2- (hydroxymethyl) methyl acrylate (MHMA), and 166 kg of toluene were placed in a 1 m ³ reaction lid in which a stirring device, a temperature sensor, a cooling tube, and a nitrogen introducing tube were installed. The mixture was heated to 105 DEG C while passing through nitrogen and refluxed, and 187 kg of tertiary amylpaoxyisononanoate (manufactured by Atpina Gilbu, trade name: Lupazol 570) was added as a polymerization initiator. , While a solution consisting of 374 g of a polymerization initiator and 3.6 kg of toluene was added dropwise over 2 hours, solution polymerization was carried out at reflux (about 105-110 ° C), and further aged for 4 hours.

170 g of stearyl phosphate / distearyl phosphate mixture (manufactured by Chemical Co., Ltd., trade name: Phoslex A-18) was added to the obtained polymer solution, and a cyclocondensation reaction was performed at reflux (about 90-110 ° C) for 5 hours. . Subsequently, the polymer solution obtained in the cyclization condensation reaction was subjected to a vent type screw extruder having a barrel temperature of 250 ° C., a rotational speed of 150 rpm, a reduced pressure of 13.3-400 hPa (10-300 mmHg), a number of rear bends, and a number of pore bends (Ø = 42 mm, L / D = 42) was introduced at a processing rate of 13 kg / hour in terms of resin amount, and subjected to a cyclization condensation reaction and devolatilization in the extruder, followed by extrusion to obtain a transparent pellet.

As a result of measuring the obtained pellet by dynamic TG, the mass reduction of 0.15 mass% was detected. In addition, the lactone ring-containing polymer had a mass average molecular weight of 147,000, a melt flow rate of 11/0 g / 10 min, a glass transition temperature of 130 ° C., 270 ° C., and a viscosity of 470 Pa.s at a shear rate of 100 (1 / s). .

Next, a single screw extruder of L / D = 36 with a filbert-type screw with a mixing section of Ø 50 mm and a multi-joint frit structure, 90 parts of heat-resistant acrylic resin pellets, AS resin (Styrak AS783 manufactured by Ukhwa Chemical Co., Ltd.) 10 Part 1 and 0.04 parts of zinc acetate did not cause melt extrusion at a processing rate of 50 kg / h at a cylinder set temperature of 270 ° C., and pellet 1A was prepared.

[Production Example 2]

In a 100L stainless steel polymerization tank equipped with a liquid lowering tank and a stirring device, 42.5 parts of methyl methacrylate, 5 parts of N-phenylmarimide, 0.5 parts of styrene, 50 parts of toluene, 0.2 parts of acetic anhydride as an organic acid, n as a chain transfer agent 0.06 part of dodecyl mercaptone was added, while nitrogen gas was bubbled for 10 minutes while stirring at 100 rpm, and the temperature was started in a nitrogen atmosphere.

When the temperature in the polymerization tank reached 100 ° C, 0.075 parts of t-butylpaoxyisoflophyllcarbonate was added to the polymerization chamber, and at the same time, 2 parts of styrene and t-butylperoxyisopropyl bubbled with nitrogen gas in the liquid lower chamber. The liquid mixture with 0.075 parts of carbonates started to be added at constant speed over 5 hours. Thus, the polymerization reaction was carried out at a polymerization temperature of 105-110 캜 for 15 hours under reflux.

Thereafter, 0.1 weight% of 9,10-dihydro-9-oxa-10-phosphafaphenanthrene-10-oxide (manufactured by Samgwang Co., Ltd., trade name "HCA") as a phosphorus antioxidant, 0.01% by weight of pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate ("A-10") as a phenolic antioxidant It was.

Next, the obtained polymerization liquid was supplied to the vent tack 30mm biaxial pressure apparatus which coat-rolled to cylinder temperature 240 degreeC, it vacuum-degassed from the vent opening, and the extruded strand was pelletized and the acrylic resin pellet (B) was obtained.

Obtained acrylic resin pellets (B) had a resin property of 390 Pa with a mass average molecular weight of 100,000, a melt flow rate of 15 g / 10 min, a glass transition temperature of 132 ° C, 270 ° C, and a shear rate of 100 (1 / s). It was s.

Example 1

The pellet 1A obtained in the production example 1 was placed in a band-like single screw extruder having a Ø65mm, L / D = 32, and a vari-up-type screw. The temperature of the pellet 1A was set to around 60 ° C by blowing the dehumidified air heated in the hopper. In addition, a nitrogen inlet tube was installed at the bottom of the hopper to introduce nitrogen gas into the extruder. While kneading at 13 hPa (10 mmHg) from the inlet of the vent, melt kneading was carried out with a barilite screw. After melt-kneading, the pellet 1A formed the film on the 90 degreeC cooling roll from the T-die of 700 mm in width through the ribbed filter of the filter area of 0.75 m <^2> and the filtration degree of 5 micrometers using the gear pump. The temperature of the cylinder, gear pump, filter, and T-die was set to 265 degreeC. The film thickness of the obtained optical film was 90 micrometers. Although the extrusion amount per unit time was 33 kg / hr, it was shape | molded continuously for 3 hours, but the so-called net wood was not found in the rib of T-die.

MMA contained in the obtained optical film was 530 ppm. It is 500 ppm of MMA sms contained in the acrylic resin composition which is a raw material, and almost no increase was found in film molding. Therefore, it can be seen that decomposition degradation did not occur during manufacture of the optical film. Moreover, the external appearance of the film was also favorable. Specifically, the b value was 0.70 and the content of the hybrid was 4 particles / m ² .

[Example 2]

The pellet 1A obtained in Production Example 1 was placed in a banded single screw extruder having a Ø65mm, L / D = 32, and unimelt screw. The temperature of the pellet 1A was 60 degreeC by blowing the dehumidification air heated to the hopper. In addition, a nitrogen inlet tube was installed at the bottom of the hopper to introduce nitrogen gas into the extruder.

The pellet 1A was melt kneaded with a unimelt screw while sucking at 13 hPa (10 mmHg) from the vent inlet. After melt-kneading, a film was formed on a cooling roll at 90 ° C. from a T-die having a width of 600 mm through a ribbed filter having a filtration area of 0.75 m ² and a filtration accuracy of 5 μm using a gear pump for pellet 1A. The temperatures of the cylinder, gear pump, filter and T-die were set to 265 ° C. The film thickness of the obtained optical film was 100 micrometers. The extrusion amount per unit time was 283 kg / hr, and molding was performed continuously for 3 hours. No so-called net wood was found in the rib of the T die.

MMA contained in the obtained optical film was 480 ppm. MMA contained in the acrylic resin composition as a raw material was 450 ppm, and almost no increase was found in film molding. Therefore, it can be seen that decomposition degradation did not occur during manufacture of the optical film. Moreover, the external appearance of the film was also favorable. Specifically, the b value was 0.95 and the content of the hybrid was 8 particles / m ² .

Example 3

The acrylic resin pellet (B) obtained in the said Production Example 2 was put into a banded single screw extruder having a Ø65mm, L / D = 32, and unimelt screw. The temperature of the pellet (B) was made into 80 degreeC by blowing the dehumidification air heated to the hopper. Nitrogen gas was also introduced to the bottom of the hopper.

The pellet (B) was melt kneaded with a unimelt screw while sucking at 13 hPa (10 mmHg) from the vent inlet. After melt-kneading, the pellet (B) was shape | molded on the 95 degreeC cooling roll from the T die of 600 mm in width through the ribbed filter of 0.75 m <^{2> of} filtration areas and 5 micrometers of filtration about using the gear pump. The temperatures of the cylinder, gear pump, filter and T-die were set to 265 ° C. The film thickness of the obtained optical film was 100 micrometers. The extrusion amount per unit time was 25.4 kg / hr, and molding was performed continuously for 5 hours, but so-called net wood was not found in the rib of the T die. MMA contained in the obtained optical film was 540 ppm. MMA contained in the acrylic resin composition as a raw material was 500 ppm, and almost no increase was found in film molding. Therefore, it can be seen that decomposition degradation did not occur during manufacture of the optical film. Moreover, the external appearance of the film was also favorable. Specifically, the b value was 0.68 and the content of the hybrid was 8 particles / m ² .

Example 4

It prepared in the same manner as in Preparation Example 2. The resin has a mass average molecular weight of 119,000, a melt flow rate of 4 g / 10 min, a glass transition temperature of 140 ° C, a viscosity of 650 Pa.s at a shear rate of 100 (1 / s), and a polymer composition of polymetha The acrylic resin pellet (C) which is a methyl methacrylate / N-methyl glutalimide copolymer obtained by making it methylate by reacting methyl methacrylate with the monomethylamine which is an imidation agent using a twin screw extruder is Ø65mm, L / D = 32 and put into a banded single screw extruder with a unmelt screw. The temperature of pellet (C) was heated to 85 degreeC by blowing the dehumidification air heated to the hopper. In addition, a nitrogen inlet tube was installed at the bottom of the hopper to introduce nitrogen gas into the extruder.

The pellet (C) was melt kneaded with a unimelt screw while sucking at 13 hPa (10 mmHg) from the vent inlet. After melt kneading, the pellets (C) were formed on a cooling roll at 100 ° C. from a T-die having a width of 600 mm by using a gear pump with a filtration area of 0.75 m ² and a filtration accuracy of 5 μm. The temperatures of the cylinder, gear pump, filter and T-die were set to 280 ° C. The film thickness of the obtained optical film was 95 micrometers. The extrusion amount per unit time was 25.4 kg / hr, and the molding was performed continuously for 2 hours.

MMA contained in the obtained optical film was 900 ppm. MMA contained in the acrylic resin composition as a raw material was 800 ppm. Moreover, b value of the film was 1.2 and content of the hybrid was 9 pieces / m <^2> .

Comparative Example 1

The pellet 1A obtained in Production Example 1 was placed in a banded single screw extruder having a Ø90 mm, L / D = 33, and valley upright screw. In addition, a nitrogen inlet tube was installed at the bottom of the hopper to introduce nitrogen gas into the extruder. Melt kneading was carried out with a vari-up light screw while sucking at 13 hPa (10 mmHg) from the inlet of the vant. After melt-kneading, the pellet 1A formed the film on the cooling roll of 95 degreeC from the T-die of width 1200mm through the ribbed filter of 1.2 m <^{2> of} filtration areas and 5 micrometers of filtration degree using the gear pump.

The temperature of the cylinder and gear pump was set to 270 degreeC, the temperature of the filter and T die was set to 280 degreeC, and the extrusion amount per unit time was 76 kg / hr.

MMA contained in the obtained optical film was 740 ppm, and b value was 1.63. Moreover, content of the hybrid of the optical film was 88 piece / m <^2> .

As described above, the optical film according to the present invention has a glass transition temperature of 110 ° C. or more and 200 ° C. or less and a viscosity of 250 Pa · s at a resin temperature of 270 ° C. when the shear rate is 100 (1 / s). It is an optical film provided with acrylic resin of more than 1000 Pa * s or less, The said optical film is a structure whose impurity content is 10 pieces / m <^2> or less. Moreover, the effect that both a physical property and an external appearance are excellent is exhibited.

  In addition, the manufacturing method of the optical film of the present invention by using an extruder having a barrier flight type screw or a screw with a mixing section, the temperature of the cylinder and die of the extruder is set to a glass transition temperature of acrylic resin + 145 ℃ less than It is a structure which shape | molds acrylic resin by the melt-extrusion method. As a result, it is possible to melt-extrude the heat-resistant acrylic resin at a low temperature, to bring about an effect that an optical film having little impurities and excellent in both physical properties and appearance can be obtained.

Specific embodiments or examples made in the detailed description of the invention are intended to clarify the technical contents of the present invention to the last, and should not be construed in a narrow sense only to such specific embodiments. It can change and implement in various ways within the Claim to describe.

The optical film of this invention has acrylic resin whose viscosity under glass transition temperature and a fixed condition is more than predetermined value, and is an optical film whose content of an impurity is below a fixed amount. Therefore, it is excellent in a physical property and an appearance. In addition, the method for producing an optical film of the present invention using an extruder equipped with a barrier flight type screw or a screw with a mixing section, the temperature of the cylinder and the die of the extruder to a temperature of less than +145 ℃ glass transition temperature of the acrylic resin To melt-extrude acrylic resin. Therefore, it is possible to manufacture the optical film excellent in a physical property and an external appearance. Therefore, the present invention can be suitably used for various optical films such as a protective film, an antireflection film, a retardation film, a polarizing film, and the like for the optical use of the same.

Claims (7)

A method for producing an optical film, characterized in that the temperature of the cylinder and die of the extruder is set to 220 ° C or higher and 300 ° C or lower using an extruder equipped with a barrier flight type screw, and the acrylic resin is molded by melt extrusion.
Method for producing an optical film, characterized in that for setting the temperature of the cylinder and die of the extruder to 220 ℃ to 300 ℃ using an extruder equipped with a screw including a mixing section and molding the acrylic resin by melt extrusion method .
The optical film production method according to claim 1, wherein the extruder comprises a polymer filter having a filtration degree of 1 µm or more and 25 µm or less.
The optical film production method according to claim 2, wherein the extruder comprises a polymer filter having a filtration degree of 1 µm or more and 25 µm or less.
The optical film production apparatus according to any one of claims 1 to 4, wherein the extruder is provided with a volatile matter removing means, and the volatile matter removing means sucks decomposition gas generated by melt kneading of the acrylic resin. Way.
Method for producing an optical film, characterized in that for setting the temperature of the cylinder and die of the extruder to 220 ℃ to 300 ℃ using an extruder equipped with a screw including a mixing section and molding the acrylic resin by melt extrusion method Optical film produced by.
The acrylic resin according to claim 2, wherein a viscosity at a resin temperature of 270 ° C is 250 Pa · s or more and 1000 Pa · s or less when the glass transition temperature is 110 ° C or more and 200 ° C or less and the shear rate is 100 (1 / s). Branches are optical films,
The optical film is a method for producing an optical film, characterized in that the optical film having an impurity content of 10 pieces / m ² or less.

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