JP2011037921A - Acrylic imide resin and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an acrylic imide resin for optical use with less generation of foreign materials, and a method for producing an acrylic imide resin for optical use, which hardly generates foreign materials, by utilizing and a tandem type reaction extruder. <P>SOLUTION: In the acrylic imide resin, a proportion of a residual carboxy group in the resin is ≤0.15 mmol/g. The method for producing the acrylic imide resin utilizes a tandem type extruder, wherein a first step reaction treating the acrylic resin and an imidizing agent is carried out in a first extruder 1, and a second step reaction treating the reaction product from the first extruder with an esterification agent is carried out in the second extruder 2, to obtain an acrylic imide resin having a proportion of a carboxy group of ≤0.15 mmol/g. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical acrylic imide resin with little foreign matter generation and a method for producing the acrylic imide resin.

  An acrylic imide resin is excellent in transparency and heat resistance, and has a small photoelastic coefficient, so that application as an optical material is being studied.

  In general, the reactive extrusion method in which a resin is heated and melted using an extruder and the molten resin and the reactant are continuously reacted is superior in productivity and low in cost compared to a batch method performed in a reaction vessel or the like. It has a feature that a thermoplastic resin can be produced efficiently. For this reason, the reactive extrusion method is also used in a method for producing an acrylic imide resin. For example, in Patent Document 1, the acrylic imide resin obtained by imidization reaction in the first extruder is pelletized and taken out, and further, the pellet is remelted and esterified by the second extruder. A method for producing an acrylic imide resin having excellent moldability is disclosed. However, this method is inefficient because the resin once taken out as pellets is remelted and passed through the second extruder, and the resin is easily deteriorated because the number of times of melting of the resin increases. As the number of pelletization increases, the chances of contact with impurities in the air increase and foreign matter may be generated, leaving room for improvement.

  Therefore, in Patent Document 2, a tandem type extruder is used, an imidization reaction is carried out by the first extruder, and an esterification reaction of the reaction product of the first extruder is carried out by the second extruder. A method for producing a thermoplastic resin with low content is disclosed.

  However, this method can reduce the number of foreign matters in the pellet, but when performing molding using a device that stays for a long time such as a polymer filter, the number of foreign matters may increase if operated for a long time, There was room for improvement.

JP 2006-27383A JP 2008-274187 A

  The present invention has been made in view of the problems of the conventional technology, and is an optical acrylic system that hardly generates foreign matter using an acrylic acrylic imide resin and a tandem reaction extruder that generate little foreign matter. It aims at providing the manufacturing method of an imide resin.

  As a result of intensive studies in view of the above problems, the present inventor focused on the ratio of carboxyl groups remaining in the acrylic imide resin, and by specifying the ratio, an optical acrylic imide resin with less foreign matter generation was obtained. As a result, the present invention was found.

  That is, the present invention relates to the following.

(I) An acrylic imide resin characterized in that the proportion of carboxyl groups remaining in the resin is 0.15 mmol / g or less.

(II) The acrylic imide resin according to (I), wherein the proportion of carboxyl groups remaining in the resin is 0.10 mmol / g or less.

(III) First extruder, second extruder, and first extruder using a tandem type extruder having parts connecting the resin discharge port of the first extruder and the raw material supply port of the second extruder In the second stage, the first stage reaction for treating the acrylic resin and the imidizing agent is performed, and in the second extruder, the second stage reaction for further treating the reaction product in the first extruder with the esterifying agent is performed. The method for producing an acrylic imide resin according to (I) or (II), which is obtained by:

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the acrylic imide resin which is useful as an optical material or a heat resistant material and hardly generates foreign matter.

It is a block diagram of the tandem type | mold reaction extruder by this invention.

  The present invention provides an acrylic imide resin, a first extruder, a second extruder, and a resin for the first extruder, wherein the ratio of the carboxyl group remaining in the resin is 0.15 mmol / g or less Using a tandem type extruder having a part that connects the discharge port and the raw material supply port of the second extruder, the first stage reaction for treating the acrylic resin and the imidizing agent is performed in the first extruder, In the two-extruder, this is a method for producing the acrylic imide resin obtained by performing a second-stage reaction in which the reaction product in the first extruder is further treated with an esterifying agent.

  The acrylic imide resin is not particularly limited as long as the ratio of the carboxyl group of the present invention is satisfied, but an acrylic imide resin containing repeating units represented by the following general formulas (1) and (2) is preferable.

  Furthermore, you may contain the repeating unit represented by General formula (3).

(However, R ¹ and R ² each independently represent hydrogen or an alkyl group having 1 to 8 carbon atoms, and R ³ represents hydrogen, an alkyl group having 1 to 18 carbon atoms, or a cycloalkyl having 3 to 12 carbon atoms. Or a substituent containing an aromatic ring having 5 to 15 carbon atoms.)

(However, R ⁴ and R ⁵ each independently represent hydrogen or an alkyl group having 1 to 8 carbon atoms, and R ⁶ represents hydrogen, an alkyl group having 1 to 18 carbon atoms, or a cycloalkyl having 3 to 12 carbon atoms. Or a substituent containing an aromatic ring having 5 to 15 carbon atoms.)

(However, R ⁷ represents hydrogen or an alkyl group having 1 to 8 carbon atoms, and R ⁸ represents an aryl group having 6 to 10 carbon atoms.)
The general formula (1) is generally often referred to as a glutarimide unit (hereinafter, the general formula (1) is abbreviated as a glutarimide unit).

As a preferable glutarimide unit, R ¹ and R ² are hydrogen or a methyl group, and R ³ is hydrogen, a methyl group, a butyl group, or a cyclohexyl group. The case where R ¹ is a methyl group, R ² is hydrogen, and R ³ is a methyl group is particularly preferred.

The glutarimide unit may be a single type or may include a plurality of types in which R ¹ , R ² , and R ³ are different.

  The glutarimide unit can be formed by imidizing the acrylic resin described in the above method for producing an acrylic imide resin.

In the general formula (2), R ⁴ is preferably a hydrogen atom, and R ⁵ is preferably a methyl group. R ⁶ is preferably a methyl group. R ⁷ is preferably hydrogen, and R ⁸ is preferably a phenyl group.

The general formula (3) is generally often referred to as an aromatic vinyl unit (hereinafter, the general formula (3) is abbreviated as an aromatic vinyl unit).
Preferred aromatic vinyl structural units include styrene in which R ⁷ is hydrogen and R ⁸ is a phenyl group, and α-methylstyrene in which R ⁷ is a methyl group and R ⁸ is a phenyl group. Of these, styrene is particularly preferred.

  The acrylic imide resin may further contain a repeating unit represented by the following general formulas (4) and (5).

(R ⁹ and R ¹⁰ each independently represent hydrogen or an alkyl group having 1 to 8 carbon atoms.)

(However, R ¹¹ and R ¹² each independently represent hydrogen or an alkyl group having 1 to 8 carbon atoms.)
The carboxyl group remaining in the resin in the present invention is a repeating unit represented by the general formula (5).

  The tandem type extruder of the present invention is, for example, two parts, a first extruder and a second extruder, which are components that connect the resin discharge port of the first extruder and the raw material supply port of the second extruder (hereinafter referred to as “the second extruder”). In some cases, they are simply connected as connecting parts). If necessary, the third extruder may be connected with a connecting component. If there are at least two or more, the number of connected devices can be set as appropriate.

  FIG. 1 shows an example of a tandem reaction extruder according to the present invention, but the present invention is not limited to this. As shown in the figure, the first extruder (1) and the second extruder (2) are arranged in a tandem type. The tandem type may be either a parallel arrangement as shown in FIG. 1 or an orthogonal arrangement in which the first extruder (1) and the second extruder (2) are arranged at right angles. The discharge port (6) of the first extruder (1) is connected to the raw material supply port (7) of the second extruder (2) via the connection component (3).

  In the present invention, the acrylic resin as the raw material can be a solid resin, and is supplied from the first extruder raw material supply port (5) by a feeder device or the like, and is heated and melted in the extruder. Examples of the feeder device include a constant weight feeder and a constant volume feeder. The imidizing agent is supplied from the imidizing agent supply port (8) of the first stage reaction provided in the part after the resin is melted in the extruder, using a supply device such as a pump, and the acrylic resin And the first stage reaction of the imidizing agent.

  The first-stage reaction product in the first extruder (1) is led to the second extruder raw material supply port (7) via the connection part (3) connected to the resin discharge port (6), 2 Charged into the extruder (2).

  Examples of the connection component (3) include those in which the resin flow path shape is a circular tube or an L-shaped tube. The connection component according to the present invention preferably has a gentle volume change of the resin flow path. Particularly preferred is a connecting part having a resin flow path with no volume change. In a connecting part having a resin flow path whose volume has changed rapidly, the resin and the reaction by-product are foamed and separated, the extrusion is fluctuated, and the reaction becomes non-uniform, which is not preferable.

  In the tandem extruder of the present invention, the pressure control mechanism (4) may be installed in the connecting part (3). It is also possible to accelerate the reaction by increasing the pressure of the first stage reaction using the pressure control mechanism (4).

  If the pressure control mechanism (4) is not provided, a vent port is provided in the first extruder (1) to remove unreacted imidizing agent, reaction by-products, decomposition products, etc. in the first stage reaction. It is also possible. The distance from the imidizing agent supply port (8) of the first stage reaction to the vent port may be appropriately set based on the reaction rate of the reaction to be performed. Examples of the pressure at the vent port include atmospheric pressure, vacuum, and the like, and preferably vacuum. Moreover, it is preferable to provide one or more vent ports, and a plurality of vent ports can be provided as necessary. The more vent ports, the better the removal of residual volatile matter is preferred, but it may be set as appropriate in consideration of the length of the extruder, the required length of the reaction zone, and the removal efficiency of volatile matter.

  Next, the first stage in the reaction product in the first extruder supplied from the first extruder (1) at the vent port (9) provided after the second extruder (2) raw material supply port (7). Remove the unreacted imidizing agent, reaction by-products, decomposition products, etc. of the eye reaction. The installation position of the vent port (9) of the second extruder is preferably installed closer to the bearing than the raw material supply port (7). Examples of the pressure at the vent port include atmospheric pressure, vacuum, and the like, and preferably vacuum. A plurality of vent ports (9) may be provided as necessary. If the second extruder has a vent port (9), residual volatile components such as unreacted imidizing agent, reaction by-products and decomposition products in the first stage reaction are removed, leading to quality improvement of the final product. preferable.

  The supply of the esterifying agent in the second stage reaction to the second extruder (2) is supplied from the esterifying agent supply port (10) of the second stage reaction using a pump or the like. The second stage reaction is performed with the reaction product and esterifying agent in FIG.

  Next, a vent port (11) is provided downstream from the esterification agent supply port (10) of the second extruder (2), and unreacted by-products, reaction by-products in the second stage reaction product, Remove decomposition products. What is necessary is just to set the distance from an esterification agent supply port (10) to a vent port suitably from the reaction rate etc. of the reaction to implement. Examples of the pressure at the vent port include atmospheric pressure, vacuum, and the like, and preferably vacuum. A plurality of vent openings may be provided as necessary. Preferably two or more. The more vent ports, the better the removal of residual volatile matter is preferred, but it may be set as appropriate in consideration of the length of the extruder and the removal efficiency of volatile matter.

  Further, in the second extruder (2), the second-stage reaction of the first-stage reaction product and the second-stage esterifying agent is not performed, and the first extruder is provided with a plurality of vents as necessary. It is also possible to carry out only devolatilization of the unreacted imidizing agent, reaction by-products, decomposition products, etc. in the stage reaction.

  Various additives such as a catalyst, an antioxidant, a heat stabilizer, a plasticizer, a lubricant, an ultraviolet absorber, an antistatic agent, a colorant, and an antishrink agent are supplied from the raw material supply port (5) of the first extruder (1). Can be supplied with raw material resin. Moreover, various additives can also be supplied from the additive supply port (12) of the second extruder (2) as required. As a method for supplying various additives from the additive supply port (12), a side feed method, an individual feed method to be added from the upper part of the extruder, or a soluble or meltable additive is dissolved or melted and added in a liquid state. The liquid addition method etc. are mentioned.

  It is preferable to have one or more vent ports (14) downstream of the additive supply port (12) from the viewpoint of removal of residual volatile matter. Also in this case, the number is not particularly limited, but a larger number is preferable because residual volatile components can be removed.

  Further, if it is not necessary to add various additives, it is not necessary to install an additive supply port in the second extruder.

  Furthermore, in the tandem reaction extruder of the present invention, a filter is provided between the parts connecting the discharge port (6) of the first extruder (1) and the raw material supply port (7) of the second extruder (2). You may do it. Moreover, you may have a filter between the components which connect the discharge port of a 2nd extruder (2), and a strand die. It is preferable to install a gear pump for boosting the resin before the filter. As the type of filter, it is preferable to use a stainless steel leaf disc filter capable of removing foreign substances from the molten polymer, and it is preferable to use a fiber type, a powder type, or a composite type thereof as the filter element.

  In the present invention, the resin discharged from the second extruder (2) is sent to the strand die in a molten state and extruded as a cylindrical strand. The strand is cooled on the cooling belt while taking shower water, and is chopped into granular pellets by a pelletizer.

  As the extruder in the present invention, a single screw extruder, a co-directional meshing type twin screw extruder, a co-directional non-meshing type twin screw extruder, a different direction meshing type twin screw extruder, a different direction non-meshing type twin screw Various extruders such as an extruder and a multi-screw extruder can be applied. Among them, in particular, various twin screw extruders are preferably applied from the viewpoint of high kneading / dispersing ability, and the same direction meshing twin screw extruder is more preferred because of high kneading / dispersing ability and productivity.

  Here, the 1st stage reaction which processes acrylic resin and an imidizing agent with a 1st extruder is performed, and the reaction product in the 1st extruder is further processed with an esterifying agent with a 2nd extruder. The production method for obtaining the acrylic imide resin by performing the stage reaction will be specifically described.

  In the first extruder of the tandem type extruder, first, an acrylic resin is used as a raw material resin (main raw material), and this is used as a secondary raw material for the first stage reaction such as ammonia or substituted amine (hereinafter referred to as an imidizing agent). ) Treated (hereinafter referred to as an acrylic imide resin intermediate). Next, this acrylic imide resin intermediate is treated with a secondary raw material (hereinafter referred to as an esterifying agent) in the second stage reaction in the second extruder of the tandem type extruder, and heat treatment or the like is performed if necessary. The acrylic imide resin of the present invention can be obtained.

  Examples of the acrylic resin of the present invention include acid anhydrides such as maleic anhydride or half esters of these and linear or branched alcohols having 1 to 20 carbon atoms; acrylic acid, methacrylic acid, maleic acid, maleic anhydride, Examples thereof include α, β-ethylenically unsaturated carboxylic acids such as itaconic acid, itaconic anhydride, crotonic acid, fumaric acid and citraconic acid. Further, a (meth) acrylic acid ester polymer such as a methyl methacrylate polymer composed of a repeating unit represented by the following general formula (2), or a repeating unit represented by the following general formula (2), And (meth) acrylic acid ester-aromatic vinyl copolymers such as methyl methacrylate-styrene copolymer composed of repeating units represented by formula (3).

(However, R ⁴ and R ⁵ each independently represent hydrogen or an alkyl group having 1 to 8 carbon atoms, and R ⁶ represents hydrogen, an alkyl group having 1 to 18 carbon atoms, or a cycloalkyl having 3 to 12 carbon atoms. Or a substituent containing an aromatic ring having 5 to 15 carbon atoms.)

(However, R ⁷ represents hydrogen or an alkyl group having 1 to 8 carbon atoms, and R ⁸ represents an aryl group having 6 to 10 carbon atoms.)
In the formula (2), R ⁴ is preferably a hydrogen atom, and R ⁵ is preferably a methyl group. R ⁶ is preferably a methyl group. R ⁷ is preferably hydrogen, and R ⁸ is preferably a phenyl group.

  The acrylic resin that can be used in the production of the acrylic imide resin of the present invention may be a linear (linear) polymer, a block polymer, a core-shell polymer, or a branch, as long as an imidization reaction is possible. It may be a polymer, ladder polymer, or crosslinked polymer. The block polymer may be an A-B type, an A-B-C type, an A-B-A type, or any other type of block polymer. The core-shell polymer may be composed of only one core and only one shell, or each may be a multilayer.

  The imidizing agent used in the imidization of the present invention is not particularly limited as long as an acrylic resin can be imidized. For example, methylamine, ethylamine, n-propylamine, i-propylamine, n-butylamine, i -Aliphatic hydrocarbon group-containing amines such as butylamine, tert-butylamine, n-hexylamine, aromatic hydrocarbon group-containing amines such as aniline, toluidine, and trichloroaniline, and alicyclic hydrocarbon group-containing amines such as cyclohexylamine Is mentioned. In addition, urea compounds that generate these amines by heating, such as urea, 1,3-dimethylurea, 1,3-diethylurea, and 1,3-dipropylurea can also be used. Of these imidizing agents, methylamine is preferable from the viewpoint of cost and physical properties.

  What is necessary is just to determine suitably the addition amount of an imidation agent by the imidation rate for expressing a required physical property. Preferably, it is 1 to 100 parts by weight with respect to 100 parts by weight of the main raw material.

  The esterifying agent used in the present invention is not particularly limited, and examples thereof include dimethyl carbonate, 2,2-dimethoxypropane, dimethyl sulfoxide, triethyl orthoformate, trimethyl orthoacetate, trimethyl orthoformate, diphenyl carbonate, dimethyl sulfate, Methyl toluene sulfonate, methyl trifluoromethyl sulfonate, methyl acetate, methanol, ethanol, methyl isocyanate, p-chlorophenyl isocyanate, dimethylcarbodiimide, dimethyl-t-butylsilyl chloride, isopropenyl acetate, dimethyl urea, tetramethylammonium hydroxide, dimethyl Diethoxysilane, tetra-N-butoxysilane, dimethyl (trimethylsilane) phosphor Aito, trimethyl phosphite, trimethyl phosphate, tricresyl phosphate, diazomethane, ethylene oxide, propylene oxide, cyclohexene oxide, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, benzyl glycidyl ether.

  The addition amount of the esterifying agent is determined by the ratio of the acid component in the resin for expressing necessary physical properties. Preferably, it is 1 to 100 parts by weight with respect to 100 parts by weight of the acrylic imide resin intermediate. Catalysts used to promote esterification include, for example, basic catalysts such as trimethylamine, triethylamine, benzyldimethylamine, tetramethylammonium hydroxide, acid catalysts such as p-toluenesulfonic acid, tetrabutyl titanate, manganese tetraacetate, and the like. Lewis catalyst is mentioned. Among these, a base catalyst is preferable, more preferably, for example, a tertiary amine such as trimethylamine, triethylamine, and benzyldimethylamine, and further preferable is triethylamine.

  The acrylic imide resin intermediate (hereinafter sometimes referred to as a high acid value resin) that is a reaction product in the first extruder is a second stage in the second extruder of the tandem type reaction extruder. A resin (hereinafter referred to as a low acid) that has been treated with an esterification agent for the eye reaction and, if necessary, subjected to heat treatment or the like, thereby reducing the proportion of acid components (mono derived from carboxyl groups and acid anhydride groups) remaining in the resin. Sometimes referred to as a valence resin). In the second extruder, even when only heat treatment (mixing / dispersing of the molten resin in the extruder) is performed, the dehydration reaction between the acid components in the high acid value resin and / or the acid component and the alkyl ester group A part or the whole of the acid component can be converted to an acid anhydride group by a dealcoholization reaction. The heat treatment is carried out at a reaction temperature in the range of 150 to 400 ° C. in order to suppress decomposition, coloring, etc. of the resin due to excessive heat history. 180-320 degreeC is preferable and 200-280 degreeC is more preferable.

  Furthermore, the esterification agent and its by-products contained in the resin can be removed by devolatilization of the low acid value resin under reduced pressure to obtain the acrylic imide resin of the present invention.

  In order to obtain the low acid value resin of the present invention, the reaction temperature is 150 to 400 ° C. in order to advance the imidization reaction or esterification reaction and suppress the decomposition, coloring, etc. of the resin due to excessive heat history. Do in range. 180-320 degreeC is preferable and 200-280 degreeC is more preferable.

  In addition to the production method as described above, the production method is not particularly limited as long as it is a method capable of obtaining an acrylic imide resin with the tandem reaction extruder of the present invention.

  Generally used catalysts, antioxidants, thermal stabilizers, plastics when treating acrylic imide resin intermediates (high acid value resins) with esterification agents and / or heat treatments, or for low acid value resins Additives such as an agent, a lubricant, an ultraviolet absorber, an antistatic agent, a colorant, and an anti-shrink agent may be added within a range that does not impair the object of the present invention.

  As the ultraviolet absorber that can be used in the present invention, a known ultraviolet absorber can be used. Preferred ultraviolet absorbers are one or more ultraviolet absorbers selected from triazine ultraviolet absorbers, benzotriazole ultraviolet absorbers, and benzophenone ultraviolet absorbers.

A preferred compound of the triazine-based ultraviolet absorber used in the present invention is 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol. . Since this has a low vapor pressure of 25 × 10 ⁻¹⁰ Pa at 25 ° C., gas volatilization from the vent and the die is small in melt extrusion, which is preferable. The gas volatility of the ultraviolet absorber can also be expressed by a temperature at which the weight is reduced by 10%. In the present invention, an ultraviolet absorber having a temperature of preferably 300 ° C. or higher, more preferably 350 ° C. or higher, more preferably 380 ° C. or higher is used. Use.

As a preferable benzotriazole-based ultraviolet absorber used in the present invention, for example, 2,2′-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazole-2- Yl) phenol], 2- (3,5-di-tert-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (2H-benzotriazol-2-yl) -p-cresol, 2- ( 2H-benzotriazol-2-yl) -4,6-bis (1-methyl-1-phenylethyl) phenol, 2-benzotriazol-2-yl-4,6-di-tert-butylphenol, 2- [5 -Chloro (2H) -benzotriazol-2-yl] -4-methyl-6- (tert-butyl) phenol, 2- (2H-benzotriazol-2- Yl) -4,6-di-tert-butylphenol, 2- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol, 2- (2H-benzotriazole) -2-yl) -4-methyl-6- (3,4,5,6-tetrahydrophthalimidylmethyl) phenol, methyl 3- (3- (2H-benzotriazol-2-yl) -5-tert- (Butyl-4-hydroxyphenyl) propionate / polyethylene glycol 300 reaction product, 2- (2H-benzotriazol-2-yl) -6- (linear and side chain dodecyl) -4-methylphenol, and the like. A particularly preferred benzotriazole ultraviolet absorber is 2- (3,5-di-tert-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole. The ultraviolet absorber is particularly preferable because the vapor pressure at 25 ° C. is as low as 10 ⁻⁵ Pa or less, and the 10% weight loss temperature is as high as 304 ° C., so that gas volatilization is small. Another particularly preferred benzotriazole UV absorber is 2,2′-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol]. The 10% weight loss temperature is 389 ° C., which is even higher, and therefore gas volatilization is small.

Preferred compounds of the benzophenone-based ultraviolet absorber used in the present invention include 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, bis (5-benzoyl-4- Hydroxy-2-methoxyphenyl) methane, 1,4-bis (4-benzoyl-3-hydroxyphenoxy) -butane and the like, and the vapor pressure at 25 ° C. is preferably as low as 10 ⁻⁵ Pa or less.

  It is preferable that the addition amount of the ultraviolet absorber in this invention is 0.1 to 5 weight% with respect to a total of 100 weight% of acrylic imide resin. More preferably, it is 0.2 to 4% by weight. More preferably, it is 0.3 to 3% by weight. When the addition amount of the ultraviolet absorber is less than 0.1% by weight, the light transmittance at 380 nm is increased, and the ultraviolet blocking effect may be insufficient, and when it is more than 5% by weight, the coloring becomes intense. There is a fear. Moreover, when there is more addition amount of a ultraviolet absorber than 5 weight%, there exists a possibility that the haze of a film molded body may become high and transparency may deteriorate. These ultraviolet absorbers may be used singly or in combination.

The content of the glutarimide unit represented by the general formula (1) in the acrylic imide resin obtained in the present invention depends on, for example, the desired retardation and the structure of R ³ . 1% by weight or more is preferable. The preferred content of glutarimide units is 1% to 95% by weight, more preferably 1 to 90% by weight. When the ratio of the glutarimide unit is smaller than this range, the heat resistance of the resulting acrylic imide resin may be insufficient or the transparency may be impaired. On the other hand, if it exceeds this range, the heat resistance and melt viscosity are unnecessarily increased, the moldability becomes worse, the mechanical strength of the resulting film becomes extremely brittle, and the transparency may be impaired.

  The content of the aromatic vinyl unit represented by the general formula (3) in the acrylic imide resin is preferably 50% by weight or less based on the total repeating units of the acrylic imide resin. When the aromatic vinyl unit is larger than this range, the heat resistance of the resulting acrylic imide resin is insufficient.

  By adjusting the ratio of the general formulas (2) and (3) and the imidizing agent that are acrylic resins as the main raw material, the unit represented by the general formula (1) and the general formula (2) Acrylic imide resin containing the unit represented by formula (3) and / or the unit represented by formula (3) in an arbitrary ratio can be obtained, and the ratio of formulas (1), (2) and (3) By adjusting, it is possible to adjust to various required physical properties. For example, when the acrylic imide resin of the present invention is first formed by polymerizing a (meth) acrylic ester-aromatic vinyl copolymer such as methyl methacrylate-styrene copolymer, for example, (meth) acrylic The ratio of the general formula (3) is determined by adjusting the polymerization ratio of the acid ester and the aromatic vinyl (the ratio of the general formula (3) can be set to 0), and further the addition of an imidizing agent during imidization By adjusting the ratio, the ratios of the general formulas (1) and (2) can be further adjusted.

  General formula (4) and general formula (5) are by-products generated when an acrylic resin is imidized with an imidizing agent. The repeating unit of the general formula (4) is stable only by applying heat, and the ratio of the general formula (4) in the acrylic imide resin is not particularly limited.

  The carboxyl group remaining in the resin in the present invention is a repeating unit represented by the general formula (5).

  In the present invention, the ratio of the carboxyl group in the acrylic imide resin needs to be 0.15 mmol / g or less. More preferably, it is 0.10 mmol / g or less. If the proportion of the carboxyl group in the acrylic imide resin is 0.15 mmol / g or less, the foreign matter derived from the resin even if it is operated for a long time and receives heat when performing molding using a device such as a filter. It is difficult to increase, and if this value is exceeded, foreign matter will increase.

  In the acrylic imide resin of the present invention, another structural unit may be further copolymerized as necessary. As the structural unit, a structural unit obtained by copolymerizing a nitrile monomer such as acrylonitrile or methacrylonitrile, or a maleimide monomer such as maleimide, N-methylmaleimide, N-phenylmaleimide, or N-cyclohexylmaleimide. Can be used. These may be directly copolymerized in an acrylic imide resin or may be graft copolymerized. The fourth structural unit is preferably contained in the acrylic imide resin.

  In the acrylic imide resin obtained in the production method of the present invention, the type containing the general formula (3) adjusts the content of each constituent unit and glutarimide unit in the methyl methacrylate-styrene copolymer. Thus, it is possible to provide a characteristic that does not substantially have orientation birefringence. Oriented birefringence refers to birefringence that develops when stretched at a predetermined temperature and a predetermined draw ratio. In this specification, unless otherwise specified, it means birefringence that develops when stretched 100% at a temperature 5 ° C. higher than the glass transition temperature of acrylic imide resin.

Here, the orientation birefringence is the product of the intrinsic birefringence derived from the polymer structure and the orientation distribution function derived from the molecular orientation state. The refractive index (nx) in the stretching axis direction and the axial refractive index (ny) orthogonal thereto. ) From the following formula: Δn _or = nx−ny
The phase difference Re (nm) measured by a phase meter is divided by the thickness d (μm).

Oriented birefringence Δn _or = Re / d
As described above, the orientation birefringence is the difference between the refractive index (nx) in the stretching axis direction and the refractive index (ny) in the axial direction perpendicular thereto, and therefore, when nx is larger than ny, it shows a positive value and vice versa. When nx is smaller than ny, a negative value is indicated.

The orientation birefringence value is preferably −0.1 × 10 ^{−3 to} 0.1 × 10 ⁻³ , and preferably −0.01 × 10 ^{−3 to} 0.01 × 10 ^−3. More preferred. When the orientation birefringence is out of the above range, the birefringence is likely to occur during the molding process with respect to the environmental change, and it becomes difficult to obtain stable optical characteristics.

The acrylic imide resin of the present invention preferably has a weight average molecular weight of 1 × 10 ⁴ to 5 × 10 ⁵ . When an excessive thermal history is given to the resin during the production process of the acrylic resin, thermal decomposition occurs, and the weight average molecular weight is less than 1 × 10 ⁴ . Furthermore, crosslinking may occur and the weight average molecular weight may exceed 5 × 10 ⁵ . When the method for producing an acrylic imide resin in the present invention is applied, the heat history for the resin can be reduced in the production process of the acrylic imide resin, and the above range of the weight average molecular weight can be achieved. When the weight average molecular weight is less than 1 × 10 ⁴ , the mechanical strength in the case of a film is insufficient, and when it exceeds 5 × 10 ⁵ , the viscosity at the time of melt extrusion is high and the molding processability is lowered. , Productivity of molded products may decrease.

  The glass transition temperature in the acrylic imide resin of the present invention is preferably 110 ° C. or higher, and more preferably 120 ° C. or higher. When the glass transition temperature is lower than the above value, the application range is limited in applications where heat resistance is required.

  The acrylic imide resin of the present invention is a quality problem in terms of thermal stability such as viscosity reduction and foaming in molding that requires a residence time of about 1 hour at a temperature of 200 to 300 ° C. such as passing through a polymer filter. The smaller the viscosity reduction rate in the thermal stability test, the better the thermal stability. The viscosity reduction rate is preferably less than 30%, more preferably less than 20%. Further, the longer the foaming start time from the start of the thermal stability test to the start of foaming, the better the thermal stability. The foaming start time is preferably 30 minutes or more, and more preferably 50 minutes or more.

  If necessary, other thermoplastic resins can be added to the acrylic imide resin of the present invention. In the molding process, the above-mentioned antioxidants, heat stabilizers, plasticizers, lubricants, ultraviolet absorbers, antistatic agents, colorants, antishrinking agents and the like that are generally used are not impaired. May be added.

  Molded products obtained from the acrylic imide resin of the present invention include, for example, video fields such as cameras, VTRs, projector lenses, viewfinders, filters, prisms, and Fresnel lenses, optical discs such as CD players, DVD players, and MD players. Lens fields such as pickup lenses for optical discs, optical recording fields for optical discs such as CD players, DVD players, MD players, liquid crystal light guide plates, liquid crystal display films such as polarizer protective films and retardation films, surface protective films, etc. Information equipment field, optical communication field such as optical fiber, optical switch, optical connector, automobile headlight, tail lamp lens, inner lens, instrument cover, sunroof, etc., vehicle field, eyeglasses, contact lens, internal vision lens, sterilization treatment Necessary for medical use Medical equipment field such as road translucent plate, pair glass lens, lighting window and carport, lighting lens and cover, building material field such as sizing for building materials, microwave cooking container (tableware), home appliances It can be used for housings, toys, sunglasses, stationery, etc.

  The present invention will be described in more detail based on examples, but the present invention is not limited to these examples. In addition, each measuring method of the physical property measured in the following Examples and Comparative Examples is as follows.

(1) Measurement of imidation rate 1 g of the product pellets was dissolved in 5 cc of dichloromethane, and IR spectrum was measured at room temperature using Travel IR manufactured by SensIR Technologies. From the obtained spectrum, determined with the absorption intensity (Abs _Ester) attributed to the ester carbonyl group of 1720 cm ^-1, the imidization ratio from the ratio of the absorption intensity assignable to an imide carbonyl group of 1660cm ^-1 (Abs _imide) It was. Here, the imidation rate refers to the proportion of the imide carbonyl group in all carbonyl groups.

(2) Measurement of ratio of carboxyl group remaining in resin 0.3 g of the product pellet was dissolved in 37.5 ml of dichloromethane, and 37.5 ml of methanol was added. To this solution, 2 drops of 1 wt% phenolphthalein ethanol solution was added, 5 ml of 0.1N sodium hydroxide aqueous solution was added, and the mixture was stirred for 1 hour. 0.1N hydrochloric acid was added dropwise to this solution, and the amount of 0.1N hydrochloric acid added (Aml) until the reddish purple color of the solution disappeared was measured.

  Next, 2 drops of 1 wt% phenolphthalein ethanol solution was added to a mixed solution of 37.5 ml of dichloromethane and 37.5 ml of methanol. To this, 5 ml of 0.1N sodium hydroxide aqueous solution was added and stirred for 1 hour. 0.1N hydrochloric acid was added dropwise to this solution, and the amount of 0.1N hydrochloric acid added (Bml) until the reddish purple color of the solution disappeared was measured.

  The ratio of the acid component (mono derived from a carboxyl group and an acid anhydride group) remaining in the resin was defined as the acid value Cmmol / g, and the following formula was used.

C = 0.1 × ((5-AB) /0.3)
0.3 g of product pellets were dissolved in 37.5 ml of dichloromethane and 37.5 ml of dimethyl sulfoxide was added. Two drops of 1 wt% phenolphthalein dimethyl sulfoxide solution were added to this solution, and 5 ml of 0.1N sodium hydroxide aqueous solution was added and stirred. 0.1N hydrochloric acid was added dropwise to this solution, and the amount of 0.1N hydrochloric acid added (A ′ ml) until the reddish purple color of the solution disappeared was measured.

  Next, 2 drops of 1 wt% phenolphthalein dimethyl sulfoxide solution was added to a mixed solution of 37.5 ml of dichloromethane and 37.5 ml of dimethyl sulfoxide. To this, 5 ml of 0.1N aqueous sodium hydroxide solution was added and stirred. 0.1N hydrochloric acid was added dropwise to this solution, and the amount of 0.1N hydrochloric acid added until the reddish purple color disappeared (B 'ml) was measured.

  The ratio of the acid component (mono derived from a carboxyl group and an acid anhydride group) remaining in the resin was defined as an acid value C ′ mmol / g, and the following formula was used.

C ′ = 0.1 × ((5-A′−B ′) / 0.3)
The ratio of the carboxyl group remaining in the resin was defined as the acid value C ″ mmol / g, and the following formula was used.

C ″ = 2 × C−C ′
(3) Foreign matter evaluation As a foreign matter evaluation method when a filter such as a polymer filter is attached for a long time, a capillary rheometer is used, the resin is packed in the capillary rheometer, and slowly extruded at the temperature when passing through the filter. I was exposed to heat for a long time. The test method is described below.

20 g of acrylic imide resin pellets are packed into a capillary rheometer (Capillograph 1D manufactured by Toyo Seiki Seisakusho Co., Ltd.), using a die having a diameter of 1 mm and a length of 10 mm, and a viscosity of 1,500 to 2,000 Pa · s. At a temperature of The piston was pushed in at a speed of 2 mm / min to obtain a strand. A strand of 10 to 20 minutes (before the start of the residence test) and a strand of 30 to 40 minutes (after the start of the residence test) are acquired from the start of measurement.

  The number of foreign matters having a size of 50 μm or more contained in the obtained 10 cm-long strand was counted by microscope observation or the like, and the total of 10 pieces was taken as the number of foreign matters.

Example 1
An apparatus equivalent to that shown in FIG. 1 was used. As for the tandem type reactive extruder, the first extruder (1) and the second extruder (2) both have a diameter of 15 mm and L / D (the ratio of the length L to the diameter D of the extruder) is 60. Using a twin screw extruder (manufactured by Technobel Co., Ltd.), a raw material resin was supplied to the first extruder raw material supply port (5) using a coil screw type constant volume feeder (manufactured by Kubota Corporation). The supply positions of the first stage reaction auxiliary material (imidizing agent) and the second stage reaction auxiliary material (esterifying agent) were the same as those shown in FIG. Also, the position of the vent in the second extruder is the same as that shown in FIG. 1, the vent of (9) is atmospheric pressure, and the degree of vacuum of the vents of (11) and (14) is -0.095 MPa. .

  Regarding the first extruder, methyl methacrylate-styrene copolymer (Mw 95,000 styrene amount 11 mol%) was used as an acrylic resin, and an acrylic imide resin intermediate (monomethylamine was used as an imidizing agent ( High acid value resin) was produced. At this time, the first extruder and the second extruder are connected by a pipe having a diameter of 10 mm and a length of 1 m (connection part (3)), and the resin discharge port of the first extruder and the second extruder raw material supply port are connected. A constant flow pressure valve was used for the pressure control mechanism (4) in the parts to be operated. The constant flow pressure valve is installed immediately before the second extruder raw material supply port (7), and the pressure at the outlet of the first extruder and the pressure at the central part of the connecting part of the first extruder and the second extruder (pressure in the connecting part) is set to 15 MPa. It adjusted so that it might become.

  Each barrel temperature of the extruder was 250 ° C., the screw rotation speed was 150 rpm, the acrylic resin supply amount was 5 kg / hour, and the addition amount of monomethylamine was 20 parts by weight with respect to 100 parts by weight of the raw material resin.

  Regarding the second extruder, an acrylic imide resin was produced using a mixed solution of dimethyl carbonate and triethylamine as an esterifying agent. At this time, each barrel temperature of the extruder was 250 ° C., the screw rotation speed was 150 rpm, the addition amount of dimethyl carbonate was 8 parts by weight with respect to 100 parts by weight of the resin, and the addition amount of triethylamine was 2 with respect to 100 parts by weight of the acrylic resin. Part by weight. Further, the esterifying agent was removed with a vent. Raw material of ultraviolet absorber 2,2′-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol] from additive supply port (12) After adding 3 parts by weight with respect to 100 parts by weight of the resin, the remaining volatile components were removed again with a vent. The resin discharged from the second extruder was extruded from a strand die, cooled in a water tank, and then cut with a pelletizer to form pellets.

  Production was carried out for about 2 hours under the above conditions, and the resulting acrylic imide resin had an imidization rate of 75% and a carboxyl group ratio of 0.05 mmol / g remaining in the resin. In addition, the number of foreign matters at the start of the residence test was 12, and the number of foreign matters after the start of the residence test was 14.

(Example 2)
Using polymethylmethacrylate (Mw: 10.5) as a raw material resin, 2 parts by weight of an imidizing agent, 6 parts by weight of an esterifying agent, and an atmospheric pressure vent in the first extruder, An acrylic imide resin was produced in the same manner as in Example 1 except that residual volatile components such as unreacted imidizing agent, reaction by-products, and decomposition products were removed and the constant flow pressure valve was fully opened.

  As a result, the obtained acrylic imide resin had an imidation ratio of 14% and the ratio of carboxyl groups remaining in the resin was 0.06 mmol / g. Further, the number of foreign matters at the start of the residence test was 11, and the number of foreign matters after the start of the residence test was 13.

(Example 3)
Using polymethyl methacrylate (Mw: 10.5) as a raw material resin, 2 parts by weight of an imidizing agent, 2 parts by weight of an esterifying agent, and an atmospheric pressure vent in the first extruder, An acrylic imide resin was produced in the same manner as in Example 1 except that residual volatile components such as unreacted imidizing agent, reaction by-products, and decomposition products were removed and the constant flow pressure valve was fully opened.

As a result, the obtained imide resin had an imidation ratio of 14% and the proportion of carboxyl groups remaining in the resin was 0.13 mmol / g. In addition, the number of foreign matters at the start of the residence test was 12, and the number of foreign matters after the start of the residence test was 19.
(Comparative Example 1)
An imide resin was produced in the same manner as in Example 1 except that the esterification agent was not added and devolatilized by the second extruder.

As a result, the obtained acrylic imide resin had an imidation ratio of 75% and the ratio of carboxyl groups remaining in the resin was 0.32 mmol / g. Further, the number of foreign matters at the start of the retention test was 11, and the number of foreign matters after the start of the retention test was 59.
Many foreign substances are generated, which is not suitable for optical applications.

DESCRIPTION OF SYMBOLS 1 1st extruder 2 2nd extruder 3 Connection component 4 Component internal pressure control mechanism which connects the resin discharge port of a 1st extruder, and a 2nd extruder raw material supply port 5 1st extruder raw material supply port 6 1st extrusion Machine discharge port 7 Second extruder raw material supply port 8 Imidizing agent supply port for first stage reaction 9 Second extruder vent port 10 Esterification agent supply port for second stage reaction 11 Second extruder vent port 12 Various additive supply ports 13 Second extruder vent port 14 Second extruder vent port

Claims (3)

An acrylic imide resin, wherein the proportion of carboxyl groups remaining in the resin is 0.15 mmol / g or less. 2. The acrylic imide resin according to claim 1, wherein the ratio of the carboxyl group remaining in the resin is 0.10 mmol / g or less. Acrylic system in the first extruder using the first extruder, the second extruder, and a tandem type extruder having a part connecting the resin discharge port of the first extruder and the raw material supply port of the second extruder It is obtained by performing a first stage reaction for treating a resin and an imidizing agent, and performing a second stage reaction for further treating the reaction product in the first extruder with an esterifying agent in the second extruder. The method for producing an acrylic imide resin according to claim 1 or 2.

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