JPWO2006054410A1 - Method for producing imide resin, and imide resin and imide resin molded article obtained thereby - Google Patents

Abstract

An object of the present invention is a method for producing an imidized acrylic resin that is excellent in transparency and heat resistance, is less likely to cause optical distortion (birefringence) even under molding stress, and has few imidation-derived foreign substances, and It is to provide an imidized acrylic resin molded body made of them. The method for producing an imidized acrylic resin of the present invention is a production method in which a (meth) acrylic ester resin is treated with an imidizing agent in the presence of a heat stabilizer, and is 210 mm long, 300 mm wide, and thick. This is a method for producing an imide resin in which the total number of imidization-derived foreign substances contained in a 3 mm molded body is 100 or less.

Description

  The present invention relates to a method for producing an imide resin, and further to an imide resin and an imide resin molded product obtained by the method for producing the imide resin.

  In recent years, electronic devices have become more and more miniaturized, and have been used for various purposes by taking advantage of light weight and compactness, as represented by notebook personal computers, mobile phones, and portable information terminals. On the other hand, in the field of flat panel displays such as liquid crystal displays and plasma displays, it is also required to suppress an increase in weight due to an increase in screen size. In applications where transparency, heat resistance, and low birefringence are required, including electronic devices such as those described above, a trend has been made to replace a member that has conventionally used glass with a transparent resin.

  Among the transparent resins, polymethyl methacrylate, which is typical, has excellent moldability and workability compared to glass, is difficult to break, is lightweight and inexpensive, and is used in liquid crystal displays, optical discs, pickup lenses, etc. Have been studied and partly put into practical use. However, acrylic resins generally have poor heat resistance, and the application range may be limited in applications where high heat resistance is required.

  Therefore, as a method for improving the heat resistance of the acrylic resin, a technique of improving the heat resistance by treating the acrylic resin with a primary amine and imidizing is known (see, for example, Patent Documents 1 and 2). ). These imidized acrylic resins (hereinafter referred to as imide resins) are excellent in transparency and heat resistance, and also become a material that hardly generates orientation birefringence by controlling the imidization rate. For example, it may be used effectively for optical applications.

On the other hand, as a general technique for removing foreign substances in a resin, a method is known in which the resin is dissolved in an organic solvent or the like, or the resin is heated and melted and filtered through a filter or the like. However, such a method cannot be removed, and as a result, a large amount of foreign matter may be contained in the molded body. In particular, when used for optical applications and the like, there is an increasing demand for foreign matter reduction, and it is very difficult to answer this demand.
JP-A-6-240017 JP-A-6-256537

  An object of the present invention is to provide a method for producing an imide resin that reduces imidation-derived foreign matter, and further provides an imide resin and an imide resin molded product with reduced imidation-derived foreign matter.

  In order to solve the above-mentioned problems, the present inventors have intensively studied, and as a result, a (meth) acrylic acid ester-based resin is treated with an imidizing agent in the presence of a thermal stabilizer. Furthermore, by using this, a method for producing an imide resin in which the total number of imidation-derived foreign substances contained in a molded article having a length of 210 mm, a width of 300 mm, and a thickness of 3 mm was 100 or less was found, and the present invention was achieved.

  Moreover, the imide resin and imide resin molding which were formed using said manufacturing method were provided.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the imide resin and imide resin molded object with which the imidation origin foreign material was reduced. Moreover, these imide resins and imide resin molded products can be used for optical applications, for example, where the demand for foreign matter reduction is increasing.

  Further, when applied to a specific imide resin, an imide resin having excellent transparency and heat resistance, small orientation birefringence and few imidization-derived foreign matters can be provided, and particularly suitable for optical applications.

  The present invention relates to a method for producing an imide resin characterized by treating an (meth) acrylic acid ester resin with an imidizing agent in the presence of a heat stabilizer. Further, the present invention relates to a method for producing an imide resin in which the total number of imidization-derived foreign substances contained in a molded body having a length of 210 mm, a width of 300 mm, and a thickness of 3 mm is 100 or less.

  In general, the foreign matter in the resin may be mixed from the environment, generated at the time of molding, or generated at the time of resin synthesis (for example, a scale). In particular, it has been found that the imide resin has a problem that foreign matter (hereinafter, abbreviated as imidization-derived foreign matter) generated during the imidation reaction occurs. The imidation-derived foreign material referred to here is a component that is different from the surrounding imide resin that occurs during the imidization reaction, and the shape is not particularly limited, but the long side of the foreign material is 10 μm or more. These can be observed with an optical microscope. For example, many of them appear yellow or colorless and transparent. In general, (meth) acrylic acid ester resins are copolymerized with acrylic acid esters such as methyl acrylate in order to suppress a zipping reaction caused by high temperature heating. During the imidation reaction, conditions such as a high reaction temperature and the presence of amines affect the tertiary hydrogen of the main chain of (meth) acrylic acid esters, and carbon radicals are released. appear. It can be considered that this carbon radical is the starting point, and a heterogeneous resin is produced by main chain cleavage or intermolecular coupling reaction. The component different from the imide resin thus produced is considered to be an imidization-derived foreign substance.

  When the imide resin of the present invention is used, for example, in optical applications, the foreign matter in the resin, especially the foreign matter derived from imidization, for example, 210 mm in length, 300 mm in width, If it is in a molded body having a thickness of 3 mm, the number is preferably 100 or less, and it is also preferable to produce so. 50 or less are more preferable, and 20 or less are more preferable.

  The imide resin of the present invention can be produced by various methods as long as it is a method of treating an (meth) acrylic acid ester resin with an imidizing agent in the presence of a heat stabilizer. For example, using an extruder, It can be obtained by adding an imidizing agent to a molten acrylic resin.

  The imidizing agent used in the present invention is not particularly limited as long as it can imidize a (meth) acrylic ester resin. For example, methylamine, ethylamine, n-propylamine, i-propylamine, n-butylamine Aliphatic hydrocarbon group-containing amines such as i-butylamine, tert-butylamine, and n-hexylamine, aromatic hydrocarbon group-containing amines such as aniline, toluidine, and trichloroaniline, and alicyclic carbonization such as cyclohexylamine Examples thereof include hydrogen group-containing amines. 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. In addition, the amount of the imidizing agent added in the production of the imide resin of the present invention can be appropriately determined so as to reach an imidization rate necessary for expressing necessary physical properties.

  When imidizing an acrylic resin with an imidizing agent, the reaction temperature should be in the range of 180 to 320 ° C. in order to promote imidization and suppress decomposition and coloring of the resin due to excessive heat history. Is preferred. Furthermore, 180-320 degreeC is preferable and 200-280 degreeC is especially preferable.

  When imidizing a (meth) acrylic acid ester resin with an imidizing agent, generally used catalysts, plasticizers, lubricants, ultraviolet absorbers, antistatic agents, coloring agents, shrinkage preventing agents, etc. You may add in the range which does not impair.

  The heat stabilizer used in the present invention is not particularly limited as long as it can suppress the occurrence of imidation-derived foreign substances, but from hindered phenol compounds, lactone compounds, phosphorus compounds, hindered amine compounds, and thioether compounds. Those composed of at least one selected compound are preferred.

  The hindered phenol compound is not particularly limited as long as it is a compound containing a phenolic hydroxyl group. For example, triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) Propionate], pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) Propionate, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, 3,9-bis [2- {3- (3-t -Butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [ 5] Undecane, 2-t-butyl-6- (3'-t-butyl-5'-methyl-2'-hydroxybenzyl) -4-methylphenyl acrylate, 2,4-di-t-amyl-6 -(3 ', 5'-di-t-amyl-2'-hydroxy-α-methylbenzyl) methylphenyl acrylate, 2-t-butyl-6- (3'-t-butyl-2'-hydroxy-5 '-Methyl-methylbenzyl) -4-methylphenyl acrylate, 2,5-di-t-butyl-6- (3', 5'-di-t-butyl-2'-hydroxy-α-methylbenzyl) methyl Examples thereof include phenyl acrylate.

  The lactone compound is not particularly limited as long as it is a compound containing a lactone ring. For example, 5,7-di-t-butyl-3- (3,4-dimethylphenyl) -3H-benzofuran-2- You can mention ON.

  The phosphorous compound is not particularly limited as long as it is phosphoric acid and its alkyl esters. For example, tris (2,4-di-t-butylphenyl) phosphite, tetrakis (2,4-di-t -Butylphenyl) -4,4'-biphenylene phosphite, trisnonylphenyl phosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, etc. Can do.

  The hindered amine compound is not particularly limited as long as it is a compound containing a 2,2,6,6, -tetramethyl-4-piperidyl group. For example, poly [{6- (1,1,3,3 -Tetramethylbutyl) amino} -1,3,5-triazine-2,4-diyl] {(2,2,6,6-tetramethyl-piperidyl) imino} hexamethylene {(2,2,6,6 -Tetramethyl-piperidyl) imino}] and the like.

  The thioether compound is not particularly limited as long as it is a compound containing a thioether group. For example, dilauryl 3,3′-thiodipropionate, dimyristyl 3,3′-thiodipropionate, distearyl 3,3 Examples include '-thiopropionate, pentaerythrityltetrakis (3-laurylthiopropionate), ditridecyl 3,3'-thiodipropionate.

  Among these compounds that can be used as heat stabilizers, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (trade name: IRGANOX 1010, Ciba Specialty Chemicals) (Registered trademark), 2-t-butyl-6- (3'-t-butyl-5'-methyl-2'-hydroxybenzyl) -4-methylphenyl acrylate (trade name: Sumilizer GM, Sumitomo) (Registered trademark owned by Chemical Co., Ltd.), 5,7-di-t-butyl-3- (3,4-dimethylphenyl) -3H-benzofuran-2-one (trade name: HP-136, Ciba Specialty (Registered trademark owned by Chemicals Co., Ltd.) is particularly preferable, and two or more kinds may be used in combination.

  The amount of the heat stabilizer added to the (meth) acrylate resin is preferably 0.01 to 5 parts by weight with respect to 100 parts by weight of the (meth) acrylate resin. By making the addition amount 0.01 parts by weight or more, the effect of suppressing the generation of imidation-derived foreign matters is likely to occur. By making the addition amount 5 parts by weight or less, it becomes easy to obtain transparency of the imide resin, and it is suitable for applications requiring transparency.

  For the imidization of the present invention, an extruder or the like may be used, or a batch type reaction vessel (pressure vessel) may be used.

  When the method for producing an imide resin of the present invention is carried out with an extruder, various extruders can be used. For example, a single screw extruder, a twin screw extruder, a multi-screw extruder, or the like can be used. In particular, a twin-screw extruder is preferable as an extruder that can promote mixing of an imidizing agent or a ring closure accelerator with respect to the raw polymer. There are non-mesh type co-rotating type, meshing type co-rotating type, non-meshing type bi-directional rotating type, meshing type bi-directional rotating type, etc. The meshing-type co-rotating type is preferable because high-speed rotation is possible and mixing of an imidizing agent or a ring-closing accelerator to be used if necessary can be promoted. These extruders may be used alone or connected in series. The extruder is preferably equipped with a vent port that can be depressurized to atmospheric pressure or lower in order to remove unreacted imidizing agent, ring closure accelerator and by-products.

  Instead of the extruder, a high-viscosity reactor such as a horizontal biaxial reactor such as Violac manufactured by Sumitomo Heavy Industries, Ltd. or a vertical biaxial agitation tank such as Super Blend can be suitably used.

  When the production method of the imide resin of the present invention is carried out in a batch-type reaction vessel (pressure vessel), the structure is particularly limited as long as the raw material polymer can be melted by heating and stirred, and an imidizing agent or a ring closure accelerator can be added. However, the viscosity of the polymer may increase with the progress of the reaction, and those with good stirring efficiency are preferred. For example, Sumitomo Heavy Industries Co., Ltd. agitation tank Max blend etc. can be illustrated.

  The production method of the imide resin of the present invention is particularly suitable for the production of an imide resin containing the repeating units represented by the following general formulas (1) and (2) and, if necessary, the following general formula (3). Can be used for

(Here, R ¹ and R ² each independently represent hydrogen or an alkyl group having 1 to 8 carbon atoms, and R ³ represents an alkyl group having 1 to 18 carbon atoms or a cycloalkyl group having 3 to 12 carbon atoms. Or a substituent containing an aromatic ring having 5 to 15 carbon atoms, hereinafter, this unit may be referred to as a glutarimide unit.)

(Here, R ⁴ and R ⁵ each independently represent hydrogen or an alkyl group having 1 to 8 carbon atoms, and R ⁶ represents an alkyl group having 1 to 18 carbon atoms or a cycloalkyl group having 3 to 12 carbon atoms. Or a substituent containing an aromatic ring having 5 to 15 carbon atoms.Hereinafter, this unit may be referred to as an acrylic ester unit or a methacrylic ester unit.)

(Here, 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. Hereinafter, the general formula (3) is referred to as an aromatic vinyl unit. Sometimes.)
In particular, the imide resin preferably has an orientation birefringence of −0.1 × 10 ^{−3 to} 0.1 × 10 ⁻³ .

A glutarimide unit can be easily formed by treating an (meth) acrylic ester resin with an imidizing agent. As preferred glutarimide units, R ¹ and R ² are hydrogen or a methyl group, and R ³ is hydrogen or a methyl 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.

  Examples of the raw material monomer that produces an acrylic ester or methacrylic ester unit as a residue include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) ) Acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate and the like. In addition, 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, itaconic acid, itaconic anhydride, Α, β-ethylenically unsaturated carboxylic acids such as crotonic acid, fumaric acid and citraconic acid can also be imidized and used in the present invention. Of these, methyl methacrylate is particularly preferred.

These acrylic acid ester units or methacrylic acid ester units may be of a single type or may include a plurality of types in which R ⁴ , R ⁵ and R ⁶ are different.

  The 3rd structural unit contained in the preferable imide resin of this invention as needed is represented by following General formula (3), and is generally called an aromatic vinyl unit in many cases.

(Here, 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.)
Preferred aromatic vinyl structural units include styrene, α-methylstyrene, and the like. Of these, styrene is particularly preferred.

These third structural units may be of a single type or may include a plurality of types in which R ⁷ and R ⁸ are different.

The content of the glutarimide unit represented by the general formula (1) in the imide resin is not particularly limited, but in order to make the orientation birefringence −0.1 × 10 ^{−3 to} 0.1 × 10 ⁻³ , In particular, the range of 1 to 30% by weight is preferable, and 3 to 25% by weight is more preferable. When the glutarimide unit is less than 1% by weight, the orientation birefringence of the resulting imide resin is less than −0.1 × 10 ⁻³ , and when it is more than 30% by weight, the orientation birefringence of the resulting imide resin is 0. It becomes larger than 1 × 10 ^−3, and its use in applications that do not want to cause orientation birefringence is limited.

  If necessary, the imide resin of the present invention may be copolymerized with a fourth structural unit different from the general formulas (1), (2), and (3). A constitution obtained by copolymerizing a nitrile monomer such as acrylonitrile and methacrylonitrile, and a maleimide monomer such as maleimide, N-methylmaleimide, N-phenylmaleimide, N-cyclohexylmaleimide as the fourth structural unit Units can be used. These may be directly copolymerized in the thermoplastic resin, or may be copolymerized in a specific form like graft copolymerization.

  The (meth) acrylic ester resin that can be used in the present invention is not particularly limited as long as imidization reaction is possible, and may be a linear (linear) polymer, or a block polymer, a core-shell polymer, or a branched polymer. It may be a ladder polymer or a crosslinked polymer. The block polymer may be an A-B type, A-B-C type, A-B-A type, or any other type of block polymer. There is no problem even if the core-shell polymer is composed of only one core and only one shell, or each layer is a multilayer.

  It is preferable that the imide resin of the present invention has substantially no orientation birefringence particularly when considering use in optical applications. Oriented birefringence refers to birefringence that develops when stretched at a predetermined temperature and a predetermined stretch ratio. In the present specification, unless otherwise specified, it refers to birefringence that develops when stretched 100% at a temperature of glass transition temperature of an imide resin + 5 ° C.

  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. ) Is defined by the following formula 1 and is a value obtained by dividing the phase difference Re (nm) measured by the phase difference meter as shown in the following formula 2 by the thickness d (μm).

  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 value of orientation birefringence 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 due to environmental changes, and stable optical characteristics may not be obtained.

  The glass transition temperature of the thermoplastic resin is preferably 110 ° C. or higher, and can be suitably used in applications requiring heat resistance.

In addition, the imide resin preferably has a weight average molecular weight of 1 × 10 ⁴ to 5 × 10 ⁵ , and the viscosity at the time of melting is set within a range that can be easily molded while ensuring the mechanical strength when formed into a molded product. be able to.

  The imide resin of the present invention can exhibit properties such as high tensile strength and bending strength, solvent resistance, thermal stability, good optical properties, and weather resistance by appropriately setting the composition and composition ratio.

  If necessary, other thermoplastic resins can be added to the thermoplastic resin of the present invention.

  Imide resins alone or blends with other thermoplastic polymers can be processed into various molded products by various plastic processing methods such as injection molding, melt extrusion film molding, blow molding, compression molding, spinning molding and the like. It can also be molded by a casting method or a spin coating method using a polymer solution obtained by dissolving an imide resin obtained in the present invention such as methylene chloride in a solvent for dissolving the imide resin.

  When molding, generally used antioxidants, heat stabilizers, plasticizers, lubricants, UV absorbers, antistatic agents, colorants, shrinkage inhibitors, etc. are added within the range that does not impair the purpose of the present invention. May be.

  Molded articles obtained from the imide resin of the present invention include, for example, imaging fields such as cameras, VTRs, projector lenses, viewfinders, filters, prisms, and Fresnel lenses, optical disc pickups such as CD players, DVD players, and MD players. Information equipment such as lenses such as lenses, optical recording fields for optical discs such as CD players, DVD players, and MD players, liquid crystal light guide plates, liquid crystal display films such as polarizer protective films and retardation films, and surface protective films Field, optical communication field such as optical fiber, optical switch, optical connector, etc., automotive headlight, tail lamp lens, inner lens, instrument cover, sunroof, etc., vehicle field, glasses, contact lens, internal vision lens, need for sterilization Doctor Medical equipment field such as supplies, road translucent plates, paired glass lenses, lighting windows and carports, lighting lenses and covers, building materials such as sizing for building materials, microwave cooking containers (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 The pellet of the product was used as it was, and IR spectrum was measured at room temperature using TravelIR manufactured by SensIR Technologies. From the obtained spectrum, the absorption intensity (Abs _Ester) attributed to the ester carbonyl group of 1720 cm ^-1, the ratio of the absorption intensity assignable to an imide carbonyl group of 1660cm ^-1 (Abs _imide), the following Equation 3 Was used to obtain the imidization ratio (Im%). Here, the imidation rate refers to the proportion of the imide carbonyl group in all carbonyl groups.

(2) Foreign matter inspection A test piece having a size of 210 mm in length and 300 mm in width was cut out from the obtained sheet-like molded product having a thickness of 3 mm. While this test piece was irradiated with light from a desk stand (National SQ948H, fluorescent lamp 27W) in a dark room, the periphery of the foreign substance observed visually was checked with an oil pen. Next, the checked foreign matter was observed with a transmission optical microscope (digital microscope (VH-Z75), manufactured by Keyence Corporation) with a magnification of 50 times. The above observation was performed on both sides of the sheet-like molded body, and the total number and type of foreign matters were measured. In order to distinguish the imidation-derived foreign material from the general foreign material, it was judged by the color of the foreign material when observed with a transmission optical microscope having a magnification of 50 times or more. It was judged that the imidation-derived foreign matters looked yellow and colorless and transparent, and the general foreign matters looked other colors.

(3) Glass transition temperature (Tg)
Using 10 mg of the product, a differential scanning calorimeter (DSC, model DSC-50 manufactured by Shimadzu Corporation) was used to measure under a nitrogen atmosphere at a heating rate of 20 ° C./min, and determined by the midpoint method. .

(4) Total light transmittance A test piece having a size of 50 mm in length and 50 mm in width was cut out from the obtained sheet-like molded product having a thickness of 3 mm. This test piece was measured according to JIS K7105 at a temperature of 23 ° C. ± 2 ° C. and a humidity of 50% ± 5% using a turbidimeter 300A manufactured by Nippon Denshoku Industries Co., Ltd.

(5) Turbidity The test piece obtained in (4) was measured according to JIS K7136 at a temperature of 23 ° C. ± 2 ° C. and a humidity of 50% ± 5% using a Nippon Denshoku turbidity meter 300A. .

(6) Oriented birefringence The product was dissolved in methylene chloride (resin concentration 25 wt%), applied onto a PET film, and dried to prepare a film having a thickness of 80 μm. A sample having a width of 50 mm and a length of 150 mm was cut out from this film, and a stretched film was prepared at a stretch ratio of 100% and at a temperature 5 ° C. higher than the glass transition temperature. A test piece of 3.5 cm × 3.5 cm was cut out from the central part in the TD direction of this uniaxial double stretched film. The phase difference of this test piece was measured using a KOBRA-21ADH manufactured by Oji Scientific Instruments at a temperature of 23 ± 2 ° C. and a humidity of 50 ± 5% at a wavelength of 590 nm and an incident angle of 0 °. The value obtained by dividing this phase difference by the thickness of the test piece measured using a Mitutoyo Digimatic Indicator was defined as orientation birefringence.

(Production Example 1)
Using commercially available polymethyl methacrylate (Sumitex MG manufactured by Sumitomo Chemical Co., Ltd.) as a raw material resin, monomethylamine as an imidizing agent, and IRGANOX 1010 (manufactured by Ciba Specialty Chemicals Co., Ltd.) as an imidizing agent, A modified resin was produced.

  The extruder used was a meshing type co-rotating twin screw extruder having a diameter of 15 mm. The set temperature of each temperature control zone of the extruder was 230 ° C., and the screw rotation speed was 150 rpm. A resin prepared by dry blending 0.2 parts by weight of a heat stabilizer from a hopper is supplied at 1 kg / hr. After the resin is melted and filled by a kneading block, 5 parts by weight of monomethylamine is injected from the nozzle to the resin. did. A seal ring and a reverse flight were placed at the end of the reaction zone to fill the resin. By-products and excess methylamine after the reaction were removed by reducing the pressure at the vent port to -0.08 MPa. The resin that came out as a strand from a die provided at the exit of the extruder was cooled in a water tank and then pelletized with a pelletizer.

  The imidation rate of the obtained imide resin was 22%, and the glass transition temperature was 123 ° C.

(Production Example 2)
It was carried out in the same manner as in Production Example 1 except that 0.2 parts by weight of IRGANOX HP2251 (manufactured by Ciba Specialty Chemicals Co., Ltd.) was used as the heat stabilizer.

  The imidization rate of the obtained imide resin was 20%, and the glass transition temperature was 122 ° C.

(Production Example 3)
The same procedure as in Production Example 1 was carried out except that the heat stabilizer was 0.2 parts by weight of heat stabilizer Sumilizer GM (Sumitomo Chemical Co., Ltd.).

  The imidation rate of the obtained imide resin was 20%, and the glass transition temperature was 121 ° C.

(Comparative Production Example 1)
The same procedure as in Production Example 1 was carried out except that no heat stabilizer was used.

  The imidation ratio of the obtained imide resin was 20%, and the glass transition temperature was 123 ° C.

(Production Example 4)
The same procedure as in Production Example 1 was conducted except that the amount of heat stabilizer IRGANOX 1010 (manufactured by Ciba Specialty Chemicals Co., Ltd.) was 0.05 parts by weight.

  The imidation rate of the obtained imide resin was 20%, and the glass transition temperature was 121 ° C.

(Production Example 5)
The same procedure as in Production Example 1 was conducted, except that the amount of heat stabilizer IRGANOX 1010 (manufactured by Ciba Specialty Chemicals Co., Ltd.) was changed to 7 parts by weight.

  The imidation ratio of the obtained imide resin was 18%, and the glass transition temperature was 116 ° C.

(Production Example 6)
The same procedure as in Production Example 1 was conducted except that the raw material resin was a commercially available methyl methacrylate-styrene copolymer (Sumipex HS manufactured by Sumitomo Chemical Co., Ltd.) and methylamine was 40 parts by weight based on the resin.

  The imidation rate of the obtained imide resin was 70%, and the glass transition temperature was 154 ° C.

(Production Example 7)
The same procedure as in Production Example 6 was performed except that 0.2 parts by weight of IRGASTAB STYL2921 (manufactured by Ciba Specialty Chemicals) was used as the heat stabilizer.

  The imidation ratio of the obtained imide resin was 72%, and the glass transition temperature was 157 ° C.

(Example 1)
The imide resin obtained in Production Example 1 was dried at 100 ° C. for 5 hours, and then extruded using a 40 mmφ single screw extruder and a 400 mm wide T die at a cylinder and T die temperature of 250 ° C. at a discharge rate of 20 kg / hr. The sheet-like molten resin was cooled with a cooling drum to obtain a sheet-like molded body having a width of about 600 mm and a thickness of 3 mm. Table 1 shows the foreign matter inspection, total light transmittance, turbidity, and orientation birefringence of the obtained molded body.

(Example 2)
A sheet-like molded article having a thickness of 3 mm was obtained in the same manner as in Example 1 except that the imide resin obtained in Production Example 2 was used. Table 1 shows the foreign matter inspection, total light transmittance, turbidity, and orientation birefringence of the obtained molded body.

(Example 3)
A sheet-like molded body having a thickness of 3 mm was obtained in the same manner as in Example 1 except that the imide resin obtained in Production Example 3 was used. Table 1 shows the foreign matter inspection, total light transmittance, turbidity, and orientation birefringence of the obtained molded body.

(Comparative Example 1)
A sheet-like molded article having a thickness of 3 mm was obtained in the same manner as in Example 1 except that the imide resin obtained in Comparative Production Example 1 was used. Table 1 shows the foreign matter inspection, total light transmittance, turbidity, and orientation birefringence of the obtained molded body.

Example 4
A sheet-like molded body having a thickness of 3 mm was obtained in the same manner as in Example 1 except that the imide resin obtained in Production Example 4 was used. Table 1 shows the foreign matter inspection, total light transmittance, turbidity, and orientation birefringence of the obtained molded body.

(Example 5)
A sheet-like molded body having a thickness of 3 mm was obtained in the same manner as in Example 1 except that the imide resin obtained in Production Example 5 was used. Table 1 shows the foreign matter inspection, total light transmittance, turbidity, and orientation birefringence of the obtained molded body.

(Example 6)
A sheet-like molded body having a thickness of 3 mm was obtained in the same manner as in Example 1 except that the imide resin obtained in Production Example 6 was used. Table 1 shows the foreign matter inspection, total light transmittance, turbidity, and orientation birefringence of the obtained molded body.

(Example 7)
A sheet-like molded body having a thickness of 3 mm was obtained in the same manner as in Example 1 except that the imide resin obtained in Production Example 7 was used. Table 1 shows the foreign matter inspection, total light transmittance, turbidity, and orientation birefringence of the obtained molded body.

Claims (8)

  A method for producing an imide resin, comprising treating a (meth) acrylic ester resin with an imidizing agent in the presence of a heat stabilizer.   2. The method for producing an imide resin according to claim 1, wherein the total number of imidization-derived foreign substances contained in a molded body having a length of 210 mm, a width of 300 mm, and a thickness of 3 mm is 100 or less.   The heat stabilizer is at least one compound selected from the group consisting of a hindered phenol compound, a lactone compound, a phosphorus compound, a hindered amine compound, and a thioether compound. Or the manufacturing method of the imide resin of 2.   The amount of the heat stabilizer added to 100 parts of the (meth) acrylic acid ester resin is 0.01 parts by weight or more and 5 parts by weight or less. The manufacturing method of the imide resin as described in 2. The imide resin is represented by the following general formulas (1) and (2) having a glass transition temperature of 110 ° C. or higher and an orientation birefringence of −0.1 × 10 ^{−3 to} 0.1 × 10 ^−3. It is an imide resin containing a repeating unit, The manufacturing method of the imide resin of any one of Claims 1-4 characterized by the above-mentioned.

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

(Here, R ⁴ and R ⁵ each independently represent hydrogen or an alkyl group having 1 to 8 carbon atoms, and R ⁶ represents an alkyl group having 1 to 18 carbon atoms or a cycloalkyl group having 3 to 12 carbon atoms. Or a substituent containing an aromatic ring having 5 to 15 carbon atoms.) The said imide resin contains the repeating unit represented by General formula (3) further, The manufacturing method of the imide resin of Claim 5 characterized by the above-mentioned.

(Here, 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 imide resin obtained by the manufacturing method of the imide resin of any one of Claims 1-6.   The imide resin molded object containing the imide resin obtained by the manufacturing method of the imide resin of any one of Claims 1-6.