JP2015052047A - Resin composition, resin sheet, liquid crystal protective sheet, and window material for building base material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition having high transparency and high rigidity.SOLUTION: The resin composition is used which contains (A) a polycarbonate, (B) a polymer having an ester bond in its side chain, and (C) a quaternary ammonium salt. The polycarbonate (A) has a weight-average molecular weight of 20,000 to 30,000 inclusive. The polycarbonate (A) is obtained by reacting bisphenol A with phosgene. The polymer (B) having an ester bond in its side chain is a polymethyl methacrylate.

Description

  The present invention relates to a resin composition, a resin sheet, a liquid crystal protective sheet, and a window material for a building substrate.

  In general, polycarbonate resins are excellent in high-temperature stability, dimensional stability, impact resistance, rigidity, and transparency, but have the disadvantages of insufficient scratch resistance and long-term UV resistance and stress birefringence. ing. On the other hand, acrylic resins such as polymethyl methacrylate are known to be excellent in transparency, surface hardness, UV resistance, weather resistance, chemical resistance, etc., although they have low dimensional stability, impact resistance and low temperature resistance. .

  Therefore, the blend of polycarbonate resin and acrylic resin is expected to eliminate the disadvantages of each component and provide a material that can be used in various applications. However, conventional blends of polycarbonate resin and acrylic resin are opaque substances that cannot be used for applications requiring transparency (see, for example, Patent Document 1). Therefore, various methods have been proposed in order to obtain a transparent blend of a polycarbonate resin and an acrylic resin.

  For example, a method of mixing an aromatic polycarbonate and syndiotactic polymethyl methacrylate in which at least 50% of all methyl methacrylate units are in syndiotactic configuration is known (see Patent Document 2). However, the mixture obtained by this method is not necessarily sufficiently transparent.

  Also, a melt kneading method is known in which a resin comprising 97 to 60% by mass of polycarbonate and 3 to 40% by mass of polymethyl methacrylate is blended using a trace type high shear molding machine (see Patent Document 3). However, the blend obtained by this method is not always sufficient in terms of transparency.

Japanese Patent Publication No. 43-13384 JP-A-6-128475 JP 2009-196196 A

  The present invention has been made in order to solve the conventional problems as described above. The object of the present invention is to provide a resin composition, a resin sheet, a liquid crystal protective sheet, and a building substrate having high transparency and excellent rigidity. Window material.

The above object is achieved by the following items (1) to (9).
[1] A resin composition comprising (A) polycarbonate, (B) a polymer having an ester bond in a side chain, and (C) a quaternary ammonium salt.
[2] The resin composition according to [1], wherein the polycarbonate (A) has a weight average molecular weight of 20,000 to 30,000.
[3] The resin composition according to any one of [1] or [2], wherein the polycarbonate (A) is obtained by reacting bisphenol A and phosgene.
[4] The resin composition according to any one of [1] to [3], wherein the polymer (B) having an ester bond in the side chain is polymethyl methacrylate.
[5] The resin composition according to any one of [1] to [4], wherein the (C) quaternary ammonium salt is a salt of a tetraalkylammonium ion and a nitrate ion.
[6] The resin composition according to any one of [1] to [5], wherein the (C) quaternary ammonium salt is tetrabutylammonium nitrate.
[7] A resin sheet obtained by molding the resin composition according to any one of [1] to [6].
[8] A liquid crystal protective sheet using the resin sheet according to [7].
[9] A window material for a building base material using the resin sheet according to [7].

  By using the resin composition of the present invention, it is possible to obtain a resin composition, a resin sheet, a liquid crystal protective sheet, and a building base material window having high transparency and excellent rigidity.

  Hereinafter, the resin composition, the resin sheet, the liquid crystal protective sheet, and the window material for a building substrate according to the present invention will be described in detail based on preferred embodiments.

  First, the resin composition of the present invention will be described.

  The polycarbonate (A) used in the present invention will be described. Polycarbonate is a resin having a carbonate bond, and is a polymer or copolymer obtained by reacting an aromatic hydroxy compound or a small amount of a polyhydroxy compound with a carbonate precursor.

As aromatic hydroxy compounds, 2,2-bis (4-hydroxyphenyl) propane (commonly called bisphenol A), 2,2-bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) Propane, 2,2-bis (hydroxy-3-methylphenyl) propane, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone, hydroquinone, resorcinol, 4,6-dimethyl-2,4,6 -Tri (4-hydroxyphenyl) heptene, 2,4,6-dimethyl-2,4,6-tri (4 Hydroxyphenyl) heptane, 2,6-dimethyl-2,4,6-tri (4-hydroxyphenyl) heptene, 1,3,5-tri (4-hydroxyphenyl) benzene, 1,1,1-tri (4 -Hydroxyphenyl) ethane, 3,3-bis (4-hydroxyaryl) oxindole, 5-chloro-3,3-bis (4-hydroxyaryl) oxindole, 5,7-dichloro-3,3-bis ( 4-hydroxyaryl) oxindole, 5-bromo-3,3-bis (4-hydroxyaryl) oxindole, etc. may be mentioned, and these may be used alone or in combination of two or more.

As the carbonate precursor, carbonyl halide, carbonate ester, haloformate or the like is used, and specific examples include phosgene, diphenyl carbonate and the like.

  Among these, bisphenol A type polycarbonate obtained by reacting 2,2-bis (4-hydroxyphenyl) propane and phosgene is preferable from the viewpoint of high transparency.

  The weight average molecular weight of the polycarbonate is preferably 20000 or more and 30000 or less. When it is at least the lower limit, the rigidity of the resin composition increases, which is preferable. When the amount is not more than the above upper limit value, workability during kneading is preferably improved.

The polymer (B) having an ester bond in the side chain used in the present invention will be described. Examples of the polymer having an ester bond in the side chain include polymethyl acrylate, polyethyl acrylate, polybutyl acrylate, polypropyl acrylate, polyvinyl acetate, polymethyl methacrylate, polyethyl methacrylate, and polymethacrylic acid. Examples include butyl and polypropyl methacrylate.

  Among these, polymethyl methacrylate is preferable because of its high transparency.

The (C) quaternary ammonium salt used in the present invention will be described.
A quaternary ammonium salt is a salt containing a cation in which four hydrocarbon groups are bonded to a nitrogen atom in the molecule. Examples of anions contained in the quaternary ammonium salt include chloride ions, bromide ions, and iodide ions. And halide ions, sulfate ions, nitrate ions and the like. Examples of ammonium salts include tetramethylammonium chloride, tetraethylammonium chloride, tetrabutylammonium chloride, benzyltrimethylammonium chloride, benzyltriethylammonium chloride, benzyltributylammonium chloride, tetramethylammonium bromide, tetraethylammonium bromide, tetrabutylammonium bromide, Examples thereof include benzyltrimethylammonium bromide, benzyltriethylammonium bromide, tetramethylammonium iodide, tetraethylammonium iodide, tetrabutylammonium iodide, benzyltributylammonium iodide, tetrabutylammonium nitrate, and tetrabutylammonium hydrogensulfate.

  Among these, tetrabutylammonium nitrate is preferable from the viewpoint of expressing the transparency of the resin.

  (C) In the presence of a quaternary ammonium salt, (A) polycarbonate and (B) a polymer having an ester bond in the side chain undergo a transesterification reaction to form a copolymer. Since this copolymer acts as a compatibilizing agent for the components (A) and (B), it can be melt-kneaded without reducing transparency.

  Since the ester bond of the component (A) is cleaved by the transesterification reaction, the molecular weight of the component (A) decreases, which causes a decrease in rigidity. However, the use of (A) polycarbonate having a molecular weight of 20000 or more can suppress a decrease in rigidity.

The resin composition of the present invention may contain an inorganic filler.
Examples of the inorganic filler include glass fiber, glass milled fiber, glass flake, glass bead, carbon fiber, silica, alumina, titanium oxide, calcium sulfate powder, gypsum, gypsum whisker, barium sulfate, talc, mica, calcium silicate. , Carbon black, graphite, iron powder, copper powder, molybdenum disulfide, silicon carbide, silicon nitride, brass fiber, stainless steel fiber, potassium titanate fiber, and the like. Among these, glass fiber fillers, glass powder fillers, glass flake fillers, and glass beads are preferable from the viewpoint of expressing the transparency of the resin sheet.

  The average particle size of the inorganic filler is not particularly limited, but is preferably 10 μm or more and 200 μm or less. More preferably, they are 15 micrometers or more and 150 micrometers or less. By setting it as this range, the molded article of the resin composition which has a favorable external appearance and sufficient surface hardness can be obtained.

  The compounding amount of the inorganic filler is 1 part by mass or more and 100 parts by mass or less with respect to (A) polycarbonate, (B) polymer having an ester bond in the side chain, and (C) 100 parts by mass of the quaternary ammonium salt. Preferably, it is 1 part by mass or more and 50 parts by mass or less. By setting it as this range, the appearance of the molded product of the resin composition of the present invention can be made excellent and the surface hardness can be made excellent.

  These inorganic fillers may be used alone or in combination of two or more. The shape of the inorganic filler is not particularly limited, but a spherical shape is preferable from the viewpoint of filling property and mold wear.

  Furthermore, nucleating agents, flame retardants, impact modifiers, foaming agents, dyes, light stabilizers, mold release agents, antioxidants, colorants, etc. that are usually used in the resin composition, as long as the object of the present invention is not impaired. An additive may be included in the resin composition of the present invention.

  In the embodiment of the present invention, the mixing method of the inorganic filler and the additive is not particularly limited.

  The mass ratio of the (A) polycarbonate / (B) polymer having an ester bond in the side chain is not particularly limited, but is preferably in the range of 70/30 to 10/90, more preferably 60/40 to 20/80. Range. Within this mass ratio range, it is possible to obtain a resin composition having characteristics of (A) polycarbonate and (B) a polymer having an ester bond in the side chain, high transparency, and excellent rigidity. it can. Two or more types of (A) polycarbonate and (B) polymers having an ester bond in the side chain may be used.

  The amount of (C) quaternary ammonium salt added is not particularly limited, but preferably (C) quaternary ammonium salt / ((A) polycarbonate and (B) total amount of polymer having ester bond in side chain) is 2. / 100 to 1/1000. By setting the mass ratio in this range, a highly transparent resin can be obtained.

The temperature and shear rate at the time of melt kneading the resin mixture containing the component (A) and the component (B) are appropriately selected. The temperature is 180 ° C. or higher and 265 ° C. or lower, preferably 230 ° C. or higher and 260 ° C. or lower. and then, the shear rate 800 sec ^-1 or more 4000Sec ^-1 or less, preferably of 1,000 sec ^-1 or more 3750Sec ^-1 or less.

  As an apparatus used for melt kneading, an ordinary mixer or kneader can be used. Specifically, a uniaxial kneading extruder, a biaxial kneading extruder, a ribbon blender, a Henschel mixer, a Banbury mixer, a drum tumbler, and the like can be used, and among these, a biaxial kneading extruder is preferable. Moreover, melt-kneading can be performed in inert gas atmosphere, such as nitrogen gas, argon gas, and helium gas, as needed. As the kneading atmosphere, it is preferable to use nitrogen gas from the viewpoint of suppressing the deterioration of the compound and the cost of the inert gas.

  The time for kneading the resin composition is not particularly limited, but is preferably 1 minute to 60 minutes, more preferably 3 minutes to 20 minutes. By setting the kneading time within this range, the reaction can be sufficiently advanced and the productivity can be improved.

Next, a resin sheet, a liquid crystal protective sheet, and a building base material window will be described.
The resin sheet, the liquid crystal protective sheet and the window material for a building substrate of the present invention are obtained by molding the resin composition.
Examples of the molding method include compression molding, transfer molding, injection molding, blow molding, extrusion molding, laminate molding, calendar molding, and the like. When injection molding is used as the molding method, the injection molding conditions are preferably between 230 ° C. and 300 ° C., and the mold temperature is preferably 80 ° C. or more from the viewpoint of improving surface hardness.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Example 1
[1] Production of resin composition (A) Polymethacrylic acid as a polymer having 60 parts by mass of polycarbonate (trade name Iupilon E-2000 weight average molecular weight 28000 manufactured by Mitsubishi Engineering Plastics) and (B) a side chain having an ester bond 40 parts by mass of methyl (trade name Sumipex EX manufactured by Sumitomo Chemical Co., Ltd.) and 1 part by mass of (C) tetrabutylammonium nitrate as a quaternary ammonium salt were kneaded using a twin-screw kneader DSM Xplore15. After kneading at a shear rate of 1050 cm ⁻¹ at 250 ° C. for 3 minutes, the mixture was cooled to 210 ° C. over 4 minutes and then kneaded for 3 minutes. The kneaded resin composition was discharged in a strand shape.

[2] Press 15 g of the resin composition obtained by melt kneading was pressed with a press machine (NanoimPro Type 510 Nanonics) to obtain a resin sheet. After raising the temperature to 160 ° C., pressure was applied with a force of 1 KN. At this time, the thickness of the resin sheet was controlled to 500 μm using a filler gauge (FT0.50M1, manufactured by Nagai Gauge).

(Example 2)
(A) Polymethyl methacrylate (manufactured by Sumitomo Chemical Co., Ltd.) as a polymer having 50 parts by mass of polycarbonate (trade name Iupilon E-2000 weight average molecular weight 28000 manufactured by Mitsubishi Engineering Plastics) and (B) an ester bond in the side chain A resin composition and a resin sheet were obtained in the same manner as in Example 1 except that the trade name Sumipex EX) was changed to 50 parts by mass.

(Example 3)
(A) Polymethylmethacrylate (manufactured by Sumitomo Chemical Co., Ltd.) as a polymer having 40 parts by mass of polycarbonate (trade name Iupilon E-2000 weight average molecular weight 28000 manufactured by Mitsubishi Engineering Plastics) and (B) side chain having an ester bond A resin composition and a resin sheet were obtained in the same manner as in Example 1 except that the trade name Sumipex EX) was changed to 60 parts by mass.

Example 4
(C) A resin composition and a resin sheet were obtained in the same manner as in Example 1 except that tetrabutylammonium bromide was used as the quaternary ammonium salt.

(Example 5)
(A) Poly (methyl methacrylate) (manufactured by Sumitomo Chemical Co., Ltd.) as a polymer having 60 parts by mass of polycarbonate (trade name Iupilon E-2000 weight average molecular weight 28000) manufactured by Mitsubishi Engineering Plastics Co., Ltd. and (B) side chain. Example except that 40 parts by weight of Sumipex EX), 1 part by weight of tetrabutylammonium nitrate as a quaternary ammonium salt, and 20 parts by weight of silica (manufactured by Admatechs, trade name SO-25R). In the same manner as in Example 1, a resin composition and a resin sheet were obtained.

(Comparative Example 1)
(B) Example 1 except that polymer having an ester bond in the side chain was not used and (A) polycarbonate (trade name Iupilon E-2000 weight average molecular weight 28000 manufactured by Mitsubishi Engineering Plastics Co., Ltd.) was changed to 100 parts by mass. Similarly, a resin composition and a resin sheet were obtained.

(Comparative Example 2)
(A) The same procedure as in Example 1 except that polycarbonate was not used and (B) polymethyl methacrylate (trade name Sumipex EX manufactured by Sumitomo Chemical Co., Ltd.) was used as the polymer having an ester bond in the side chain. Thus, a resin composition and a resin sheet were obtained.

(Comparative Example 3)
(C) A resin composition and a resin sheet were obtained in the same manner as in Example 1 except that the quaternary ammonium salt was not used.

  The obtained resin composition and resin sheet were evaluated as follows. The evaluation results are shown in Table 1.

<Light transmittance measurement>
The light transmittance of 550 nm was measured for the resin sheet obtained in each Example and Comparative Example using an ultraviolet visible spectrophotometer (UV mini1240, manufactured by Shimadzu Corporation). At this time, the thickness of the resin sheet was measured with a micrometer (M310-25 manufactured by Mitutoyo Corporation), and the measurement result of the light transmittance was converted to the result when the thickness of the resin molded product was 500 μm.
Moreover, the external appearance (color) of the obtained resin sheet was visually evaluated.

<Surface hardness measurement>
About the resin sheet obtained in each Example and the comparative example, pencil hardness was measured using the pencil hardness meter (product made from tribostation TYPE32 Shinto Kagaku). Measurement was performed in accordance with JIS-K5600-5-4.

<Scratch resistance>
Using the resin sheets obtained in each of the examples and comparative examples, the tip is a tungsten carbide with a diameter of 1.0 mmφ by a test method based on ISO 1518, and the pressing load is set by the fixing position of the built-in metal spring. A scratch tester (MODEL318 manufactured by ERICHSEN) was pressed perpendicularly to the test piece, and scratch resistance was evaluated with a load that was visually scratched. A load of 10N or more was rated as ◯, and a load less than 10N was rated as ×.

<Measurement of rigidity>
A tensile test was performed on the resin sheets obtained in each Example and Comparative Example. As a test piece for the tensile test, a test piece having a thickness of 500 μm, a width of 5 mm, and a length of 76 mm was obtained by punching it from a resin sheet. Using a company STM-T-50), it was sandwiched between chucks and evaluated by a tensile test. The pulling speed was measured at 1 mm / min.

Examples 1-6 were excellent in transparency, surface hardness, and rigidity. Since the comparative example 1 did not use the polymer which has an ester bond in the (B) side chain, it resulted in inferior scratch property. Since the comparative example 2 did not use (A) polycarbonate, it was inferior in rigidity and resulted in coloring. Since the comparative example 3 did not use the (C) quaternary ammonium salt, it resulted in inferior transparency.

The resin composition of the present invention is excellent in surface hardness, transparency, and rigidity, and can be used for molded articles such as electric / electronic OA equipment, optical media, automobile parts, and building members. Specifically, it can be used for a display protective film, a window material for a building substrate, and the like.

Claims (9)

  A resin composition comprising (A) a polycarbonate, (B) a polymer having an ester bond in a side chain, and (C) a quaternary ammonium salt.   The resin composition according to claim 1, wherein the (A) polycarbonate has a weight average molecular weight of 20,000 to 30,000.   The resin composition according to claim 1, wherein the polycarbonate (A) is obtained by reacting bisphenol A and phosgene. The resin composition according to any one of claims 1 to 3, wherein the polymer (B) having an ester bond in a side chain is polymethyl methacrylate.   The resin composition according to any one of claims 1 to 4, wherein the (C) quaternary ammonium salt is a salt of a tetraalkylammonium ion and a nitrate ion.   6. The resin composition according to claim 1, wherein the (C) quaternary ammonium salt is tetrabutylammonium nitrate.   A resin sheet obtained by molding the resin composition according to claim 1.   A liquid crystal protective sheet comprising the resin sheet according to claim 7. A window material for a building base material, wherein the resin sheet according to claim 7 is used.