JP2006316252A - Transparent plate made of polycarbonate resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transparent plate made of a polycarbonate resin and having high heat ray shielding performances while maintaining transparency for visible light. <P>SOLUTION: The transparent plate made of the polycarbonate resin is obtained by kneading a transparent polycarbonate resin with tin-doped indium oxide powder and a dispersing agent composed of an ester of a fatty acid in (80:20) to (0:100) ratio of a saturated fatty acid to an unsaturated fatty acid and a polyhydric alcohol and molding the kneaded material into a platy form. In the transparent plate, the amount of the compounded tin-doped indium oxide powder based on 100 pts.wt. of the polycarbonate resin satisfies the relationship of formula (1): 0.06×A<SP>-1</SP>≤B≤0.5×A<SP>-0.3</SP>äwherein, A is the plate thickness (mm); and B is the amount (pts.wt.) of the compounded tin-doped indium oxide powder}. The ratio of the dispersing agent to the tin-doped indium oxide powder satisfies the relationship of formula (2): 0.2≤C/B≤20 äwherein, C is the amount (pts.wt.) of the compounded dispersing agent}. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a polycarbonate resin transparent plate. More specifically, the present invention relates to a transparent plate made of polycarbonate resin that is colorless and transparent and has a high heat ray shielding function.

  2. Description of the Related Art In recent years, plate-shaped molded products made of polycarbonate resin are frequently used for housing general window materials, building materials for greenhouses for greenhouse cultivation, roofing materials for garages, roofing materials for stockyards, building materials for barns, and the like. On the other hand, these plate-shaped molded bodies have been required to have a function of high heat ray (infrared ray) shielding properties with diversification of applications.

  In view of this, it is known that plate-shaped molded products made of polycarbonate resin use organic dyes such as phthalocyanine, organometallic complex salts such as dithiol, etc. as materials having a heat ray shielding effect. . However, the organic dye absorbs visible light and the molded product is colored. Therefore, the organic dye is not suitable for applications requiring high transparency, and the organic metal complex salt has a problem that the heat ray shielding effect disappears due to deterioration over time. .

  Further, in order to maintain transparency by transmitting visible light while shielding heat rays, antimony-doped tin oxide (hereinafter sometimes referred to as ATO), tin-doped indium oxide (hereinafter sometimes referred to as ITO). It is known that zinc oxide or the like is blended in a transparent thermoplastic resin. For example, JP-A-7-70481 (Patent Document 1) and JP-A 2000-178428 (Patent Document 2) disclose a molding material in which ITO powder is blended with a transparent thermoplastic resin. However, heat ray shielding inorganic fine particles such as ATO, ITO and zinc oxide are insoluble in solvents, resins, etc., so even if the primary particles are finely divided and melt-kneaded and dispersed in the resin In this case, there is a problem that the haze value increases due to scattering or diffusion of visible light incident on the molded body, and the quality such as mechanical strength is also deteriorated. Therefore, these molding materials are mostly used as a film in a laminate or as a thin film of a coating layer, and are molded by melting and kneading in a resin (for example, 0.2 mm or more). There were many difficulties to do.

Therefore, in Japanese Patent Application Laid-Open No. 2000-234066 (Patent Document 3), the heat ray shielding inorganic compound fine particles are combined with a specific dispersant to prevent deterioration of the haze value and mechanical strength of the molded body and improve the heat ray shielding property. It has been proposed to do.
However, in the prior art of Patent Document 3, by using a dispersant, the inorganic compound fine particles are added in a small addition amount (rate) to a relatively thick molded body (for example, about 4 mm) to shield against heat rays. Although performance has been achieved, it is indispensable to increase the amount (rate) of the heat-shielding inorganic compound in order to obtain high heat-shielding performance with a relatively thin molded body (for example, about 1 mm). In order to prevent the increase in the haze value associated therewith, it is necessary to optimize the components and addition amount of the dispersant again, and this has not been studied.

JP-A-7-70481 JP 2000-178428 A JP 2000-234066 A

  It is an object of the present invention to provide a polycarbonate resin transparent plate having high heat ray shielding performance while maintaining high transparency to visible light, not only when the plate thickness is thick but also when it is thin.

As a result of intensive studies to solve such problems, the present inventor blended ITO powder with a transparent polycarbonate resin and kneaded, and when the kneaded product was molded, a dispersant comprising a specific component in the kneaded product By adding a specific amount, the dispersibility of the ITO powder is remarkably improved. As a result, it is possible not only to maintain the transparency while suppressing the haze value, but also to greatly improve the heat ray shielding property. As a result, the inventors have found out that the present invention can be achieved.
Thus, according to the present invention, a transparent polycarbonate resin, tin-doped indium oxide powder, and an ester of fatty acid and polyhydric alcohol in which the weight ratio of saturated fatty acid and unsaturated fatty acid is 80:20 to 0: 100. A mixture containing a dispersant is formed into a plate shape,
The compounding quantity of the said tin dope indium oxide powder with respect to 100 weight part of said polycarbonate-type resin is Formula (1).
0.06 × A ⁻¹ ≦ B ≦ 0.5 × A ^−0.3 (1)
(Where A is the plate thickness (mm) and B is the blending amount (part by weight) of the tin-doped indium oxide powder), and the ratio of the tin-doped indium oxide powder and the dispersant is expressed by the formula (2)
0.2 ≦ C / B ≦ 20 (2)
A polycarbonate resin transparent plate satisfying the relationship (wherein C is a dispersant blending amount (part by weight)) is provided.

According to the present invention, tin-doped indium oxide (ITO) powder is dispersed at a high concentration on a relatively thin transparent plate (for example, a plate thickness of 0.2 to 0.7 mm), and maintains high transparency to visible light. A polycarbonate resin transparent plate having high heat ray shielding performance as it is can be obtained.
Furthermore, according to the present invention, there is provided a polycarbonate resin transparent plate having a transmittance of infrared light having a long wavelength of 1500 nm or more and a haze value of 5% or less at a thickness of 0.2 mm or more. Obtainable.

  The polycarbonate resin transparent plate of the present invention (sometimes referred to as a molded product) has a weight ratio of 80:20 to 0: transparent polycarbonate resin, tin-doped indium oxide powder, saturated fatty acid and unsaturated fatty acid. A mixture containing a dispersant composed of an ester of 100 fatty acid and a polyhydric alcohol is formed into a plate shape.

This polycarbonate resin transparent plate of the present invention has a thickness of A (mm), a blending amount of tin-doped indium oxide powder with respect to 100 parts by weight of the polycarbonate resin B (parts by weight), and a dispersion with respect to 100 parts by weight of the polycarbonate resin. When the compounding amount of the agent is C (parts by weight), it is characterized in that it is molded while satisfying the following formulas (1) and (2).
0.06 × A ⁻¹ ≦ B ≦ 0.5 × A ^−0.3 (1)
0.2 ≦ C / B ≦ 20 (2)

The polycarbonate resin transparent plate of the present invention that satisfies the above conditions has characteristics that the transmittance for infrared light having a long wavelength of 1500 nm or more is 50% or less and the haze value is 5% or less, and it is plate-like. There is no particular limitation, and it may be any of a flat plate shape, a corrugated plate shape, a hollow plate shape and the like.
Hereinafter, each component of the polycarbonate resin transparent plate and production of the transparent plate will be described.

[Transparent polycarbonate resin]
The polycarbonate resin used in the present invention is not particularly limited, and is a commercially available polycarbonate resin having a high light transmittance, or a polycarbonate resin other than a polycarbonate resin as long as it is transparent and does not impair the light transmittance. What blended these resins can be used.

In the present invention, the polycarbonate resin is produced by reacting a dihydric phenol and a carbonate precursor by a solution method or a melting method.
Representative examples of dihydric phenols are 2,2-bis (4-hydroxyphenyl) propane [bisphenol A], bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) cyclohexane, , 2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5-methylphenyl) propane, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxy) Phenyl) sulfone and the like. A preferable dihydric phenol is a bis (4-hydroxyphenyl) alkane system, and bisphenol A is particularly preferable among them.
Examples of the carbonate precursor include carbonyl halide, carbonyl ester, and haloformate. Specific examples include phosgene, diphenyl carbonate, dihaloformate of dihydric phenol, and mixtures thereof. Of these, phosgene and diphenyl carbonate are preferable. .
Moreover, as resin which can be mix | blended with a polycarbonate-type resin, polyester-type resins, such as a polyethylene terephthalate resin (PET), a polyarylate resin, a polycaprolactone, a polystyrene-type resin, etc. are mentioned.
The form of the polycarbonate-based resin used during production is not particularly limited, and may be any of pellets, granules, and powders.

[ITO powder]
The average primary particle diameter of the ITO powder used in the present invention is preferably 200 nm or less, more preferably 100 nm or less, and particularly preferably 80 to 20 nm in order to maintain transparency. When the average primary particle diameter of the ITO powder exceeds 200 nm, the influence of scattering by visible light becomes large, and the transparency of the formed plate material is lowered, which is not preferable. On the other hand, when it becomes smaller than 20 nm, secondary aggregation tends to occur, and the transparency tends to decrease unless the dispersion material is carefully optimized.
The production method of the ITO powder is not particularly limited as long as the average primary particle diameter meets the above-mentioned conditions, and a product produced by a known method or a commercially available ITO powder can be used. Furthermore, the ITO powder may have been subjected to a known surface treatment (for example, a silane coupling agent).

[Dispersant]
As described above, the dispersant for ITO powder in the present invention is composed of an ester of a fatty acid composed of a saturated fatty acid and an unsaturated fatty acid and a polyhydric alcohol.
(A) Saturated fatty acid In the present invention, the saturated fatty acid used as a raw material for the dispersant is preferably a saturated fatty acid having 8 to 30 carbon atoms, such as caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, pentadecyl. Examples thereof include acids, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, montanic acid, melicic acid, and the like, and one or more of these fatty acids can be used in combination. Among these fatty acids, it is more preferable to use lauric acid, behenic acid, stearic acid and the like.

(B) Unsaturated fatty acid In the present invention, the unsaturated fatty acid used as a raw material for the dispersant is preferably a monoenoic acid having 14 to 24 carbon atoms, such as myristoleic acid, palmitoleic acid, oleic acid, elaidic acid, vacsen. Acid, gadoleic acid, erucic acid, nervonic acid and the like can be mentioned, and one or more of these fatty acids can be used in combination. Among these fatty acids, it is more preferable to use oleic acid, erucic acid or the like.

(C) Polyhydric alcohol In the present invention, the polyhydric alcohol used as a raw material for the dispersant is preferably a trihydric to polyhydric alcohol, such as glycerin, diglycerin, pentaerythritol, sorbitan, triglycerin. , Tetraglycerin, sorbitol and its isomers, mannitol, pentaglycerin and the like. Among these polyhydric alcohols, it is more preferable to use diglycerin.

  When the carbon number of the saturated fatty acid and unsaturated fatty acid and the valence of the polyhydric alcohol are smaller than the above range, the compatibility with the polycarbonate-based resin of the dispersant tends to deteriorate, and conversely, when the carbon number is larger than the above range. The compatibility of the dispersing agent with the ITO powder tends to deteriorate, and it is conceivable that the dispersibility of the ITO powder deteriorates and the transparency is lowered as a result.

[Amount of each component]
Each component used for the polycarbonate resin transparent plate of the present invention is blended with a ratio satisfying the above formula (1) with respect to 100 parts by weight of the polycarbonate resin.
0.06 × A ⁻¹ ≦ B ≦ 0.5 × A ^−0.3 (1)
0.2 ≦ C / B ≦ 20 (2)
A: Thickness (mm)
B: ITO powder content (parts by weight)
C: Dispersant content (parts by weight)
At this time, the ratio of the saturated fatty acid and the unsaturated fatty acid constituting the dispersant is preferably 80:20 to 0: 100, and more preferably 60:40 to 0: 100. Furthermore, the blending amount of the dispersant is preferably 2 parts by weight or less, particularly preferably 1 part by weight or less, based on 100 parts by weight of the polycarbonate resin. If it exceeds 2 parts by weight, the impact resistance of the molded product tends to decrease, such being undesirable.

  In the formula (1), the blending amount of the ITO powder with respect to 100 parts by weight of the polycarbonate resin is determined by the desired thickness (mm) of the transparent plate. That is, according to Equation (1), the amount of ITO powder added decreases as the thickness of the transparent plate increases. FIG. 1 shows the correlation between the thickness of the transparent plate and the blending amount of the ITO powder in the present invention.

As shown in FIG. 1, for example, when the desired thickness of the transparent plate is 0.5 mm, the blending amount of the ITO powder is 0.12 to 0.66 parts by weight, and the desired thickness is 0.00. The blending amount of the ITO powder in the case of 7 mm is 0.09 to 0.58 parts by weight. In order to maintain the visible light transmittance and the heat ray shielding effect and suppress the increase in the haze value, it is preferable to control the blending amount of the ITO powder according to the plate thickness. .5 is a set value for satisfying these conditions. If the blending amount of the dispersant is less than 0.06 × A ^{−1 in} Formula 1, the ITO powder is not sufficiently dispersed, and the heat ray shielding effect tends to decrease, such being undesirable. On the other hand, if the blending amount of the dispersant is more than 0.5 × A ^{−0.3 in} Formula 1, the transparency (transmittance of visible light) tends to decrease, which is not preferable. According to Formula 1: 0.06 × A ⁻¹ ≦ B ≦ 0.5 × A ^−0.3 , for example, when the plate thickness A is 0.2 to 2 mm, the ITO blending amount B is 0.3 to 0.03 weight. Parts ≦ B ≦ 0.96 to 0.38 parts by weight, and when the thickness A is 3 to 8 mm, the ITO blending amount B is 0.02 to 0.0075 parts by weight ≦ B ≦ 0.32 to 0.2176 weights. Part.
Moreover, the range of the more preferable compounding quantity of ITO is shown in the following formula | equation (3).
0.06 × A ⁻¹ ≦ B ≦ 0.4 × A ^−0.5 (3)

In the formula (2), the blending amount of the dispersant with respect to 100 parts by weight of the polycarbonate resin is determined by the blending amount of the ITO powder obtained in the formula (1). In this case, the blending amount of the dispersant is preferably 0.2 to 20 times the blending amount of the ITO powder, more preferably 0.5 to 10 times, and particularly preferably 0.8 to 8 times. When the blending amount of the dispersing agent is less than 0.2 times the blending amount of the ITO powder, it is not preferable because good dispersion of the ITO powder into the polycarbonate resin cannot be expected. When exceeding 20 times, excessive dispersion The agent is not preferred because it may reduce various physical properties of the molded article.
At this time, as shown in Table 4, the blending amount of the dispersant with respect to 100 parts by weight of the polycarbonate resin is preferably 2 parts by weight or less, and more preferably 1 part by weight or less. If the amount of the dispersant exceeds 2 parts by weight, the impact strength of the molded product tends to decrease, such being undesirable.

  When the saturated fatty acid exceeds 80% in the ratio of the saturated fatty acid to the unsaturated fatty acid in the fatty acid that is the raw material of the dispersant, the transparency of the molded product is hindered and the haze value is increased. On the other hand, even when the fatty acid does not contain a saturated fatty acid and is 100% of an unsaturated fatty acid, the transparency of the molded product can be maintained extremely well. In order to elucidate the reason, the inventor within the specific range of the present invention, when the proportion of unsaturated fatty acid in the fatty acid to be reacted with the polyhydric alcohol is significantly higher than that of the saturated fatty acid and when the unsaturated fatty acid only is used The heat resistance was evaluated by an accelerated test. This evaluation method will be described in detail in the examples described later. As shown in Table 3, the results are almost numerically changed in both the transmittance and haze value of infrared light (heat rays) with a wavelength of 1500 nm. I know it's not there. This is considered to show that unsaturated fatty acid exists stably in a plate-shaped molded object. Therefore, by using an ester having an unsaturated fatty acid as a dispersant, transparency and heat ray shielding performance can be further improved, and when the equivalent performance is required, the amount of ITO added can be reduced and can be produced at low cost. There are advantages.

[Manufacture of polycarbonate resin transparent plate]
The polycarbonate resin transparent plate of the present invention having the above-mentioned configuration is a step of melting and kneading ITO powder and a dispersant in a transparent polycarbonate resin, and extruding the kneaded material into a plate shape or pelletizing the molten kneaded material. It can be manufactured by a process of injection molding.
Hereinafter, each step will be described.

(Melt kneading)
The method for melting and kneading the ITO powder and the dispersant in the transparent polycarbonate resin is not particularly limited. For example, the ITO powder and the polycarbonate resin surface-treated with the dispersant in advance are mixed with a super mixer, a Henschel mixer, a tumbler, or the like. Mixing or mixing polycarbonate resin and ITO powder and dispersing agent at the same time with super mixer, Henschel mixer, tumbler, etc., and melting and kneading using single screw extruder, twin screw extruder, etc., or polycarbonate resin In addition, a method in which the ITO powder and the dispersant are separately filled in an extruder and melt-kneaded is exemplified. At this time, the transparent polycarbonate resin, the ITO powder, and the dispersant are melt-kneaded at the above blending ratio.
As long as the properties of the present invention, that is, the transmittance for infrared light having a long wavelength of 1500 nm or more is 50% or less and the haze value is 5% or less, the heat ray shielding property and transparency are not impaired, for example, a colorant, You may add well-known additives, such as antioxidant, a ultraviolet absorber, and a light stabilizer.

(Extrusion molding)
The extrusion molding method of the molded body of the present invention is not particularly limited, and the molded body can be obtained by a known method using a single screw extruder, a twin screw extruder or the like. At this time, the plate thickness of the molded body is, for example, 0.2 to 8 mm, preferably 0.5 to 5 mm.
(injection molding)
Moreover, after making a raw material mixture into a pellet form by melt-kneading, a plate-shaped molded object can also be obtained using an injection molding machine. Also in this case, the thickness of the molded body is, for example, 0.2 to 8 mm, preferably 0.5 to 5 mm.

  The transparent plate made of polycarbonate resin of the present invention thus obtained has a transmittance of infrared light having a long wavelength of 1500 nm or more as described above of 50% or less, preferably 40% or less, and a haze value of 5%. Hereinafter, it preferably has a characteristic of 3% or less. Here, as shown in FIG. 1, when the plate thickness of the plate-shaped molded body is less than 0.2 mm, the blending amount of the ITO powder is remarkably increased in order to maintain the heat ray shielding effect, and as a result, the haze value is increased. Therefore, the transparency is lowered, which is not preferable. Therefore, the plate thickness is preferably 0.2 mm or more as described above. Further, when the transmittance of infrared light having a long wavelength of 1500 nm or more exceeds 50%, the heat ray shielding effect is lowered, which is not preferable. On the other hand, if the haze value exceeds 5%, the transparency of the transparent plate is remarkably lowered.

Here, the effectiveness of the ITO powder and the dispersant in the present invention will be described.
In order to examine the effectiveness of the ITO powder and the dispersant, three types of transparent plate samples 1 to 3 (plate thickness 0.35 mm) were prepared, and the correlation between light transmittance and wavelength for these samples 1 to 3 was measured. The results are shown in FIG.
Sample 1 (the present invention) was prepared by the above method using 100 parts by weight of a transparent polycarbonate resin, 0.2 parts by weight of ITO powder and 1 part by weight of a dispersant. In addition, what was produced from the fatty acid which made oleic acid which is unsaturated fatty acid and lauric acid which is saturated fatty acid 7: 3, and diglycerin which is a polyhydric alcohol was used for the dispersing agent.
Sample 2 was prepared in the same manner as Sample 1 except that the dispersant was omitted.
Sample 3 was prepared in the same manner as Sample 1 except that the ITO powder and the dispersant were removed.

  According to FIG. 2, the light transmittance is relatively high in the vicinity of 500 nm in the visible light region, but in samples 1 to 3 in the infrared region having a wavelength of 1500 nm or more exceeding the visible light region. It shows that there is a big difference. That is, in the transparent plate having a relatively thin plate thickness of 0.35 mm, the heat ray shielding effect that makes it difficult to transmit infrared light is highest in the sample 1 of the present invention, and then in the order of the sample 2 and the sample 3. Samples 1 and 2 have a significantly higher heat ray shielding effect than sample 3, which indicates that the heat ray shielding effect by ITO powder is effective. Further, since sample 1 has a higher heat ray shielding effect than sample 2, a dispersant is used. It turns out that it is effective.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these descriptions.

[Examples A to G group and Comparative examples A to F group]
ITO powder having an average primary particle size of 30 nm (Type B (H) manufactured by Fuji Titanium Industry Co., Ltd.) with respect to 100 parts by weight of polycarbonate resin (trade name “Iupilon E-2000” manufactured by Mitsubishi Engineering Plastics Co., Ltd.) And a dispersant (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) were blended in the blending amounts shown in Tables 1 and 2 and introduced into a twin screw extruder (PCM45 manufactured by Ikegai Co., Ltd.). Example of plate thickness shown in Table 1 using a sheet die after being kneaded and pelletized, then introduced into a single screw extruder (D2025 manufactured by Toyo Seiki Seisakusho Co., Ltd.), melted and kneaded at a barrel temperature of 280 ° C. In addition, a plate-like molded body sample of Comparative Example was prepared, and the dispersant was also the ratio of unsaturated fatty acid and saturated fatty acid in the fatty acid that is the raw material, the type thereof, and the type of polyhydric alcohol. Also written.
In Examples D4 to D9 in the Example D group, a flat plate of 1 to 8 mm (120 cm × 120 cm) was prepared by an injection molding machine (M-140AI-SJ, manufactured by Meiki Seisakusho) after pelletization. Similarly, data was collected.

In Example A group (Actual A1 to A3), a dispersant having a ratio of unsaturated fatty acid to saturated fatty acid of 20:80 is used, and the blending amount of the dispersant with respect to the blending amount of the ITO powder is 0.5. Double to 10 times.
In Example B group (B1 and B2), a dispersant having a ratio of unsaturated fatty acid to saturated fatty acid of 20:80 is used, and the blending amount of the dispersant with respect to the blending amount of the ITO powder is 0.5. Double to 10 times.
In Example C group (actual C1 to actual C14), a dispersant having a ratio of unsaturated fatty acid to saturated fatty acid of 40:60 is used, and the blending amount of the dispersant with respect to the blending amount of the ITO powder is 0.5. Double to 10 times.

In Example D group (real D1 to real D9), a dispersant having a ratio of unsaturated fatty acid to saturated fatty acid of 70:30 is used, and the blending amount of the dispersant with respect to the blending amount of the ITO powder is 0.5. Double to 10 times.
In Example E group (real E1 and real E2), a dispersant having a ratio of unsaturated fatty acid to saturated fatty acid of 70:30 is used, and the blending amount of the dispersant with respect to the blending amount of the ITO powder is 1 to 5 times.
In Example F group (real F1 and real F2), a dispersant having a ratio of unsaturated fatty acid to saturated fatty acid of 100: 0 is used, and the blending amount of the dispersant with respect to the blending amount of the ITO powder is 5 times to 10 times.
In Example G group (Real G1 to Real G3), a dispersant having a ratio of unsaturated fatty acid to saturated fatty acid of 100: 0 is used, and the blending amount of the dispersant with respect to the blending amount of the ITO powder is 0.5. Double to 5 times.

In Comparative Example A group (ratio A1), no ITO powder and dispersant were used.
In Comparative Example B group (ratio B1 to B3), no dispersant was used.
In Comparative Example C group (ratio C1 to C5), a dispersant having a ratio of unsaturated fatty acid to saturated fatty acid of 0: 100 is used, and the blending amount of the dispersant with respect to the blending amount of the ITO powder is 0.5. Double to 11 times.

In Comparative Example D group (ratio D1 and ratio D2), a dispersant having a ratio of unsaturated fatty acid to saturated fatty acid of 0: 100 is used, and the blending amount of the dispersant with respect to the blending amount of the ITO powder is 5 times to 10 times.
In Comparative Example E group (ratio E1 and ratio E2), a dispersant having a ratio of unsaturated fatty acid to saturated fatty acid of 0: 100 is used, and the blending amount of the dispersant with respect to the blending amount of the ITO powder is 1 to 5 times.
In Comparative Example F group (ratio F1 to ratio F3), a dispersant having a ratio of unsaturated fatty acid to saturated fatty acid of 40:60 is used, and the blending amount of the dispersant with respect to the blending amount of the ITO powder is 0.5. Double to 22 times.

  With respect to the obtained plate-like molded products of Examples and Comparative Examples, the light transmittance (%) and haze value (%) of light having wavelengths of 500 nm and 1500 nm were measured, and the results are shown in Tables 1 and 2. . In addition, real C7, real E2, real G2, ratio A1, ratio B1, ratio C4, and ratio E2 were evaluated with the same evaluation items after being exposed to a high temperature of 120 ° C. for 48 hours, and the results are shown in Table 3. (Heat resistance evaluation). Each physical property evaluation at that time was performed as follows.

(Light transmittance)
The light transmittance was measured for the plate-like molded body samples of Examples and Comparative Examples using a spectrophotometer (UV-3100PC manufactured by Shimadzu Corporation).
(Cloudiness value)
The plate-like molded body samples of Examples and Comparative Examples were measured using a haze meter (NDT-2000 manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with Japanese Industrial Standard (JIS K 7136).
(Heat resistance evaluation)
The plate-like molded body samples of Examples and Comparative Examples were exposed at 120 ° C. for 48 hours in a gear oven (manufactured by Toyo Seiki Seisakusho), and then the light transmittance and haze value were measured.

Tables 1 and 2 show the following.
When the unsaturated fatty acid and saturated fatty acid by the specific ratio of this invention are used as a fatty acid of a dispersing agent like Example AE group, and the dispersing agent is mix | blended 0.5 to 10 times the compounding quantity of ITO powder , And as in Example F and G groups, only unsaturated fatty acids were used as the fatty acid of the dispersant, and the dispersant was blended at 0.5 to 5 times the blending amount of the ITO powder at 500 nm. While maintaining the light transmittance as high as approximately 83% or more, all the light transmittance at 1500 nm is excellent at 50% or less, and all the haze values are suppressed to 5% or less. Among them, Examples C13 and D8 have significantly improved characteristics such as a haze value of 2% or less and a light transmittance at 1500 nm of 7% or less.

On the other hand, when ITO powder and a dispersant are not used as in Comparative Example A1, the light transmittance at 1500 nm is inferior although the haze value is low, and when ITO powder is used without a dispersant as in Comparative Example B group Has a poor light transmittance at 1500 nm and a high haze value.
As in Comparative Examples C to E, when only saturated fatty acid is used as the fatty acid of the dispersant, and the dispersant is blended 0.5 to 11 times the blending amount of the ITO powder, the haze value is slightly improved. The light transmittance at 1500 nm is inferior to 51% or more.
As in Comparative Example F1, even when the unsaturated fatty acid and saturated fatty acid of the specific ratio of the present invention were used as the fatty acid of the dispersant, when the dispersant was blended 22 times the blending amount of the ITO powder, the haze value and 1500 nm Both light transmittances are inferior.
As in Comparative Examples F2 and F3, even when the unsaturated fatty acid and the saturated fatty acid of the specific ratio of the present invention are used as the fatty acid of the dispersant, the blending amount of the ITO powder when the plate thickness is 0.35 mm is in the formula (1) This exceeds the upper limit of 0.5 × a ^-0.3, is excellent in light transmittance at 1500 nm, haze is inferior.
That is, according to the present invention, it was found that a polycarbonate resin transparent plate having high heat ray shielding performance while maintaining high transparency to visible light can be obtained.

  From Table 3, examples containing unsaturated fatty acids (real C7, real E2, real G2), comparative examples not containing (ratio A1, ratio B1, ratio C4, ratio E2), any combination, Almost no change is observed in both the transmittance and haze value of infrared light (heat rays) at a wavelength of 1500 nm after exposure at 120 ° C. for 48 hours compared to before exposure. This is considered to indicate that the unsaturated fatty acid is present at least as stably as the saturated fatty acid in the plate-shaped molded article, and considering the initial performance, according to the present invention. It has been found that by using an ester having an unsaturated fatty acid as a dispersant, the transparency and heat ray shielding performance are further improved, and the amount of ITO added can be reduced when the equivalent performance is required.

[Examples H to K group and Comparative examples G to J group]
Except that the ITO powder and the dispersant were changed to the blending amounts and plate thicknesses shown in Table 3, the plate-shaped molded body samples of Examples H to K and Comparative Examples G to J were the same as the above Examples and Comparative Examples. Was made.
In Example H group (actual H1), a dispersant having a ratio of unsaturated fatty acid to saturated fatty acid of 20:80 was used, and the blending amount of the dispersant with respect to the blending amount of the ITO powder was five times.
In Example I group (Real I1 to Real I5), a dispersant having a ratio of unsaturated fatty acid to saturated fatty acid of 40:60 is used, and the blending amount of the dispersant with respect to the blending amount of the ITO powder is 1 to 11 times.
In Example J group (actual J1), a dispersant having a ratio of unsaturated fatty acid to saturated fatty acid of 70:30 was used, and the blending amount of the dispersant with respect to the blending amount of the ITO powder was five times.
In Example K group (actual K1), a dispersant having a ratio of unsaturated fatty acid to saturated fatty acid of 100: 0 was used, and the blending amount of the dispersing agent with respect to the blending amount of the ITO powder was five times.

In Comparative Example G group (ratio G1), no ITO powder and dispersant were used.
In Comparative Example H group (ratio H1), no dispersant was used.
In Comparative Example I group (ratio I1 to ratio I6), a dispersant having a ratio of unsaturated fatty acid to saturated fatty acid of 0: 100 is used, and the blending amount of the dispersing agent with respect to the blending amount of the ITO powder is 1 to 11 times.
In Comparative Example J group (ratio J1), a dispersant having a ratio of unsaturated fatty acid to saturated fatty acid of 0: 100 was used, and the blending amount of the dispersant with respect to the blending amount of the ITO powder was 5 times.

  A DuPont impact test (ASTM-D2794, weight weight: 300 g, striker tip: R = 6.3 mm, drop height 100-500 mm) was performed on these obtained samples, and the results are shown in Table 4. Indicated.

  From the results of Comparative Example G1 and Comparative Example H1 shown in Table 4, it can be seen that the impact resistance is deteriorated by adding ITO powder, but the impact resistance is added by adding a dispersant as in Comparative Example I1. It can be seen that is improved. However, as in Examples I5 and I6 and Comparative Examples I5 and I6, when the blending amount of the dispersant is 2.2 parts by weight or more, impact resistance tends to deteriorate. The blending amount of the dispersant with respect to parts is preferably 2 parts by weight or less.

  The polycarbonate resin transparent plate of the present invention has high transparency and heat ray shielding properties, so that it is used for automobile windows, railway windows, aircraft windows, housing general window materials, daylighting windows, roofing materials, and greenhouses for greenhouse cultivation. It can be suitably used for various purposes such as building materials for greenhouses, greenhouse materials, roofing materials for garages, roofing materials for stock yards, building materials for barns.

It is a graph which shows the correlation of the plate | board thickness in the polycarbonate resin transparent board of this invention, and the compounding quantity of ITO powder. It is a graph which shows the correlation of the light transmittance and wavelength in the polycarbonate resin transparent board of this invention.

Claims (8)

A mixture comprising a transparent polycarbonate-based resin, tin-doped indium oxide powder, and a dispersant composed of an ester of a fatty acid and a polyhydric alcohol having a weight ratio of saturated fatty acid and unsaturated fatty acid of 80:20 to 0: 100. , Molded into a plate,
The compounding quantity of the said tin dope indium oxide powder with respect to 100 weight part of said polycarbonate-type resin is Formula (1).
0.06 × A ⁻¹ ≦ B ≦ 0.5 × A ^−0.3 (1)
(Where A is the plate thickness (mm) and B is the blending amount (part by weight) of the tin-doped indium oxide powder), and the ratio of the tin-doped indium oxide powder and the dispersant is expressed by the formula (2)
0.2 ≦ C / B ≦ 20 (2)
A polycarbonate resin transparent plate characterized by satisfying the relationship (wherein C is a dispersant blending amount (parts by weight)).   The polycarbonate resin transparent plate according to claim 1, wherein the blending amount of the dispersant is 2 parts by weight or less with respect to 100 parts by weight of the polycarbonate resin.   The polycarbonate resin transparent plate according to claim 1 or 2, wherein the plate thickness is 0.2 to 8 mm.   The polycarbonate-based resin transparent plate according to any one of claims 1 to 3, wherein the tin-doped indium oxide powder has an average primary particle size of 200 nm or less.   The polycarbonate resin transparent plate according to any one of claims 1 to 4, wherein a transmittance for infrared light having a long wavelength of 1500 nm or more is 50% or less and a haze value is 5% or less.   The transparent plate made of polycarbonate resin according to any one of claims 1 to 5, wherein the saturated fatty acid is selected from one or more of saturated fatty acids having 8 to 30 carbon atoms.   The polycarbonate resin transparent plate according to any one of claims 1 to 6, wherein the unsaturated fatty acid is selected from one or more of unsaturated fatty acids having 14 to 24 carbon atoms.   The polycarbonate resin transparent plate according to any one of claims 1 to 7, wherein the polyhydric alcohol is selected from one or two of trivalent to trivalent polyhydric alcohols.

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