JP5933391B2 - Antistatic polycarbonate resin composition for transparent molded body - Google Patents

Description

The present invention relates to an antistatic polycarbonate resin composition for transparent molded articles, and more specifically, for transparent molded articles designed to improve transparency despite containing an antistatic agent that lowers transparency. The present invention relates to an antistatic polycarbonate resin composition.

  As an example of a resin composition (molded product) containing a polyether ester antistatic agent, an aromatic dicarboxylic acid having 6 to 20 carbon atoms containing 2 to 30 mol% of an aromatic dicarboxylic acid substituted with a sulfonate group 5 to 40 parts by mass of a specific polyetherester antistatic agent obtained by polycondensation of an acid, a poly (alkylene oxide) glycol having a number average molecular weight of 200 to 50,000, and a glycol having 2 to 10 carbon atoms, An antistatic polycarbonate film or sheet that is contained in 95 to 60 parts by mass of a polycarbonate resin is known (Patent Document 1).

Japanese Patent Laid-Open No. 10-219095

  The antistatic polycarbonate film or sheet of Patent Document 1 can exhibit good antistatic performance by the polyether ester antistatic agent, but on the other hand, there is a problem that white turbidity occurs and transparency decreases. there were. The reason why the white turbidity thus occurs and the transparency is lowered is that the linear polyether ester contained in the polycarbonate resin as an antistatic agent forms a lamellar structure and the crystallinity is increased. it is conceivable that.

The present invention has been made under the circumstances described above, and the problem to be solved is for a transparent molded article that can improve transparency in spite of containing a polyether ester antistatic agent. The object is to provide an antistatic polycarbonate resin composition.

In order to solve the above problems, an antistatic polycarbonate resin composition for transparent molded bodies according to the present invention (hereinafter referred to as an antistatic polycarbonate resin composition) is added to 100 parts by mass of a polycarbonate resin, 16.9 to 17 .1 part by mass of a polyether ester antistatic agent and 0.4 to 4.3 parts by mass of a carbodiimide compound.

Antistatic polycarbonate resin composition of the present invention, it is preferable to further contain a heat Ndadoamin based light stabilizer. And it is preferable that the total light transmittance is 60.2% or more and the haze value is 68.4% or less when formed into a 2 mm thick plate.

As in the antistatic polycarbonate resin composition of the present invention, when 16.9 to 17.1 parts by mass of a polyetherester-based antistatic agent is contained in 100 parts by mass of the polycarbonate resin, the following examples are used. As supported by the data, the surface resistivity of the molded product is 10 ¹² to 10 ¹³ Ω / □, and good antistatic performance is exhibited.
In addition , when a carbodiimide compound is contained as in the antistatic polycarbonate resin composition of the present invention, the carbodiimide compound reacts with the polyester chain of the polyether ester antistatic agent, so that The chain molecular chain is branched from the middle of the polyester chain by the molecular chain of the carbodiimide compound, or the end of the polyester chain is modified by the carbodiimide compound, so the polyether ester forms a lamellar structure It becomes difficult to suppress crystallization. And like the antistatic polycarbonate resin composition of this invention, when the content of the carbodiimide compound with respect to 100 mass parts of polycarbonate resin is 0.4-4.3 mass parts, the composition of this invention is polyetherester. Even if it contains a system antistatic agent, since white turbidity due to crystallization is unlikely to occur, a plate having a thickness of 2 mm is improved , as described in the examples below, the total light transmittance is improved and the haze value is lowered. When formed into a total light transmittance of 60.2% or more and a haze value of 68.4% or less, the transparency can be improved.

  Further, when a hindered amine light stabilizer is further contained, the weather resistance deterioration of the polyether ester antistatic agent is suppressed, so that a good antistatic performance can be exhibited over a long period of time. As shown in the example data, the effect that the haze value can be lowered is also obtained.

It is a graph which shows the relationship between carbodiimide content of an antistatic polycarbonate resin composition, and a total light transmittance. It is a graph which shows the relationship between carbodiimide content and haze value of an antistatic polycarbonate resin composition.

  The antistatic polycarbonate resin composition of the present invention is a composition comprising a polycarbonate resin, a polyether ester antistatic agent, and a carbodiimide compound as essential components, and a hindered amine light stabilizer and other additives as optional components. Is included.

  As the main component polycarbonate resin, all commercially available polycarbonate resins having an aromatic polycarbonate structure can be used. Among them, the polycarbonate resin obtained from bisphenol A as an aromatic component (diphenol component) is transparent and heat resistant. It is preferably used because of its excellent properties and mechanical strength. The molecular weight is not particularly limited, but a viscosity average molecular weight of about 10,000 to 50,000 is preferable. An example of a commercially available polycarbonate resin is K1300WP manufactured by Teijin Chemicals Limited.

  Polyether ester antistatic agents include (aromatic) polycarboxylic acids having 4 to 20 carbon atoms, poly (alkylene oxide) glycols having a number average molecular weight of 200 to 50,000, and glycols having 2 to 10 carbon atoms. Can be used, and among them, polyether esters having a photorefractive index of 1.53 or more and 1.64 or less are preferably used. This is because such a polyether ester contributes to the improvement of transparency because the optical refractive index is close to the optical refractive index (1.585) of the polycarbonate resin.

  As a commercially available product of a preferred polyether ester-based antistatic agent, for example, RAN manufactured by Takemoto Yushi Co., Ltd. (which has a carboxylic acid component less than a glycol component and a refractive index of 1.53), Takemoto Yushi ( R02 manufactured by Co., Ltd. (having a carboxylic acid component more than or equal to the glycol component and having a light refractive index of 1.56), and the like. In particular, the latter R02 has a light refractive index higher than that of the former RAN. Therefore, it is preferably used.

The content of the polyether ester antistatic agent is suitably 5 to 67 parts by mass with respect to 100 parts by mass of the polycarbonate resin . Polycarbonate resin composition is less than 5 parts by mass turned surface resistivity of 10 ¹⁴ Ω / □ order (molded body), Ri is Na difficult to exhibit a sufficient antistatic properties, whereas, polyether ester antistatic When the content of the agent is more than 67 parts by mass, even if a carbodiimide compound is contained, the white turbidity of the polycarbonate resin composition (molded product) becomes strong and the transparency is lowered. The very preferable content of the polyether ester antistatic agent is 16.9 to 17.1 parts by mass. With such a content, the antistatic performance and the transparency are improved.

式中、Ｒは有機系結合単位を示し、脂肪族、脂環族、芳香族のいずれかである。ｎは１以上の整数であり、ｎが２以上の整数である場合、Ｒは同一でも異なっていてもよい。 The carbodiimide compound is a substance represented by the following structural formula, and aromatic, aliphatic or alicyclic carbodiimide compounds produced by various known methods are preferably used.

In the formula, R represents an organic bond unit, and is either aliphatic, alicyclic or aromatic. n is an integer greater than or equal to 1, and when n is an integer greater than or equal to 2, R may be same or different.

  Specific carbodiimide compounds used in the present invention include bis (propylphenyl) carbodiimide, bis (dipropylphenyl) carbodiimide, aromatic polycarbodiimide, poly (4-4′-dicyclohexylmethanecarbodiimide), poly (4,4 '-Diphenylmethanecarbodiimide), poly (p-phenylenecarbodiimide), poly (m-phenylenecarbodiimide), poly (tolylcarbodiimide), poly (diisopropylphenylenecarbodiimide), poly (methyl-diisopropylphenylenecarbodiimide), poly (triisopropylphenylenecarbodiimide) And aromatic monocarbodiimides, aliphatic polycarbodiimides, and aromatic polycarbodiimides. These carbodiimide compounds may be used alone or in combination of two or more. Moreover, as a polymer of a carbodiimide compound, what has a molecular weight of 2,000-50,000 is preferable.

  When such a carbodiimide is contained together with the polyether ester of the antistatic agent, the polyester chain of the polyether ester reacts with the carbodiimide, and the linear molecular chain of the polyether ester is changed from the middle of the polyester chain by the molecular chain of the carbodiimide. Since it becomes a branched structure or the terminal of the polyester chain is modified with carbodiimide, the polyether ester hardly forms a lamellar structure and crystallization is suppressed. Therefore, white turbidity due to crystallization of the polyether ester hardly occurs, and the transparency of the polycarbonate resin composition (molded article) is improved.

  It is preferable to use a carbodiimide compound having a number average molecular weight of 2,000 or more as described above. If it contains less than 2,000 molecular weight, it will decompose and shorten the molecular chain, making the molecular chain of the polyether ester sufficiently branched to block the lamellar structure or modifying the molecular chain end. Therefore, it becomes difficult to improve transparency by suppressing white turbidity due to crystallization.

  As a commercially available product of a preferred carbodiimide compound, Stabaxol P400 (a carbodiimide having an aromatic main chain having a number average molecular weight of 4,000 or more) manufactured by Rhein Chemie Japan, and Stabaxol P (aroma prepared by Rhein Chemie Japan). Carbodiimide having an aliphatic main chain and having a number average molecular weight of 3,000 to 4,000), Carbodilite LA-1 manufactured by Nisshinbo Chemical Co., Ltd. (carbodiimide having an aliphatic main chain, and having a number average molecular weight of Stabaxol) Larger than P and smaller than Stabaxol P400).

The content of the carbodiimide compound is preferably 0.1 to 9 parts by mass with respect to 100 parts by mass of the polycarbonate resin, as will be described in detail in the examples below. The total light transmittance can be improved as compared with a polycarbonate resin composition (molded article) not contained. The more preferable content of the carbodiimide compound is 0.4 to 4.3 parts by mass , and when it is contained in this range, as will be described in detail in the examples below, a polycarbonate resin composition (molding) that does not contain a carbodiimide compound body) than to improve the total light transmittance, lower the haze value, can you to improve transparency.

  In addition to the above essential components, the polycarbonate resin composition of the present invention contains an appropriate amount of a hindered amine light stabilizer (HALS) and an ultraviolet absorber (UVA) to suppress the weather resistance deterioration of the polyether ester antistatic agent. Thus, it is preferable to exhibit good antistatic performance over a long period of time. In particular, the former hindered amine light stabilizer is preferable because the effect of lowering the haze value can be obtained as shown in the data of Examples described later. Since the polycarbonate resin is decomposed by the base of the hindered amine light stabilizer, it is desirable to use a low basic hindered amine stabilizer.

  As a commercially available product of a preferred hindered amine light stabilizer, for example, Tinuvin 622 (N-R type, low base type hindered amine light stabilizer) manufactured by BASF can be mentioned, and as a commercially available product of a preferable ultraviolet absorber. Examples thereof include LA31 (triazole ultraviolet absorber) manufactured by ADEKA and Tinuvin 1577 (triazine ultraviolet absorber) manufactured by BASF.

  Of course, the antistatic polycarbonate resin composition of the present invention may be appropriately blended with a heat stabilizer, a lubricant, a flame retardant, a plasticizer, other various additives, a dye and other colorants.

  In addition, the antistatic polycarbonate resin composition of the present invention can be molded as an independent molded product by injection molding described later, or can be molded as a surface layer portion of a polycarbonate resin plate by coextrusion molding.

  Next, more specific examples and comparative examples of the present invention will be described.

[Examples 1-7]
Antistatic polycarbonate resin compositions having the compositions of Examples 1 to 7 shown in Table 1 below were prepared, and colorless and transparent plates each having a thickness of 2 mm were prepared by injection molding.
And the total light transmittance and haze value of the plate body of these Examples 1-7 were measured using the direct reading haze computer NDH5000 by Suga Test Instruments Co., Ltd. The measured values are shown in Table 1 below. Moreover, the surface resistivity of the plate bodies of Examples 1 to 7 was measured using Hiresta UP manufactured by Mitsubishi Chemical Analytech Co., Ltd. The measured values are shown in Table 1 below.

  Further, the total light transmittance and the carbodiimide content of the plates of Examples 1 to 4 were plotted, and a graph showing the relationship between the total light transmittance and the carbodiimide content was created and shown in FIG. Moreover, the graph which shows the relationship between haze value and carbodiimide content was plotted by plotting the haze value and carbodiimide content of the board body of Examples 1-4, and it showed in FIG.

[Comparative Example 1]
The antistatic polycarbonate resin composition of Comparative Example 1 having the composition shown in Table 1 below was prepared, and a colorless and transparent plate having a thickness of 2 mm was produced by injection molding. The total light transmittance, haze value, and surface resistivity of this plate were measured in the same manner as in Examples 1 to 7, and the measured values are also shown in Table 1 below. Further, the total light transmittance and haze value of the plate of Comparative Example 1 were plotted in the graph of FIG. 1 and the graph of FIG.

As shown in Table 1 and FIG. 1, the plate bodies of Examples 1 to 4 containing 0.4 to 4.3 parts by mass of a carbodiimide compound having an aromatic main chain (Stabaxol P400) contain a carbodiimide compound. Compared with the plate of Comparative Example 1 that does not, the total light transmittance increases by about 10 to about 18%, and as shown in Table 1 and FIG. 2, the haze value decreases by about 32% at the maximum, and the transparency is increased. It has improved significantly. And the board of Example 5 containing the carbodiimide compound (Stabaxol P) which has an aromatic principal chain, and the board of Examples 6 and 7 containing the carbodiimide compound (carbodilite LA-1) which has an aliphatic principal chain As shown in Table 1, the total light transmittance increases by about 14 to about 16% and the haze value decreases by about 19 to about 26% as compared with the plate of Comparative Example 1 that does not contain a carbodiimide compound. The transparency has been greatly improved. From this, it can be seen that the carbodiimide compound is an effective compound for improving the transparency of the molded article of the polycarbonate resin composition containing the polyether ester antistatic agent.
Moreover, as shown in Table 1, the plate bodies of Examples 1 to 7 containing the carbodiimide compound have a surface resistivity of 10 ¹² Ω / □ to 10 as in the plate body of Comparative Example 1 not containing the carbodiimide compound. ^It has good antistatic performance in the range of ¹³ Ω / □, and it can be seen from this that the carbodiimide compound has no fear of inhibiting the efficacy of the polyether ester antistatic agent.

この関係式において、全光線透過率（Ｙ）が、カルボジイミド化合物を含まない比較例１の板体の全光線透過率（５０．３）と等しくなるときのカルボジイミド含有量（Ｘ）を算出すると、Ｘ＝９．０２であった。
上記より、本発明の帯電防止性ポリカーボネート樹脂組成物のカルボジイミド化合物の含有量を９質量部以下にすれば、全光線透過率が、カルボジイミド化合物を含まない帯電防止性ポリカーボネート樹脂組成物より上昇し、透明性を改善できることが判る。そして、図１のグラフから、カルボジイミド化合物が０．１質量部含まれていれば、全光線透過率が上昇することも明らかである。従って、カルボジイミド化合物の含有量は、０．１〜９質量部とするのが適切であり、特に、実施例のようにカルボジイミド化合物の含有量が０．４〜４．３質量部であると、図１に示すように全光線透過率が６０．２％以上となり、図２に示すようにヘーズ値が６８．４％以下となって、透明性の十分な改善効果を得ることができる。 Next, in the graph of FIG. 1, a linear equation indicating the relationship between the total light transmittance (Y) and the carbodiimide content (X) based on the plot values of Examples 2, 3, and 4 was obtained. The following relational expression was obtained.

In this relational expression, when the total light transmittance (Y) is equal to the total light transmittance (50.3) of the plate of Comparative Example 1 not containing a carbodiimide compound, the carbodiimide content (X) is calculated. X = 9.02.
From the above, if the content of the carbodiimide compound of the antistatic polycarbonate resin composition of the present invention is 9 parts by mass or less, the total light transmittance is increased from the antistatic polycarbonate resin composition not containing the carbodiimide compound, It can be seen that the transparency can be improved. And it is also clear from the graph of FIG. 1 that if the carbodiimide compound is contained in an amount of 0.1 part by mass, the total light transmittance increases. Accordingly, the content of carbodiimide compound, Ri suitable der that a 0.1 to 9 parts by weight, in particular, when the content of carbodiimide compound as in example is from 0.4 to 4.3 parts by weight As shown in FIG. 1, the total light transmittance is 60.2% or more, and the haze value is 68.4% or less as shown in FIG. 2, so that a sufficient improvement effect of transparency can be obtained.

  Furthermore, in Table 1, when Example 2 and Example 5 are contrasted, the plate body of Example 2 containing an aromatic carbodiimide compound (Stabaxol P400) having a large molecular weight is more aromatic carbodiimide compound (Stabaxol). The total light transmittance is higher and the haze value is lower than the plate of Example 5 containing P). From this, it can be said that a carbodiimide compound having an aromatic main chain has a higher molecular weight and is more effective in improving transparency.

  Further, comparing Example 1, Example 6, and Example 7, compared with the polyether ester antistatic agent (RAN) used in Example 1, the optical refractive index is more similar to the optical refractive index of the polycarbonate resin. The plate bodies of Example 6 and Example 7 containing the polyether ester-based antistatic agent (R02) having a higher total light transmittance than the plate body of Example 1 and the haze value of Example It is lower than 1 plate. From this, it can be said that the polyether ester antistatic agent having a light refractive index close to that of the polycarbonate resin is more effective for improving the transparency.

  And when Example 6 and Example 7 are compared, the haze value of the plate body of Example 7 containing the hindered amine light stabilizer is higher than that of the plate body of Example 6 not containing the hindered amine light stabilizer. The transparency is improved by about 5%. From this, it can be seen that the hindered amine light stabilizer exhibits a secondary effect of lowering the haze value in addition to the effect of suppressing the weather resistance deterioration.

Claims (3)

To 100 parts by mass of polycarbonate resin, a polyether ester-based antistatic agent of 16.9 to 17.1 parts by weight, and wherein that it contained carbodiimide compound of from 0.4 to 4.3 parts by weight, transparency Antistatic polycarbonate resin composition for molded articles. 2. The antistatic polycarbonate resin composition for transparent molded bodies according to claim 1 , further comprising a hindered amine light stabilizer. The total light transmittance when molded into a 2 mm-thick plate is 60.2% or more, and the haze value is 68.4% or less, according to claim 1 or 2, Antistatic polycarbonate resin composition for transparent molded body .

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