JP4754328B2 - Antistatic resin composition - Google Patents

Description

  The present invention relates to an antistatic thermoplastic resin composition, and more particularly to a thermoplastic resin composition having an antistatic function even after washing with water.

Antistatic resin compositions are widely used in industry and are used for various purposes. Particularly in recent years, antistatic polymer materials have become widespread in IC chip packaging, and variations in materials have been diversified from general-purpose plastics to engineering plastics. However, the conventional antistatic thermoplastic resin composition has developed its function as an additive exhibiting the antistatic function bleeds to the surface of the molded product.
For this reason, when a molded product is used, there is a problem that the function does not appear when the additive that exhibits the antistatic function is wiped off. In particular, when used in daily necessities, there is a problem that the antistatic function is lost when washed with water or wiped with a cloth containing water.

As a method for imparting an antistatic function to a resin, an aromatic vinyl resin composition containing a polyurethane elastomer and an organic sulfonate or thiocyanate has been disclosed as in Patent Document 1.
Further, as disclosed in Patent Document 2, an antistatic resin composition comprising a rubber-reinforced styrene resin, a thermoplastic polyurethane elastomer, and an alkali metal salt is disclosed.
Further, as in Patent Document 3, a resin composition in which an aromatic dicarboxylic acid having a sulfonic acid (salt) group or an ester-forming derivative thereof and an anionic antistatic agent comprising an essential constituent unit of a diol is combined with a polyolefin resin. It is disclosed.
Further, as disclosed in Patent Document 4, a conductive resin composition containing a thermoplastic resin other than a polyurethane resin, a polyurethane resin, and a dissociable inorganic salt is disclosed.
Further, as disclosed in Patent Document 5, a conductive resin composition containing an ester of a dibasic acid and an alkylene oxide and an alkali metal salt in a thermoplastic polyurethane resin is disclosed.
Furthermore, as disclosed in Patent Document 6, an antistatic agent composition for a thermoplastic resin comprising an organic sulfonic acid type surfactant, a phenolic acid inhibitor and a polyether polyester is disclosed.

Japanese Patent Laid-Open No. 06-248037 Patent Claims Japanese Patent Laid-Open No. 07-188513 JP 09-157371 A Claims JP, 2001-316593, A Claims JP, 2002-020617, A Claims JP, 2003-003058, A Claims

As conductive resin materials, dissociable inorganic salts such as lithium perchlorate have been proposed. Furthermore, in order to disperse the dissociable inorganic salt uniformly, a material in which a dissociable inorganic salt is dispersed in an organic solvent such as a plasticizer is melt-kneaded with a resin has been proposed. When a resin composition using these dissociable inorganic salts is molded, it is wiped with water when it is cleaned in daily life, so the dissociable inorganic salts deposited on the surface are removed and the conductivity is maintained for a long time. Can not do it.
An object of the present invention is to provide a thermoplastic resin composition that does not lose its antistatic function even when washed with a liquid such as water, and a molded article using the same.

That is, the first invention of the present application is
(A) Thermoplastic resins other than polyurethane-based thermoplastic resins
(Based on the total amount of (a) and (b)) 5 to 95% by weight,
(B) Ether type polyurethane-based thermoplastic resin
(Based on the total amount of (a) and (b)) 5 to 95% by weight,
and,
(C) Sulfonate metal salt represented by the following chemical formula (based on 100 parts by weight of the total amount of (a) and (b)) 0.2 to 10 parts by weight

(Where x = 4 to 12, y = 4 to 12, x / x + Y = 4/6 to 6/4, M represents a monovalent metal), (d) the number average molecular weight is Mn = 7,000 to 10,000 polyethylene glycol, wherein the weight ratio (c / d) of (c) to (d) is dissolved and blended at a ratio of 2/8 to 7/3. An antistatic resin composition.

According to a second aspect of the present invention, the thermoplastic resin other than the component (a) polyurethane-based thermoplastic resin is ABS (acrylonitrile / butadiene / styrene block copolymer), HIPS (high impact polystyrene), PS (polystyrene). The antistatic property according to any one of the preceding items, wherein the antistatic property is one or more thermoplastic resins selected from the group consisting of: ASA (acrylonitrile / styrene / acrylic rubber copolymer) and PP (polypropylene). It is a resin composition.

Furthermore, the third invention of the present application is that the component (b) ether type polyurethane thermoplastic resin is a reaction between a polyether oligomer component having a main skeleton of polyethylene glycol, polypropylene glycol or a copolymer thereof and a diisocyanate compound. The antistatic resin composition according to any one of the preceding items, wherein the antistatic resin composition is an ether type polyurethane resin obtained by:

  When the resin composition according to the present invention is used in a building material or equipment that is wiped with water when it is cleaned in daily life, the specific resistivity is sufficiently low even before water cleaning, and the water cleaning Even afterwards, a low resistivity can be maintained. In addition, the difference between the surface resistivity and the volume resistivity is small, and a uniform and low resistivity can be maintained from the surface to the inner surface of the molded body.

Ingredient (a)
Specific examples of the resin other than the polyurethane-based thermoplastic resin that is the component (a) used in the present invention include a styrene-based resin, an olefin-based resin, and an acrylic acid-based resin. These resins can be used alone or in combination of two or more.
Styrenic resins include high impact polystyrene (HIPS), acrylonitrile / butadiene / styrene copolymer (ABS resin), acrylonitrile / ethylene propylene rubber / styrene copolymer (AES resin), acrylonitrile / styrene / acrylic rubber copolymer (ASA or AAS resin).
Examples of the olefin resin include polypropylene resin and polyethylene resin.
Specific examples include homopropylene and propylene-ethylene copolymers.

  The thermoplastic polyurethane in the present invention is one or more selected from polyethylene glycol having a molecular weight of 400 to 6,000, polycaprolactone type polyol, adipic ester type polyol and ether type polyol (excluding polyethylene glycol). It is a linear polymer comprising a long-chain glycol consisting of a polyol, a short-chain glycol having a molecular weight of less than 400 and a diisocyanate having NCO groups at both ends as structural units, and is structurally a reaction part between the long-chain glycol and the diisocyanate And an elastomer composed of a hard segment which is a reaction portion of the short-chain glycol and the diisocyanate.

  The polycaprolactone-type polyol constituting the long-chain glycol of the soft segment is obtained by ring-opening caprolactone, specifically, poly (lactone glycol), poly (valerolactone glycol), poly (butyrolactone glycol) ). The adipic acid ester type polyol is obtained from adipic acid and glycol, and specific examples thereof include poly (ethylene adipate), poly (propylene adipate), and poly (butylene adipate). Examples of ether type polyols (excluding polyethylene glycol) include poly (1,2-propylene oxide) glycol, poly (1,3-propylene oxide) glycol, poly (tetramethylene oxide) glycol, poly (hexamethylene oxide) glycol, etc. Is mentioned. In addition, it is preferable that the molecular weight of the said polyol is 400-6000, and poly (tetramethylene oxide) glycol is especially preferable among the said polyol.

  The proportions of polyethylene glycol having a molecular weight of 400 to 6,000 constituting the soft segment and the polyol are 10 to 60% by weight and 90 to 40% by weight, respectively. If the polyethylene glycol is less than 10% by weight, the antistatic property is inferior, and if it exceeds 60% by weight, blistering due to water absorption and delamination are caused. Preferably, they are 15 to 40% by weight and 85 to 60% by weight, respectively.

  Examples of the diisocyanate include known aliphatic, alicyclic, aromatic substituted aliphatic, aromatic or heterocyclic diisocyanates, and 4,4'-diphenylmethane diisocyanate is particularly preferable. The short-chain glycol having a molecular weight of less than 400 is a known aliphatic, alicyclic, aromatic-substituted aliphatic, aromatic or heterocyclic glycol, and particularly preferably ethylene glycol or tetramethylene glycol. General diisocyanates and glycols are exemplified in JP-A-62-115058.

  The composition ratios of the soft segment and the hard segment constituting the thermoplastic polyurethane elastomer (B) of the present invention are 50 to 95% by weight and 50 to 5% by weight, respectively. If the soft segment is less than 50% by weight, the antistatic property is inferior, and if it exceeds 95% by weight, blistering due to water absorption occurs, which is not preferable. Preferably, they are 60 to 90% by weight and 40 to 10% by weight, respectively.

Ingredient (b)
The polyurethane-based thermoplastic resin used in the component (b) of the present invention is an ether-type thermoplastic resin having a urethane group.
Here, the ether-type thermoplastic resin is a structural unit composed of an ether-type polyol not containing an ester skeleton of polycaprolactone and an adipic acid ester skeleton and a diisocyanate compound having NCO groups at both ends, as described above. It is a polymer.
The ether type polyurethane-based thermoplastic resin of the present invention is a linear multi-block copolymer of a polyurethane obtained by a reaction of a long-chain glycol and an isocyanate as a soft segment and a polyurethane composed of a short-chain glycol and an isocyanate as a hard segment. Yes, a crosslinking agent (chain extender) is also used if necessary.
Here, as a general classification according to the kind of long-chain glycol, polyethylene oxide, polypropylene oxide, or a copolymer thereof can be cited as a polyether type.
Short chain glycols include aliphatic glycols such as ethylene glycol, 1,4-butanediol and 1,6-hexanediol, alicyclic glycols such as cyclohexanedimethanol, and hydroquinone bis (2-hydroxyethyl). Aromatic glycols such as ethers are usually used.

  On the other hand, 4,4′-diphenylmethane diisocyanate (MDI), 2,4 ′ and 2,6-toluene diisocyanate (TDI) are used as the isocyanate. In addition, as the cross-linking agent (chain extender), aromatic diamines such as 3,3-dichloro-4,4-diaminodiphenylmethane (MOCA) are used. The (a) thermoplastic polyurethane resin can be used alone or in combination of two or more.

Ingredient (c)
The sulfonic acid metal salt used in the component (c) of the present invention is represented by the following chemical formula.

Here, x = 4 to 12, y = 4 to 12, x / x + Y = 4/6 to 6/4, and M represents a metal.
Examples of the metal include sodium, potassium, and magnesium, and sodium is preferable.

  Next, component (d) used in the present invention is polyethylene glycol. This component (d) is effective in increasing the solubility and dissociation stability of the sulfonic acid metal salt in the composition of the present invention. The polyethylene glycol preferably has a number average molecular weight of Mn = 7,000 to 10,000, more preferably 7,000 to 9,000.

Mixing ratio of each composition component (1) Mixing ratio of component (a) thermoplastic resin other than polyurethane-based thermoplastic resin and (b) ether type polyurethane-based thermoplastic resin:
Component (a) is 5 to 95% by weight (based on the total amount of (a) and (b)), preferably 50 to 90% by weight, more preferably 70 to 90% by weight,
Component (b) is 5 to 95% by weight (based on the total amount of (a) and (b)), preferably 10 to 50% by weight, more preferably 10 to 30% by weight.
When the amount of the component (a) is less than 10% by weight, there is a problem in moldability, and when it is more than 90% by weight, the antistatic performance is deteriorated.
Also,
When the amount of the component (b) is less than 10% by weight, there is a problem in the reduction of antistatic performance and bleed resistance.

(2) Compounding ratio of component (a) and component (b) to component (c):
The compounding amount of the component (c) sulfonic acid metal salt is 0.2 to 10 parts by weight, preferably 0.2 to 7 parts by weight based on 100 parts by weight of the total amount of the component (a) and the component (b). More preferably, it is 0.5-5 weight part, More preferably, it is 0.5-4.5 weight part, Especially preferably, it is 0.5-1.5 weight part.
When the amount of the component (c) is less than 0.2 parts by weight, the antistatic performance is poor, and when it is more than 10 parts by weight, the antistatic performance is not improved and the cost is disadvantageous.

(3) Compounding amount of component (c) sulfonic acid metal salt and component (d) polyethylene glycol:
The compounding ratio (weight ratio) (c / d) of the component (c) and the component (d) is 2/8 to 7/3, preferably 3/7 to 5/5, more preferably 3/7 to 4/6.
If the ratio of the component (c) is less than 2/8, there will be a problem with the antistatic performance, and if it is more than 7/3, the formulation will be sticky and problems with handling and workability will result.

How to mix each component:
The mixing of each component of the present invention can be carried out without any problem using ordinary equipment and equipment used for mixing and kneading ordinary thermoplastic resins. As the extruder, a single shaft with a vent, a biaxial different direction, and a biaxial same direction extruder are desirable. Further, instead of the extruder, a kneader such as a super mixer, a Banbury mixer, a kneader, a tumbler, or a Buss kneader may be used.
However, the component (c) sulfonic acid metal salt is preferably mixed and dissolved in the component (d) polyethylene glycol in advance and then blended into the mixture of the components (a) and (b).

  EXAMPLES Next, although an Example and a comparative example are given and this invention is demonstrated concretely, this invention is not limited at all by these Examples.

Explanation of each component used in examples (1) Component (a) Thermoplastic resin other than polyurethane-based thermoplastic resin ABS: manufactured by Technopolymer Co., Ltd. Grade name: Techno ABS350
HIPS: HT516 manufactured by PS Japan
PS: HF77 made by PS Japan Co., Ltd.
ASA: WMG160 manufactured by UMG ABS Co., Ltd.
PP: Nippon Polypro Co., Ltd. BC08AHA

(2) Component (b) Polyurethane-based thermoplastic resin TPU (Pandex T-8180LN / ether type): DIC Bayer Polymer Ltd. (hardness 80A)
TPU (Pandex T-1180N / Adipate type): DIC Bayer Polymer Ltd. (hardness 80A)
TPU (Pandex T-2180N / Lactone / Ester type): DIC Bayer Polymer Ltd. (hardness 80A)
TPU (Pandex T-9280N / carbonate type): DIC Bayer Polymer Ltd. (hardness 80A)

(3) Component (c) Metal sulfonate S-604 (Alkanesulfonic acid Na / PEG: 4/6): Takemoto Yushi Co., Ltd. (x = 6, y = 6)
Alkanesulfonic acid Na / PEG: 3/7
Alkanesulfonic acid Na / PEG: 1/9
Alkanesulfonic acid Na / PEG: 2/8
Alkanesulfonic acid Na / PEG: 7/3
Alkanesulfonic acid Na / PEG: 8/2
Here, sodium alkane sulfonate is (x = 6, y = 6) manufactured by Kao Corporation, and PEG has a polyethylene glycol number average molecular weight of 8,600 manufactured by Wako Pure Chemical Industries.

PEG-SN13-40 (didodecyl sulfosuccinic acid Na / PEG: 4/6): Sanko Chemical Co., Ltd. PEG-DOSN10 (dioctyl sulfosuccinic acid Na: 1/9): Sanko Chemical Co., Ltd. PEG-αOSN (α olefin sulfone) Acid Na: 6/4): Sanko Chemical Industries Co., Ltd. S-460C (Na dodecyl benzene sulfonate: 5/5): Takemoto Yushi Co., Ltd. S-412M (Na dodecyl benzene sulfonate): Takemoto Yushi Co., Ltd. 500 (Na sulfonate / mineral oil: 61/39): Made by Matsumura Oil Research Co., Ltd.

(4) (d) Polyethylene glycol: Reagent / Wako Pure Chemical Industries, Ltd. (number average molecular weight: 6,000, 7,000, 8,600, 10,000, 11,000)

Test method:
(1) Method of washing with water Gauze containing ion exchange water sufficiently wipes the front and back surfaces of the molding plate, and then wipes off moisture with clean gauze.
(2) Specific resistance measurement method and measuring instrument (2.1) Preparation of test piece The sample pellet was previously dried in an atmosphere of 80 ° C. for 3 hours with a hot air drier, and the pellet was clamped at 80 ton / cm A plate of 64 mm × 64 mm × 3 mm (length × width × thickness) was formed by the injection molding machine ² . The molding temperature was a cylinder temperature of 200 ° C to 220 ° C and a mold temperature of 50 ° C.

(2.2) Measurement of resistivity The injection molded plate prepared in 1 above was applied with a high resistivity meter Hi-Lester UP (MCP-HT450 type) manufactured by Mitsubishi Chemical Corporation at an applied voltage of 500 V in accordance with ASTM D257. The surface resistivity and volume resistivity were measured. The resistivity of each sample was an average value (n = 5) of five measured values.

(3) Bleed property:
Measurement method: Under a 40 ° C., 90% RH atmosphere, the state of bleeding out on the plate surface after one week was evaluated by visual observation and tactile observation.
Judgment: No ○
△ is not
X is clearly recognized.
Indicates.

(4) Formability:
Measurement method: Sample pellets are dried in a hot air dryer for 3 hours in an 80 ° C. atmosphere beforehand, and the pellets are 64 mm × 64 mm × 3 mm (length × width × thickness) using an injection molding machine with a clamping pressure of 80 ton / cm ^2. ) Plate. The molding temperature was a cylinder temperature of 200 ° C to 220 ° C and a mold temperature of 50 ° C.
Judgment: ○ can be molded without any problem. Δ indicates that some deformation occurred, and the automatic eject pin did not sufficiently disengage from the mold.
Indicates.

(Example 1)
Each component was blended according to the blending shown in Table 1.
Each component is blended, mixed, and pre-dried blended in a tumbler mixer, and then the resin composition is melt-mixed at a temperature of 160 ° C. to 250 ° C. by a 47 mm co-directional twin-screw extruder to form a string-like resin from the die The molten mixture was cooled in a water tank and passed through a cutter to produce pellets of the antistatic resin composition.
Thereby, a sample pellet (shape: cylindrical shape, size: diameter 4 mm, height 3 mm) was prepared.
The sample pellets were previously dried in a hot air dryer at 80 ° C. for 3 hours, and the pellets were 64 mm × 64 mm × 3 mm (length × width × thickness) using an injection molding machine with a clamping pressure of 80 ton / cm ² . Plates were molded. The molding temperature was a cylinder temperature of 200 ° C to 220 ° C and a mold temperature of 50 ° C.
About this sample, bleed property, moldability, surface specific resistance before and after water washing, and volume specific resistivity were measured. The results are shown in Table 1.

(Examples 2-31 and Comparative Examples 1-21)
The tests were performed in the same manner as in Example 1 according to the formulations shown in Tables 1 to 8. The results are shown in each table. In addition, the blending ratio in each table is based on weight unless otherwise specified.
Moreover, what extracted these tables | surfaces and plotted the surface specific resistance before and behind water washing | cleaning, and the volume specific resistivity with a line graph are shown in FIGS. 1-3.

As can be seen from Example 1 in Table 1, it can be seen that even if the proportion of the component (b) ether type polyurethane thermoplastic resin is 10% by weight, still good results can be obtained.
Similarly, Example 8 shows that even if the proportion of component (b) is 90% by weight, still good results can be obtained.
From Example 7, it can be seen that even when the proportion of the component (c) sulfonic acid metal salt is 10 parts by weight and from Example 5, even 1 part by weight, still good results are obtained.
Moreover, it can be seen from Comparative Example 4 that the composition lacking the component (a) is inferior in moldability.

  From the examples and comparative examples in Table 2, it is shown that the component (c) sulfonic acid metal salt of the present invention produces the best results, and in particular, the weight ratio of the component (c) to the polyethylene glycol (d). The case where (c / d) is 2/8 to 7/3 indicates that it is particularly excellent.

  Table 3 shows the optimum range of the number average molecular weight Mn of polyethylene glycol (d), and it can be seen that the range of Mn = 7000 to 10,000 is good. FIG. 1 shows a plot in which the horizontal axis is the order of this table and the vertical axis is the specific resistivity.

  Table 4 shows the results of testing by changing the type of the component (b) polyurethane-based thermoplastic resin. According to this, it can be seen that the ether type is the most excellent. A plot of this table is shown in FIG.

  Table 5 shows the results of testing using HIPS as a thermoplastic resin other than (a) polyurethane-based thermoplastic resin. It can be seen that good results are shown within the scope of the present invention.

  Table 6 shows the results of testing using PS / ASA as a thermoplastic resin other than (a) polyurethane-based thermoplastic resin. It can be seen that good results are shown within the scope of the present invention.

  Table 7 shows the results of testing using PP as a thermoplastic resin other than (a) polyurethane-based thermoplastic resin. It can be seen that good results are shown within the scope of the present invention.

  Table 8 shows the results of tests using various resins as the thermoplastic resin other than (a) polyurethane-based thermoplastic resin. Both are within the scope of the present invention and show good results. Among them, ABS / TPU (T-8180LN • ether type) of Example 2 shows a difference between the surface resistivity efficiency and the volume resistivity. It can be seen that it is small and excellent in homogeneity throughout the composition. A plot of this table is shown in FIG.

  According to the present invention, it is possible to prevent the antistatic function from being damaged by washing with water or wiping with water-containing cloth, so that the antistatic function is required in outdoor use parts and daily necessities. It can be used in many resin molded products.

5 is a line graph in which the results of Comparative Example 14 to Comparative Example 15 shown in Table 3 are plotted. It is the line graph which plotted the result to Example 2-Comparative Example 18 shown in Table 4. It is the line graph which plotted the result to Example 2-Example 30 shown in Table 8. FIG.

Claims (3)

(A) Thermoplastic resins other than polyurethane-based thermoplastic resins
(Based on the total amount of (a) and (b)) 5 to 95% by weight,
(B) Ether type polyurethane-based thermoplastic resin
(Based on the total amount of (a) and (b)) 5 to 95% by weight,
and,
(C) Sulfonate metal salt represented by the following chemical formula (based on 100 parts by weight of the total amount of (a) and (b)) 0.2 to 10 parts by weight

(Where x = 4 to 12, y = 4 to 12, x / x + Y = 4/6 to 6/4, M represents a monovalent metal), (d) the number average molecular weight is Mn = 7,000 to 10,000 polyethylene glycol, wherein the weight ratio (c / d) of (c) to (d) is dissolved and blended at a ratio of 2/8 to 7/3. Antistatic resin composition.   The thermoplastic resin other than the component (a) polyurethane-based thermoplastic resin is ABS (acrylonitrile / butadiene / styrene block copolymer), HIPS (high impact polystyrene), PS (polystyrene), ASA (acrylonitrile / styrene / acrylic rubber). The antistatic resin composition according to claim 1, wherein the antistatic resin composition is one or more thermoplastic resins selected from the group consisting of a copolymer) and PP (polypropylene).   The component (b) ether type polyurethane-based thermoplastic resin is an ether type polyurethane resin obtained by a reaction of a polyether oligomer component having a main skeleton of polyethylene glycol, polypropylene glycol or a copolymer thereof and a diisocyanate compound. The antistatic resin composition according to claim 1, wherein the antistatic resin composition is characterized.

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