JP2007031500A - Polyester resin composition, and film, sheet or formed article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antistatic polyester resin composition that comprises an antistat incorporated therewith by kneading and is excellent in transparency and antistaticity, and a film, a sheet or a formed article formed from the same. <P>SOLUTION: (1) The antistatic polyester resin composition comprises 100 pts.mass of a polyester resin and, incorporated therewith, 0.1-5 pts.mass of a dialkyl sulfosuccinate salt as an antistat. (2) The antistatic polyester resin composition comprises 100 pts.mass of the polyester resin and, incorporated therewith, 0.1-5 pts.mass of the dialkyl sulfosuccinate salt and 0.1-5.0 pts.mass of an ester from a polyhydric alcohol and a fatty acid as antistats. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a polyester resin composition and a film, sheet, or molded product, and more particularly, to a polyester resin composition excellent in antistatic properties and transparency, and a film, sheet, or molded product molded therefrom.

  Many commonly used plastics have low electrical conductivity and are easily charged. When the plastic is charged, it becomes an obstacle in the production process, the product is soiled, and printing failure occurs. Therefore, an antistatic agent is used for the purpose of preventing the charging.

  As the antistatic agent, a low molecular surfactant is generally used. Antistatic methods using an antistatic agent are roughly classified into a method of applying an antistatic agent to a plastic surface (coating type) and a method of kneading inside a plastic (kneading type). The coating-type antistatic agent has a high initial antistatic effect because an antistatic layer is applied to the plastic surface, but the manufacturing process becomes complicated because a coating process, a drying process, and the like are necessary. In addition, when the surface antistatic layer easily falls due to rubbed or attached water droplets, and the surface antistatic layer once falls, the antistatic property is lost and the sustainability of the effect is poor. On the other hand, in the case of a kneading type antistatic agent, a kneading type antistatic agent has become the mainstream industrially because it is simple without increasing the number of manufacturing steps and has a long-lasting effect.

  However, there are few kneading type antistatic agents effective in polyester resins, and coating type antistatic agents are mainly used. As the kneading type antistatic agent, a sulfonate type antistatic agent is generally used. Although this sulfonate type antistatic agent has a high antistatic effect, it is not compatible with the polyester resin and is transparent. Various blends have been devised to reduce the properties, moldability, and mechanical properties.

A method in which an alkyl sulfonate, a polyhydric alcohol fatty acid ester, and a fatty acid alkylolamide are used in combination with a lactic acid polyester resin (polylactic acid) is known (for example, see Patent Document 1). When blended, the antistatic property is not sufficient, and when the blending amount of the antistatic agent is increased, the transparency is inhibited and coloring is observed. The present inventors previously proposed a method of adding a glycerin monofatty acid ester and an alkyl sulfonate as an antistatic agent to a biodegradable polyester resin (see Patent Document 2). As a result of continuing research on the previously proposed technique, the present inventors have promoted hydrolysis of the polyester resin during processing by adding an alkyl sulfonate, and depending on the processing conditions, the molecular weight of the polyester resin is large. It has been found that the mechanical properties of the molded product may be reduced, or so-called processing unevenness may be observed.
JP 2003-261757 A JP 2004-67801 A

  An object of the present invention is to provide an antistatic polyester resin composition comprising a kneaded antistatic agent having excellent transparency and antistatic properties, and a film, sheet or molded product molded therefrom. is there.

  As a result of intensive research in view of the above problems, the present inventors have blended a specific anionic surfactant as an antistatic agent with a polyester resin, thereby reducing transparency and reducing the antistatic effect. In addition, it was found that a polyester resin composition having a small decrease in molecular weight during processing can be obtained. In addition, the inventors have found that the antistatic property is further improved by blending an ester composed of a polyhydric alcohol and a fatty acid, thereby completing the present invention.

That is, the present invention has the following configuration.
1. A polyester resin composition comprising 0.1 to 5 parts by mass of a dialkylsulfosuccinate as an antistatic agent with respect to 100 parts by mass of a polyester resin.

2. It is characterized by containing 0.1 to 5 parts by mass of dialkylsulfosuccinate as an antistatic agent and 0.1 to 5.0 parts by mass of an ester composed of a polyhydric alcohol and a fatty acid with respect to 100 parts by mass of the polyester resin. Polyester resin composition.

3. 3. The polyester resin composition as described in 1 or 2 above, wherein an antistatic agent is kneaded and contained.

4). 4. The polyester resin composition as described in any one of 1 to 3 above, wherein the polyester resin is a biodegradable polyester resin.

5. 5. The polyester resin composition as described in 4 above, wherein the biodegradable polyester resin is an aliphatic polyester resin.

6). 6. The polyester resin composition as described in 5 above, wherein the aliphatic polyester resin is a lactic acid polyester resin.

7). A film, sheet, or molded article, which is molded from the polyester resin composition according to any one of 1 to 6 above.

  As is apparent from the above, according to the present invention, the antistatic property is high, the transparency and the workability are excellent, the mechanical properties are deteriorated, the resin is not hydrolyzed at the time of processing, and there is no coloration. Film, sheet or molded product can be obtained.

The present invention will be described in more detail.
There is no limitation in particular in the polyester resin in this invention, The polymer which consists of arbitrary diol, dicarboxylic acid, and hydroxycarboxylic acid can be used. As the diol, for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-cyclohexanedimethanol and the like can be used. Examples of the dicarboxylic acid include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, malonic acid, maleic acid, fumaric acid, succinic acid, adipic acid, and sebacic acid. Examples of the hydroxycarboxylic acid include lactic acid, glycolic acid, citric acid, malic acid, tartaric acid, 3-hydroxybutyric acid, p-hydroxybenzoic acid, p- (2-hydroxyethoxy) benzoic acid, 4-hydroxycyclohexanecarboxylic acid, Alternatively, ε-caprolactone, β-propiolactone, β-methyl-β-propiolactone, δ-valerolactone, glycolide, lactide and the like which are present as cyclic condensates can be mentioned.

  Examples of the polyester resin suitably used in the present invention include polyethylene terephthalate, polyethylene succinate, polybutylene terephthalate, polybutylene succinate, polycaprolactone, polylactic acid, and polyglycolic acid. Further, the polyester resin may be not only a homopolymer based on a single monomer but also a copolymer using a monomer that exhibits desired physical properties and characteristics. Examples of such a resin include polybutylene terephthalate adipate, polybutylene succinate adipate, poly DL-lactic acid, a copolymer of polyethylene glycol adipate and poly L-lactic acid, and the like. Further, for the purpose of improving processability and physical properties, a trihydric or higher polyhydric alcohol such as glycerin or pentaerythritol, or a polycarboxylic acid may be added, and the main chain of the polyester resin may be branched. Two or more kinds of polyester resins may be mixed and used.

  Of these, biodegradable polyester resins include polylactic acid, polyglycolic acid, polycaprolactone, poly 3-hydroxyalkanoate, polyethylene succinate, polybutylene succinate, polybutylene succinate adipate and other aliphatic polyesters, poly Examples thereof include aromatic copolyesters such as butylene terephthalate adipate and polyethylene terephthalate adipate.

  Among aliphatic polyesters, a lactic acid-based polyester resin (polylactic acid) can be used particularly preferably in the present invention. Polylactic acid here means polyester containing 50 parts by mass or more of L-form lactic acid or D-form lactic acid as a monomer. Polylactic acid is preferable because it has high biodegradability and transparency, and has a low environmental impact.

  The method for producing the polyester resin is not particularly limited and can be produced by a known method. For example, it can be produced by polycondensation of diol and dicarboxylic acid or anhydride, ring-opening polymerization of a cyclic product of hydroxycarboxylic acid, or transesterification polymerization using a diester of dicarboxylic acid. Further, an acid anhydride, an isocyanate compound, an epoxy compound, a polyvalent metal compound, or the like may be used as a chain extender for the resin.

  The dialkylsulfosuccinate used in the present invention is a compound represented by the following formula (1) obtained by esterifying maleic anhydride and a higher alcohol and then sulfating with sodium sulfite under acidic conditions.

(However, R ₁ and R ₂ are alkyl groups, and M is a metal atom.)

The alkyl group of the dialkyl sulfosuccinate is not particularly limited and may have any carbon number, but considering the processability during production, compatibility with the resin, antistatic properties, etc., the carbon number of 4 to Those having 20 are preferable, and those having 6 to 18 carbon atoms are particularly preferable. Further, the alkyl groups R ₁ and R ₂ may be the same or different. The alkyl group can be used regardless of whether it is linear or branched. As the dialkylsulfosuccinate, lithium salt, sodium salt, magnesium salt, potassium salt, calcium salt and the like can be used, but the metal ion preferably has a smaller molecular weight, and sodium salt is usually used.
In the present invention, when an ester composed of a polyhydric alcohol and a fatty acid is used in addition to the dialkylsulfosuccinate, the antistatic property can be further improved. Examples of the polyhydric alcohol constituting the ester composed of a polyhydric alcohol and a fatty acid that can be used in the present invention include ethylene glycol, propylene glycol, isosorbide, glycerin, trimethylolpropane, erythritol, pentaerythritol, sorbitan, xylitol, sorbitol, Examples include sugar. In addition, dehydration condensation alcohols of these polyhydric alcohols can also be used. Examples of the dehydrated condensed alcohol include polyglycerin and polypentaerythritol. Furthermore, alcohols obtained by adding alkylene oxide to these polyhydric alcohols can also be used. Two or more kinds of these polyhydric alcohols may be used.

  Fatty acids that can be used for esters composed of polyhydric alcohols and fatty acids are not particularly limited, but are saturated fatty acids such as caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, linoleic acid Unsaturated fatty acids such as linolenic acid and erucic acid can be used. As these fatty acids, two or more kinds of mixed fatty acids may be used.

  The ester comprising the polyhydric alcohol and fatty acid of the present invention can be produced by a known ester reaction. For example, it can be produced by a direct esterification reaction between a polyhydric alcohol and a fatty acid or a transesterification reaction between a polyhydric alcohol and an oil. In the present invention, the esterification rate is preferably 10% or more and 90% or less, when the ratio of the hydroxyl group esterified with a fatty acid in the hydroxyl group of the starting polyhydric alcohol is defined as the esterification rate. More preferably, it is 10% or more and 50% or less. When the esterification rate is less than 10%, the compatibility with the resin is low and bleeding tends to occur. On the other hand, when the esterification rate exceeds 90%, the hydrophilicity is lowered and the antistatic property is hardly exhibited.

  In the polyester resin composition of the present invention, the amount of dialkyl sulfosuccinate added to the resin is 0.1 to 5.0 parts by weight, particularly 0.1 to 2.0 parts by weight, based on 100 parts by weight of the polyester resin. preferable. If the amount of dialkylsulfosuccinate added is less than 0.1 parts by mass, a sufficient antistatic effect cannot be obtained, and if it exceeds 5.0 parts by mass, the transparency and mechanical properties of the resin are reduced, Bleed out from the resin.

  In the present invention, when the ester composed of a polyhydric alcohol and a fatty acid is used in combination with a dialkylsulfosuccinate, the addition amount is 0.1 to 5.0 parts by weight, particularly 0.1 to 2 parts per 100 parts by weight of the polyester resin. 0.0 part by mass is preferred. If the amount of ester consisting of polyhydric alcohol and fatty acid is less than 0.1 parts by mass, a sufficient synergistic effect cannot be obtained, and if it exceeds 5.0 parts by mass, the transparency and mechanical properties of the resin are reduced. Or bleed out from the resin.

  These resins also include other antistatic agents, plasticizers, stabilizers, lubricants, processability improvers, antioxidants, hydrolysis inhibitors, slip agents, pigments, fillers, flame retardants, antifogging agents, etc. These additives may be used in combination, but these additives can be used in combination as long as the effects of the antistatic agent of the present invention are not impaired.

  The polyester resin composition according to the present invention may be used in combination with a copolymer other than those described above as long as the object of the present invention is not impaired. For example, impact resistance may be enhanced by mixing an ethylene / glycidyl methacrylate copolymer in a ratio of 4: 1 to polylactic acid.

  The polyester resin composition according to the present invention can be subjected to thermoforming such as extrusion and injection using an extruder, an injection molding machine or the like used for ordinary plastic molding. The polyester resin and dialkylsulfosuccinate, and the ester composed of polyhydric alcohol and fatty acid may be added separately and kneaded in a molding machine, or may be mixed in advance. In the case of polymer blending, a twin screw extruder is preferred. However, depending on the type of processing machine, when the addition amount of the antistatic agent is high, the resin may slip and cannot be processed, or even if processed, it may not be kneaded sufficiently, resulting in poor dispersion. For this reason, a masterbatch in which the antistatic agent of the present invention or an ester composed of a polyhydric alcohol and a fatty acid is contained in a high concentration with respect to the polyester resin in advance is prepared by a twin screw extruder or a Banbury mixer, and this is charged with a predetermined charge. It is preferable to mix and mold with a polyester resin so as to obtain an inhibitor concentration or the like. The resin composition of the present invention can be formed into a sheet or film by T-die, inflation or the like. The film may be either stretched or unstretched. A molded product can also be obtained using an injection molding machine or the like.

  Hereinafter, the present invention will be described in detail with reference to examples, but the embodiment of the present invention is not limited thereto. For the evaluation of this example, the following were used as polyester resin, dialkylsulfosuccinate, ester composed of polyhydric alcohol and fatty acid (hereinafter sometimes simply referred to as ester).

[Polyester resin-1] Polylactic acid (Lacia H-440: manufactured by Mitsui Chemicals, Inc.)
[Polyester resin-2] Polyethylene terephthalate (Dianite PA-500: manufactured by Mitsubishi Rayon Co., Ltd.)
[Polyester resin-3] GF-reinforced polybutylene terephthalate (Novadur 5010G30: manufactured by Mitsubishi Engineering Plastics)

[Dialkylsulfosuccinate-1] Sodium dioctylsulfosuccinate (Aerosol OT: Cytec Industries)

[Dialkylsulfosuccinate-2] sodium bistridecylsulfosuccinate (Aerosol TR: manufactured by Cytec Industries)

[Ester-1] glycerol monolaurate (Poem M-300: manufactured by Riken Vitamin Co., Ltd.): Esterification rate 33%

[Ester-2] glycerol monostearate (Riquemar S-100: manufactured by Riken Vitamin Co., Ltd.): Esterification rate 33%

[Ester-3] polyglycerol monostearate (Riquemar S-71-D: manufactured by Riken Vitamin Co., Ltd.): Esterification rate 28%

[Ester-4] polyglycerol monooleate (Riquemar DXO-100: manufactured by Riken Vitamin Co.): esterification rate 25%

The test method is as follows.
[Test-1] Surface Specific Resistance A test piece having a size of 100 × 100 mm and a thickness of 2 mm was used. The surface resistivity of a test piece aged at room temperature of 20 ° C. and humidity of 65% RH for 1 week was measured with a hyper insulation meter SEM-10 (manufactured by Toa Denpa Kogyo Co., Ltd.) under the same conditions. The applied voltage was 500 V and the value after 1 minute was read.

[Test-2] Charged voltage half-life A test piece having a size of 45 × 40 mm and a thickness of 2 mm was used. A test piece aged at room temperature of 20 ° C. and humidity of 65% RH for 1 week was measured with a STATIC HONESTETER S-5109 type (manufactured by Sicid Electrostatic Co., Ltd.) under the same conditions. The applied voltage was 9 KV, the application time was 10 seconds, the discharge height was 1.5 cm, the power receiving height was 1.0 cm, and the disk rotation speed was 1000 rpm.

[Test-3] Transparency test A test piece having a size of 45 × 40 mm and a thickness of 2 mm was used. HAZE (turbidity) was measured by Σ90 COLOR MEASING SYSTEM (manufactured by Nippon Denshoku). Those with a HAZE of 20 or more were rated as “x” and those with a HAZE of less than 20 as “◯”.
In Example 7, since the polyester resin 3 was originally opaque, HAZE was not measured, so “−” was set.

Examples 1-5, Comparative Examples 1-4
[Prototype 1] Preparation of master batch After adding 20 parts by mass of dialkylsulfosuccinate-1 to 80 parts by mass of the above polyester resin-1, 180 by a small different-direction twin screw extruder equipped with a strand die. The mixture was melt-kneaded at 0 ° C., and the strand was cooled with water and cut to prepare a master batch containing 20% of dialkylsulfosuccinate-1. Similarly, a master batch containing 20% of each of dialkyl sulfosuccinate-2 and esters-1 to 4 was prepared. The prepared master batch was sufficiently dried and then subjected to the following test sample preparation.

[Prototype 2] Preparation of test sample Master batch prepared as described above so that the concentration of the additive is the predetermined amount (described in Table 1) of the following test sample with respect to polyester resin-1 for each Example or Comparative Example. A test piece was prepared at 190 ° C. by injection molding using a 2 mm-thick flat plate mold, and the surface resistivity, half-life, and HAZE were measured.

Example 6
Polyester resin-2 is added to 1.0 part by mass of dialkylsulfosuccinate-1 and 1.0 part by mass of ester-1 with respect to 100 parts by mass of the polyester resin-2, and is mixed with a small different direction twin screw extruder equipped with a strand die. Was melt-kneaded at 260 ° C., and the strand was cooled with water and cut to prepare pellets. After sufficiently drying the pellet, a test piece was prepared at 260 ° C. by injection molding using a 2 mm thick flat plate mold, and the surface resistivity, half-life, and HAZE were measured.

Example 7
Polyester resin-3 is added to 1.0 part by mass of dialkylsulfosuccinate-1 and 1.0 part by mass of ester-1 with respect to 100 parts by mass of the polyester resin-3. Was melt-kneaded at 270 ° C., and the strand was cooled with water and cut to prepare pellets. After the pellets were sufficiently dried, test pieces were prepared at 270 ° C. by injection molding using a 2 mm-thick flat plate mold, and surface specific resistance, half-life, and HAZE were measured.

Example 8 Comparison between Kneading Type and Coating Type
The test piece molded in Example 4 was immersed in water having a water temperature of 30 ° C. for 10 hours. After 10 hours, the test piece was thoroughly drained and after aging at room temperature of 20 ° C. and humidity of 65% RH for 1 week, the surface resistivity and half-life were measured.

Comparative Example 5
On the surface of the test piece molded in Comparative Example 1, an aqueous solution diluted to 1.0% by mass of dialkylsulfosuccinate-2 and 1.0% by mass of ester-3 was applied using a bar coater. For 30 minutes in a gear oven. After drying, the test piece was immersed in water having a water temperature of 30 ° C. for 10 hours. After 10 hours, the test piece was thoroughly drained and after aging at room temperature of 20 ° C. and humidity of 65% RH for 1 week, the surface resistivity and half-life were measured.
The test and evaluation results are shown in Table 2.

Comparison of molecular weight reduction Example 9
It was 115,000 when the test piece shape | molded in Example 1 was melt | dissolved in chloroform, and the weight average molecular weight (polystyrene conversion) was measured with GPC (gel permeation chromatograph). It was confirmed that there was little decrease in molecular weight during processing.

Comparative Example 6
It was 121,000 when the test piece shape | molded by the comparative example 1 was melt | dissolved in chloroform, and the weight average molecular weight (polystyrene conversion) was measured with GPC (gel permeation chromatograph).

Comparative Example 7
Polyester resin-1 is adjusted so that 100 parts by weight of alkyl sulfonate: Anstex HT-100 (manufactured by Toho Chemical Co., Ltd.) is 1.5 parts by weight, and a test piece is molded with an injection tester. did. The molded test piece was dissolved in chloroform and the weight average molecular weight (polystyrene conversion) was measured by GPC (gel permeation chromatograph).

Claims (7)

A polyester resin composition comprising 0.1 to 5 parts by mass of a dialkylsulfosuccinate as an antistatic agent with respect to 100 parts by mass of a polyester resin. It is characterized by containing 0.1 to 5 parts by mass of dialkylsulfosuccinate as an antistatic agent and 0.1 to 5.0 parts by mass of an ester composed of a polyhydric alcohol and a fatty acid with respect to 100 parts by mass of the polyester resin. Polyester resin composition. The polyester resin composition according to claim 1 or 2, wherein an antistatic agent is kneaded and contained. The polyester resin composition according to claim 1, wherein the polyester resin is a biodegradable polyester resin. The polyester resin composition according to claim 4, wherein the biodegradable polyester resin is an aliphatic polyester resin. The polyester resin composition according to claim 5, wherein the aliphatic polyester resin is a lactic acid-based polyester resin. A film, sheet, or molded product, which is molded from the polyester resin composition according to any one of claims 1 to 6.