JP7130939B2 - Polybutylene terephthalate resin masterbatch for film and polybutylene terephthalate resin composition for film - Google Patents

Description

The present invention relates to a polybutylene terephthalate resin masterbatch for films and a polybutylene terephthalate resin composition for films. In particular, the present invention relates to a polybutylene terephthalate resin masterbatch and a polybutylene terephthalate resin composition for films, which are suitably used for film applications requiring transparency and antistatic properties.

Thermoplastic polyester resins, particularly polybutylene terephthalate resins (hereinafter abbreviated as PBT resins), have excellent mechanical properties, moldability, heat resistance, chemical resistance, and other properties suitable for use as engineering plastics. It is mainly used for molded products, and is used for various automobile parts, electrical parts, construction parts, etc. In recent years, it has also been applied to film applications that take advantage of the gas barrier properties, heat resistance, and shape retention properties of PBT resins.

Conventionally, a masterbatch (hereinafter abbreviated as MB) containing inorganic particles has been used for the purpose of antistatic in consideration of productivity as a film material. However, in film applications, the addition of fine inorganic particles has the problem of poor dispersibility and insufficient film transparency.

In response to such problems, for example, Patent Document 1 describes a resin composition obtained by blending a polyester MB containing 1 to 2% by weight of inorganic particles having an average particle size of 0.5 to 3 μm and a polyester resin containing no inorganic particles. is proposed.

As a method for improving dispersibility, for example, Patent Document 2 proposes a resin composition in which inorganic particles having an average particle size of 5 to 50 μm surface-treated with hexamethyldisilazane are directly blended with polyester.

WO2013/146524 JP-A-7-286095

As described above, antistatic properties and transparency are required as film properties. Films using conventionally known PBT resin compositions have antistatic effects, but have poor dispersibility of inorganic particles and transparency. was insufficient. Also, even when surface-treated inorganic particles were used in consideration of dispersibility, when the intrinsic viscosity of the PBT resin exceeded a specific value, the dispersibility of the inorganic particles was poor and the transparency was insufficient.

An object of the present invention is to solve the above-mentioned problems and to provide a PBT resin masterbatch for films and a PBT resin composition that can achieve both antistatic properties and transparency.

In order to solve such problems, the present inventors reached the present invention as a result of earnest research and examination.
That is, the present invention
(1) With respect to 100 parts by weight of polybutylene terephthalate resin containing no inorganic particles, with respect to 100 parts by weight of polybutylene terephthalate resin (a) having an intrinsic viscosity of 0.9 to 1.5 dl / g, the average particle diameter is from 0.5 to A polybutylene terephthalate resin composition for films containing 5 to 7 parts by weight of a polybutylene terephthalate resin masterbatch for films containing 5 to 10 parts by weight of 3 μm silicon dioxide (b), and the resin composition is extruded . A polybutylene terephthalate resin composition for films, wherein the inorganic particle aggregates exceeding 50 μm in the film formed by the above are 7 pcs/4 cm ² or less,
(2) The polybutylene terephthalate resin composition for films according to (1), wherein the polybutylene terephthalate resin containing no inorganic particles contains a PBT resin having an intrinsic viscosity of 0.9 to 1.5 dl/g.
(3) With respect to 100 parts by weight of polybutylene terephthalate resin containing no inorganic particles, with respect to 100 parts by weight of polybutylene terephthalate resin (a) having an intrinsic viscosity of 0.9 to 1.5 dl / g, the average particle diameter is from 0.5 to The film according to (1) or (2), wherein 5 to 7 parts by weight of a polybutylene terephthalate resin masterbatch for film containing 5 to 10 parts by weight of 3 μm silicon dioxide (b) is mixed and/or melt-kneaded. A method for producing a polybutylene terephthalate resin composition for

According to the present invention, it is possible to obtain a polybutylene terephthalate resin masterbatch for film and a polybutylene terephthalate resin composition which have excellent transparency and excellent production processability.

Embodiments of the present invention will be described in detail below, but the present invention is not limited to the following embodiments at all, and can be implemented with appropriate modifications within the scope of the purpose of the present invention. .

The PBT resin MB for film of the present invention contains (a) PBT resin and (b) inorganic particles. Further, the PBT resin composition of the present invention contains (A) a PBT resin MB for film and a PBT resin containing no inorganic particles.

The (a) PBT resin used in the present invention is prepared from a raw material containing terephthalic acid or an ester-forming derivative thereof and 1,4-butanediol or an ester-forming derivative thereof as a main component, and a normal polymerization such as a polycondensation reaction. It is a polymer obtained by a reaction. Examples of ester-forming derivatives of terephthalic acid include lower alkyl esters of terephthalic acid. More specific examples include methyl ester, ethyl ester, propyl ester, and butyl ester of terephthalic acid.

The (a) PBT resin is further copolymerized with terephthalic acid or a derivative thereof and 1,4-butanediol or a derivative thereof and other dicarboxylic acid or a derivative thereof, as long as the object of the present invention is not impaired. may be one obtained by copolymerizing other diols or derivatives thereof. Dicarboxylic acids or derivatives thereof used as copolymerization components include isophthalic acid, adipic acid, oxalic acid, sebacic acid, dodecanedioic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid and the like. Diol components or derivatives thereof used as copolymer components include ethylene glycol, 1,3-trimethylene glycol, 1,5-pentanediol, 1,6-hexanediol, cyclohexanediol, polyethylene glycol, polypropylene glycol, polytetra methylene glycol and the like. The content of the copolymer component is preferably 20 mol % or less with respect to the polyester obtained by polycondensing terephthalic acid or its ester-forming derivative and 1,4-butanediol or its ester-forming derivative.

(a) Preferred examples of PBT resins and copolymers include polybutylene terephthalate, polybutylene (terephthalate/isophthalate), polybutylene (terephthalate/adipate), polybutylene (terephthalate/sebacate), polybutylene (terephthalate/decanedicarboxylate) , polybutylene (terephthalate/naphthalate), and the like. Here, "/" indicates a copolymer component. You may mix|blend 2 or more types of these.

The (a) PBT resin used in the present invention should have an intrinsic viscosity in the range of 0.9 to 1.5 dl/g. If the intrinsic viscosity is less than 0.9 dl/g, it may be difficult to produce a film depending on the processing method. Moreover, when the intrinsic viscosity exceeds 1.5 dl/g, it becomes difficult to produce a masterbatch itself. More preferably, the intrinsic viscosity is 0.95-1.25 dl/g. In addition, the intrinsic viscosity of the PBT resin is a value measured at a temperature of 23° C. after dissolving the PBT resin using an octochlorophenol solution.

The method for producing the (a) PBT resin used in the present invention is not particularly limited, and a known polycondensation method, ring-opening polymerization method, or the like can be used. Either a batch polymerization method or a continuous polymerization method may be used, and both a method of obtaining polybutylene terephthalate by transesterification reaction and polycondensation reaction and a direct polymerization method of obtaining polybutylene terephthalate by esterification reaction and polycondensation reaction are applicable. can do. A continuous polymerization method is preferable in that the amount of carboxy terminal groups can be reduced and the effect of improving fluidity is increased, and a direct polymerization method is preferable in terms of cost.

In order to effectively promote the polycondensation by the esterification reaction and the polycondensation by the transesterification reaction, it is preferable to add a catalyst during these reactions. Specific examples of catalysts include organic titanium compounds, tin compounds, zirconia compounds, antimony compounds, and the like.

More specific examples of the organotitanium compound include titanic acid methyl ester, tetra-n-propyl ester, tetra-n-butyl ester, tetraisopropyl ester, tetraisobutyl ester, tetra-tert-butyl ester, and cyclohexyl ester. , phenyl ester, benzyl ester, tolyl ester, or mixed ester thereof.

More specific examples of the tin compounds include dibutyltin oxide, methylphenyltin oxide, tetraethyltin, hexaethyldistin oxide, cyclohexahexyldistin oxide, didodecyltin oxide, triethyltin hydroxide, triphenyltin hydro Alkyl oxides, triisobutyltin acetate, dibutyltin diacetate, diphenyltin dilaurate, monobutyltin trichloride, dibutyltin dichloride, tributyltin chloride, dibutyltin sulfide, butylhydroxytin oxide, methylstannoic acid, ethylstannoic acid, butylstannoic acid, etc. stannoic acid and the like.

More specific examples of the zirconia compound include zirconia compounds such as zirconium tetra-n-butoxide.

More specific examples of the antimony compound include antimony trioxide and antimony acetate.

Among these, organic titanium compounds and tin compounds are preferred in terms of catalytic effect, and further, tetra-n-propyl titanate, tetra-n-butyl ester, and tetraisopropyl titanate in terms of having higher catalytic effect. Esters are preferred, and tetra-n-butyl esters of titanic acid are particularly preferred. Two or more of these catalysts can also be used in combination.

The amount of the catalyst added is preferably in the range of 0.005 to 0.5 parts by weight, more preferably in the range of 0.010 to 0.2 parts by weight, per 100 parts by weight of the (a) PBT resin.

The inorganic particles (b) used in the present invention have an average particle diameter of 0.5 to 5 μm. If it is less than 0.5 μm, the antistatic property is lowered and the effect of imparting film productivity is lowered, which is not preferable. On the other hand, if it exceeds 5 μm, the transparency of the film may be impaired due to the formation of coarse protrusions, which is not preferable. From the viewpoint of transparency, it is more preferably 3 μm or less.

The average particle size is the value of the number average particle size obtained from the particle size distribution measured by the laser light scattering method using water or ethylene glycol as a catalyst.

In the present invention, the amount of the inorganic particles (b) added to the PBT resin in the polybutylene terephthalate resin master batch is in the range of 5 to 10 parts by weight with respect to 100 parts by weight of the polybutylene terephthalate resin (a). . It is preferably in the range of 6 to 8 parts by weight. If it is less than 5 parts by weight, the amount of the inorganic particles in the film is so small that the dispersibility is deteriorated and the antistatic effect cannot be obtained. On the other hand, when the amount exceeds 10 parts by weight, it is difficult to supply all the inorganic particles in the production process of the masterbatch, and the productivity of the masterbatch is deteriorated. In addition, as a result of not being able to supply all the inorganic particles in the masterbatch production process, the amount of inorganic particles added becomes less than 10 parts by weight, and there is a possibility that a masterbatch containing the desired inorganic particles cannot be produced. I don't like it.

As the inorganic particles used in the present invention, particles made of metal oxides, carbonates, silicates, sulfates and aluminates such as titanium, aluminum, silicon, calcium, magnesium and barium can be used.

Specific examples include, but are limited to, particles of silicon dioxide, titanium dioxide, alumina, aluminosilicate, calcium oxide, calcium carbonate, barium sulfate, and naturally-derived talc, mica, kaolinite, zeolite, and the like. not. From the viewpoint of antistatic properties, silicon dioxide, calcium carbonate and talc are preferred, and silicon dioxide is particularly preferred.

In order to prevent agglomeration of these inorganic particles, it is preferable to add them after slurring them with glycols and then mechanically dispersing them with a medium sales type dispersing machine such as a sand grinder, an attritor, or an ultrasonic wave. Moreover, it is also preferable to add an alkali metal compound, an ammonium compound, a phosphorus compound, or the like after improving the dispersion efficiency. The timing and method of addition of the inorganic particles (b) described above when producing the polybutylene terephthalate resin masterbatch are not particularly limited.

Depending on the purpose of use, the polybutylene terephthalate masterbatch for films of the present invention may contain, in addition to inorganic particles, heat-resistant agents, inert particles such as crosslinked polymer particles, whitening agents, UV inhibitors, and infrared-absorbing dyes. , heat stabilizers, surfactants, antioxidants, and the like. As antioxidants, aromatic amine-based and phenol-based antioxidants can be used. Available.

Additives other than these inorganic particles can be added in a total amount of preferably 5% by weight or less, more preferably 3% by weight or less, in the polybutylene terephthalate resin masterbatch.

The polybutylene terephthalate resin composition for film of the present invention contains a polybutylene terephthalate resin containing no inorganic particles and a polybutylene terephthalate resin masterbatch containing the inorganic particles of the present invention.

The PBT resin containing no inorganic particles used in the present invention is a PBT resin containing no inorganic particles, and is the same as the (a) PBT resin used when producing the polybutylene terephthalate masterbatch for films described above. PBT resin can be used.

Also, the PBT resin containing no inorganic particles preferably has an intrinsic viscosity in the range of 0.9 to 1.5 dl/g. Inorganic particles having a particle size that would otherwise easily aggregate can be easily dispersed by using a PBT resin having such an intrinsic viscosity. When the intrinsic viscosity is 0.9 dl/g or more, the production of the film is easy, which is preferable. Further, by making it 1.5 dl/g or less, the dispersibility of the inorganic particles in the masterbatch is improved, and a film excellent in transparency can be obtained.

The PBT resin composition obtained in the present invention contains 3 to 10 parts by weight of the PBT resin masterbatch for films with respect to 100 parts by weight of the PBT resin containing no inorganic particles. It is preferably 5 to 7 parts by weight. When the amount is 3 parts by weight or more, an antistatic effect can be obtained, and the film can be produced with good productivity. By setting the amount to 10 parts by weight or less, a film having excellent transparency can be obtained.

In the PBT resin composition of the present invention, ordinary additives such as antioxidants, stabilizers, ultraviolet absorbers, colorants, release agents, flame retardants and a small amount of other additives are added to the extent that the effects of the present invention are not impaired. A seed polymer can be added.

Examples of antioxidants include 2,6-di-t-butyl-4-methylphenol, tetrakis(methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate)methane, tris Phenolic compounds such as (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate, sulfur such as dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate and phosphorus compounds such as trisnonylphenyl phosphite and distearyl pentaerythritol diphosphite.

Stabilizers include benzotriazole compounds including 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, as well as benzophenone compounds such as 2,4-dihydroxybenzophenone, mono- or distearyl phosphate, trimethyl phosphate. Phosphate esters such as

Since a synergistic effect may be obtained by combining two or more of these various additives, they may be used in combination.

Additives exemplified as antioxidants, for example, may act as stabilizers or UV absorbers. In addition, some of the stabilizers exemplified have anti-oxidation and UV-absorbing properties. That is, the above classifications are for convenience and are not intended to limit the action.

Examples of release agents include vegetable waxes such as carnauba wax and rice wax, animal waxes such as beeswax and lanolin, mineral waxes such as montan wax, petroleum waxes such as paraffin wax and polyethylene wax, castor oil and the like. Oil-based waxes such as derivatives, fatty acids and derivatives thereof, and higher fatty acid derivatives include higher fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid and montanic acid, and monovalent or divalent or higher alcohols. esters, partial saponification of these higher fatty acid esters with metal oxides such as Ca(OH) ₂ , NaOH, Mg(OH) ₂ , Zn(OH) ₂ , LiOH, Al(OH) ₃ ; fully saponified products obtained from higher fatty acids and metal oxides or metal hydroxides; complex esters obtained by condensing esters of higher fatty acids and polyhydric alcohols using dicarboxylic acids such as adipic acid as a binder; mono- or diamides obtained from fatty acids and monoamines or diamines;

As a method for producing the PBT resin masterbatch for films and the PBT resin composition of the present invention, a twin-screw extruder is used, and raw materials are supplied and kneaded from the upstream side of the extruder at a cylinder temperature of 230 to 300 ° C. However, it may be melt-kneaded at a temperature of 200 to 350 ° C. using a known melt mixer such as a single-screw or twin-screw extruder, Banbury mixer, kneader or mixing roll, and each component may be mixed. They may be mixed together in advance and then melt-kneaded. The PBT resin composition for films of the present invention can also be obtained by a method of mixing (dry blending) pellets of a PBT resin masterbatch and PBT resin pellets. Furthermore, with respect to the total amount of 100 wt. After kneading and pelletizing by a method or the like, it may be added before molding. In addition, it is preferable that the amount of water adhering to each component is small, and it is desirable to pre-dry each component, but it is not always necessary to dry all components.

The PBT resin masterbatch for films and the PBT resin composition of the present invention are molded by a commonly used method for molding thermoplastic resin films, but are preferably used for extrusion molding. The PBT resin masterbatch and PBT resin composition for films of the present invention can also be used in molding by general molding methods such as injection molding, extrusion molding, blow molding, transfer molding, and vacuum molding.

The PBT resin masterbatch for films and the PBT resin composition of the present invention are excellent in dispersibility of inorganic particles and antistatic properties in the production of thin-film molded articles such as films, and are therefore preferable for general film applications, not limited to single-layer and multi-layer applications. Applies. In particular, it is suitable for thin films of 30 μm or less and which require transparency.

The effects of the present invention will be described in more detail below with reference to examples and comparative examples. The gist of the present invention is not limited only to the following examples. In addition, Example 1, Example 2, and Example 5 are reference examples. Raw materials used in Examples and Comparative Examples are shown below.
(a-1) PBT: Toray Industries, Inc. polybutylene terephthalate (intrinsic viscosity 0.95 dl/g)
(a-2) PBT: Toray Industries, Inc. polybutylene terephthalate (intrinsic viscosity 1.25 dl/g)
(a-3) PBT: Toray Industries, Inc. polybutylene terephthalate (intrinsic viscosity 0.75 dl/g)
(b-1) Inorganic particles: Silicon dioxide Sylophobic 100 manufactured by Fuji Silysia Chemical Co., Ltd., average particle size 2.7 μm
(b-2) Inorganic particles: Silicon dioxide Sylophobic 704 manufactured by Fuji Silysia Chemical Co., Ltd., average particle size 6.2 μm

An evaluation method in each example and comparative example will be described. Unless otherwise specified, the number of evaluation n was set to n=3 and the average value was obtained.

(1) Intrinsic viscosity (IV) of PBT resin
An octochlorophenol solution was used to dissolve the PBT resin and measured at a temperature of 23°C.

(2) Inorganic particle dispersibility in the PBT resin masterbatch for films Using the pellets of the PBT resin masterbatch obtained in each example and comparative example, a small single screw extruder (Laboplast manufactured by Toyo Seiki Seisakusho Co., Ltd.) 300 g of the pellets were put into a mill), the cylinder temperature was set to 260° C., the screw rotation speed was set to 100 rpm, and the pressure when passing through a 20 μm filtration filter was measured. The pressure immediately after the start of flow and the pressure when the flow was stabilized were measured, and the difference between them was obtained and used as an index of dispersibility. It can be said that the smaller the pressure difference, the better the dispersibility.

(3) Dispersibility of Inorganic Particles in PBT Resin Composition Pellets of the PBT resin composition were prepared according to the compositions described in Examples and Comparative Examples. The obtained PBT resin composition pellets were put into a single screw extruder (VS40-25 type manufactured by Shinko Machinery Co., Ltd.) having a 40 mm T die, and the cylinder temperature was set to 260 ° C., the die temperature to 260 ° C., and the screw rotation speed to 100 rpm. , the film was extruded at a film-forming speed of 10 m/min to prepare a film-shaped test piece of 20 mm x 20 mm x 30 µm. Observe the whole film-shaped test piece using a digital microscope (VHX-900 manufactured by Keyence Corporation), observe the aggregates of inorganic particles present, measure the diameter of the aggregates, and count the number by size. evaluated.

[Examples 1 and 2 and Comparative Examples 1 to 3]
According to the composition shown in Table 1, all of the components were supplied from the main inlet of the twin-screw extruder, melt-kneaded by a twin-screw extruder with a screw diameter of 40 mmφ set at a cylinder temperature of 250 ° C., and pelletized PBT resin master. got a batch. Using the obtained pellets, the dispersibility of the inorganic particles in the PBT resin masterbatch was evaluated by the method described in (2) above. As is clear from the evaluation results of Examples 1 and 2 and Comparative Examples 1 and 3, the PBT resin masterbatch of the present invention was excellent in dispersibility of inorganic particles.

[Examples 3 to 7 and Comparative Examples 4 to 6]
Each component was put into a tumbler according to the composition shown in Table 2, and physical mixing was performed for 5 minutes with the tumbler set at a rotation speed of 50 rpm to obtain a PBT resin composition obtained by mixing a PBT resin masterbatch and a PBT resin containing no inorganic particles. Obtained. Using the obtained pellets, a film-shaped test piece was prepared by the method described in (3) above, and the dispersibility of the inorganic particles in the PBT resin composition was evaluated. In Comparative Example 6, resin composition pellets were produced by directly melt-kneading a polybutylene terephthalate resin and inorganic particles without using a masterbatch. As is clear from the evaluation results of Examples 3-7 and Comparative Examples 4-6, the PBT resin composition of the present invention was excellent in the dispersibility of inorganic particles in the film.
Tables 1 and 2 show the compositions and evaluation results of Examples 1-7 and Comparative Examples 1-6.

The PBT resin masterbatch for films and the PBT resin composition of the present invention are particularly effective for film applications such as food packaging, various containers, wall materials, and floor materials that require thinness and transparency.

Claims (3)

With respect to 100 parts by weight of polybutylene terephthalate resin containing no inorganic particles, 100 parts by weight of polybutylene terephthalate resin (a) having an intrinsic viscosity of 0.9 to 1.5 dl / g, and having an average particle diameter of 0.5 to 3 μm A polybutylene terephthalate resin composition for films containing 5 to 7 parts by weight of a polybutylene terephthalate resin masterbatch for films containing 5 to 10 parts by weight of silicon dioxide (b), and obtained by extruding the resin composition. A polybutylene terephthalate resin composition for film, wherein the amount of inorganic particle aggregates exceeding 50 μm in the film is 7 pcs/4 cm ² or less. The polybutylene terephthalate resin composition for film according to claim 1, wherein the polybutylene terephthalate resin containing no inorganic particles contains a PBT resin having an intrinsic viscosity of 0.9 to 1.5 dl/g. With respect to 100 parts by weight of polybutylene terephthalate resin containing no inorganic particles, 100 parts by weight of polybutylene terephthalate resin (a) having an intrinsic viscosity of 0.9 to 1.5 dl / g, and having an average particle diameter of 0.5 to 3 μm 3. The polybutylene terephthalate resin for films according to claim 1 or 2, wherein 5 to 7 parts by weight of a polybutylene terephthalate resin masterbatch for films containing 5 to 10 parts by weight of silicon dioxide (b) is mixed and/or melt-kneaded. A method of making the composition.