KR101153909B1 - Copolyester, process for producing the same, and polyester film - Google Patents

Abstract

The present invention provides a flexible polyester film which can be manufactured at low cost by reducing a manufacturing cost of a polyester resin or a film having excellent transparency and flexibility, and a preferred flexible polyester resin. A copolyester synthesized from an acid component and a glycol component containing an excess of fatty acid or a derivative thereof containing 15 to 95% by weight of fatty acid dimer and 5 to 85% by weight of fatty acid trimer, and its melt viscosity is 250 1000-3000 poise (P) in degreeC. Moreover, it is a flexible polyester film melt-molded from the said copolyester.

Description

Copolyester, its manufacturing method and polyester film {COPOLYESTER, PROCESS FOR PRODUCING THE SAME, AND POLYESTER FILM}

The present invention relates to copolyesters and flexible polyester films capable of forming flexible moldings, and more particularly, polyesters suitable for applications such as industrial materials and packaging materials requiring transparency, easy moldability and heat resistance. It relates to a copolyester of a film and its raw material.

As a conventional flexible film, a polyvinyl chloride type film is typical. This polyvinyl chloride film has excellent weather resistance, is suitable for various processing, for example, embossing, and the like, and furthermore, the polyvinyl chloride film has been advantageously available at low cost, and thus has been preferably used as a flexible film.

However, polyvinyl chloride-based films have a problem in that toxic gases are generated when the film is burned by a fire or the like, and there is a problem that plasticizers are likely to bleed out. On request, new flexible films made of different resins are required.

For flexible films having improved defects of polyvinyl chloride-based films, flexible films made of copolyester resins have been proposed in consideration of the use of copolymerized polyester resins in which soft segments are copolymerized with polyesters.

For example, an elastic film made of a resin obtained by copolymerizing a polybutylene terephthalate with a long chain polyether such as polytetramethylene glycol (see Japanese Patent Application Laid-Open No. 57-48577), and an amount of unsaturated fatty acid in polyethylene terephthalate. Resin for elastic yarns copolymerized with chain long-chain aliphatic dicarboxylic acid (see, for example, Japanese Patent Application Laid-Open No. 42-8709), and long-chain aliphatic dicarboxylic acid which is an unsaturated fatty acid dimer in polybutylene terephthalate. Long-chain aliphatic dicars, which are unsaturated fatty acid dimers in copolymers of polybutylene terephthalate and polyethylene terephthalate, for copolymers of elastomeric resins for shaped products (e.g., see Japanese Patent Application Laid-Open No. 54-15913). A flexible film made of a resin copolymerized with an acid (see, for example, Japanese Patent No. 351875 and Japanese Patent No. 3200848) It is.

As a method of obtaining a polyester resin or a resin composition containing a long chain aliphatic dicarboxylic acid as a copolymerization component in a predetermined ratio, in addition to the method of copolymerizing a long chain aliphatic dicarboxylic acid in a predetermined ratio to the polyester in a polymerization step. And a method of melt-mixing and copolymerizing a long chain aliphatic dicarboxylic acid copolyester and an aromatic polyester at a constant ratio are known (e.g., JP-A-6-73277 and JP-A-2002-12749). Reference).

However, an elastic film made of a resin obtained by copolymerizing a polybutylene terephthalate with a long chain polyether has good flexibility, blocking resistance, and the like, but has poor weather resistance, heat resistance, transparency, and the like, thereby replacing the polyvinyl chloride-based film. It is difficult to satisfy the characteristic calculated | required by the film for use.

Moreover, resin which copolymerized long-chain aliphatic dicarboxylic acid with polyethylene terephthalate and polybutylene terephthalate has favorable characteristics as a copolyester for elastic yarns and a film. In particular, a resin obtained by copolymerizing a long chain aliphatic dicarboxylic acid with a polybutylene terephthalate-based polyester has an advantage of being easily molded into fibers, films, sheets, and other molded products because of its high crystallinity. Various copolymerization compositions and copolymerization methods are disclosed in Japanese Patent Application Laid-Open No. 54-15913, Japanese Patent No. 35187575, Japanese Patent No. 3200848, Japanese Patent Laid-Open No. 6-73277 and Japanese Patent Application Laid-Open No. 2002-12749. Is proposed.

However, in these prior arts, long-chain aliphatic dicarboxylic acids of high purity (e.g., high purity of 95 wt% or more and 99 wt% or more) that can be obtained through 1,4-butanediol or plural distillations and purifications are used. Because of its use, the cost is high and it becomes a relatively expensive resin product. Therefore, it cannot find a promising use and is not industrialized.

Therefore, the main object of the present invention is to solve the drawbacks of the prior art, that is, a flexible polyester film which can be manufactured at low cost by greatly reducing the manufacturing cost of a polyester resin or a film excellent in transparency and flexibility, and the It is providing the flexible polyester resin suitable for a film. In addition, it is possible to produce a flexible polyester resin or film having excellent whitening resistance, heat resistance, and bleed-out resistance over time at low cost.

In order to achieve the above object, the present invention uses relatively low-purity rather than high-purity products as dimerized fatty acids or derivatives thereof. In this case, as the relatively low-purity dimerized fatty acid or its derivatives, the composition of the content of the fatty acid dimer, the content of the fatty acid trimer, etc. is within a specific range, and the melt viscosity of the copolymer is kept within a specific range. By employing the specific conditions of the present invention, even when employing a low-purity product of a dimerized fatty acid or a derivative thereof, it is possible to produce a copolyester resin having excellent transparency and flexibility, and to prepare a copolyester film having excellent transparency and flexibility. It became the knowledge and the present invention that it became possible.

That is, the copolyester of the present invention is an acid component containing an excess of fatty acid or derivative thereof containing 15 to 95% by weight of fatty acid dimer and 5 to 85% by weight of fatty acid trimer, and glycol It is a co-polyester synthesized from the components, characterized in that the melt viscosity of the co-polyester is 1000 to 3000 poise at 250 ℃, thereby achieving a significant reduction in the manufacturing cost.

According to the present invention, in order to overcome the problem of high cost, even if a dimerized fatty acid having a purity of 95% by weight or less or a derivative thereof, which can be prepared without undergoing multiple distillation and purification steps after the dimerization reaction, it has excellent transparency and flexibility. It can be set as the flexible polyester resin and the flexible film which can be put into practical use. Therefore, according to the present invention, it is possible to remarkably reduce raw material costs when producing copolyesters and polyester films having excellent flexibility, transparency, and the like, thereby producing flexible polyester resins or films that are highly cost-effective and suitable for practical use. Can be. Taking advantage of these advantages, the flexible film obtained in the present invention can be suitably used for applications such as industrial materials, packaging materials and the like requiring flexibility and easy moldability, or as a substitute for polyvinyl chloride-based flexible films.

The copolyester of the present invention is a copolyester synthesized from an acid component and a glycol component comprising an excessed fatty acid or a derivative thereof containing a fatty acid dimer and a fatty acid trimer in a specific ratio. That is, it is a copolyester which contains as an essential structural unit the soft segment which has the residue which consists of an excess fatty acid or its derivative as a main component, and if necessary, residues of other acid components (for example, aromatic dicarboxylic acid, etc.) It includes a hard segment as its main component.

In the copolyester, the aromatic dicarboxylic acid residue constituting the hard segment is preferably formed of an aromatic dicarboxylic acid and an ester-forming derivative thereof. Specifically, for example, isophthalic acid, terephthalic acid, diphenyl-4,4'-dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalene-2,7-dicarboxylic acid, naphthalene-1 , 5-dicarboxylic acid, diphenoxyethane-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, diphenylether-4,4'-dicarboxylic acid And ester forming derivatives thereof. Among them, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid and ester forming derivatives thereof are preferable. In addition, these aromatic dicarboxylic acid components may be 1 type, or may use 2 or more types together.

It is preferable that content of this aromatic dicarboxylic acid residue is 50-99 mol% of an acid component residue. More preferably, it is 55-95 mol%, More preferably, it is 60-93 mol%. When content of an aromatic dicarboxylic acid residue is less than 50 mol%, the heat resistance of copolyester may fall and also the mechanical property of the film obtained from this may fall.

In the copolyester, the residues of the dimerized fatty acids or their derivatives constituting the soft segment are formed from the dimerized fatty acids or derivatives thereof produced by the dimerization reaction of unsaturated fatty acids having 10 to 30 carbon atoms represented by the following formula. It is preferable. This dimerized fatty acid or its derivative (hereinafter referred to as dimerized fatty acid component) contains a dimerized fatty acid or its ester-forming derivative in which unsaturated fatty acid is dimerized as a main component.

CH ₃ (CH ₂ ) _m (CH = CH-CH ₂ ) _k (CH ₂ ) _n COOR

(Wherein R is a hydrogen atom or an alkyl group, m is an integer of 1 to 25, k is an integer of 1 to 5, n is an integer of 0 to 25, and m, k and n are 8 ≦ m + 3k + n The relation of ≤ 28 is satisfied.)

Examples of the unsaturated fatty acid include eroxane, docosapentaenoic acid, docosahexaenoic acid and the like having 22 carbon atoms, such as linoleic acid, linolenic acid and oleic acid having 18 carbon atoms.

In the dimerization reaction of this unsaturated fatty acid, a trimer is also produced together with the dimer, and therefore, in the dimerization reaction product obtained by the dimerization reaction, not only the dimer but also a by-product trimer and an unreacted monomer are included. In order to obtain a high-purity (e.g., 98% by weight or more) fatty acid dimer product from this dimerization reaction product, it is necessary to repeat the purification.

However, in the present invention, since a relatively low purity product is used rather than high purity, the dimerization reaction product obtained by the dimerization reaction can be used as a dimerized fatty acid component of a polymerization raw material without any special purification. However, even in this case, it is necessary to prepare the reaction conditions such that the content of the dimer and the trimer is 15 to 95% by weight and 5 to 85% by weight, or to separate or purify as necessary. Preferably the dimer content is 70 to 92% by weight and the trimer content is 6 to 30% by weight. More preferably, the dimer content is 70 to 90% by weight, and the trimer content is 13 to 30% by weight.

The unreacted monomers remaining in the dimerized fatty acid component used as the polymerization raw material are preferably very small in order to sufficiently improve the degree of polymerization at the time of polymerization, that is, the ones with the highest total content of dimers and trimers. desirable. For example, it is preferable that the sum total of content of a dimer and trimer is 90-100 weight%, and its 97-100 weight% is more preferable.

When both the content of the dimer and the trimer in the dimerized fatty acid component are too small, especially when the sum of the content is too small, the reactivity decreases during the preparation of the copolyester, and it is difficult to increase the degree of polymerization. It is difficult to set the viscosity level. In addition, when there is too much trimer content, the crosslinking degree of polyester will increase and for that reason, a polymerization degree and a mechanical characteristic will fall easily.

When the dimer content and the trimer content are within the above-mentioned ranges specified in the present invention, the copolymer polyester resin of the prior art manufactured using the high-purity fatty acid (eg, the dimer content is 98% by weight or more) used in the prior art, The superior quality equivalent to that of the film can be produced at a significantly lower cost than that according to the prior art, and the cost can be significantly reduced. By achieving remarkably low cost, it is possible to develop for low cost flexible film applications that have been difficult to apply until now in terms of manufacturing cost, and therefore the present invention is particularly promising as an alternative to polyvinyl chloride-based flexible films. .

The dimerized fatty acid component used in the preparation of the copolyester of the present invention includes a dimer or trimer (hereinafter, collectively referred to as an excess) as described above, and the excess is an unsaturated bond produced by a dimerization reaction. This exists. This may be used as it is as a polymerization raw material, and may also be used after reducing the unsaturated bond by hydrogenation. However, especially in the case of using a resin or a film requiring heat resistance, weather resistance and transparency, it is preferable to use a dimerized fatty acid component obtained by removing an unsaturated bond by hydrogenation.

As this dimerized fatty acid component, the dimer acid which is a C36 dimerized fatty acid, and its ester formation derivative are preferable. Dimer acid can be obtained by dimerizing unsaturated fatty acids having 18 carbon atoms such as linoleic acid, linolenic acid, or oleic acid. For example, dimer acid is commercially available from Unichema International, Inc. (PRIPOL) (registered trademark). It is becoming. In addition, various ester forming derivatives of dimerized fatty acids are also commercially available. The dimerized fatty acid component used by this invention may be prepared using these commercial items.

In the copolyester of the present invention, the amount of the residue of the dimerized fatty acid component is preferably 1 to 50 mol% of the acid component residue in the copolyester, more preferably 5 to 45%, still more preferably 7 40 mol%. When the amount of the residue of the dimerized fatty acid component exceeds 50 mol% and the amount of the aromatic dicarboxylic acid residue is less than 50 mol%, the heat resistance of the polyester is lowered and the mechanical properties of the film obtained therefrom may be lowered. Can be.

In the present invention, the dimerized fatty acid component employed as the polymerization raw material is a dimerization reaction of unsaturated fatty acids in a conventional manner to produce a reaction product containing dimers and trimers at desired levels, and the reaction product is used as is or as necessary. It is good to prepare by processing accordingly.

For example, when the raw material for unsaturated fatty acid is oil derived from natural products, such as crude tall oil and crude soybean oil, it is purified by a conventional method to obtain purified fatty acid. To dimerize the purified unsaturated fatty acid, 2 to 10 parts by weight of clay and 0.2 to 2.0 parts by weight of water are added as a polymerization catalyst to 100 parts by weight of the purified fatty acid, and about 200 to 280 ° C. The reaction is performed at a pressure of 2 to 10 kg / cm 2 for about 0.5 to 8 hours. Next, 0.1-2 weight part of phosphoric acid is added, and it reacts at about 60-150 degreeC for about 20-150 minutes, and iron content in a clay is removed. Further, this is filtered to remove clay and distilled to remove unreacted monomer fatty acid. In the reaction product obtained by this dimerization reaction, about 70-80 weight% of dimers are normally contained. This reaction product may be purified by molecular distillation or the like as necessary. The dimerized fatty acid component may be used as a dimerized fatty acid ester by mixing the dimerized fatty acid with various alcohols and then esterifying them under a transesterification catalyst such as an acid.

From the viewpoint of controlling the crystallization rate of the polyester, the glycol component of the copolymerized polyester of the present invention preferably contains a 1,4-butanediol residue, and if necessary, glycol residues other than 1,4-butanediol represented by the following formula: (Hereinafter referred to as other glycol moieties).

-O-X-O-

(Wherein, X is an alkylene group other than the tetramethylene group, or the alkylene group has a side chain composed of an alkyl group or a cycloalkyl group, or is composed of a cycloalkylene group and an alkylene group.)

As the glycol component (hereinafter referred to as another glycol component) for other glycol residues, specifically, for example, ethylene glycol, 1,3-propanediol, 1,2-propanediol, 2-methyl-1,3-propane Diol, 1,3-butanediol, 1,2-butanediol, 1,5-pentylglycol, 2,2-dimethyl-1,3-propanediol, 2-ethyl-1,3-propanediol, 1,6-hexane Diol, 2-methyl-2-ethyl-1,3-propanediol, 1,8-octanediol, 1,10-decanediol, 1,3-cyclobutanediol, 1,3-cyclobutanedimethanol, 1,3 -Cyclopentane dimethanol, 1, 4- cyclohexane dimethanol, etc. can be mentioned. Among these, it is preferable to use ethylene glycol, 1,3-propanediol from a viewpoint of polymer reactivity, market availability, and cost.

Although the combination of these glycol components is not specifically limited, Especially, it is especially preferable to use 1, 4- butanediol, ethylene glycol, and / or 1, 3- propanediol together in order to control the crystallization rate of polyester.

In the copolyester of the present invention, the amount of the 1,4-butanediol residue is preferably 10 to 100 mol% of the glycol moiety, more preferably 20 to 90 mol%, still more preferably 45 to 85 mol. %to be. On the other hand, the amount of the other glycol residues is preferably 90 mol% or less, more preferably 10 to 80 mol%, still more preferably 15 to 55 mol%. If the amount of the 1,4-butanediol moiety is less than 10 mol%, the crystallization rate of the polyester decreases, the adhesion is difficult at the time of formation, and the formation becomes difficult, or the transparency of the obtained molded product may decrease.

In the copolyester of this invention, other components may be copolymerized in the range which does not impair the objective of this invention other than the said acid component and the glycol component, or the resin which consists of other components can also be mixed. For example, as other copolymerizable acid components, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 5-sodium sulfoiso Phthalic acid, trimellitic acid, trimesic acid and the like, or ester derivatives thereof, p-oxy benzoic acid, p-hydroxymethyl benzoic acid, or ester derivatives thereof as hydroxycarboxylic acid component, or 1,12 as alcohol component Dodecanediol, diethylene glycol, polyoxyalkylene glycol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, spiroglycol, or bisphenol A, bisphenol S and these And ethylene oxide adducts, trimethylolpropane, and the like.

In the copolyester of this invention, the melt viscosity needs to be 1000-3000 poise at 250 degreeC, More preferably, it is 1300-2300 poise. If the melt viscosity of the polyester exceeds 3000 Poise, the extrusion state is unstable when the polyester is extruded into a film or the like, which tends to be a film or a molded article having a nonuniform film thickness. Moreover, the part which thickened partially is whitened, and it becomes easy to become a speckle. If the melt viscosity is less than 100 poise, film formation and molding are difficult due to the lack of viscosity.

As a method for making 250 degreeC melt viscosity of the copolyester of this invention in the said range, controlling the polymerization degree and intrinsic viscosity (IV) to an appropriate level is mentioned. Specifically, the range of intrinsic viscosity is preferably 0.4 to 1.5, more preferably 0.5 to 1.2, and particularly preferably 0.7 to 0.9. The melt viscosity level may be adjusted by blending a compatibilizer during polymerization or polymer melt kneading.

The method for producing the copolyester of the present invention is not particularly limited, and can be produced by the same method as a conventional polyester polymerization method. For example, a method of directly copolymerizing a monomer composition containing a glycol component such as 1,4-butanediol, a dimerized fatty acid component and another acid component in a predetermined ratio may be produced in the polymerization step, or two or more kinds may be used. The method of copolymerizing a polymer and / or a copolymer by melt-kneading in an extruder and making it into a predetermined | prescribed polymerization composition may be sufficient.

As the latter method by melt kneading, an aliphatic-aromatic polyester copolymer composed of an aromatic polyester polymerized from an aromatic dicarboxylic acid and a glycol component and an aromatic dicarboxylic acid, a dimerized fatty acid component and a glycol component is melt kneaded in an extruder. To a copolymerized polyester of the specific polymerization composition, and the like. In this method, there is a cost advantage of using a universal aromatic polyester such as polyethylene terephthalate (PET) or polybutylene terephthalate (PBT), and furthermore, copolymerization by changing the mixing amount of the aromatic polyester and the copolymer. There is an advantage in handling properties that can easily adjust the polymerization composition in polyester, and is preferable as an industrial production method.

Among them, an aromatic polyester comprising at least one member selected from the group consisting of terephthalic acid residues and / or isophthalic acid residues, ethylene glycol residues, 1,3-propanediol residues and 1,4-butanediol residues as main components, and An aliphatic-aromatic polyester copolymer composed of terephthalic acid residues and dimerized fatty acid components, and at least one member selected from the group consisting of ethylene glycol residues, 1,3-propanediol residues, and 1,4-butanediol residues as an ingredient is contained in the extruder. More preferred is a method of melt kneading at the above to obtain copolyester of the specific polymerization composition. The aromatic polyester is particularly preferably composed of a terephthalic acid residue and / or an isophthalic acid residue and an ethylene glycol residue, and examples thereof include polyethylene terephthalate (PET) and ethylene terephthalate and isophthalate copolymer (PET / I). can do. Moreover, as an aliphatic-aromatic polyester copolymer, what consists of a terephthalic acid residue, a dimerized fatty acid component, and a 1, 4- butanediol residue is especially preferable.

It is preferable to add the following compatibilizers at the time of copolymerization or resin kneading | mixing of the copolyester obtained by the said method, in order to increase the melt viscosity or to improve transparency.

As this compatibilizing agent, for example, various glycids such as diglycidyl hexahydrophthalate, diglycidyl terephthalate, diglycidyl phthalate, bisphenol-S diglycidyl ether, polyethylene glycol diglycidyl ether, etc. Various ester compounds and hydrochloric acids of various fatty acids such as dioxane, 1,4-phenylenebisoxazoline, 1,3-phenylenebisoxazoline, various fatty acids such as stearic acid, oleic acid, lauric acid, and polyethers, And organic acids such as sulfuric acid, nitric acid, and p-toluenesulfonic acid. Especially, it is preferable to use bisoxazoline or an organic acid.

Although the mechanism is not necessarily clear about the increase of melt viscosity or the improvement of transparency by adding the said compatibilizer, For example, it can demonstrate by the following model.

[Effective Effect by Addition of Bisoxazoline]

When bisoxazolin which is a bifunctional compound is added, it is thought that reaction of the carboxylic acid terminal in a copolyester chain is accelerated | stimulated, molecular weight increases, and melt viscosity improves. In addition, when bisoxazoline is added when melt-kneading the aromatic polyester and the aliphatic-aromatic polyester copolymer, in addition to the effect of increasing the melt viscosity, two functional groups of bisoxazoline are heterogeneous polymers (in the case of the present invention) Is added to the carboxylic acid terminal of the aromatic polyester and the aliphatic-aromatic polyester copolymer) to form a block copolymer, which increases the compatibility between the different polymers, and as a result, transparency It is thought to improve.

[Effects of Adding Organic Acids]

When the organic acid is added during the melt kneading of the aromatic polyester and the aliphatic-aromatic polyester copolymer, the acid-catalytic effect of the organic acid promotes the transesterification reaction between the different polymers, thereby facilitating copolymerization, and further promoting homogenization of the polymer chain, thereby providing transparency. It is believed that this is improved.

The addition amount in the case of adding the above-mentioned compatibilizer to the copolyester may be such that the melt viscosity is at the desired viscosity level and is sufficient in order to exhibit the desired transparency, and generally 0.1 to 5% by weight is preferable.

In this invention, in order to acquire favorable softness, it is preferable that the glass transition point (Tg) is 25 degrees C or less, More preferably, it is 20 degrees C or less, More preferably, it is 15 degrees C or less.

The polyester film of this invention is a film which can obtain a film | membrane by a conventional method after adding various particle | grains and additives as needed to the copolymerization polyester which has said polymerization composition and melt viscosity as needed, for example, It can be melt-extruded, cooled and solidified and produced by stretching or heat treatment as necessary.

The particles to be added in the polyester film are appropriately selected according to the purpose and use, and are not particularly limited unless the effect of the present invention is impaired. Examples thereof include inorganic particles, organic particles, crosslinked polymer particles, internal particles generated in a polymerization system, and the like. can do. You may add 2 or more types of these particles. From the viewpoint of the mechanical properties of the polyester resin composition, the amount of such particles added is preferably 0.01 to 10% by weight, more preferably 0.02 to 1% by weight.

Moreover, the average particle diameter of the particle to add becomes like this. Preferably it is 0.001-10 micrometers, More preferably, it is 0.01-2 micrometers. When the average particle diameter is in this preferred range, defects in the resin composition and defects in the film are less likely to occur, leading to deterioration in transparency and deterioration in moldability.

Although the kind of inorganic particle is not specifically limited, For example, various carbonates, such as calcium carbonate, magnesium carbonate, and barium carbonate, various sulfates, such as calcium sulfate and barium sulfate, various composite oxides, such as kaolin and talc, lithium phosphate, and phosphoric acid Fine particles made of various phosphates such as calcium and magnesium phosphate, various oxides such as aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, various salts such as lithium fluoride, and the like can be used.

As the organic particles, fine particles made of calcium oxalate, terephthalate such as calcium, barium, zinc, manganese or magnesium can be used. Examples of the crosslinked polymer particles include fine particles made of a single monomer or a copolymer of vinyl monomers of divinylbenzene, styrene, acrylic acid and methacrylic acid. In addition, organic fine particles, such as a polytetrafluoroethylene, a benzoguanamine resin, a thermosetting epoxy resin, an unsaturated polyester resin, a thermosetting urea resin, and a thermosetting phenol resin, can be used.

Examples of the internal particles produced in the polymerization system include particles produced by a known method of adding an alkali metal compound, an alkaline earth metal compound, or the like into the reaction system and further adding a phosphorus compound.

In the polyester film of the present invention, known additives such as flame retardants, heat stabilizers, antioxidants, ultraviolet absorbers, antistatic agents, plasticizers, tackifiers, fatty acid esters, etc. You may mix | blend an appropriate amount with organic lubricants, such as a wax, or antifoamers, such as polysiloxane, and coloring agents, such as a pigment or dye.

In the film, the layer structure may be a single layer, or may be a laminated structure in which a layer for imparting new functions such as an activity, adhesiveness, adhesiveness, heat resistance, and weather resistance is formed on the surface. For example, when laminating layers (B layer, C layer) having different compositions of resins or additives to a polyester layer (A layer) copolymerized with a dimerized fatty acid component, a two-layer structure of A / B or B / A three-layer structure such as A / B, B / A / C, or A / B / C is exemplified. In addition, if necessary, a multilayered laminated structure may be employed rather than three layers, and the ratio of the laminated thicknesses of the respective layers may be arbitrarily set.

In the present invention, the polyester film preferably has an elastic modulus in the range of 1 to 1000 MPa at 25 ° C. When the elastic modulus is in this preferred range, when used in the form of a film, the deformation is small, no handling problems occur, and the low temperature formation is excellent. In order to make elasticity modulus into 25-1000 Mpa, the method of optimizing the copolymerization amount of a dimerized fatty acid component, using a dimerized fatty acid component with high softening effect, etc. can be mentioned, for example.

The polyester film of this invention may be an unstretched film, or a stretched film may be sufficient. The stretched film may be either a uniaxial stretched film drawn in either of the longitudinal direction or the width direction of the film, or a biaxially stretched film drawn in both the longitudinal direction and the width direction of the film.

The thickness of a film should just be an optimal thickness according to the use to be used. The thickness is the range of 0.5-1000 micrometers normally, Preferably it is 1-500 micrometers, More preferably, it is 5-200 micrometers from a viewpoint of film forming stability.

The polyester film of this invention may improve adhesiveness and printability by surface-treating, such as corona discharge treatment as needed. Various coatings may be applied, and the type, coating method and thickness of the coating compound are not particularly limited as long as they do not impair the effects of the present invention. Moreover, it can also be used by forming, printing, etc., such as embossing as needed.

The polyester film of this invention can be used as various industrial materials and packaging materials which require easier moldability as a single sheet or a composite sheet. As a composite sheet, it can be attached to base materials, such as a metal, a wood, a paper, a resin sheet, or a resin board, for example.

Specific uses include applications in which conventional flexible films and films that are easy to mold have been used, such as packaging films, wrap films, stretch films, partition films, and films for building materials such as wallpaper and plywood decorative sheets. It is not limited to this.

Hereinafter, the present invention will be described in detail by way of examples. In addition, the characteristics were measured and evaluated by the following method.

(1) Composition ratio (content) of monomer, dimer and trimer in dimerized fatty acid component

Analysis was performed by high performance liquid chromatography, and the composition ratio (content) of the monomer, dimer and trimer was determined from the peak areas of the respective components.

(2) intrinsic viscosity of polyester

The polyester was dissolved in orthochlorophenol and measured at 25 ° C.

(3) Melt viscosity of copolyester

The copolyester was vacuum dried at 150 ° C. for at least 5 hours, and then measured at 250 ° C. using a melt viscosity index.

(4) film forming stability

The stability at the time of forming a polyester film was determined based on the following criteria.

Good: A discharge amount is constant and stable film forming can be performed.

Normal: Although discharge becomes temporarily unstable, there is almost no problem in film forming property.

Poor: Discharge amount is clearly unstable, and stable film forming is difficult.

(5) transparency of the film

The transparency of the polyester film was determined based on the following criteria from the haze value measured using a Suga Test Machine Co., Ltd. product fully automatic direct haze computer HGM-2DP.

Especially good: less than 10% haze value,

Good: Haze value 10% or more but less than 30%,

Normal: Haze value 30% or more but less than 70%,

Poor: Haze value 70% or more

(6) Whitening resistance of film with time

The haze value of the film after being put into a gear oven at 40 ° C. for one week was measured using a Suga Tester Co., Ltd. product, a fully automatic haze computer HGM-2DP, and the whitening resistance according to the time passed according to the following criteria. Was determined.

Especially good: less than 15% of haze value,

Good: Haze value 15% or more but less than 40%,

Normal: Haze value 40% or more but less than 70%,

Poor: Haze value 70% or more

(7) elastic modulus of the film

An elastic modulus was measured at 25 ° C. using a tensile tester (“Tensilon” manufactured by Orient Tech Co., Ltd.) at a tensile speed of 300 mm / min for a sample having a width of 10 mm and a length of 50 mm after the film was kept at a measurement temperature for 30 seconds. The elasticity modulus (MPa) of the longitudinal direction and the width direction of a film was measured at ten points, respectively, and the average value was calculated | required.

[Preparation of Aromatic Polyester (polymerization)]

(PET)

To the mixture of 100 parts by weight of dimethyl terephthalate and 60 parts by weight of ethylene glycol, 0.09 part by weight of magnesium acetate and 0.03 part by weight of diantimony trioxide were added, followed by a transesterification reaction by heating up by a conventional method. Next, 0.026 parts by weight of trimethyl phosphate is added to the transesterification product, and then transferred to the polycondensation reaction layer. Next, the pressure of the reaction system was gradually lowered while heating up and heating, and the polymerization was carried out by a conventional method at 290 ° C under reduced pressure of 1 mmHg to produce polyethylene terephthalate (PET) having an intrinsic viscosity of 0.65.

(PBT)

To a mixture of 100 parts by weight of dimethyl terephthalate and 80 parts by weight of 1,4-butanediol, 0.05 part by weight of tetrabutyl titanate and 0.02 part by weight of antioxidant ("IRGANOX1010" (product of Chiba Specialty Chemicals)) were added to a conventional method. Heating was carried out, and finally, the temperature was raised to 210 ° C to effect transesterification. After the transesterification reaction, 0.01 parts by weight of trimethyl phosphate, 0.07 parts by weight of tetrabutyl titanate and 0.03 parts by weight of antioxidant ("IRGANOX1010") were added, and the temperature was gradually raised and reduced under pressure to finally reach 245 DEG C, 1 Torr. The polycondensation reaction was carried out below to produce polybutylene terephthalate (PBT) having an intrinsic viscosity of 0.85.

(PET / I)

To a mixture of 83 parts by weight of dimethyl terephthalate, 17 parts by weight of dimethyl isophthalate, and 60 parts by weight of ethylene glycol, 0.09 part by weight of magnesium acetate and 0.03 part by weight of diantimony trioxide were added, and the mixture was heated and heated by a conventional method to carry out a transesterification reaction. After the addition, 0.026 parts by weight of trimethyl phosphate was added, and the same polycondensation reaction as in the case of PET was carried out to produce an ethylene terephthalate isophthalate copolymer (PET / I) having an intrinsic viscosity of 0.65.

(PPT)

To the mixture of 100 parts by weight of dimethyl terephthalate and 87 parts by weight of 1,3-propanediol, 0.06 parts by weight of tetrabutyl titanate was added, followed by heating by a conventional method, and finally the temperature was raised to 220 ° C to conduct a transesterification reaction. After the transesterification reaction, 0.05 parts by weight of trimethyl phosphate and 0.04 parts by weight of tetrabutyl titanate were added, and the temperature was gradually increased and reduced in pressure, and finally, polycondensation reaction was carried out at 260 DEG C and 1 Torr or less to obtain polypropylene tere with an intrinsic viscosity of 0.70. Phthalate (PPT) was produced.

[Preparation of Aromatic-aliphatic Copolyester (polymerization)]

(Copolymerized Polyester 1)

3 parts by weight of sulfuric acid was added to a mixture of 50 parts by weight of dimer acid ("Pripol 1025" ("PRIPOL1025") (manufactured by Unichema International)) and 50 parts by weight of methanol, refluxed for 10 hours, and dried to obtain 2.2% of a monomer and a dimer. Dimer acid dimethyl having 36 carbon atoms consisting of 78.6% and trimer 19.2% was prepared.

61 parts by weight of dimethyl terephthalate, 33 parts by weight of dimer acid dimethyl having 36 carbon atoms (composed of a composition of 2.2% monomer, dimer 78.6%, and trimer 19.2%), 20 parts by weight of ethylene glycol, and 1,4-butanediol 40 parts by weight and 0.1 parts by weight of tetrabutyl titanate were mixed and subjected to transesterification by a conventional method, and then 1,4-phenylenebisoxazoline was added in an amount equivalent to 2 parts by weight based on 100 parts by weight of the obtained resin. The polycondensation reaction was carried out under high temperature and reduced pressure to prepare a copolyester of 25 ° C melt viscosity of 1900 poise and intrinsic viscosity of 0.85. The composition of the obtained copolyester was 85 mol% of terephthalic-acid residues, 15 mol% of dimer acid residues, 20 mol% of ethylene glycol residues, and 80 mol% of 1, 4- butanediol residues.

(Copolymerized Polyester 2)

95 parts by weight of dimethyl terephthalate, 22 parts by weight of dimer acid having 36 carbon atoms, 15 parts by weight of ethylene glycol, 50 parts by weight of 1,4-butanediol, and 0.1 parts by weight of tetrabutyl titanate were mixed to obtain an ester by a conventional method. After the exchange reaction, a polycondensation reaction was carried out under high temperature and reduced pressure to prepare a copolymerized polyester having a melt viscosity of 1800 poise and an intrinsic viscosity of 0.82 at 25 ° C. The composition of the obtained copolyester was 94 mol% of terephthalic acid residues, 6 mol% of dimer acid residues, 15 mol% of ethylene glycol residues, and 85 mol% of 1, 4- butanediol residues.

(Copolymerized Polyester 3 ~ 7)

The same as Copolyester 2, except that dimethyl terephthalate and dimer acid of 36 carbon atoms obtained above were used as the acid component, and ethylene glycol and butanediol were used as the glycol component and mixed in the proportions of the compositions shown in Table 1. The polymerization was carried out until the intrinsic viscosity shown in Table 1 by the method, to synthesize a copolyester of the viscosity level shown in Table 1.

In addition, the copolyester 7 has a viscosity other than this invention (comparative example).

(Copolymerized Polyester 8, 9)

Dimethyl terephthalate and dimethyl dimer having 36 carbon atoms obtained above were used as the acid component, butanediol and 1,4-cyclohexanedimethanol or 2,2-dimethyl-1,3-propanediol were used as the glycol component. Except mixing in the ratio which consists of the composition shown in Table 1, it superposed | polymerized by the method similar to copolyester 1 until it became intrinsic viscosity shown in Table 1, and synthesize | combined the copolymer of the viscosity level shown in Table 1.

In the said Table 1, the residue of an acid component and the residue of a glycol component were abbreviated as follows.

DMT: Terephthalic Acid Residue

C36: dimer acid residue (36 backbone carbon atoms)

EG: ethylene glycol residues

BG: butanediol residue

CHDM: 1,4-cyclohexanedimethanol residues

NPG: 2,2-dimethyl-1,3-propanediol residues

(Copolymerized Polyester 10)

A dimerized fatty acid component (44% monomer, 2.5% monomer, 82.3% dimer) prepared by using crude rapeseed oil containing a high concentration of erucic acid as a raw material, purified by a conventional method, and subjected to a dimerization reaction. Consisting of a trimer of 15.2%) and dimethyl terephthalate as acid components, ethylene glycol and butanediol as glycol components, and mixing at a proportion of the composition shown in Table 2, by the same method as in Copolymerization Polyester 1. The polymerization was carried out until the intrinsic viscosity shown in Table 2 was obtained to synthesize copolyesters having the viscosity levels shown in Table 2.

(Copolymerized Polyester 11)

Coarse soybean oil containing a high concentration of 18 unsaturated fatty acids containing 18 carbon atoms as a raw material, produced by purification by a conventional method and subjected to a dimerization reaction, or by purification or separation according to a conventional method, if necessary, by carbon number 36 Dimethyl dimer acid (consisting of 1.8% of monomer, 62.5% of dimer, and 35.7% of trimer) and dimethyl terephthalate were used as acid components, and ethylene glycol and butanediol were used as glycol components. Except mixing in the ratio, it superposed | polymerized by the method similar to copolyester 1 until it became intrinsic viscosity shown in Table 2, and synthesize | combined the copolyester of the viscosity level shown in Table 2.

(Copolymerized Polyester 12 ~ 15)

Dimethyl terephthalate (the composition ratio of monomers, dimers, and trimers) having 36 carbon atoms prepared by the same method as in the case of the copolyester 11 and dimethyl terephthalate is used as an acid component, Viscosity shown in Table 2 by using ethylene glycol and butanediol as the glycol component, and mixing at the ratio of the composition shown in Table 2 until the intrinsic viscosity shown in Table 2 by the same method as Copolyester 2. Levels of copolyesters were synthesized. In the case of the copolyester 15, however, the degree of polymerization did not increase in the polymerization step, thereby obtaining a polymer.

In addition, the copolyesters 14 and 15 have a copolymer composition (comparative example) other than that specified in the present invention.

In Table 2, residues of acid components and glycol components were abbreviated as follows.

DMT: Terephthalic Acid Residue

C36: dimer acid residue (36 backbone carbon atoms)

C44: dimerized fatty acid residue (44 backbone carbon atoms)

EG: ethylene glycol residues

BG: butanediol residue

[Manufacture of Film]

(Example 1)

The copolyester 1 was fed to a vented bidirectional twin screw extruder (3 vent parts, L / D = 42), and passed through two vacuum vent parts and a short tube while heating at 260 ° C. Next, the sheet was extruded from a slit-shaped die into a sheet, adhered to a casting drum by an electrostatic application method, and cooled and solidified to obtain an unstretched film. The unstretched film can be produced stably, and the physical properties of the obtained film have good transparency as shown in Table 3, and bisoxazoline is added to the copolyester 1, so that the flexibility and the resistance over time to change) was also excellent.

(Examples 2-5)

A non-stretched film was produced in the same manner as in Example 1 except that each of the copolyesters 2, 3, 8, and 9 was used. Physical properties of the obtained unstretched film are as shown in Table 3.

The film of Example 2 was excellent in transparency.

Although the film of Example 3 was somewhat inferior to film forming stability and transparency compared with Example 2, it was a practical use level and had comparatively favorable flexibility.

The film of Example 4 and the film of Example 5 showed good film forming stability, flexibility and excellent transparency.

(Example 6)

It formed into a film like Example 2 except having used the said copolyester 4. The physical properties of the obtained unstretched film were as shown in Table 3, the transparency was good, and had a casting property immediately after film formation. However, over time, whitening progressed.

(Example 7)

The copolymerized polyester 4 and the copolymerized polyester 5 were blended at a ratio of 20% by weight and 80% by weight, and 2 parts by weight of 1,4-phenylenebisoxazoline was added to 100 parts by weight of the resin composition, followed by melt blending. Copolyester was produced. A non-stretched film was produced in the same manner as in Example 2 except for using this copolyester. The characteristic of the obtained film was as showing in Table 3, and showed favorable film forming stability, transparency, and flexibility.

(Examples 8-11)

The unstretched film was produced like Example 2 except having used the said co-polyester 10-13, respectively. Physical properties of the obtained unstretched film are as shown in Table 4.

The film of Example 8 showed good film forming stability and transparency.

Although the film of Example 9 was inferior to film forming stability a little compared with Example 2, it was a practical use level and the softness | flexibility characteristic was favorable.

The film of Example 10 exhibited good film forming stability, flexibility, and particularly excellent transparency compared to Example 2.

Although the film of Example 11 was inferior to film forming stability and transparency compared with Example 2, it was a practical level and had comparatively favorable casting characteristic.

[Preparation of Copolyester Polyester and Production of Film]

(Example 12)

The above PET is used as the aromatic polyester, and the above copolyester 6 is used as the aliphatic-aromatic polyester, and the PET and the copolyester 6 are mixed at a ratio of 12% by weight and 88% by weight, and the biaxial biaxial method It is supplied to an extruder (3 vent parts, L / D = 42), and it passes two vacuum vent parts and a single pipe | tube while heating at 260 degreeC, and the gut after discharge from a discharge vent is immediately taken out of ice water. It was quenched to prepare a copolyester having physical properties shown in Table 5.

In addition, the PET and copolyester 6 were mixed at a ratio of 12% by weight and 88% by weight, and supplied to a vented bidirectional twin screw extruder (3 vent parts, L / D = 42), and heated at 260 ° C. After passing through two vacuum vent sections and a single tube, they were extruded from a slit-like die into a sheet, adhered to a casting drum by an electrostatic application method, and cooled and solidified to obtain an unstretched film. The unstretched film could be prepared stably, and the physical properties of the obtained film showed good film forming stability, flexibility, and whitening resistance over time as shown in Table 6.

(Example 13)

PET is used as the aromatic polyester, Copolyester 6 is used as the aliphatic-aromatic polyester, PET and Copolyester 6 are mixed at a ratio of 12% by weight and 88% by weight, and the resin mixture 100 After adding 2 parts by weight of p-toluenesulfonic acid to parts by weight, it was supplied to a vented bidirectional twin screw extruder (3 vents, L / D = 42) and heated at 260 DEG C. After passing through, the gut after discharge from the discharge vent was immediately quenched in ice water to prepare a copolyester having the physical properties shown in Table 5.

The PET and copolyester 6 were mixed at a ratio of 12% by weight and 88% by weight, and 2 parts by weight of p-toluenesulfonic acid was added to 100 parts by weight of the resin mixture. (3 vent sections, L / D = 42), passed through 2 vacuum vent sections and a single tube while heating at 260 ° C, extruded from a slit die into a sheet to adhere to the casting drum by electrostatic application. It was made to cool and solidified, and it was set as the unstretched film. The unstretched film could be prepared stably and the physical properties of the obtained film are as shown in Table 6, and compared with Example 12, the improvement of transparency, in particular by the addition of p-toluenesulfonic acid, was observed.

(Example 14)

PPT is used as the aromatic polyester, Copolyester 6 is used as the aliphatic-aromatic polyester, PPT and Copolyester 6 are mixed at a ratio of 12% by weight and 88% by weight, and the resin mixture 100 After adding 2 parts by weight of p-toluenesulfonic acid to parts by weight, it was supplied to a vented bidirectional biaxial extruder (3 parts of vent, L / D = 42) and heated at 260 ° C., whereby 2 vacuum vents and a single tube were heated. After passing through, the gut after discharge from the discharge vent was immediately quenched in ice water to prepare a copolyester having the physical properties shown in Table 5.

In addition, the PPT and copolyester 6 were mixed at a ratio of 12% by weight and 88% by weight, and 2 parts by weight of p-toluenesulfonic acid was added to 100 parts by weight of the resin mixture, followed by a vented biaxial extruder. (3 vent sections, L / D = 42), passed through 2 vacuum vent sections and a single tube while heating at 260 DEG C, extruded from a slit die into a sheet form, and adhered to the casting drum by electrostatic application. It cooled and solidified and it was set as the unstretched film. The unstretched film could be manufactured stably, the physical properties of the obtained film are as shown in Table 6, it was possible to obtain a film excellent in transparency and flexibility.

(Example 15)

PET / I is used as aromatic polyester, Copolyester 6 is used as aliphatic-aromatic polyester, PET / I and copolyester 6 are mixed at a ratio of 80% by weight and 20% by weight, and 2 parts by weight of p-toluenesulfonic acid was added to 100 parts by weight of the resin mixture, and then supplied to a vented bidirectional biaxial extruder (3 vent parts, L / D = 42), and the vacuum vent part was heated at 260 ° C. Two places and a single pipe were passed through, and the gut after discharge from the discharge vent was immediately quenched in ice water to prepare a copolyester having physical properties shown in Table 5.

In addition, the PET / I and copolyester 6 are mixed at a ratio of 80% by weight and 20% by weight, and 2 parts by weight of p-toluenesulfonic acid is added to 100 parts by weight of the resin mixture. It is supplied to a twin-screw extruder (3 vent parts, L / D = 42) and passed through two vacuum vent parts and a single tube while heating at 260 ° C., and then extruded into a sheet form from a slit-like die and cast drum by electrostatic application. It adhere | attached on the film, and it solidified by cooling to make it an unstretched film. The unstretched film could be produced stably, the physical properties of the obtained film are as shown in Table 6, and a film excellent in film forming stability and transparency was obtained.

(Comparative Example 1)

A film was formed in the same manner as in Example 2 except that the copolyester 14 was used, but the viscosity due to gelation increased, so that a film could not be obtained.

(Comparative Example 2)

A film was formed in the same manner as in Example 2 except that the copolyester 7 was used, but the viscosity of the molten polymer was too low to form a film stably.

The flexible copolyester and the flexible film obtained in the present invention can be suitably used for applications such as industrial materials, packaging materials and the like requiring flexibility, transparency, and easy moldability.

Claims (16)

A copolyester synthesized from an acid component and a glycol component comprising a fatty acid or a derivative thereof containing 15 to 95% by weight of fatty acid dimer and 5 to 85% by weight of fatty acid trimer, and the melt viscosity of the copolymerized polyester. The copolymer polyester which is 1000-3000 poise at 250 degreeC. The copolyester according to claim 1, wherein the glycol component contains 1,4-butanediol. The copolyester according to claim 1, wherein the glycol component comprises at least one of 1,4-butanediol, ethylene glycol and 1,3-propanediol. The copolyester according to claim 1, wherein the content of fatty acid dimer is 70 to 90% by weight and the content of fatty acid trimer is 10 to 30% by weight in the fatty acid or derivatives thereof. The copolyester according to claim 1, wherein the acid component contains a fatty acid or a derivative thereof and an aromatic dicarboxylic acid. The content of the fatty acid (derivative) residue in the acid component residues in the repeating unit constituting the copolyester is 1 to 50 mol%, and the content of the aromatic dicarboxylic acid residues is 50 to 99 mol%. Moreover, content of the 1, 4- butanediol residue in a glycol component residue is 10-100 mol%, The copolyester characterized by the above-mentioned. The copolyester according to claim 1, wherein the fatty acid dimer contained in the fatty acid or derivatives thereof is a dimer acid or a dimer acid derivative. The copolyester according to claim 1, which is prepared by adding a compatibilizer. The copolyester according to claim 8, wherein the compatibilizer is a compound having reactivity with at least one of a hydroxy group and a carboxyl group. The copolyester according to claim 9, wherein the compatibilizer is bisoxazoline. 10. The copolyester of claim 9 wherein the compatibilizer is an organic acid. The copolyester according to claim 11, wherein the organic acid is p-toluenesulfonic acid. A process for producing a copolyester according to claim 1, wherein the copolyester according to claim 1 is produced by melt kneading an aromatic polyester with an aliphatic-aromatic copolyester formed by copolymerizing a fatty acid or a derivative thereof. The composition of claim 13, wherein the component of the aromatic polyester is at least one of a terephthalic acid residue and an isophthalic acid residue, and 1 selected from the group consisting of ethylene glycol residues, 1,3-propanediol residues and 1,4-butanediol residues. Consisting of more than one species; The component of the aliphatic-aromatic copolyester is one selected from the group consisting of terephthalic acid residues, residues of fatty acids or derivatives thereof, ethylene glycol residues, 1,3-propanediol residues, and 1,4-butanediol residues. The manufacturing method of the copolyester characterized by the above. The composition of claim 13, wherein the component of the aromatic polyester consists of at least one of a terephthalic acid residue and an isophthalic acid residue and an ethylene glycol residue; The component of the aliphatic-aromatic copolyester is a terephthalic acid residue, a residue of a fatty acid or a derivative thereof, and a 1,4-butanediol residue. The polyester film formed using the copolyester as described in any one of Claims 1-12.