JP2018104619A - Polybutylene terephthalate-based resin for film or laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polybutylene terephthalate-based resin that enables increase in a melt tension, inhibition of a neck-in phenomenon (a drawdown phenomenon), and reduction in fluctuations in a width of a resin film (film fluctuation), when a resin film is produced from a PBT-based resin by a T-die method or when the resin is laminated on a metal base material or the like, and to provide a uniform resin film or laminate material at a high speed.SOLUTION: The polybutylene terephthalate-based resin for a film or a laminate is a resin composed mainly of polybutylene terephthalate produced by copolymerizing a polyfunctional component, has a relationship of a content of the polyfunctional component and an intrinsic viscosity of the resin, which satisfies formula (1) as given below, and has a melt tension of 5 mN or more. Formula (1) satisfies IV<1×10×(M/(1-(1/(f×(φ/100)-2×φ/100+1)))), in which IV is an intrinsic viscosity (dl/g); M is a molecular weight of a repeating unit of the polybutylene terephthalate resin; f is the number of functional groups of the polyfunctional component; and φ is a content (mol%) of the polyfunctional component.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a resin (hereinafter referred to as a PBT resin) mainly composed of a polybutylene terephthalate resin suitable for a film or laminate material. More specifically, the present invention relates to a PBT resin in which neck-in, film width fluctuation, etc. are suppressed when extrusion from a T die is performed by a melt extrusion method (T die method), and melting characteristics are improved.

Conventionally, polybutylene terephthalate resin (hereinafter also referred to as PBT resin) is a resin having characteristics such as heat resistance, moldability, electrical characteristics, low water absorption, and chemical resistance, and is used for electronic parts and automobile parts by injection molding. Widely used.
On the other hand, since PBT resin is also excellent in gas barrier properties and fragrance retention properties, it is in demand as a film for packaging, a laminate material for a metal plate, and the like. However, since the PBT resin has a low melt tension (tension generated when the molten resin is pulled), the following problems occur when manufacturing a film for packaging and the like and a laminate material on a metal plate. It was.
(1) When a resin film is manufactured by the T-die method or when a resin is laminated on a metal plate or the like, the product film width called a neck-in phenomenon (also referred to as a draw-down phenomenon) becomes narrower than the die exit width. The phenomenon occurs and the yield is low.
(2) When producing a film by the T-die method or laminating it on a metal plate or the like, fluctuations in the film width (hereinafter referred to as film shaking) and accompanying film thickness fluctuations are likely to occur. In particular, when the line speed during film production is large, the film shake increases, so the line speed cannot be increased and the productivity is low.
FIG. 6 shows a schematic diagram of neck-in and film shaking.

  As a solution to these problems, for example, Patent Document 1 discloses a PBT resin for the purpose of providing an injection molding material that can be molded easily in a molten state and gives a molded product having good mechanical properties. doing. This PBT-based resin has a crosslinking point provided from a structural unit derived from 0.05 to 3 mol% of tricarboxylic acid, tetracarboxylic acid, triol, tetraol, dihydroxycarboxylic acid or hydroxydicarboxylic acid. .

On the other hand, as a polyester resin which is in demand along with the PBT resin, a polyethylene terephthalate resin (hereinafter also referred to as a PET resin) can be given.
For example, in Patent Document 2, as a method of increasing the melt tension in a polyester resin, at least one component of a trivalent or higher polyvalent carboxylic acid or polyhydric alcohol compound is copolymerized, and the intrinsic viscosity [η] and the melt tension are set. Although an extruded product made of a specified polyester resin is disclosed, lamination to a film or a metal plate is not disclosed.

Further, Patent Document 3 discloses a polyester derived from butylene glycol and an aromatic dibasic acid (for example, terephthalic acid) in order to eliminate the above-described problems that occur when a polyester resin is laminated by the T-die method. A PET-based resin having a segment and a polyester segment derived from butylene glycol and an aliphatic dibasic acid (eg, adipic acid) is disclosed.
Patent Document 4 manufactures a resin film that can be coated on a metal plate with a uniform film thickness and good adhesion without causing film shaking or pulsation even when laminated on a metal plate by a high-speed extrusion laminating method. Therefore, a PET resin containing a certain amount of isophthalic acid as a copolymerization component is disclosed.

  Further, Patent Document 5 discloses that a PBT resin and a polyfunctional epoxy compound are reacted in the presence of a catalyst in order to improve melt tension and provide a material having characteristics suitable for blow molding, vacuum molding, film extrusion molding, and the like. An improved polyester resin is disclosed.

US Pat. No. 3,692,744 JP 2001-200038 A Japanese Patent Laid-Open No. 10-086308 JP 2005-126516 A JP-A-1-242618 Seiichi Nakahama, Takuhei Nose, Saburo Akiyama, Kohei Sakurai, Yoshiharu Tomita, Masao Doi, Kazuyuki Horii, Essential Polymer Chemistry, Kodansha (1988).

The above Patent Documents 1 to 5 all have room for improvement with respect to the current demand for PBT resins.
That is, Patent Documents 3 and 4 disclose a PET resin instead of a PBT resin, but do not satisfy the required characteristics even when applied to a PBT resin as it is.
Further, Patent Document 1 discloses disclosure relating to a PBT-based resin. However, the final object to be achieved is an injection molding product, which is used for manufacturing a film or a laminate product by extrusion molding required by the present inventors. It does not satisfy the characteristics required for PBT-based resins.
Similarly, Patent Document 2 does not describe a film or laminate product required by the present inventors.

Furthermore, Patent Document 5 also discloses a PBT resin, but it is intended to improve its properties by adding and reacting other components to the PBT resin after monomer polymerization. Here, generally when adding other components to the polymer, for example, when the granular or pellet polymer is melted with an extruder or the like, the other components are added and kneaded. There is. In particular, when the other component is a polyfunctional component (such as a chain extender), the concentration of the added component is unevenly distributed in the polymer, resulting in a problem that gelation occurs partially. . Gel contamination in the film is a serious product defect and must be avoided. Therefore, in order to avoid the possibility of gel contamination, the inventors have chosen to improve the properties of the PBT resin by copolymerization at the monomer polymerization stage.
As described above, the present inventors have intensively studied in view of the above problems, and as a result, have come up with the present invention.

In order to solve the above-described problem, an embodiment embodying an example of the present invention is characterized by the following points that are selectively listed.
(A) a resin mainly composed of polybutylene terephthalate copolymerized with a polyfunctional component,
The content of the polyfunctional component and the intrinsic viscosity of the resin satisfy the following formula (1),
A polybutylene terephthalate resin for film or laminate having a melt tension of 5 mN or more.
IV <1 × 10 ⁻⁴ × (M / (1- (1 / (f × (φ / 100) -2 × φ / 100 + 1)) ^0.5 )) ^0.87 (1)
IV: Intrinsic viscosity (dl / g)
M: Molecular weight of repeating unit of polybutylene terephthalate resin f: Number of functional groups of polyfunctional component φ: Content of polyfunctional component (mol%)
(B) In the said Formula (1), (phi) exceeds 0.6 mol%, The polybutylene terephthalate-type resin as described in (A) characterized by the above-mentioned.
(C) The polybutylene terephthalate resin according to (A) or (B), wherein in the formula (1), IV ≧ 0.7 dl / g.
(D) The polyfunctional component is one or more selected from trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, trimethylolpropane, and pentaerythritol. The polybutylene terephthalate resin according to any one of (A) to (C).
(E) A film comprising the polybutylene terephthalate resin according to any one of (A) to (D).
(F) A film comprising a polybutylene terephthalate resin according to (A) to (D) and a resin composition containing a resin different from the resin.
(G) A laminate material obtained by laminating the resin film according to (E) or (F) so as to be in contact with a metal substrate.
(H) Melt a polybutylene terephthalate resin according to (A) to (D) or a resin composition containing a polybutylene terephthalate resin according to (A) to (D) and a resin different from the resin. A method for producing a laminate material, which is extruded in the form of a film from a T-die in a resin state and adhered to a metal substrate before the molten resin is solidified.

  According to the present invention, when a resin film is manufactured by a T-die method in a PBT resin or when a resin is laminated on a metal plate or the like, the melt tension is increased and the neck-in phenomenon (draw-down phenomenon) is suppressed. High speed, thin and uniform film and laminate material can be obtained. Furthermore, it becomes possible to reduce the width fluctuation (film fluctuation) of the resin film, which can contribute to the improvement of the yield and the significant cost reduction of the product.

In the case where a linear polymer is produced by the reaction between bifunctional monomers (monomer A and monomer B), it is a schematic view when a trifunctional monomer is added to the reaction system. It is a schematic diagram which shows the case where a resin film is shape | molded by the T-die method. It is a schematic diagram which shows the laminate material 1 with the polybutylene terephthalate-type resin of this embodiment. It is a schematic diagram which shows the laminate material 2 with the polybutylene terephthalate-type resin of this embodiment. It is a schematic diagram which shows arrangement | positioning of the apparatus used for the extrusion lamination method. It is a schematic diagram which shows generation | occurrence | production of a film | membrane shake and neck in in this embodiment.

Hereinafter, the polybutylene terephthalate resin according to the present embodiment will be described in detail.
The polybutylene terephthalate-based resin according to the present embodiment is characterized by having a polyfunctional component in a part of the resin mainly composed of polybutylene terephthalate.
That is, the polybutylene terephthalate resin of this embodiment is branched into a polybutylene terephthalate main chain by copolymerizing polyfunctional components in polybutylene terephthalate composed of terephthalic acid or dimethyl terephthalate and 1,4-butylene glycol. In the melt extrusion method (T-die method), the melt tension is increased during molding of a resin film or the like.
FIG. 1 shows a schematic diagram when a trifunctional monomer (polyfunctional component) is introduced into a linear polymer.

In this embodiment, a polyfunctional component means the polyhydric carboxylic acid or polyhydric alcohol which has a 3 or more functional group.
Examples of the polyvalent carboxylic acid having 3 or more functional groups include trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, and the like. Of these, trimellitic anhydride is preferably used from the viewpoint of availability and cost, but is not limited thereto.
Examples of the polyhydric alcohol having three or more functional groups include, but are not limited to, trimethylolpropane and pentaerythritol.

  It is preferable to have at least one of the polyfunctional components listed above in a part of the polybutylene terephthalate resin. Moreover, you may have two or more types of components among the polyfunctional components mentioned above.

About the minimum of content of the polyfunctional component in polybutylene terephthalate type resin, what is necessary is just content in which the melt tension of this resin will be 5 mN or more. When the melt tension is less than 5 mN, neck-in and film shake at the time of film production are not reduced, and the film productivity cannot be increased.
On the other hand, regarding the upper limit, the number of functional groups (f) of the polyfunctional component, the content (φ) of the polyfunctional component, the intrinsic viscosity (IV) of the resin, and the molecular weight (M) of the repeating unit of the resin satisfy the formula (1). Must be in range.
Equation (1) was derived with reference to the theory of Flory gelation (Non-patent Document 1).
If the formula (1) is not satisfied, the resin gels and the film mixes with the gel. In the worst case, the resin does not flow during the polymerization reaction or extrusion of the resin, and the polymerization apparatus or the extruder is damaged. There is a fear.
Examples of resin gelation are cases where the polyfunctional component content (φ) is large and the formula (1) is not satisfied even if the intrinsic viscosity (IV) of the resin is low, or the polyfunctional component content is small. However, there are cases where the intrinsic viscosity (IV) of the resin is high and the formula (1) is not satisfied.
In the case of using a plurality of polyfunctional components, the number of functional groups f of the polyfunctional component is a weighted average weighted by the ratio of the number of functional groups of each polyfunctional component to the total content of the polyfunctional component. Become. Moreover, content ((phi)) of a polyfunctional component is the sum total of content of each polyfunctional component.
Further, the molecular weight M of the repeating unit of the resin is an average molecular weight when the resin has a plurality of repeating units.

IV <1 × 10 ⁻⁴ × (M / (1- (1 / (f × (φ / 100) -2 × φ / 100 + 1)) ^0.5 )) ^0.87 (1)
IV: Intrinsic viscosity (dl / g)
M: Molecular weight of repeating unit of polybutylene terephthalate resin f: Number of functional groups of polyfunctional component φ: Content of polyfunctional component (mol%)

The content of the polyfunctional component in the polybutylene terephthalate resin can be appropriately set depending on the use and the like as long as it is within the above range, but in order to set the melt tension to 5 mN or more, it is generally 0.05 mol% or more. Is preferred.
When the polyfunctional component content in the polybutylene terephthalate resin is less than 0.05 mol%, it is necessary to increase the molecular weight of the resin, that is, the intrinsic viscosity (IV) in order to increase the melt tension, but the IV is high. If it is too high, the melt viscosity of the resin becomes large, and it becomes difficult to perform molding processing, such as an increase in load when the resin is melt-kneaded with an extruder.

Further, for example, it is considered that a resin containing a polyfunctional component as in the present embodiment has a higher cost than a resin not containing a polyfunctional component (hereinafter referred to as a general-purpose resin). For this reason, in the actual film production stage, it is common practice to use a resin having a high polyfunctional component content diluted with a general-purpose resin.
In the case as described above (when used as a so-called master batch), the content of the polyfunctional component is preferably more than 0.6 mol%. On the other hand, when the amount of the polyfunctional component is large, it is necessary to lower the intrinsic viscosity (IV) of the resin in order to satisfy the formula (1). However, if the amount is too low, the melt viscosity and mechanical strength of the resin are lowered. The content of the functional component is preferably 3 mol% or less.

  In extrusion molding of a film or the like, it is preferable that the resin has a high melt viscosity. The higher the molecular weight of the resin, that is, the intrinsic viscosity (IV), the higher the melt viscosity, and the preferred intrinsic viscosity is 0.7 dl / g or more. However, if the IV is too high, as described above, the melt viscosity becomes high and the molding process becomes difficult, so the upper limit of IV is preferably 2.0 dl / g or less.

The polybutylene terephthalate resin of the present invention is copolymerized with other bifunctional components within a range that does not impair the properties of polybutylene terephthalate, such as heat resistance, moldability, electrical characteristics, low water absorption, chemical resistance, etc. May be.
Examples of the bifunctional component include a dicarboxylic acid component, a diol component, and a hydroxycarboxylic acid component. Specifically, for example, isophthalic acid component, sodium 5-sulfoisophthalate component, 2,6-naphthalenedicarboxylic acid component, oxalic acid component, adipic acid component, sebacic acid component, 4,4′-biphenylenedicarboxylic acid component, ethylene A glycol component, a propylene glycol component, a neopentyl glycol component, a hydroxybenzoic acid component, a hydroxynaphthoic acid component, etc. are mentioned.

  The polybutylene terephthalate resin of the present invention may be added with known lubricants, heat stabilizers, ultraviolet absorbers, pigments, carbon black, ketjen black, graphite, antioxidants, antistatic agents, etc., if necessary. An agent may be included.

  As a method for producing the polybutylene terephthalate resin of the present invention, known methods such as a direct polymerization method in which terephthalic acid and butylene glycol are polymerized and a transesterification method in which dimethyl terephthalate and butylene glycol are polymerized can be used. For example, after putting dimethyl terephthalate and butanediol in a reaction vessel together with a catalyst such as titanium (IV) n-butoxide monomer and reacting while heating from room temperature to 230 ° C. in a nitrogen atmosphere to obtain a low molecular weight PBT prepolymer, A method of polymerizing PBT at 250 ° C. under vacuum is exemplified. In this case, the polyfunctional component may be added together with the raw material at the start of the reaction, or added to the low molecular weight PBT prepolymer and then polymerized under vacuum in order to uniformly disperse the polyfunctional component in the resin. Is important.

When bifunctional components other than terephthalic acid, dimethyl terephthalate, or butylene glycol are copolymerized, it is usually added together with other raw materials at the start of the reaction.
In addition, when additives such as known lubricants, heat stabilizers, ultraviolet absorbers, pigments, carbon black, ketjen black, graphite, antioxidants, antistatic agents, etc. are added, the reaction starts or low molecular weight PBT The addition is usually performed either after the prepolymer.

  In order to further increase the intrinsic viscosity (IV) of the resin, it is also possible to perform solid phase polymerization in which the resin is heated to a melting point or lower and polymerized. The method for solid phase polymerization is not particularly limited, and a known method is used. For example, there is a method in which solid phase polymerization is performed by heating the pellet-shaped resin to 180 to 200 ° C. while stirring in a nitrogen atmosphere or under vacuum.

<Polybutylene terephthalate resin film>
Next, the polybutylene terephthalate resin film in this embodiment will be described.
Since the polybutylene terephthalate resin in the present embodiment has the above-described configuration, it is possible to obtain a thin and uniform resin film with high speed and no unevenness. Moreover, since it has the heat resistance and chemical resistance which are the characteristics which PBT resin has generally, it is used suitably for the wall surface etc. of a unit bath, for example.

  As a method for producing a film made of polybutylene terephthalate resin in the present embodiment, a known method can be applied. For example, as shown in FIG. 2, a resin film can be obtained by supplying a resin to an extruder and continuously extruding the melt-kneaded resin from a T die and winding it while cooling with a chill roll.

Moreover, the embossing roll which gave the uneven | corrugated process to the surface between T dies and a chill roll is provided, and the film surface can be embossed by letting the film extruded from the T die pass between them.
Usually, when embossing is performed, the distance between the T die and the chill roll becomes longer, so that there is a problem that the neck-in becomes larger than that without the embossing roll and the yield deteriorates. However, by using the polybutylene terephthalate resin of the present invention having a high melt tension, neck-in can be suppressed and the yield can be increased.

  The obtained resin film may be further stretched by a tenter method or a tubular method in order to increase heat resistance, setability and strength.

  When producing the polybutylene terephthalate resin film in the present embodiment, different types of resins may be mixed (blended) to produce the film. By manufacturing a film by mixing general-purpose polybutylene terephthalate that does not contain a polyfunctional component, the cost can be reduced as described above, and the amount of the polyfunctional component in the film can be easily adjusted, and the physical properties of the film. And optimum melt tension according to the manufacturing conditions.

  Further, for example, as disclosed in Japanese Patent No. 3807070 and Japanese Patent No. 4560777, for example, a polyethylene terephthalate resin component may be mixed with the polybutylene terephthalate resin. In this case, there is an advantage that preferable heat resistance and the like can be appropriately obtained by resin mixing.

  In addition to the polyethylene terephthalate resin components listed above, polyethylene, polypropylene, ethylene-α-olefin copolymers, polyamide elastomers, polyester elastomers, polyether elastomers, styrenic thermoplastic elastomers and other elastomers, ionomer resins, polyphenylene Ether, aromatic polycarbonate, polyester resin other than PBT and PET, epoxy resin, and the like can be appropriately mixed according to required characteristics.

  Further, when producing the polybutylene terephthalate resin film in the present embodiment, known lubricants, heat stabilizers, ultraviolet absorbers, pigments, carbon black, ketjen black, graphite, antioxidants, antistatics, if necessary. An agent or the like may be added.

  The method for containing and mixing the different types of resins and various additives described above is not particularly limited, and known methods can be used. For example, a method of mixing with a polybutylene terephthalate resin and supplying it to an extruder, a method of adding in the middle of the extruder, and the like can be mentioned.

  The thickness of the polybutylene terephthalate resin film in the present embodiment is not particularly limited as long as it is an optimum thickness for the application, but is generally in the range of 35 to 250 μm.

<Laminate with polybutylene terephthalate resin>
As the metal base material on which the polybutylene terephthalate resin is laminated in the present embodiment, known various surface-treated steel plates, light metal plates such as aluminum, or foils thereof are used.
Surface-treated steel sheets are steel sheets that have been cold-rolled steel sheets after temper rolling or secondary cold rolling, that is, SR materials and DR materials, galvanized, tin-plated, nickel-plated, electrolytic chromic acid treatment, chromic acid treatment What performed 1 type or 2 types or more of surface treatments, such as these, can be used.
As the light metal plate, an aluminum alloy plate is used in addition to a so-called pure aluminum plate. Also in the case of a light metal plate, it is desirable that chromic acid treatment or chromic acid / phosphoric acid treatment is performed.

  In the case where the polybutylene terephthalate resin in the present embodiment is laminated on a metal substrate, a known adhesion primer may be provided as desired.

  The laminate 1 with the polybutylene terephthalate resin of this embodiment is formed by laminating the polybutylene terephthalate resin film 10 of this embodiment so as to contact the metal substrate 20 as shown in FIG. . Moreover, the base film F can also be laminated | stacked on the polybutylene terephthalate-type resin film 10 of this embodiment like the laminate material 2 shown in FIG.

  In this embodiment, as the base film F, it can select from a well-known resin film by a use, for example, a polyester film, a polycarbonate film, a polyimide film etc. are mentioned. Moreover, the base film F may be a single layer, or may be a film of two layers or three or more layers. An adhesive layer or the like may be formed on the surface of the base film F as necessary.

Next, the manufacturing method of the laminate 2 with the polybutylene terephthalate resin in this embodiment will be described with reference to FIG.
In FIG. 5 showing the arrangement of the apparatus used for the extrusion lamination method, an extruder 52 for polybutylene terephthalate resin 10, a die 53 for supplying the polybutylene terephthalate resin in a film form along the path of the metal substrate 20, A laminate for adhering the pre-roll 54, the metal substrate 20, the polybutylene terephthalate resin 10 and the film F, which are bonded to the metal substrate 20 before the molten film is solidified. A roll 55 and a quenching means 56 for quenching the laminate material L to be formed are arranged in this order.

In the apparatus shown in FIG. 5, the metal substrate 20 is passed through the laminating roll 55, and the molten film of the polybutylene terephthalate resin 10 from the die 53 is extruded onto the film F and then received by the pre-roll 54. The polybutylene terephthalate resin 10 is fused to the metal substrate 20 before the molten film is solidified.
The laminate material thus manufactured can be embossed on the surface of the laminate material by passing it between embossing rolls having an uneven surface.

<Coating steel>
A decorative steel sheet is manufactured by adhering a printed film or the like to the laminate material manufactured by the above method. This manufacturing method is not particularly limited, and a known method is used.

<< Example >>
Hereinafter, the present invention will be described more specifically with reference to examples.

<Measurement of intrinsic viscosity (IV)>
The resin was added to a solution in which phenol and 1,1.2,2-tetrachloroethane were mixed at a ratio of 1: 1 (weight ratio) so as to have concentrations of 1 g / dl, 0.5 g / dl, and 0.3 g / dl. And dissolved at 130 ° C. for about 15 minutes. The relative viscosities of these solutions were measured at 30 ° C. with a relative viscometer (Model Y-501 Relative Viscometer, manufactured by Viscotek). Next, the specific viscosity was obtained from these relative viscosities, and a straight line obtained by plotting the value obtained by dividing the specific viscosity by the solution concentration against the solution concentration was obtained by extrapolating the concentration to 0.

<Measurement of melt tension>
The resin melted at 250 ° C. with a capillograph 1D (manufactured by Toyo Seiki Seisakusho) was extruded into a cord shape from a nozzle having a diameter of 1 mm at a shear rate of 121.6 sec ⁻¹ , and the cord was wound at 20 m / min. Sometimes the tension on the cord was measured with a load cell.

<Presence / absence of gelation>
The resin was dissolved in chloroform, and the molecular weight distribution measured by gel permeation chromatography [apparatus: HLC-8220GPC, column: TSKgel SuperHZM (2 pcs) + TSKgel SuperHZ2500] (manufactured by Tosoh Corporation), shoulder peak on the high molecular weight side ( The presence or absence of gel) was evaluated.

<Neck-in and film shaking during film formation>
Neck-in and film shake were defined as follows (see FIG. 6), and the values of neck-in and film shake were measured.
Neck-in: The difference between the lip width of the T-die and the width of the manufactured film.
Film sway: Maximum position fluctuation in the film width direction during film production.

<Confirmation of film unevenness>
After manufacturing the resin film, the presence or absence of unevenness of the film was visually confirmed.

<Example 1>
88.2 parts by weight of dimethyl terephthalate, 57.3 parts by weight of butylene glycol, and 0.046 part by weight of titanium (IV) n-butoxide monomer were placed in a reaction vessel, heated from room temperature to 210 ° C. The reaction was carried out while removing. After the distillation of methanol almost disappeared, 5.2 parts by weight of a solution of 0.52 parts by weight of trimellitic anhydride (TMA) dissolved in butylene glycol was added, the temperature was raised to 250 ° C., and the polymerization reaction was performed under vacuum. Went. After the resin had a predetermined viscosity, it was extruded from the reaction vessel into cooling water and cut into pellets to obtain a resin having an intrinsic viscosity (IV) of 0.8 dl / g.
The pellet-shaped resin thus obtained was stirred and heated to 190 ° C. under vacuum to carry out solid phase polymerization to obtain a resin having an IV of 1.23 dl / g. The melt tension of the obtained resin was as high as 28 mN, and no gelation was observed.

<Examples 2-3>
A resin was obtained in the same manner as in Example 1 except that the amount of trimellitic anhydride and the intrinsic viscosity (IV) were changed as shown in Table 2. Table 1 shows the melt tension and the presence or absence of gelation.

<Comparative Examples 1-2>
A resin was obtained in the same manner as in Example 1 except that trimellitic anhydride was not added, or trimellitic anhydride was added and IV was not satisfied with formula (1). As shown in Table 1, when no trimellitic anhydride was added, the melt tension of the resin was as low as 4 mN (Comparative Example 1). On the other hand, when the formula (1) was not satisfied, gelation was observed although the melt tension was high (Comparative Example 2).

<Examples 4 to 5, Comparative Example 3>
The resin of Example 2, the resin of Comparative Example 1, and the color master (resin mixed with the pigment of Comparative Example 1) were mixed at the ratio shown in Table 2, supplied to the extruder, and melt-kneaded at 260 ° C. . The resin was extruded at 200 kg / hr from a 1320 mm wide T-die attached to the extruder, and the resin was solidified by a chill roll about 100 mm below the T-die to produce a film at a line speed of 30 m / min. Table 2 shows the presence or absence of film neck-in, film shaking, and film unevenness.
Comparative Example 3 not containing the resin of Example 2 corresponds to the prior art, and those having neck-in and film fluctuations equal to or less than those of Comparative Example 3 are film forming evaluation x, and those better than Comparative Example 3 are film forming characteristics. It was set as evaluation (circle). Those containing 51% and 25% of the resin of Example 2 were good with small neck-in and film shaking (Examples 4 to 5). In any case, no unevenness of the film was observed.

<Comparative Examples 4-5>
The ratios shown in Table 3 for the resin of Comparative Example 1 and the color master (resin mixed with the resin of Comparative Example 1) and the chain extender (Joncrill MB (Joncry ADR4300S, master batch containing BASF 30%)) The mixture was fed to the extruder and melt kneaded at 260 ° C. The resin was extruded at 250 kg / hr from a 1500 mm wide T-die attached to the extruder, and the resin was solidified with a chill roll about 50 mm below the T-die to produce a film at a line speed of 40 m / min. Table 3 shows the presence or absence of film neck-in, film shaking, and film unevenness.
Comparative Example 4 comprising the resin and color master of Comparative Example 1 has the same material composition as Comparative Example 3 and corresponds to the prior art. When a chain extender is added to the resin and color master of Comparative Example 1, the neck-in and film shake are small compared to Comparative Example 4, but the film formability evaluation is good, but the film is uneven and the overall evaluation is poor. (Comparative Example 5).

  As described above, according to the present invention, it was possible to produce a uniform resin film free from neck-in, film shaking, film unevenness and the like. On the other hand, according to the production method shown in the comparative example, gelation in the resin film, film shaking during production, and the like occurred.

  It should be noted that the above-described embodiment and each example can be variously modified without departing from the spirit of the present invention.

  As described above, according to the present invention, when a resin film is produced by a T-die method in a PBT resin or when a resin is laminated on a metal substrate or the like, the melt tension is increased, and the neck-in phenomenon ( It is possible to suppress the draw-down phenomenon) and to reduce the width fluctuation (film fluctuation) of the resin film. Moreover, a uniform resin film and laminate material can be obtained at high speed. The present invention is not limited to a single-layer resin film, and can be applied to a wide range of industries such as a multilayer resin film and a multilayer resin-coated laminate plate.

1: Laminate material 2: Laminate material 10: Polybutylene terephthalate resin 20: Metal base material 52: Extruder 53: Die 54: Pre-roll 55: Laminate roll 56: Rapid cooling means F: Base film L: Laminate material

Claims (8)

A resin based on polybutylene terephthalate copolymerized with polyfunctional components,
The content of the polyfunctional component and the intrinsic viscosity of the resin satisfy the following formula (1),
A polybutylene terephthalate resin for film or laminate having a melt tension of 5 mN or more.

IV <1 × 10 ⁻⁴ × (M / (1- (1 / (f × (φ / 100) -2 × φ / 100 + 1)) ^0.5 )) ^0.87 (1)

IV: Intrinsic viscosity (dl / g)
M: Molecular weight of repeating unit of polybutylene terephthalate resin f: Number of functional groups of polyfunctional component φ: Content of polyfunctional component (mol%)
In the said Formula (1), (phi) exceeds 0.6 mol%, The polybutylene terephthalate-type resin of Claim 1 characterized by the above-mentioned.
In the said Formula (1), it is IV> = 0.7dl / g, The polybutylene terephthalate-type resin of Claim 1 or 2 characterized by the above-mentioned.
2. The polyfunctional component is one or more selected from trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, trimethylolpropane, and pentaerythritol. The polybutylene terephthalate resin according to any one of -3.
A film comprising the polybutylene terephthalate resin according to any one of claims 1 to 4.
The film which consists of a resin composition containing the polybutylene terephthalate-type resin of Claims 1-4, and resin different from this resin.
A laminate material, wherein the resin film according to claim 5 or 6 is laminated so as to be in contact with a metal substrate.
  A resin composition containing the polybutylene terephthalate resin according to claim 1 or the polybutylene terephthalate resin according to claim 1 and a resin different from the resin in the form of a molten resin. A method for producing a laminate material, wherein the laminate material is extruded into a film and adhered to a metal substrate before the molten resin is solidified.