JP2001316477A - Polyester resin and polyester sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop a polyester sheet excellent in properties, especially, trans parency, flexibility, and mechanical properties. SOLUTION: There are provided a polyester resin being a block copolymer comprising 20-80 mass % (A) aromatic polyester resin having a heat of crystalline melting (ΔHc) satisfying formula (1) and 80-20 mass % (B) thermoplastic resin having a terminal carboxyl content of at most 20-80 mass %, a refractive index (at 25 deg.C) of 1.460 to below 1.470, and a softening temperature of -35 to 15 deg.C and having a limiting viscosity [η] of 0.6-1.5 dl/g as determined in a phenol/tetrachloroethane 1/1 mixture at 25 deg.C and a polyester sheet having a haze of at most 2. 0<=ΔHc<=20 (1) (wherein ΔHc is the heat of crystalline melting as determined from a melting peak in a differential scanning calorimetry and is expressed in a unit J/g).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester resin comprising a block copolymer of a polyester resin and a thermoplastic resin.
20-80% by mass of polyester resin and thermoplastic resin 80
The present invention relates to a novel polyester resin comprising a block polymer of up to 20% by mass and a polyester sheet having flexibility, excellent transparency and excellent mechanical properties comprising such a polyester resin.

[0002]

BACKGROUND ART Conventionally, vinyl chloride resins have been widely used for soft materials because their physical properties are easily controlled by compounding additives such as softeners. However, addition of plasticizers and metal-based stabilizers has been widely used. The effects of things on the human body were pointed out,
In particular, incineration is considered to be one of the causes of dioxin generation, and it is well known that it is a major social problem in terms of environment and sanitation.

On the other hand, a polyester-polyether type block copolymer having a hard segment of a polyester of an aromatic dicarboxylic acid and an aliphatic glycol and a soft segment of a polyalkylene glycol has been known for its cold resistance, heat resistance, oil resistance and mechanical properties. It is used as industrial material such as sheets and films because it is excellent in various properties such as characteristics, and there is little concern about the effects of residual monomers and additives even in molded products, and it is excellent in hygiene and safety. However, they cannot be said to have sufficient properties in terms of flexibility. Japanese Patent Application Laid-Open No. H11-106496 proposes a method of imparting flexibility by kneading an aliphatic polyester, but it is difficult to obtain a resin having uniform physical properties if heat histories are different due to transesterification by kneading. There is a disadvantage that.

Japanese Patent Application Laid-Open No. H11-166045 proposes a method of copolymerizing a high-molecular-weight polyalkylene glycol. However, since it contains 50% by weight or more of short-chain ester units, it is necessary to ensure flexibility. However, there is a problem that sheet whitening occurs due to the crystallinity of the polyalkylene glycol unit. Further, in general, in the modification of flexibility by compounding an additive to polyester, a method of adding a rubber material as a flexibility component has been adopted, but since the compatibility between the rubber material and the polyester is low, the dispersion particle size is reduced. Is difficult to control, and a considerable amount of rubber material needs to be added in order to develop flexibility.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to improve the properties of conventional polyester sheets, especially polyesters having excellent transparency, flexibility and mechanical properties. In seat development.

[0006]

That is, the present invention provides:
(A) 20 to 80% by mass of an aromatic polyester resin having a heat of crystal fusion (ΔHc) satisfying the following formula (1);
The terminal carboxyl group is 5KOHmg / g or less, the refractive index at 25 ° C is 1.460 or more and less than 1.470, and the softening temperature is -35.
80 to 20% by mass of the thermoplastic resin in the range of ~ 15 ° C
A block copolymer comprising a polyester resin having an intrinsic viscosity [η] of 0.6 to 1.5 dl / g measured in a mixed solvent of phenol / tetrachloroethane at 25 ° C. 0 ≦ ΔHc ≦ 20 (1) (ΔHc is the heat of crystal fusion determined from the melting peak of the differential scanning calorimetry, and the unit is J / g.) Further, a polyester sheet made of the polyester resin, 50 ° C. , 95% RH, and a polyester sheet having a haze value of 2 or less after treatment under the conditions of 60 hours. Hereinafter, the present invention will be described in detail.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION As the aromatic polyester resin (A) having a heat of crystal fusion (ΔHc) satisfying the above formula (1), terephthalic acid, isophthalic acid, naphthalene-1,4 or 2, 6-dicarboxylic acid, anthracene dicarboxylic acid, 4,4′-diphenyl dicarboxylic acid, 4,4′-diphenyl ether dicarboxylic acid,
-Sulfoisophthalic acid, mainly a dicarboxylic acid unit mainly containing an aromatic dicarboxylic acid unit such as sodium 3-sulfoisophthalate and ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,4-butanediol, 1, 6-hexanediol, neopentyl glycol, polyethylene glycol, polypropylene glycol, polyethylene glycol-polypropylene glycol block copolymer, polytetramethylene glycol, polyhexamethylene glycol, etc., alone or in combination, cyclohexanediol, cyclohexanedimethanol, 1, 1-bis (4-
(2-hydroxyethoxy) phenyl) cyclohexane, 4,4′-bis (2-hydroxyethoxy) benzene, alcohol components represented by the following general formula (2), and glycols such as ethylene oxide adducts of these derivatives And a polyester comprising a unit.

[0008]

Embedded image (Wherein, X is _{-CH 2 -,> C (CH} 3) 2,> C (C
F ₃ ) ₂ , —O—, —S—, or> SO ₂ , R and R ′ represent hydrogen or an alkyl group of C1 to C5, and n and m are numbers satisfying 1 ≦ n + m ≦ 4 It is. )

Among the compounds represented by the general formula (2), an ethylene oxide adduct of bisphenol A having a structure in which X is> C (CH ₃ ) ₂ is preferable.
When the sum of m and n is greater than 4, heat resistance tends to decrease. When the polyester resin of the present invention is formed into a sheet, a polyester resin obtained by copolymerizing 5 to 35 mol% of a dicarboxylic acid unit other than terephthalic acid is particularly preferable for improving transparency.

The polyester resin of the present invention preferably contains an aromatic dicarboxylic acid unit in an amount of at least 80 mol%, more preferably at least 85 mol%, of all the acid components. This is because if the content of the aromatic dicarboxylic acid unit is less than 80 mol%, the mechanical strength of the molded article may decrease, and the productivity may decrease. As an acid component other than the aromatic dicarboxylic acid, an aliphatic dicarboxylic acid unit can be contained in the entire acid component in a range of less than 20 mol%, preferably less than 15 mol%. This is because if it is contained in an amount of 20 mol% or more, the mechanical strength of the molded article may be reduced. As the aliphatic dicarboxylic acid used in the present invention, oxalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, sebacic acid, azelaic acid, dodecanedioic acid, dimer acid,
1,3 or 1,4-cyclohexanedicarboxylic acid,
Cyclopentanedicarboxylic acid, 4,4'-dicyclohexyldicarboxylic acid, and the like.

Further, the component (A) of the present invention may contain a trivalent or higher polyhydric carboxylic acid and a polyhydric alcohol, and specific examples thereof include trimellitic acid, pyromellitic acid and anhydrides thereof. And polyhydric alcohols such as trimethylolpropane, pentaerythritol and glycerin. As a preferred content,
The range of 0.05 to 2 mol% is preferred. If it is lower than this range, there is no effect of blending, and if it is higher, the reaction tends to be difficult to control due to gelation. More preferably, 0.1 to
It is in the range of 1 mol%. Further, the heat of crystal fusion of the component (A) determined from the melting peak of the differential scanning calorimetry (DSC) is preferably in the range of 0 to 20 J / g. If the heat of crystal fusion exceeds 20 J / g, the appearance of the molded article tends to decrease.

On the other hand, the component (B) of the present invention has a terminal carboxyl group of 5 KOH mg / g or less and a refractive index at 25 ° C. of 1.46.
As a thermoplastic resin having a softening temperature in the range of 0 to less than 1.470 and a softening temperature of −35 to 15 ° C., a number average molecular weight of 500 to
2,000 polycaprolactone polyols, polycarbonate diols, and terminal (meth) acrylates, allyl ethers, and the like thereof. And an esterified product of phthalic acid and an aliphatic compound having a hydroxyl group terminal having 2 to 12 carbon atoms.

(B) The terminal carboxyl group of the component is 5 KOHm
If it exceeds g / g, the mechanical properties tend to decrease due to the aging of the molded article. Further, it is desirable that the refractive index of the component (B) at 25 ° C. is 1.460 or more and less than 1.470. If it is less than 1.460, the appearance of the molded article tends to decrease, while if it is 1.470 or more, the flexibility tends to decrease. Further, when the softening temperature of the component (B) is lower than -35 ° C., the heat resistance of the molded article tends to decrease, and when it is 15 ° C. or higher, the compatibility with the component (A) is low and the mechanical properties tend to decrease. is there.

The preferable content ratio of the component (A) and the component (B) in the polyester resin of the present invention is as follows.
Component (B) is 80 to 20% by mass relative to 80% by mass. More preferably, the content of the component (B) is 70 to 30% by mass relative to the content of the component (A) 30 to 70% by mass. If the content of the component (A) exceeds 80% by mass, the flexibility becomes inferior. If the content is less than 20% by mass, the thermal stability decreases, the blocking reaction stagnates, and the mechanical properties of the molded product deteriorate. It tends to decrease.

Next, the polyester resin of the present invention can be produced by a known direct polymerization method or transesterification method, and the degree of polymerization in a mixed solvent of phenol / tetrachloroethane equivalent at 25 ° C. The measured intrinsic viscosity [η] is preferably a polymerization degree of 0.6 to 1.5 dl / g. If it is less than 0.6 dl / g, the viscosity tends to be low and the loss during molding tends to be large. On the other hand, if it exceeds 1.5 dl / g, the load at the time of extrusion is large and a sufficient discharge amount cannot be obtained,
The appearance of the molded article may be impaired.

In order to produce the polyester sheet of the present invention, the polyester resin is dried and dried at a temperature of 150 to 300 ° C. in accordance with a usual polyester sheet production method.
-In addition to a method of melt extrusion from a die and forming a sheet having a thickness of 20 to 2000 μm on a casting drum having a surface temperature of 5 to 50 ° C, a calendering method or the like may be used. The polyester sheet thus obtained is 5
When the haze value after treatment under the conditions of 0 ° C., 95% RH and 60 hours is 2 or less, required strength and performance of the sheet can be secured while maintaining flexibility and transparency. The thickness of the polyester sheet of the present invention is not particularly limited, but is usually selected in the range of 20 to 2000 μm.

The molded article using the polyester resin of the present invention may be subjected to various conventionally known processing treatments to impart specific performance, or may be blended with an appropriate additive. Examples of processing include ultraviolet, α-ray, β-ray,
Irradiation with γ-rays or electron beams, corona treatment, plasma irradiation treatment, flame treatment, etc., application of a resin such as vinylidene chloride, polyvinyl alcohol, polyamide, polyolefin, lamination, metal deposition, and the like are included. Examples of additives include polyether, polyamide,
Resins such as polyolefin and polymethyl methacrylate,
Examples include inorganic particles such as silica, talc, kaolin, and calcium carbonate, pigments such as titanium oxide and carbon black, ultraviolet absorbers, release agents, antiblocking agents, easy sealants, antistatic agents, and flame retardants. Next, the present invention will be described more specifically with reference to Examples, Production Examples and Comparative Examples, but it is needless to say that the present invention is not limited to these Examples.

[0018]

EXAMPLES The ΔHc, intrinsic viscosity, flexibility and the like in each example were determined by the following methods. ΔHc: Using a DSC measurement device (manufactured by Shimadzu Corporation), the sample was kept at 280 ° C. for 5 minutes under a nitrogen stream, rapidly cooled to −30 ° C., and then heated to 280 ° C. at a rate of 10 ° C./min. The temperature and calorie of the melting peak at that time were calculated. Intrinsic viscosity: measured in a mixed solvent of phenol / tetrachloroethane equivalent at 25 ° C. Flexibility: Shore D surface hardness was measured according to ASTM-K7215. The Shore D hardness has no unit.

Transparency: A 2 mm sheet obtained by using a 40 mmφ single screw extruder was measured with a Nippon Denshoku haze meter.
Measurements were made immediately after film formation and after treatment at 50 ° C., 95% RH for 5 hours. Tensile strength: measured in accordance with ASTM-D638. Formability: Using a Capillograph (Toyo Seiki Seisakusho), 270 ° C., shear rate 60 sec. ⁻¹ , L / D = 10
Time for the strand extruded at 400 mm to reach 400 mm [s
ec.] was used as an index of moldability.

[Production Example 1] 3.51 kg of terephthalic acid
And 0.65 kg of isophthalic acid and 2.42 kg of ethylene glycol in a reaction vessel.
The esterification reaction was performed by heating and stirring at 3 ° C. for 3 hours. Then, the temperature was raised to 260 ° C., and 1.5 g of antimony trioxide was added as a polymerization catalyst to progress the polymerization reaction. The obtained polyester resin has an intrinsic viscosity [η] = 0.74 and ΔHc =
It was 16.

[Production Example 2] 3.85 kg of terephthalic acid
The polyester resin obtained in the same manner as in Example 1 using 1,73 kg of ethylene glycol, 1.00 kg of 1,4-cyclohexanedimethanol, and 1.3 g of antimony trioxide has an intrinsic viscosity [η]. = 0.79, no melting peak was observed.

[Production Example 3] 4.00 kg of terephthalic acid
1.80 kg of ethylene glycol, 325.6 g of 1,4-butanediol, 521.1 g of 1,4-cyclohexanedimethanol, 16.2 g of trimethylolpropane, and 1.monitor of antimony trioxide. 4 g of the polyester resin obtained in the same manner as in Example 1, the intrinsic viscosity [η] = 0.90, the melting peak was unclear and ΔH
c = 2.6.

[Production Example 4] 4.32 kg of terephthalic acid
And 2.4 g of ethylene glycol and 1.5 g of antimony trioxide, a polyester resin obtained in the same manner as in Example 1 had an intrinsic viscosity [η] = 0.68, ΔH
c = 35.2.

[Production Example 5] 3.02 kg of terephthalic acid
1.29 kg of isophthalic acid, 2.42 kg of ethylene glycol and 10.29 kg of trimethylolpropane.
Example 1 using 46 g and 1.5 g of antimony trioxide
The polyester resin obtained in the same manner as in Example 1 had an intrinsic viscosity [η] = 0.82 and no melting peak.

Example 1 3.5 kg of the polyester resin of Production Example 1 was prepared with a terminal carboxyl group of 0.1 KOHmg /
g, the refractive index at 25 ° C. is 1.463, and the softening temperature is −25.
° C, adipic acid-containing thermoplastic resin (W-120
0, manufactured by Dainippon Ink and Chemicals, Inc.) and melt-kneaded under reduced pressure to obtain a block copolymer. The obtained resin had an intrinsic viscosity [η] = 0.91. Table 1 shows the results of molding and evaluation of this resin.

[Example 2] 3.5 kg of the polyester resin of Production Example 2 was added with a terminal carboxyl group of 0.1 KOHmg /
g, the refractive index at 25 ° C. is 1.463, and the softening temperature is −25.
° C, adipic acid-containing thermoplastic resin (W-120
0, manufactured by Dainippon Ink and Chemicals, Inc.) and melt-kneaded under reduced pressure to obtain a block copolymer. The obtained resin had an intrinsic viscosity [η] of 1.00. The results of evaluating this resin in the same manner as in Example 1 are shown in Table 1.

[Example 3] 2.0 kg of the polyester resin of Production Example 2 was prepared with a terminal carboxyl group of 0.1 KOHmg /
g, the refractive index at 25 ° C. is 1.463, and the softening temperature is −25.
° C, adipic acid-containing thermoplastic resin (W-120
And 3.0 kg of Dainippon Ink and Chemicals, Inc.) were melt-kneaded under reduced pressure to obtain a block copolymer. The obtained resin had an intrinsic viscosity [η] of 1.22. The results of evaluating this resin in the same manner as in Example 1 are shown in Table 1.

Example 4 The amount of the polyester resin of Production Example 3 was 3.75 kg and the terminal carboxyl group was 0.6 KOH mg /
g, refractive index at 25 ° C is 1.469, softening temperature is 14 ° C
Adipic acid-containing thermoplastic resin (W-4000,
And 1.25 kg of the mixture were melt-kneaded under reduced pressure to obtain a block copolymer. The obtained resin had an intrinsic viscosity [η] = 1.07. The results of evaluating this resin in the same manner as in Example 1 are shown in Table 1.

[Comparative Example 1] The polyester resin of Production Example 4 was 3.5 kg, and the terminal carboxyl group was 0.1 KOH mg / kg.
g, the refractive index at 25 ° C. is 1.463, and the softening temperature is −25.
° C, adipic acid-containing thermoplastic resin (W-120
0, manufactured by Dainippon Ink and Chemicals, Inc.) and melt-kneaded under reduced pressure to obtain a block copolymer. The obtained resin had an intrinsic viscosity [η] = 0.95. The results of evaluating this resin in the same manner as in Example 1 are shown in Table 1.

Comparative Example 2 The amount of the polyester resin of Production Example 5 was 4.75 kg and the terminal carboxyl group was 0.1 KOH mg /
g, the refractive index at 25 ° C. is 1.463, and the softening temperature is −25.
° C, adipic acid-containing thermoplastic resin (W-120
0, manufactured by Dainippon Ink and Chemicals, Inc.) was melt-kneaded with 0.25 kg under reduced pressure to obtain a block copolymer. The obtained resin had an intrinsic viscosity [η] = 0.86. The results of evaluating this resin in the same manner as in Example 1 are shown in Table 1.

Comparative Example 3 0.25 kg of the polyester resin of Production Example 5 was used and the terminal carboxyl group was 0.1 KOH mg /
g, the refractive index at 25 ° C. is 1.463, and the softening temperature is −25.
° C, adipic acid-containing thermoplastic resin (W-120
0, manufactured by Dainippon Ink and Chemicals, Inc.) and melt-kneaded with 4.75 kg under reduced pressure to obtain a block copolymer. The obtained resin had an intrinsic viscosity [η] of 1.48. This resin was tacky and could not be evaluated as a molded article.

[Comparative Example 4] The polyester resin of Production Example 5 was 2.5 kg, and the terminal carboxyl group was 194 KOHmg /
g, 2.5 kg of a fatty acid-containing thermoplastic resin (P-1009, manufactured by Unichema Co., Ltd.) having a refractive index of 1.479 at 25 ° C. and a softening temperature of 0 ° C., and melt-kneading under reduced pressure; A copolymer was obtained. The resulting resin has an intrinsic viscosity [η]
= 1.26. The results of evaluating this resin in the same manner as in Example 1 are shown in Table 1.

[Comparative Example 5] The polyester resin of Production Example 5 was 2.5 kg, and the terminal carboxyl group was 0 KOHmg / g.
2.5 kg of dimethylpolysiloxane (KF-54, manufactured by Shin-Etsu Chemical Co., Ltd.) having a refractive index of 5.505 at 5 ° C. and a softening temperature of −30 ° C. was melt-kneaded under reduced pressure, A polymer was obtained. The obtained resin had an insoluble content and the intrinsic viscosity could not be measured. The results of evaluating this resin in the same manner as in Example 1 are shown in Table 1.

[0034]

[Table 1]

[0035]

As described above, the polyester sheet formed from the polyester resin according to the present invention has improved flexibility and transparency while maintaining the excellent properties of the conventional polyester resin. It also has excellent properties in tensile strength and moldability. Therefore, the polyester resin of the present invention is expected to be used in a wide range of fields such as soft transparent sheets, surface protective materials, building materials, and interior parts.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F071 AA43X AA45X AA75 AA81 AA85 AA87 AF14 AF26 AF30Y AH03 AH19 BA01 BB06 BC01 BC10 4J031 AA49 AB04 AC03 AD01

Claims (2)

[Claims] 1. An aromatic polyester resin having (A) a heat of crystal fusion (ΔHc) satisfying the following formula (1): 20 to 80.
% By mass and (B) a thermoplastic resin having a terminal carboxyl group of 5 KOHmg / g or less, a refractive index at 25 ° C of 1.460 or more and less than 1.470, and a softening temperature of -35 to 15 ° C. A block copolymer consisting of 20% by mass and having an intrinsic viscosity [η] of 0.6 to 1.5 as measured in a mixed solvent of phenol / tetrachloroethane at 25 ° C.
dl / g polyester resin. 0 ≦ ΔHc ≦ 20 (1) (ΔHc is the heat of crystal fusion determined from the melting peak of differential scanning calorimetry, and the unit is J / g.) 2. A polyester sheet comprising the polyester resin according to claim 1, wherein the polyester sheet has a haze value of 2 or less after being treated at 50 ° C., 95% RH and 60 hours. And polyester sheet.