JP2006063184A - Hydrolysis-resistant polyester resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a copolymer polyester resin having adhesive strength to a polyester material and holding excellent hydrolysis resistance with excellent productivity. <P>SOLUTION: The hydrolysis-resistant polyester resin comprises 5-20 mol% of a ≥15C linear saturated aliphatic dicarboxylic acid in the whole carboxylic acid component. Besides the dicarboxylic acid, a hydroxycarboxylic acid, as necessary, can be used as the carboxylic acid. The polyester resin has ≥75% relative viscosity retention after allowing the resin to stand under conditions of 85°C and 85%RH for 1,000 h. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a copolyester resin excellent in adhesion to a polyester material and hydrolysis resistance.

  As an adhesive for a polyester base material, a copolyester similar to the constituent component of the polyester is generally suitable. However, a polyester resin is inherently easily hydrolyzed and often used in a high temperature and high humidity condition. It is a problem.

  As a method for imparting hydrolysis resistance, dimer acid is copolymerized as dicarboxylic acid in Patent Document 1 and Patent Document 2.

JP 2002-47471 A JP 2003-183365 A

  However, while dimer acid can improve hydrolysis resistance, it does not necessarily have excellent adhesive strength, and this monomer has a high viscosity at room temperature and is difficult to be charged into a polymerization kettle. was there. An object of the present invention is to provide a polyester that improves the adhesion while maintaining the hydrolysis resistance of the polyester and at the same time is excellent in productivity.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by using a specific aliphatic dicarboxylic acid as a monomer component, and have reached the present invention.

That is, the gist of the present invention is as follows.
(1) A hydrolysis-resistant polyester resin comprising 5 to 20 mol% of a linear saturated aliphatic dicarboxylic acid having 15 or more carbon atoms in all carboxylic acid components.
(2) The polyester resin according to (1), which has a relative viscosity retention of 75% or more after being left in an 85 ° C., 85% RH state for 1000 hours.

  According to the present invention, a sufficient adhesive strength of 10 N / 20 mm or more with respect to a polyester material and a high level of hydrolysis resistance with a relative viscosity retention of 75% or more after being left at 85 ° C. and 85% RH for 1000 hours. A polyester resin that retains its performance is provided, and its industrial utility value is extremely high.

  Hereinafter, the present invention will be described in detail.

  The polyester resin as used in the present invention is mainly composed of equimolar amounts of a dicarboxylic acid (A) component and a glycol (B) component, and a hydroxycarboxylic acid (C) component or the like is copolymerized as necessary. .

  As the dicarboxylic acid component (A), it is necessary to use a linear saturated aliphatic dicarboxylic acid having 15 or more carbon atoms from the viewpoint of hydrolysis resistance. There is no particular upper limit on the number of carbon atoms, and the larger the value, the better the hydrolysis resistance, but 22 or less is usually available. The straight-chain saturated aliphatic dicarboxylic acid having 15 or more carbon atoms is solid at normal temperature and can be charged into the polymerization apparatus in the form of powder as a raw material. Since dimer acid used heretofore is a viscous liquid at room temperature, the present invention does not require any special equipment, compared to the need for a heating-type charging equipment for reducing the viscosity. It can be simplified.

  As linear saturated aliphatic dicarboxylic acids, pentadecanedioic acid (15 carbon atoms), hexadecanedioic acid (16), octadecanedioic acid (18), eicosanedioic acid (20), etc. are commercially available, The product name EMEROX 115 manufactured by Cognis, EMEROX 116 manufactured by the company, EMEROX 118 manufactured by the company, and product name SL20 manufactured by Okamura Oil Co., Ltd. can be easily obtained.

  The proportion of the linear saturated aliphatic dicarboxylic acid component having 15 or more carbon atoms is preferably 5 mol% to 20 mol%, more preferably 5 mol% to 13 mol% in the total carboxylic acid component. . If it is less than 5 mol%, the hydrolysis resistance becomes insufficient, and if it is more than 20 mol%, the adhesion performance to the polyester material becomes poor, such being undesirable. The “total carboxylic acid component” means a dicarboxylic acid (A) component, a hydroxycarboxylic acid (C) component, a monocarboxylic acid component, a trivalent or higher carboxylic acid component that can be used as a constituent component of the polyester of the present invention. Means the sum of

  As the other dicarboxylic acid component constituting the component (A), aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, 4,4′-dicarboxybiphenyl, 5-sodium sulfoisophthalic acid, Saturated aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, fumaric acid, maleic acid, itaconic acid, mesaconic acid, citraconic acid, etc. Examples include saturated aliphatic dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 2,5-norbornenedicarboxylic acid, and alicyclic dicarboxylic acid of tetrahydrophthalic acid. . These may be anhydrous.

  Among the dicarboxylic acid components, aromatic dicarboxylic acids are preferable, and terephthalic acid and isophthalic acid, which are versatile, are particularly preferable.

  As the component (B), ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-1 , 3-propanediol, 2,2-diethyl-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methyl-1,3-propanediol, 2 -Ethyl-2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,5-pentanediol 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, diethylene Ethylene oxide adduct or propylene oxide adduct of aliphatic glycol such as glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, bisphenol A, bisphenol S, bisphenol C, bisphenol Z, bisphenol AP, 4,4'-biphenol , 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol and other alicyclic glycols, polyethylene glycol, polypropylene glycol and the like. 1,2-propanediol, 1,4-butanediol and neopentyl glycol are preferred.

  In the polyester of the present invention, hydroxycarboxylic acid (C) can be used depending on purposes such as appropriate flexibility, improved adhesion, and adjustment of glass transition temperature. The component (C) is preferably 0 to 50 mol%, more preferably 10 to 40 mol%, still more preferably 20 to 40 mol% of the total carboxylic acid component. When the ratio of (C) component is higher than 50 mol%, the adhesive force with respect to a polyester raw material will become small, and it exists in the tendency for hydrolysis resistance to fall.

  As the component (C), p-hydroxybenzoic acid, m-hydroxybenzoic acid, o-hydroxybenzoic acid, lactic acid, oxirane, β-propiolactone, β-butyrolactone, γ-butyrolactone, δ-valerolactone, ε- Caprolactone, glycolic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxyisobutyric acid, 2-hydroxy-2-methylbutyric acid, 2-hydroxyvaleric acid, 3-hydroxyvaleric acid, 4-hydroxy Examples include valeric acid, 5-hydroxyvaleric acid, 6-hydroxycaproic acid, 10-hydroxystearic acid, and among them, ε-caprolactone having versatility is preferable.

  If the amount is small, a tri- or higher functional carboxylic acid component or an alcohol component may be added as a copolymerization component.

  Examples of the tri- or higher functional carboxylic acid component include aromatics such as trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic acid anhydride, and trimesic acid. Examples thereof include carboxylic acids and aliphatic carboxylic acids such as 1,2,3,4-butanetetracarboxylic acid.

  Examples of the tri- or higher functional alcohol component include glycerol, trimethylolpropane, trimethylolethane, pentaerythritol, α-methylglucose, mannitol, and sorbitol.

  These do not necessarily need to be used alone, and can be used in combination of two or more according to the properties desired to be imparted to the resin. At this time, the proportion of the tri- or higher functional monomer is suitably about 0.2 to 5 mol% with respect to the total carboxylic acid component or the total alcohol component. If the amount added is less than 0.2 mol%, the added effect is not manifested, and if the amount exceeds 5 mol%, the gelation may exceed the gel point during polymerization.

  Moreover, monocarboxylic acid and monoalcohol may be copolymerized with the polyester resin. Examples of monocarboxylic acids include lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, benzoic acid, p-tert-butylbenzoic acid, cyclohexane acid, 4-hydroxyphenyl stearic acid, and the like. Examples of the alcohol include octyl alcohol, decyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, and 2-phenoxyethanol.

  The polyester resin can be produced by combining the above monomers and polycondensing by a known method. For example, all the monomer components and / or low polymers thereof can be produced at 180 to 250 ° C. under an inert atmosphere. A method of obtaining a polyester resin by conducting an esterification reaction for about 5 to 10 hours and then proceeding a polycondensation reaction until reaching a desired molecular weight at a temperature of 220 to 280 ° C. under a reduced pressure of 130 Pa or less, etc. be able to.

  In the esterification reaction and polycondensation reaction, if necessary, organic titanate compounds such as tetrabutyl titanate, alkali metals such as zinc acetate and magnesium acetate, acetates of alkaline earth metals, trioxide Polymerization is performed using an organic tin compound such as antimony, hydroxybutyltin oxide, or tin octylate. In this case, the amount of catalyst used is preferably 1.0% by mass or less based on the mass of the resin to be produced.

  Further, when a desired acid value or hydroxyl value is imparted to the polyester resin, a polybasic acid component or a polyvalent glycol component is further added following the polycondensation reaction, and depolymerization is performed in an inert atmosphere. be able to.

  When the copolyester resin of the present invention is allowed to stand at 85 ° C. and 85% RH for 1000 hours, the relative viscosity retention is preferably 75% or more. Sufficient hydrolysis resistance cannot be obtained when the relative viscosity retention is 75% or less under the above conditions.

  The number average molecular weight of the copolyester resin of the present invention is preferably 4,000 or more, more preferably 8,000 or more, further preferably 12,000 or more, and 15,000 or more. It is particularly preferred. A number average molecular weight of less than 4,000 is not preferable because sufficient adhesive force cannot be obtained with respect to the polyester material.

  The glass transition temperature (hereinafter referred to as Tg) of the copolymerized polyester resin is not particularly limited, but is preferably −40 to 40 ° C., and most preferably −10 to 10 ° C. from the viewpoint of adhesiveness to polyester.

  The copolymerized polyester resin of the present invention includes a curing agent, various additives, pigments such as titanium oxide, zinc white, and carbon black, dyes, polyester resins, urethane resins, olefin resins, acrylic resins, alkyds as necessary. Resins, cellulose derivatives and the like can be blended.

  Moreover, additives such as a pigment dispersant, an ultraviolet absorber, a release agent, a pigment dispersant, and a lubricant can be blended with the copolymerized polyester resin of the present invention as necessary.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.
(1) Configuration of copolymer polyester resin
^It calculated | required from < ¹ > H-NMR analysis (The product made by a Varian, 300MHz).
(2) Number average molecular weight of copolymerized polyester resin The number average molecular weight is determined by GPC analysis (liquid feeding unit LC-10ADvp type and UV-visible spectrophotometer SPD-6AV type manufactured by Shimadzu Corporation), detection wavelength: 254 nm, solvent : Chloroform, polystyrene conversion).
(3) Glass transition temperature of copolymerized polyester resin Using 10 mg of the copolymerized polyester as a sample, measurement was performed using a DSC (Differential Scanning Calorimetry) apparatus (DSC7 manufactured by PerkinElmer Co., Ltd.) at a temperature rising rate of 10 ° C./min. Then, an intermediate value of two bending point temperatures derived from the glass transition in the obtained temperature rise curve was determined, and this was defined as the glass transition temperature (Tg).
(4) Relative viscosity 100 mg of copolyester resin is dissolved in 20 ml of a mixed solvent of phenol / 1,1,2,2-tetrachloroethane = 5/5 (mass ratio), and 20 ± 0 using an Ubbelohde automatic viscometer. The flow time of each of the sample solution and the solvent was measured at a temperature of 0.01 ° C., and the relative viscosity was calculated by (flow time of the sample solution / flow time of the solvent).
(5) Relative viscosity retention rate Each resin (sheet or pellet) is placed on a Teflon (registered trademark) sheet and left for 1000 hours under conditions of 85 ° C. and 85% RH (relative viscosity after being left for 1000 hours). / Relative viscosity before standing) × 100 (%), relative viscosity retention was calculated. In practice, a value of 75% or more is an acceptable value.
(6) Adhesive strength Polyester film (thickness 40 μm, manufactured by Unitika Co., Ltd.) was coated with a resin solution using a desktop coating apparatus (manufactured by Yasuda Seiki, film applicator No. 542-AB, equipped with bar coater). By heating for 1 minute in an oven set at 100 ° C., a resin film having a thickness of about 10 μm was formed on the substrate. Subsequently, two coated polyester films were prepared, and the coated surfaces were temporarily bonded to each other, and then pressure-bonded for 1 minute with a hot press set at 85 ° C. to prepare a sample cut to a width of 20 mm. Thereafter, the adhesive strength at a tensile rate of 50 mm / min was measured in an atmosphere of a temperature of 20 ° C. and a humidity of 50% using an Intesco precision universal material testing machine 2020 type. 10 N / 20 mm or more was regarded as acceptable.

Example 1
490 g (29.5 mol parts) of terephthalic acid, 490 g (29.5 mol parts) of isophthalic acid, 350 g (11 mol parts) of octadecanedioic acid (manufactured by Cognis, product name EMEROX118), 342 g (30 mol parts) of ε-caprolactone The mixture consisting of 335 g (54 mol parts) of ethylene glycol, 531 g (51 mol parts) of neopentyl glycol and 2102 g of Irganox 1010 was heated at 240 ° C. for 3 hours in an autoclave with stirring to carry out an esterification reaction. . Next, the temperature was raised to 260 ° C., 1.3 g of zinc acetate was added as a catalyst, the system pressure was gradually reduced to 13 Pa after 1.5 hours, and a polycondensation reaction was performed. After 4 hours, the system was pressurized with nitrogen gas, and the resin was discharged in the form of a sheet to obtain the copolymerized polyester shown in Table 2. The number average molecular weight of this polyester was 25000, the glass transition point was 0 ° C., the relative viscosity retention was 80%, and the adhesive strength was 14 N / 20 mm. Table 1 shows the preparation composition and production conditions, and Table 2 shows the results.

Examples 2-5, Comparative Examples 1-7
The monomers used, the molar ratio thereof, the polymerization catalyst, and the polymerization temperature were set as shown in Table 1, and the same operation as in Example 1 was performed to obtain a copolymerized polyester shown in Table 2. However, in Comparative Example 1, the resin was dispensed in a pellet form.

In Examples 1 to 5, all had a relative viscosity retention of 75% or more, excellent hydrolysis resistance, and sufficient adhesive strength.

  On the other hand, each comparative example has the following problems.

  In Comparative Example 1, since a linear saturated aliphatic dicarboxylic acid component having 15 or more carbon atoms was not used, the hydrolysis resistance was poor.

  In Comparative Example 2, since the proportion of the linear saturated aliphatic dicarboxylic acid component having 15 or more carbon atoms exceeded the upper limit defined in the present invention, the adhesive strength was insufficient.

  In Comparative Example 3, the ratio of the linear saturated aliphatic dicarboxylic acid component having 15 or more carbon atoms was lower than the lower limit specified in the present invention, so that the hydrolysis resistance was poor.

  In Comparative Examples 4 and 5, since a linear saturated aliphatic dicarboxylic acid component having 15 or more carbon atoms was not used, hydrolysis resistance was insufficient.

  In Comparative Example 6, since the amount of the hydroxycarboxylic acid as the component (C) exceeded the upper limit specified in the present invention, the adhesive strength was low and the hydrolysis resistance was inferior.

In Comparative Example 7, since dimer acid was used instead of linear aliphatic dicarboxylic acid having 15 or more carbon atoms, the adhesive strength was poor.

Claims (2)

  A hydrolysis-resistant polyester resin comprising 5 to 20 mol% of a linear saturated aliphatic dicarboxylic acid having 15 or more carbon atoms in all carboxylic acid components. The polyester resin according to claim 1, which has a relative viscosity retention of 75% or more after being left in an 85 ° C, 85% RH state for 1000 hours.