JPH10110040A - Molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyester resin and its molding, excellent in adhesion to a polyolefin resin and very excellent in moisture permeability by the polycondensation of a polybasic acid component and a specified glycol component. SOLUTION: This molded article comprises a polyester resin obtained by the polycondensation of a polybasic acid component (A) and a glycol component (B) consisting of a hydrogenated polybutadiene polyol and a poly(alkylene oxide) glycol. The polybasic acid component A preferably consists of 20-90wt.% aromatic dicarboxylic acid and 10-80wt.% branched polybasic acid having a 2C or higher alkyl group on the side chain. It is desirable that the glycol component B contains 10-60wt.% hydrogenated polybutadiene polyol, 30-89wt.% poly(alkylene oxide) glycol and 1-60wt.% other glycol component. This molded article is useful as the back sheet for a paper diaper.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded article made of a polyester resin, and more particularly, to the molding of a film or the like having excellent adhesion (adhesion) to a polyolefin and having excellent moisture permeability. It is about things.

[0002]

2. Description of the Related Art Generally, polyester resins have heat resistance,
Although it is excellent in weather resistance and the like, it is used in various applications, and is particularly effectively used in the fields of molded articles, adhesives, pressure-sensitive adhesives, and paints. For example, JP-A-59-2
No. 15373 discloses a hot-melt adhesive, a short-chain ester unit composed of an organic dicarboxylic acid mainly composed of an aromatic dicarboxylic acid and an alkylene glycol, an organic dicarboxylic acid mainly composed of an aromatic dicarboxylic acid, and 1,1.
A long chain ester unit comprising 2-polybutadiene glycol or a hydrogenated product thereof and / or a long chain ester unit comprising 1,2-polybutadiene dicarboxylic acid or a hydrogenated product thereof and an alkylene glycol have been proposed.

[0003] Japanese Patent Application Laid-Open No. 3-167284 discloses that
An aliphatic polyester using a dicarboxylic acid or polyol having a hydrogenated polybutadiene structure as an adhesive has been proposed. JP-A-61-7370 discloses that an aromatic dicarboxylic acid or a derivative thereof, a dimer acid or a hydrogenated product thereof, or a derivative thereof and an aliphatic dicarboxylic acid or a derivative thereof other than the dimer acid are used as an acid component and have 2 carbon atoms. A thermoplastic copolymer polyester elastomer having a glycol component of a long-chain glycol containing no ether bond in a molecule having an alkylene glycol of 10 to 10 and an average molecular weight of 350 to 6000, and a low molecular weight miscible with the thermoplastic copolymer polyester elastomer An adhesive composition comprising a thermoplastic has been proposed.

[0004]

However, Japanese Patent Application Laid-Open No. Sho 59-215373 and Japanese Patent Application Laid-Open No. Hei 3-16728 disclose the above.
No. 4, JP-A-61-7370 relates to an adhesive and a pressure-sensitive adhesive. No studies have been made on molded articles using the resin composition. No consideration is given to the adhesiveness (adhesion) to the resin. Polyolefin resins have excellent properties such as excellent chemical properties and are lightweight and inexpensive, so they have been widely used in molded products and nonwoven fabrics, but polyolefin resins such as polyethylene and polypropylene are non-polar. Because of its high crystallinity, the adhesiveness with various adhesives is extremely poor, and the adhesiveness with the formed coating film is poor even when various paints are applied or when the molded product is heat-sealed. This is a major difficulty in developing polyolefin resins for various uses.

In recent years, molded articles made of polyester resins have been used in various places such as foods and medical treatments, and are particularly regarded as important in medical and sanitary goods which require moisture permeability. Therefore, development of a molded article having excellent adhesion (adhesion) performance to a polyolefin-based resin is particularly desired. Under such circumstances, the present invention provides a molded article made of a polyester resin, which has excellent adhesiveness (adhesion) to a polyolefin resin and has extremely excellent moisture permeability, which solves the above problems. With the goal.

[0006]

Means for Solving the Problems However, the inventors of the present invention have conducted intensive studies to solve such problems, and as a result, the polybasic acid component (A), preferably an aromatic dicarboxylic acid (a)
-1) and a polybasic acid component (A) comprising a branched polybasic acid (a-2) having an alkyl group having 2 or more carbon atoms in a side chain, a hydrogenated polybutadiene polyol (b-1) and a poly (alkylene oxide) A) A molded product made of a polyester resin (I) obtained by polycondensation of a glycol component (B) made of a glycol (b-2) was found to meet the above object, and the present invention was completed.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The polyester resin (I) of the present invention comprises a polybasic acid component (A) and a hydrogenated polybutadiene polyol (b-1) and a poly (alkylene oxide) glycol (b-2) as glycol components (B), respectively. It is configured as an essential component.

The polybasic acid component (A) used in the present invention is not particularly limited as long as it is a divalent or higher valent acid. In the present invention, the aromatic dicarboxylic acid (a-
It is preferable to include 1) and a branched polybasic acid (a-2) having an alkyl group having 2 or more carbon atoms, preferably 2 to 20 in the side chain.

As the aromatic dicarboxylic acid (a-1),
For example, terephthalic acid, isophthalic acid, phthalic anhydride, phthalic acid, 1,4-naphthalic acid, 1,5-naphthalic acid, diphenic acid, 4,4'-oxybenzoic acid, diglycolic acid, 4,4'-sulfonyl Dibenzoic acid, 2,5-
Naphthalenedicarboxylic acid and the like can be mentioned. Among them, terephthalic acid and isophthalic acid are particularly preferable in terms of low cost and reactivity. However, it is not limited to these.
If necessary, it can be used as a monoester or diester of the above acid. Examples of the branched polybasic acid (a-2) having an alkyl group having 2 or more carbon atoms, preferably 2 to 20 in its side chain include hydrogenated dimer acid and 1-butylhexanedicarboxylic acid.

The amount of each of the polybasic acid components (A) is 20 to 90% by weight, preferably 30 to 90% by weight, based on the total amount of the polybasic acid component (A). It is desired that the content of the branched polybasic acid (a-2) having an alkyl group having 2 or more carbon atoms in its side chain is 10 to 80% by weight, preferably 20 to 70% by weight. If the amount of (a-1) is less than 20% by weight, the cohesive strength is weak and the adhesive strength is reduced. On the other hand, if it exceeds 90% by weight, the compatibility is deteriorated and the adhesive strength is undesirably reduced. or,
If the blending amount of (a-2) is less than 10% by weight, the compatibility is poor and the adhesive strength is reduced. If it exceeds 80% by weight, the cohesive strength is weakened and the adhesive strength is undesirably reduced.

In the present invention, the above polybasic acid component (a-1),
In addition to (a-2), if necessary, other acid components include, for example, succinic acid, glutaric acid, 2,2-dimethylglutaric acid, pimelic acid, suberic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid It is also preferable to use an acid such as an acid in combination.

The hydrogenated polybutadiene polyol (b-1), which is an essential component of the glycol component (B), has a structure represented by the following formula 1 and has a molecular weight of 30:
It is preferably from 0 to 6000, particularly preferably from 500 to 3000.
The iodine value is preferably 0 to 50, preferably 0 to 20, and the hydroxyl value is preferably 15 to 400, preferably 30 to 250.

[0013]

Embedded image Here, n is an integer of 3 to 110.

The poly (alkylene oxide) glycol (b-2) includes polytetramethylene glycol, polyethylene glycol, polypropylene glycol and the like having a molecular weight of 600 to 4000.
Among them, polytetramethylene glycol having a molecular weight of 1,000 to 2,000 is preferable. In the present invention, it is also preferable to use one or two of the above glycol components in combination, such as using polytetramethylene glycol and polyethylene glycol in combination.

In the present invention, alkylene glycols having 2 to 20 carbon atoms are used as other glycol components in addition to the glycol (B) components (b-1) and (b-2), for example, ethylene glycol, diethylene glycol, Propylene glycol, dipropylene glycol,
Trimethylene glycol, triethylene glycol,
1,4-butanediol, 1,5-pentanediol,
1,6-hexanediol, neopentyl glycol,
Examples thereof include 1,9-nonanediol and 2,2'-butylethylpropanediol, and one or more kinds are used. Among them, ethylene glycol, 1,4-butanediol and the like are preferably employed.

The amount of each of the above-mentioned glycol (B) components is not particularly limited, but the amount of the hydrogenated polybutadiene polyol (b-
1) is 10 to 60% by weight, preferably 30 to 60% by weight, poly (alkylene oxide) glycol (b-2)
Is desirably 30 to 89% by weight, preferably 40 to 70% by weight, and the other glycol component is 1 to 60% by weight, preferably 1 to 30% by weight.

When the amount of the hydrogenated polybutadiene polyol (b-1) is less than 10% by weight, the adhesion to the polyolefin is reduced. When the amount is more than 60% by weight, the cohesion is weak and the adhesion is reduced. If the amount of the poly (alkylene oxide) glycol (b-2) is less than 30% by weight, the moisture permeability will be poor. Further, if the content of the other glycol component exceeds 60% by weight, the compatibility is poor and the adhesive strength is undesirably reduced.

Thus, in the present invention, the polybasic acid component (A) and the glycol component (B) are polycondensed to obtain a polyester resin (I). The method for producing the polyester resin (I) is as follows. Can be carried out according to a known ordinary method without any particular limitation. For example, the polybasic acid component (A) and the glycol component (B)
, Or a step of directly transesterifying them, or subjecting them to a transesterification reaction followed by polycondensation. In that case, you may use arbitrary various catalysts, stabilizers, modifiers, additives, etc. For example, examples of the esterification catalyst include dibutyltin oxide and zinc acetate, and examples of the polymerization catalyst include tetra-n-butyl titanate and antimony trioxide. The polybasic acid component (A) and the glycol component (B) are in a molar ratio of the polybasic acid component (A):
It is desirable to carry out the reaction at a glycol component (B) = 1: 1.1 to 1: 2.0, preferably 1: 1.2 to 1: 1.8.

According to the above method, the polyester resin (I)
Is obtained, the obtained polyester resin (I) has excellent compatibility, and the polyester resin (I) has a molecular weight of 5,000 to 50,000, preferably 7000 to 50,000.
30,000 and a viscosity of 10 to 10,000 poise (190
° C), preferably 100 to 5000 poise (190
C) and a glass transition temperature (Tg) of -60 to 50C, preferably -50 to 30C, and the effect of the present invention is remarkably exhibited.

The resin (I) of the present invention may contain various additives as required. Examples of the additive include derivatives of various acids such as dioctyl phthalate, diphenyl phthalate, and triphenyl phosphate;
Glycol derivatives, glycerin derivatives, epoxy derivatives, low and medium molecular weight polyester plasticizers, polyether plasticizers, process oils such as paraffinic, naphthenic and aromatics, and softeners or stabilizers such as castor oil, Inorganic / organic fillers, pigments, other thermoplastic resins, and the like can be incorporated as needed to the extent that the effects of the present invention are not impaired.

In the present invention, the resin (I)
Is melt-molded according to a known method such as extrusion molding, and is formed into a molded product such as a film or a sheet. If necessary, a solvent such as dimethylsulfoxide is also used. Among the molded products, for example, in the case of a film, there is no particular limitation,
It can be set to several μm to several hundred μm, preferably 5 to 50 μm, particularly preferably 10 to 30 μm. In the present invention, in the film (a thickness of 10 [mu] m), the moisture permeability of 3000g / m ² · 24hr or more, preferably desired to be 3000~10000g / m ² · 24hr.

Thus, the molded article made of the resin (I) of the present invention can be used not only for metals and synthetic resins (excluding polyolefins) but also for non-polar and highly crystalline materials such as polyethylene and polypropylene, which are extremely difficult to adhere. Polyolefin resins and their molded products (films, sheets, cups,
Etc.) or excellent adhesion (adhesion) to non-woven fabric etc.
It has performance and is also excellent in moisture permeability,
Particularly, it is very useful for various uses such as a back sheet of a disposable diaper.

[0023]

The present invention will be specifically described below with reference to examples. In the examples, “parts” and “%” are based on weight unless otherwise specified. Example 1 0.70 mol (37 parts) and 0.30 mol of terephthalic acid as a polybasic acid component (A) in a reactor equipped with a stirrer, a thermometer, a gas inlet and a distillation port under a nitrogen gas atmosphere. (63 parts) (trade name: PP-1010, manufactured by Unichema) 0.10 mol (18 parts) of hydrogenated polybutadiene polyol (trade name: Polytail HA, manufactured by Mitsubishi Chemical Corporation) as a glycol component (B), average 0.50 mol (79 parts) of polytetramethylene glycol having a molecular weight of 2000,
0.90 mol (3 parts) of 1,4-butanediol, and 2.0 × 10 ⁻⁴ mol / acid of zinc acetate and 3.0 × 10 ⁻⁴ mol / acid of antimony trioxide as a catalyst were charged under a nitrogen atmosphere. At 240 ° C. to carry out an esterification reaction.

Next, tetra n-butyl titanate 1 ×
Add 10 ^-4 mol / acid and add 3 to 250 ° C. under 1 Torr.
The polyester resin (I) of the present invention is subjected to time polycondensation.
(Molecular weight 25,000, glass transition temperature (Tg) -3)
7 ° C.), and then pelletized with a pelletizer. The pellet was attached to an extruder having a screw diameter of 40 mmφ and L / D = 28, a lip opening of 0.6 mm, and a width of 500 mm.
Extruded at a temperature 50 ° C. higher than the melting point of the resin using a T-die, and brought into contact with a cooling roll having a diameter of 350 mmφ in which water having a temperature of 25 ° C. circulates to form a take-off film at 10 m / min. The obtained film was evaluated as follows.

(Adhesion) The above film (size: length 20)
cm, width 5 cm, thickness: 50μ) and a non-woven fabric made of polyethylene at 130 ° C by a hot roll, and then
C. for one day, and then further left for one day at 20.degree. C. and 60% RH. (Moisture Permeability) The moisture permeability of the above film was measured according to JIS Z 02
The measurement was performed based on the 08 cup method.

Example 2 A polyester resin (I) was obtained in the same manner as in Example 1 except that an acid component and a glycol component as shown in Table 1 were used (molecular weight 21,000, glass transition temperature (T
g) at −40 ° C.), and a film was prepared according to Example 1. About the obtained film, the same evaluation as Example 1 was performed.

Comparative Example 1 A polyester resin (I) was obtained in the same manner as in Example 1 except that an acid component and a glycol component as shown in Table 1 were used (molecular weight 23,000, glass transition temperature (T
g) at −41 ° C.), and a film was prepared according to Example 1. About the obtained film, the same evaluation as Example 1 was performed.

Comparative Example 2 A polyester resin (I) was obtained in the same manner as in Example 1 except that an acid component and a glycol component as shown in Table 1 were used (molecular weight 21,000, glass transition temperature (T
g) at −35 ° C.), and a film was prepared according to Example 1. About the obtained film, the same evaluation as Example 1 was performed.

Comparative Example 3 A polyester resin (I) was obtained in the same manner as in Example 1 except that an acid component and a glycol component as shown in Table 1 were used (molecular weight 18,000, glass transition temperature (T
g) at −55 ° C.) and a film was prepared according to Example 1. About the obtained film, the same evaluation as Example 1 was performed.

Comparative Example 4 A polyester resin (I) was obtained in the same manner as in Example 1 except that an acid component and a glycol component as shown in Table 1 were used (molecular weight 25,000, glass transition temperature (T
g) -19 ° C), and a film was prepared according to Example 1. About the obtained film, the same evaluation as Example 1 was performed. Table 2 shows the evaluation results of the examples and the comparative examples.

[0031]

TABLE 1 Acid component Glycol component (a-1) (a-2) (b-1) (b-2) Other glycol components ( %) (%) (%) (%) (%) TPA PP-1010 PTHA PTMG 1,4-BG (37) (63) (18) (79) (3) 〃2 TPA PP-1010 PTHA PTMG 1,4-BG (20) (80) (26) (68 (6) Comparative Example 1 TPA PP-1010 − PTMG 1,4-BG (37) (63) (97) (3) 〃2 TPA PP-1010 PTHA − 1,4-BG (37) (63) ( 97) (3) ３ 3-PP-1010 PTHA PTMG 1,4-BG (100) (18) (79) (3) ４ 4 TPA-PTHA PTMG 1,4-BG (100) (18) (79) (3)

Note) The symbols in the table are as follows. (A-1): aromatic dicarboxylic acid (a-2): branched polybasic acid having an alkyl group having 2 or more carbon atoms in the side chain (b-1): hydrogenated polybutadiene polyol (b-2): poly ( Alkylene oxide) glycol (%): In the acid component, the weight% of each component with respect to the entire acid component. In the glycol component, the weight% of each component with respect to the entire glycol component. TPA: terephthalic acid, PP-1010: Pripol 1
010 (manufactured by Uniqema), PTHA: Polytail HA
(Manufactured by Mitsubishi Chemical Corporation), PTMG: polytetramethylene glycol, 1,4-BG: 1,4-butanediol

[0033]

Table 2 Adhesion (g / inch) Moisture permeability (g / m ² · 24 hr) Example 1 1890 3800 2 1510 3500 Comparative Example 1 10 4800 〃 2 2100 1500 ３ 3 420 3700 ４ 4 860 3000

[0034]

The molded article made of the polyester resin of the present invention has excellent adhesiveness to polyolefin and exhibits excellent moisture permeability.

Claims (6)

[Claims] 1. A polyester obtained by polycondensing a polybasic acid component (A) and a glycol component (B) comprising a hydrogenated polybutadiene polyol (b-1) and a poly (alkylene oxide) glycol (b-2). A molded article characterized by comprising resin (I). 2. The polybasic acid component (A) comprises an aromatic dicarboxylic acid (a-1) and a branched polybasic acid (a-2) having an alkyl group having 2 or more carbon atoms in a side chain. The molded product according to claim 1, wherein 3. A branched polybasic acid having an aromatic dicarboxylic acid (a-1) in an amount of 20 to 90% by weight and an alkyl group having 2 or more carbon atoms in a side chain, based on the entire polybasic acid component (A). a-
The molded article according to claim 2, wherein 10) to 80% by weight of 2) is blended. 4. A hydrogenated polybutadiene polyol (b-1) in an amount of 10 to 60% by weight based on the whole glycol component (B), and a poly (alkylene oxide) glycol (b-
The molded product according to claim 1, wherein 30 to 89% by weight of 2) and 1 to 60% by weight of another glycol component are blended. 5. The molded product according to claim 1, which is used as a film. 6. The molded article according to claim 1, which is used as a back sheet for a disposable diaper.