JPH0245657B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to aqueous polyester hot melt adhesives. More specifically, the present invention relates to a water-based polyester hot melt adhesive having excellent water resistance, solvent resistance, and adhesive properties. Traditionally, hot melt adhesives have been used in film, powder, pellet, and paste forms to bond textiles, nonwoven fabrics, films, metals, etc., and will continue to grow due to their ease of handling and excellent adhesive strength. It is expected. Thermoplastic resins that are currently preferred include ethylene/vinyl acetate copolymers, polyamide resins, and copolymerized polyester resins. However, each of these thermoplastic resins has some drawbacks. That is, ethylene/vinyl acetate copolymers have insufficient solvent resistance and heat resistance, and polyamide resins have excellent solvent resistance but poor water resistance. On the other hand, polyester resin has extremely excellent properties such as solvent resistance, water resistance, heat resistance, and adhesiveness, and is highly evaluated as a resin with the best balance of each performance. However, when these polyester resins having excellent performance are used as an aqueous paste, there are disadvantages in terms of performance. That is, when dispersing polyester resin powder in water, it is necessary to use a water-soluble resin such as polyethylene oxide or carbomethyl cellulose, or a surfactant, which results in a decrease in water resistance, adhesiveness, etc. Therefore, there is a strong desire to develop a technology for making polyester resin water-based without impairing the above-mentioned excellent performance. As a result of extensive research into water-based polyester hot melt adhesives with excellent water resistance, adhesion, solvent resistance, and heat resistance, the present inventors found that
We have arrived at the present invention. That is, in the present invention, (A) 0.5 to 20 mol% of the polycarboxylic acid component
Amorphous polyester resin (A′) with a molecular weight of 3000 to 30000 and/or crystalline polyester (A″) which is an aromatic dicarboxylic acid containing a sulfonic acid metal group, (B) a polyester resin with a boiling point of 60 to
Contains a water-soluble organic compound at 200°C, (C) water, (D) thermoplastic resin powder with a particle size of 200μ or less, and (A), (B), (C) and (D) are of the following formula (1) ), (2), (3), and (4). Formula (1) (A) + (B) + (C) + (D) = 100 (weight ratio) Formula (2) (A) + (D) / (B) + (C) = 5 ~ 70/95 ~30 (weight ratio) Formula (3) (D)/(A)+(D)=0~0.98 (weight ratio) Formula (4) (B)/(B)+(C)=0~0.66 (weight ratio) (However, in the case of (D) = 0, (A) is amorphous polyester resin (A'): crystalline polyester resin (A'') = 5
The ratio is ~30:95~70 (weight ratio). ) In the present invention, by using a water-based polyester resin mainly consisting of a sulfonic acid metal base-containing polyester resin (A), a water-based polyester hot melt adhesive having excellent water resistance, adhesiveness, solvent resistance, and heat resistance can be obtained. . In the polyester resin (A) of the present invention, the sulfonic acid metal group-containing aromatic dicarboxylic acid accounts for 0.5 to 20 mol % of the polycarboxylic acid component. Specifically, the polycarboxylic acid component includes 40 to 99.5 mol% of an aromatic dicarboxylic acid containing no sulfonic acid metal group, 59.5 to 0 mol% of an aliphatic or alicyclic dicarboxylic acid, and 0.5 mol% of an aromatic dicarboxylic acid containing a sulfonic acid metal group. ~
It consists of 20 mol%, and the polyol component has 2 to 2 carbon atoms.
8 aliphatic glycol or/and carbon number 6~
A polyester resin comprising 12 alicyclic glycols is preferable. Examples of aromatic dicarboxylic acids that do not contain sulfonic acid metal groups include terephthalic acid, isophthalic acid, orthophthalic acid, and 2,6-naphthalenedicarboxylic acid. The aromatic dicarboxylic acid containing no sulfonic acid metal group preferably accounts for 40 to 99.5 mol % of the polycarboxylic acid component. If it is less than 40 mol%, the mechanical strength and water resistance of the polyester resin will be poor, which is not preferable. If it exceeds 99.5 mol%, the polyester resin will no longer be dispersed in the system. Examples of aliphatic or alicyclic dicarboxylic acids include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, dimer acid, tetrahydrophthalic acid, hexahydrophthalic acid, hexahydroisophthalic acid, and hexahydroterephthalic acid. etc. can be mentioned. Aliphatic or cycloaliphatic dicarboxylic acids are 59.5% of the polycarboxylic acid component.
It is preferable that it is 0 mol%. If it exceeds 59.5 mol%, water resistance and coating strength will decrease and tackiness will appear. Furthermore, p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, hydroxypivalic acid, γ-butyrolactone, ε-caprolactone, etc. can be used if necessary. If necessary, a trifunctional or higher functional polycarboxylic acid such as trimellitic acid or pyromellitic acid may be used in an amount of 5 mol % or less based on the total polycarboxylic acid component. Examples of aliphatic glycols having 2 to 8 carbon atoms include ethylene glycol, propylene glycol, 1,3
-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, diethylene glycol, 1,6-hexanediol and the like. Examples of the alicyclic glycol having 6 to 12 carbon atoms include 1,4-cyclohexanedimethanol. The aliphatic glycol having 2 to 8 carbon atoms and/or the alicyclic glycol having 6 to 12 carbon atoms accounts for 95 to 100 mol% of the total polyol component. Further, if necessary, a trifunctional or higher functional polyol such as trimethylolpropane, trimethylolethane, glycerin, pentaerythritol, etc. may be used in an amount of 5 mol % or less based on the total polyol component. Furthermore, a polyalkylene glycol having a molecular weight of 7,000 or less, preferably 5,000 or less, such as polyethylene glycol, polypropylene glycol, or polytetramethylene glycol, is used if necessary, as long as it is 15% by weight or less, preferably 10% by weight or less based on the total polyol component. be able to. Examples of aromatic dicarboxylic acids containing sulfonic acid metal bases include metals such as sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, and 5-[4-sulfophenoquine]isophthalic acid. I can give you some salt. Metal salts include Li, Na, K, Mg,
Examples include salts such as Ca, Cu, and Fe, but especially Na,
K salt is preferred. The amount of the aromatic dicarboxylic acid containing a sulfonic acid metal group is 0.5 to 20 mol % based on the polycarboxylic acid component. Preferably it is 0.5 to 10 mol%, more preferably 1.0 to 7 mol%. If the amount is less than 0.5 mol %, the polyester resin will not be dispersed in water at all, and if it exceeds 20 mol %, the resulting film will have very poor water resistance. The molecular weight of the polyester resin of the present invention is 3000~
30,000, preferably 6,000 to 25,000. molecular weight
If it is less than 3,000, the adhesive strength will be poor, and if it exceeds 30,000, the dispersibility in water will be poor, which is not preferable. The polyester resin of the present invention can be produced by conventional methods. The polyester resin used in the present invention may be either crystalline or amorphous, or may be a mixture thereof. In particular, amorphous polyester resin (A′): crystalline polyester resin (A″) = 5 to 30:
A mixing ratio of 95 to 70 (weight ratio) is preferable. The water-soluble organic compound (B) with a boiling point of 60 to 200°C used in the present invention is preferably an organic compound having a solubility in water 1 at 20°C of 20 g or more and containing no heteroatoms other than oxygen. . Specifically, aliphatic and alicyclic alcohols,
Examples include ether, ester, and ketone compounds. More specifically, for example, methanol,
Monohydric alcohols such as ethanol, n-propanol, i-propanol, n-butanol, i-butanol, sec-butanol, tert-butanol, glycols such as ethylene glycol, propylene glycol, methyl cellosolve, ethyl cellosolve, isopropyl cellosolve , tert-butyl cellosolve, n-butyl cellosolve, 3-methyl-3-methoxybutanol, glycol derivatives such as n-butyl cellosolve acetate, ethers such as dioxane and tetrahydrofuran, esters such as ethyl acetate, methyl ethyl ketone, cyclohexanone, cycloocta These include ketones such as non, cyclodecanone, and cyclohexanone. Particularly preferred are n-butyl cellosolve, ethyl cellosolve, isopropanol and the like. These water-soluble organic compounds can be used alone or in combination of two or more. The boiling point of these water-soluble organic compounds must be in the range of 60 to 200°C. If the boiling point does not reach 60°C, it is difficult to maintain a temperature sufficient to mix or dissolve the polyester resin in the organic compound. Furthermore, water-based polyester obtained when the boiling point exceeds 200℃
After applying hot melt adhesives, fast drying is not achieved. Furthermore, if an amide or sulfonic acid ester compound is used as the water-soluble compound, the drying properties will be poor and at the same time the storage stability of the aqueous polyester hot melt adhesive will be poor. The thermoplastic resin powder (D) of the present invention is a pulverized product of thermoplastic resins such as conventional polyester resins, polyethylene/vinyl acetate, and the polyester resin (A) of the present invention. In particular, crystalline polyester resins having a melting point of 70 to 200°C are preferred. The crystalline polyester resin is preferably a crystalline polyester resin in which a sulfonic acid metal group-containing aromatic dicarboxylic acid is not copolymerized and/or a crystalline polyester resin (A'') of the present invention, particularly a polyalkylene resin having a molecular weight of 7000 or less. A crystalline polyester resin having a glycol component of 15% by weight (based on the resulting polymer) is preferred.
These crystalline polyester resins are used as resin powder after being finely pulverized. Furthermore, the particle size of the thermoplastic resin powder is 200μ or less, preferably 100μ
It is as follows. If the particle size exceeds 200 μm, problems such as a smooth and uniform film cannot be obtained when applying the obtained aqueous polyester hot melt adhesive, or clogging occurs when a rotary screen is used. A water-based polyester resin can be obtained by blending the polyester resin (A), water (C), and, if necessary, a water-soluble organic compound (B). The aqueous polyester hot melt adhesive of the present invention is produced by stirring and mixing a previously prepared aqueous polyester resin and thermoplastic resin powder. On the other hand, water-based polyester resin can be prepared by, for example, mixing (A) polyester resin and (B) water-soluble organic compound in advance at 50 to 200°C, then adding (C) water to this, or mixing (A) and (B) together. add mixture to water
Manufactured by methods such as stirring at 40-120°C.
When mixing the thermoplastic resin powder with the aqueous polyester resin, water may be added if necessary. In these methods, (A) polyester resin, (B)
The blending ratio of the water-soluble organic compound, (C) water, and (D) thermoplastic resin powder is an important factor in maintaining the performance of water-based polyester hot melt adhesive, and the formula
It is necessary to satisfy the compounding ratio (weight ratio) of (1), (2), (3) and (4). Formula (1) (A) + (B) + (C) + (D) = 100 Formula (2) (A) + (D) / (B) + (C) = 5 ~ 70 / 95 ~ 30 Formula ( 3) (D)/(A)+(D)=0~0.98 Formula (4) (B)/(B)+(C)=0~0.66 (A) Polyester resin contained in water-based polyester hot melt adhesive and (D) If the thermoplastic resin powder content does not reach 5% by weight or exceeds 70% by weight, the viscosity of the aqueous polyester hot melt adhesive becomes undesirably low or too high. Contained in water-based polyester hot melt adhesive (D)
If the thermoplastic resin powder exceeds 0.98 to the sum of (A) polyester resin and (D) thermoplastic resin powder, it will not be uniformly dispersed in the aqueous polyester resin. If the amount of the water-soluble organic compound (B) contained in the water-based polyester hot-melt adhesive exceeds 0.66 relative to the sum of the water-soluble organic compound (C) and the water-soluble organic compound (B), the drying properties will deteriorate, which is undesirable. The aqueous polyester hot melt adhesive of the present invention may optionally contain crosslinking agents such as amino resins, epoxy resins, and isocyanate compounds, and water-based resins such as acrylic emulsion and acetic acid emulsion. The water-based polyester hot melt adhesive of the present invention can be used as an adhesive for textile products such as textiles and non-woven fabrics, metals such as steel plates and aluminum plates, paper, and plastic films due to its unprecedented excellent water resistance, solvent resistance, heat resistance, and It exhibits adhesive properties. The water-based polyester hot melt adhesive of the present invention may contain water-soluble resins, thickeners such as amines, pigments, dyes, and various additives, if necessary. EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples. In the examples, parts simply refer to parts by weight. Evaluation of various properties was performed according to the following methods. (1) Molecular weight Measured using a molecular weight measuring device (model 115 manufactured by Hitachi, Ltd.). (2) Crystal melting point Measured using a differential scanning calorimeter (manufactured by Shimadzu Corporation) at a heating rate of 10°C/min. (3) Softening point Fully automatic melting point measuring device (manufactured by METTLER,
The measurement was carried out using MODEL FP-1). (4) Particle size of aqueous dispersion Measured using a grindmeter and an optical microscope. (5) Adhesiveness Compliant with JIS K 6854. (6) Water resistance In accordance with JIS L 1042, the peel strength retention rate was measured after washing three times. (7) Solvent resistance After performing dry cleaning at 50° C. three times using perchloroethylene, the retention rate of peel strength was measured. Production example 1 430 parts of dimethyl terephthalate, 466 parts of dimethyl isophthalate, 45 parts of dimethyl 5-sodium sulfoisophthalate, 443 parts of ethylene glycol,
400 parts of neopentyl glycol, 0.44 parts of zinc acetate,
0.05 part sodium acetate and antimony trioxide
0.43 part was charged into a reaction vessel, and the transesterification reaction was carried out at 140°C to 220°C over 4 hours. Then,
While raising the temperature to 260°C, the pressure inside the reaction system was gradually reduced to 5 mmHg after 1 hour. and finally 260
A polycondensation reaction was carried out for 1 hour at a temperature of 0.1 to 0.3 mmHg to obtain an amorphous polyester resin (B-1) having a molecular weight of 7000 and a softening point of 152°C. As a result of compositional analysis such as NMR, the composition of polyester resin (B-1) is 48 mol% terephthalic acid, 49 mol% isophthalic acid, 3 mol% 5-sodium sulfoisophthalic acid, 52 mol% ethylene glycol, and neopentyl glycol. It was 48 mol%. Further, crystalline polyester resin (A-1) ~
(A-5), amorphous polyester resin (B-2) ~
(B-4) was obtained. Their characteristic values are shown in Table 1-1
and -2.

【table】

[Table] Example 1 24 parts of polyester resin (A-1), 6 parts of polyester resin (B-1) and 10 parts of n-butyl cellosolve were melt-mixed at 130°C, and then 60 parts of water was added to this molten mixture. By adding with stirring, a blue-white stable aqueous polyester resin (C-1) with a particle size of 1 μm or less was obtained. Next, 100 parts of the obtained aqueous resin (C-1) C and
A uniformly dispersed aqueous polyester hot melt adhesive (D-1) was obtained by mixing with 30 parts of powder of crystalline polyester resin (2) having a particle size of 100 μm or less while stirring. The water-based polyester hot melt adhesive (D-1) thus obtained was applied onto polyester/cotton (65/35) broadcloth using a rotary screen to give a basis weight of 15 g/m ² . After drying at ℃ for 3 minutes, it was bonded to the untreated broadcloth for 10 seconds at 150 ℃ and 0.5 kg/cm ² . The peel strength of the obtained adhesive broad is 650g/
inch, and the peel strength retention rate after washing test and dry cleaning test was 95% and 90%, and it was found to have excellent adhesion, water resistance, and solvent resistance. Examples 2 to 6 Comparative Examples 1 to 7 Water-based polyester resin (C
-2) After obtaining (C-5), the water-based polyester hot melt adhesive (D-2) shown in Table 3 was used.
(D-6) was obtained. Table 4 shows the properties and performance of the aqueous polyester hot melt adhesive obtained. For comparison, aqueous polyester resins (C-6) to (C-10) were obtained in exactly the same manner as in Example 1 except for the formulations shown in Tables 2 and 3. A stable dispersion of the aqueous polyester resins (C-6) and (C-9) could not be obtained. Next, water-based polyester hot melt adhesives (D-7) to (D-
11). Table 4 shows the performance of the resulting aqueous polyester hot melt adhesive. In addition, the water-based polyester hot melt adhesive (D-11), which is made by dispersing the amorphous polyester resin powder () in the water-based polyester resin (C-5), has poor stability, and when left at 40°C for 200 hours, the resin powder Aggregation and sedimentation were observed.

【table】

【table】

【table】 Abbreviations indicate the following. TPA: Terephthalic acid EG: Ethylene glycol IPA: Isophthalic acid BD: Butanediol AA: Adipic acid PTMG: Polytetramethylene glycol

【table】

【table】

Claims (1)

[Claims] 1 (A) 0.5 to 20 mol% of the polycarboxylic acid component
is an aromatic dicarboxylic acid containing a sulfonic acid metal group, an amorphous polyester resin (A′) with a molecular weight of 3,000 to 30,000 and/or a crystalline polyester resin (A″), (B) a polyester resin with a boiling point of 60
~200℃ water-soluble organic compound, (C) water, (D) particle size 200μ
Contains the following crystalline thermoplastic resin powder with a melting point of 70 to 200°C, and (A), (B), (C) and (D) have the following formula:
A water-based polyester hot melt adhesive characterized by satisfying (1), (2), (3), and (4). Formula (1) (A) + (B) + (C) + (D) = 100 (weight ratio) Formula (2) (A) + (D) / (B) + (C) = 5 ~ 70/95 ~30 (weight ratio) Formula (3) (D)/(A)+(D)=0~0.98 (weight ratio) Formula (4) (B)/(B)+(C)=0~0.66 (weight ratio) (However, in the case of (D) = 0, (A) is amorphous polyester resin (A'): crystalline polyester resin (A'') = 5
The ratio is ~30:95~70 (weight ratio). )