JPH0657230A - Hot-melt adhesive - Google Patents

Abstract

PURPOSE:To obtain a hot-melt adhesive having excellent adhesiveness and a long open time by using a saturated polyester resin prepared by polycondensing a specified polybasic acid component with a specified polyhydric alcohol. CONSTITUTION:The hot-melt adhesive comprises a saturated polyester prepared by polycondensing a polybasic acid component containing 2-20mol% dimer acid with a polyhydric alcohol component containing 2-20mol% 1,4- cyclohexanedimethanol. The dimer acid used is a dimer of a 10C or higher unsaturated fatty acid. It is necessary that the polybasic acid component should contain 2-20mol% dimer acid. When the dimer content is below this range, the dimer does not contribute to the prolongation of the open time and the improvement of adhesiveness. On the contrary, when this content is excessively high, the heat stability becomes poor. It is also necessary that the polyhydric alcohol should contain 2-20mol% 1,4-cyclohexanedimethanol. When the content is below this range, it does not contribute to the prolongation of the open time and the improvement of adhesiveness. On the contrary, when it is excessively high, the adhesiveness is poor.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a hot melt adhesive using a novel polyester resin. More specifically,
The present invention relates to a hot melt adhesive having excellent adhesiveness and long open time (pot life).

[0002]

2. Description of the Related Art Hot melt adhesives are solvent-free, instant adhesive, and adhere to a relatively wide range of adherends, and are economical and convenient. It has been widely used for interior materials for construction and various other packaging applications, and has been used in large quantities. However, there are problems such as a decrease in adhesive strength depending on the type of adherend, temperature dependence of adhesive strength, and open time. In order to solve these problems, JP-A-57-165475 and JP-A-57-157475 have been proposed.
In Japanese Patent Laid-Open No. 133173, the applicant of the present invention discloses that 1,4-cyclohexanedimethanol and a molecular weight of 30 are used as polyhydric alcohol components in order to improve adhesiveness with a synthetic resin molded product.
The adhesive strength was improved by using glycol of 0 or more. In JP-A-60-110723, dimer acid or its derivative is used as a polycondensation component of polyester to improve the temperature dependence of the adhesive force.

[0003]

However, the open time has been pointed out as a problem of the prior art in Japanese Patent Laid-Open No. 60-110723, but it has not been solved by the technique disclosed in the same, and the bonding is not performed. There is an urgent need for the development of hot-melt adhesives with excellent properties and long open times.

[0004]

[Means for Solving the Problems] The inventors of the present invention have conducted diligent research in view of such circumstances, and as a result, as a result, a polybasic acid component containing 2 to 20 mol% of dimer acid and 2 to 20 mol% of 1,4 −
We have found that a hot melt adhesive made of a saturated polyester resin obtained by polycondensation with a polyhydric alcohol component containing cyclohexanedimethanol has excellent adhesive strength and has a long open time, and completed the present invention. . The present invention is described in detail below. The dimer acid used in the present invention is a dimer of an unsaturated fatty acid having 10 or more carbon atoms, and specific examples thereof include a dimer acid obtained by polymerizing tall oil fatty acid as shown in Chemical formula 1.

[0005]

[Chemical 1]

As the dimer of linoleic acid, Versadim 288 (manufactured by Henkel Japan Ltd.) and Empol10
4 (manufactured by Emery Co., USA) and the like. As other polybasic acid components, aromatic dicarboxylic acids and aliphatic dicarboxylic acids are used, and specifically, terephthalic acid, isophthalic acid, malonic acid, succinic acid, adipic acid, pimelic acid, speric acid, azelaic acid. , Sebacic acid, and their lower alkyl esters, acid anhydrides, etc., which are used in combination with an aromatic dicarboxylic acid and one or more aliphatic dicarboxylic acids.

It is essential that the polyhydric alcohol component contains 1,4-cyclohexanedimethanol, and the other polyhydric alcohol components include propylene glycol, ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, 1,3
-Butylene glycol, 2,3-butylene glycol,
1,4-butanediol, 1,6-hexanediol,
2-ethyl-1,3-hexanediol, 2,2,4-
General polyhydric alcohols such as trimethyl-1,3-pentanediol, neopentyl glycol, trimethylolethane, trimethylolpropane, glycerin, pentaerythritol, and polytetramethylene glycol can be used in combination.

The hot melt adhesive of the present invention essentially contains 2 to 20 mol% of dimer acid in the polybasic acid component, preferably 3 to 12 mol%. If the amount of the dimer acid is less than the above range, it does not contribute to the extension of the open time and the improvement of the adhesive force. In addition, it is essential and preferable that the polyhydric alcohol component contains 2 to 20 mol% of 1,4-cyclohexanedimethanol.
10 to 10 mol%. When the amount of 1,4-cyclohexanedimethanol is less than the above range, it does not contribute to the extension of the open time and the improvement of the adhesive force. On the contrary, when it is more than the above range, the softening point is lowered and the glass transition point of the resin is increased to lower the adhesive force. , Not preferable.

The polyester resin of the present invention is produced by polycondensing the above polybasic acid component and polyhydric alcohol component. The polyester resin produced has a heat of crystal fusion of 2 to 20 J / g. (Measurement with a differential scanning calorimeter) is preferable, and further 3 to 15 J / g is preferable. If the heat of crystal fusion is low, the heat of fusion becomes close to amorphous, and the strength of the resin is weak and the adhesive strength is reduced. On the other hand, if it is high, the crystallization speed becomes fast, the open time becomes short, and the crystal shrinkage becomes large, so that the adhesive strength is lowered. The molecular weight is 7,000-3
Approximately 0000 is preferable, and further 10,000 to 2000
0 is preferred. When the molecular weight is low, the cohesive force of the adhesive is reduced and the adhesive force is reduced. On the contrary, if it is high, the viscosity at the time of heat melting is high, resulting in poor workability. About the softening point, 80-14
0 degreeC is preferable and 90-130 degreeC is more preferable. When the softening point is low, the cohesive force at high temperature is lowered, resulting in poor high temperature adhesiveness.

The method for producing the hot melt adhesive of the present invention as described above is not particularly limited, and can be carried out according to a known ordinary method. For example, a method in which the polybasic acid component containing the dimer acid and the polyhydric alcohol component containing 1,4-cyclohexanedimethanol are simultaneously or stepwise directly esterified or subjected to an ester exchange reaction and then polymerized, etc. Can be adopted. Any known various catalysts, stabilizers, modifiers or additives may be used during the polymerization or transesterification reaction. The following methods may be mentioned as methods for controlling the heat of crystal fusion and the softening point of the polyester resin produced by the above production method.

Heat of crystal fusion Control is performed by balancing with a raw material such as phthalic acid, dimer acid, cyclohexanedimethanol that destroys crystallinity. That is, when the amount of the raw material is increased, the heat of crystal fusion is lowered. -Softening point Controlled by the ratio of aromatic acid and aliphatic acid. That is, increasing the ratio of the aliphatic acid lowers the softening point. The hot melt adhesive of the present invention obtained by such a method,
It is useful for bonding synthetic resin, particularly vinyl chloride resin sheets, films, leathers, foams or the like, or wood, metal plate, paper, leather and the like. In use, the hot melt adhesive of the present invention (powder, film,
After setting an appropriate amount of fibrous material) between the adherends and heating and pressing to a temperature sufficient to melt the hot melt adhesive, or after melting the hot melt adhesive and coating it on the substrate There is a method of stacking a base material on it, and it is also possible to use various commercially available applicators, and various methods are adopted depending on the purpose.

[0012]

EXAMPLES The present invention will be specifically described below with reference to examples. In addition, "%" in the examples means weight basis unless otherwise specified. Example 1 4 equipped with a stirrer, rectification column, nitrogen inlet tube and vacuum device
1 mol of polybasic acid component (10 mol% of dimer acid [Harima Chemicals Co., Ltd., Haridimer 300], 40 mol% of terephthalic acid, 25 mol% of isophthalic acid, 25 mol% of sebacic acid) in a 2-necked flask with a large amount of polybasic acid Polyhydric alcohol component (1,4-cyclohexanedimethanol 2 mol%,
1,4-butanediol (98 mol%,) 1.5 mol and dibutyltin oxide 0.001 mol as a catalyst were charged, an esterification reaction was performed at 180 to 240 ° C., and then 0.001 mol of tetra-n-butyl titanate was added. Then, a polycondensation reaction was carried out at 250 ° C. under a reduced pressure of 1 Torr or less to obtain a resin having a molecular weight of 18,000, a melt viscosity of 230 poises, a softening point of 90 ° C. and a heat of crystal fusion of 6.2 J / g. This resin is melted and heated at 200 ° C. and applied on a vinyl chloride resin film (110 μ, plasticizer content 35%) to a thickness of 300 μ, and the predetermined open time (30, 60,
(120, 180 seconds), the vinyl chloride resin fill described above was superposed thereon, and pressed at a pressure of 100 g / cm ² for 30 seconds, and the 180 ° peel strength was measured.

Examples 2 and 3 and Comparative Examples 1 to 6 Polyester resins were obtained in the same manner as in Example 1 with the resin compositions shown in Tables 1 and 2. Table 3 shows the resin properties and adhesive strength of the polyester resins for hot melt adhesives obtained in Examples and Comparative Examples.

[0014]

[Table 1] Polybasic acid component (mol%) Polyhydric alcohol component (mol%) DA-300 TPA IPA DDA SebA AdA CHDM 1,4BG PTMG Example 1 10 40 25 0 25 25 0 2.2 97.8 0 Example 2 5 50 30 0 0 15 3.5 91.5 5 Example 3 3 40 37 20 0 0 7.2 7.2 92.8 0

[0015]

[Table 2] Polybasic acid component (mol%) Polyhydric alcohol component (mol%) DA-300 TPA IPA SebA AdA CHDM EG 1,4BG 1,6HG PTMG Comparative Example 1 5 55 30 0 10 10 0 0 93.1 6.9 0 Comparative Example 2 0 45 0 0 55 11.2 15.2 73.1 0 0 Comparative Example 3 5 55 55 30 0 10 0 0 88.5 6.5 5 Comparative Example 4 15 85 0 0 0 0 24.8 0 75.2 0 0 Comparative Example 5 0 70 70 20 10 0 7.2 0 92.8 0 0 Comparative Example 6 25 75 0 0 0 3.2 3.2 96.8 0 0 Note) The molecular weights of the polyester resins of Examples and Comparative Examples were all 15,000 to 18,000. (Measured by end group method)

Abbreviations in Tables 1 and 2 are as follows: DA-300; dimer acid manufactured by Harima Chemicals, TPA; terephthalic acid, IPA; isophthalic acid, DDA; dodecanedicarboxylic acid, SebA; sebacic acid, AdA; adipic acid. , CHDM; 1,4-cyclohexanedimethanol, EG; ethylene glycol, 1,4BG; 1,4-butanediol, 1,6HG; 1,6-hexanediol, PTMG; polytetramethylene glycol (molecular weight 1000)

[0017]

[Table 3] Resin Adhesive force (g / inch) Melt viscosity Softening point Crystal heat of fusion Open (poise) (℃) (J / g) 30 seconds 60 seconds 120 seconds 180 seconds Example 1 230 90 90 6.2 5270 5670 4120 3530 (material) (material) (boundary) (boundary) Example 2 260 103 103 7.2 6820 6430 4760 4050 (material) (material) (boundary) (material) (boundary) Example 3 380 91 11.7 7580 7230 6950 3500 (material) (material) (material) (boundary) Comparative Example 1 230 104 8.7 2710 1750 1620 1380 (boundary) (boundary) (boundary) (boundary) Comparative Example 2 310 98 13.9 2950 2310 1970 1110 (material) (boundary) (boundary) (boundary) Comparative Example 3 220 220 105 8.8 2700 1620 1370 1010 (boundary) (boundary) (boundary) (boundary) Comparative Example 4 400 154 17.2 3600 1310 870 0 (material) (boundary) (boundary) (boundary) Comparative example 5 200 155 20.7 1180 550 0 0 (boundary) (boundary) (boundary) (boundary) Comparative example 6 230 158 15 .0 2350 450 0 0 (boundary) (boundary) (boundary) (boundary)

Note) Measuring method: Melt viscosity enhancement type flow tester (CFT-500 manufactured by Shimadzu Corporation)
Using C), nozzle: φ1mm × 1cm, load: 30k
g, temperature; measured at 190 ° C.・ Softening point high flow tester (CFT-500 manufactured by Shimadzu Corporation)
Nozzle: φ0.5 mm × 1 mm, load: 2)
The temperature was raised from 40 ° C. at a rate of 3 ° C./min under the condition of 0 kg, and the temperature at which the resin began to flow was measured. Heat of fusion of crystals Differential scanning calorimeter (DSC-7 manufactured by Perkin Elmer)
Was used to measure the heat of fusion by raising the temperature from -50 to 180 ° C at a rate of 20 ° C / min. -Adhesion (180 ° peel strength) Tensile tester (Autograph AG-10 manufactured by Shimadzu Corporation)
0), test speed 100mm / min, 20
It was measured under the conditions of ° C and 65% RH. (Material) is material destruction,
The (boundary) represents interfacial peeling.

[0019]

EFFECT OF THE INVENTION The hot melt adhesive obtained by the present invention is an adhesive which can prolong the open time and is excellent in adhesiveness as compared with the conventional polyester hot melt adhesives. Good adhesive strength can be obtained by heating at a relatively low temperature for a short time, which is economical and excellent in workability.

Claims (4)

[Claims] 1. A saturated polyester resin obtained by polycondensing a polybasic acid component containing 2 to 20 mol% of dimer acid and a polyhydric alcohol component containing 2 to 20 mol% of 1,4-cyclohexanedimethanol. Hot melt adhesive characterized by 2. The heat of crystal fusion measured by a thermal analysis of a differential scanning calorimeter is 2 to 20 J / g.
Hot melt adhesive described 3. The hot melt adhesive according to claim 1, having a molecular weight of 7,000 to 30,000. 4. The hot melt adhesive according to claim 1, which has a softening point of 80 to 140 ° C.