JPS60110723A - Hot melt adhesive - Google Patents

Abstract

PURPOSE:The titled adhesive having excellent heat resistance and low-temperature adhesiveness and retaining stable bonding force over a wide temperature range, comprising a specified thermoplastic copolyester elastomer. CONSTITUTION:A hot melt adhesive comprising a thermoplastic copolyester elastomer having an intrinsic viscosity as determined at 20 deg.C in a phenol/tetrachloroethane (1:1 weight ratio) solvent mixture of 0.5-1.5 is obtained by mixing an acid component comprising 50-95mol% (A) aromatic dicarboxylic acid (esterifiable derivative) with 5-40mol% (B) dimer acid, or its hydrogenated product or esterifiable derivative and 0-30mol% (C) aliphatic dicarboxylic acid (esterifiable derivative) other than component B with a glycol component comprising 60-95mol% (D) 2-10C alkylene glycol and 5-40mol% (E) long-chain glycol of an average MW of 350-6,000 so that the sum of component B and component E may be 10-70mol% and reacting the resulting mixture.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyester elastomer resin-based 1-melt adhesive that has excellent heat resistance and low-temperature adhesion when adhering various types of plastics, metals, wood, etc.

Botmelt adhesive is solvent-free and has instant adhesive properties.

In recent years, it has come to be used in large quantities mainly in light adhesive fields such as packaging and bookbinding due to its economy and convenience, such as adhesion to a relatively wide range of adherends.

However, there are still many problems when applying true melt adhesives to the field of semi-structural product assembly. That is, ethylene-vinyl acetate copolymer, polyethylene, and the like, which are general-purpose true melt adhesives, have a low softening point and therefore have a problem of poor heat resistance. In recent years, polyester resins and polyamide resins with high softening properties have been used as adhesives with good heat resistance, but they have problems such as hardening quickly after application, short open time, and poor adhesion at low temperatures. have. One possible countermeasure to this problem is to lower the glass transition point of the hot melt adhesive to lower the solidification temperature of the adhesive and improve the adhesive performance at low temperatures; however, in many cases, lowering the glass transition point Since the softening point of the adhesive also decreases, in this case a problem arises in that the heat resistance after bonding deteriorates.

On the other hand, a copolymerized polyetherester elastomer made of polyester and polyalkylene glycol such as polytetramethyone-nonglycol has been proposed as an adhesive with excellent low-temperature properties and heat resistance, but sufficient adhesion has not yet been obtained and product 1. It is insufficient as a melt adhesive for applications such as the assembly field.

Therefore, it is desired to develop a hot melt adhesive that has excellent adhesive properties from low to high temperatures.

As a result of various intensive studies aimed at providing an adhesive with excellent performance as described above, the present inventors used specific amounts of dimer acid and long chain glycol having a molecular weight that can be used as one unit of elastomer. The present invention was achieved based on the discovery that an adhesive made of a thermoplastic copolymerized polyester elastomer surprisingly has excellent adhesive properties and maintains stable adhesive strength from low to high temperatures.

That is, 1 the present invention comprises 50 to 95 mol% of an aromatic dicarboxylic acid or its ester-forming derivative (1), a dimer acid or its hydrogenated product, or its ester-forming derivative (
■) 5 to 40 mol% and an aliphatic dicarboxylic acid other than dimer acid or its ester-forming derivative (■) 0 to 30 mol% as an acid component, and 60 to 95 mol of alkylene glycol (IV) having 2 to 10 carbon atoms. %, average molecular weight approximately 350~
6000 long-chain glycol (V) The glycol component is 5-40 mol%, the sum of the component (II) and the component (V) is 10-70 mol%, and the intrinsic viscosity [phenol:te(・lachloroethane- This is a melt adhesive consisting of a thermoplastic copolymerized polyether elastomer having a temperature of 0.5 to 1.5 (measured at 20°C in a mixed solvent of 1:1 (weight ratio)).

The thermoplastic copolymerized polyester elastomer of the present invention is composed of a hard segment consisting of an aromatic dicarboxylic acid component and a soft segment consisting of a dimer acid and a long-chain alcohol component. It is something. ) The aromatic dicarboxylic acid component that constitutes the dosegment raises the softening point of the adhesive and contributes to imparting heat resistance, and its amount is 50 to 95 mol% of the acid component.
, preferably in the range of 60 to 90 mol%. When the proportion of the aromatic dicarboxylic acid component is less than 50 mol%, the heat resistance and adhesion strength (1) become low; on the other hand, when it exceeds 95 mol%,
That is, if the proportion of the timer acid component is less than 5%, the effect of the soft segment will be reduced and the adhesive strength at low temperatures will be poor. Other fatty acid (FJ) dicarboxylic acid components are appropriately used within the range of 0 to 30 mols for the purpose of adjusting the softening point and f4 melt viscosity of the resin. Describe the dimer acid and long chain glycol components that make up the soft segment.

It contributes to lowering the glass transition point and maintaining adhesive properties at low temperatures.The amount of dimer acid is 5 to 40 mol% of the total acid component, and the long chain glycol component is 3 to 40% by mole of the total glycol component.
40 mol%, and the sum of the amounts of both components is 10 to 70 mol%. If the sum of both components exceeds 70 mol%, i
ti+ thermal properties, adhesive strength becomes lower.

On the other hand, if it is less than 10 mol%, the low-temperature properties will be poor (and the adhesive will become hard and brittle, reducing the adhesiveness at room temperature. In this way, the presence of both dimer acid and long-chain glycol in the rough 1-segment) is essential, and if dimer acid is used alone, dimer acid itself has a relatively low molecular weight and has good compatibility with the hard segment part, so either the two will mix together or the low temperature properties will be insufficient, resulting in a long-term When chain glycol is used alone, it has poor compatibility with aromatic dicarboxylic acids (and therefore poor heat resistance and adhesive strength).
Furthermore, the melt viscosity also increases, making it impractical for use as a hot melt adhesive.

Examples of aromatic dicarboxylic acids that are constituents of the thermoplastic copolymer polyester elastomer of the present invention include terephthalic acid and isophthalic acid.

Examples include phthalic acid and naphthalene dicarboxylic acid, and one or more of these can be used, but terephthalic acid or a mixture of terephthalic acid and isophthalic acid is particularly preferably used. da imer acid has 10 carbon atoms
It is a dimer of the above-mentioned unsaturated fatty acids, and a preferred example is Versadime 288 (
Empol 104 (manufactured by Henkel Japan), Empol 104 (U.S. Emery Co., Ltd.) and Empol 101 (manufactured by Henkel Japan), Empol 104 (manufactured by Henkel Japan!
0 (manufactured by Emery, USA) and the like can also be preferably used.

Examples of aliphatic dicarboxylic acids other than dameric acid include succinic acid, adipic acid, acelaic acid, sebacic acid,
The number of carbon atoms in the methylene group is 4 to 20, such as dodecanedioic acid
One or two saturated aliphatic dicarboxylic acids can be used.

As the alkylene glycol, those having 2 to 10 carbon atoms are used, such as ethylene glycol, trimethylene glycol, 1,4-butanediol, 1,5-
Bentanediol, 1,6-hexanediol, and neopentyl glycol are preferably used. The long chain glycol component is about 350 to 6000. Preferably about 6
Polyalkylene glycols having an average molecular weight of 00 to 400o are used, such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhebutamethylene glycol, polyoctamethylene glycol, polynonamethylene glycol, polybutadiene glycol, poly Isoprene glycol, copolymers thereof, hydrogenated products thereof, polyolefin glycols, and the like are preferably used.

The thermoplastic copolymerized polyester elastomer in the present invention has an intrinsic viscosity in the range of (1.5 to 1.5).If the intrinsic viscosity is less than 0.5, there is a tendency for the adhesive strength to decrease; If it exceeds 5, the melt viscosity becomes too high and is inappropriate for use.

The method for producing the thermoplastic copolymerized polyester elastomer in the present invention is not particularly limited, and can be carried out in accordance with known ordinary methods. For example, a method in which the aromatic dicarboxylic acid component 5 dimer acid, other aliphatic dicarboxylic acid components, alkylene glycol components, and long chain glycol components are directly esterified simultaneously or stepwise, or transesterified and then polymerized. Can be adopted. Alternatively, a method may be adopted in which a copolymerized polyester of high molecular weight or low molecular weight is transesterified with a dimer acid or its hydrogenated product, or a long chain glycol component, and then polymerization is carried out depending on the case. Any known catalysts, stabilizers, modifiers or additives may be used during these polymerization or transesterification reactions.

The Botmelt adhesive of the present invention can be applied in a molten state onto an adherend using a general hot melt applicator or roll coater, or in the form of a powder, chip, or tape.

It is also possible to form the adhesive into various shapes such as a string, film, or wave, and then to fuse the adherend by placing scissors on the adherend and heating it at a temperature above the softening point of the adhesive.

The present invention will be explained in more detail below with reference to Examples.

Note that the characteristic values in one example were measured by the following method.

ti) Softening point ("c) It was measured by the ring and ball method according to JIS JAI-7.

(2) T-type peel strength kg/25mm) JIS K
-6854, at a peeling rate of 50 mm/min.

(3) Shear creep softening temperature ("C) 2.5cmx
A load of 450 g was applied in the shear direction to the test piece bonded with an adhesive area of 2.5 cm.

The temperature was raised to 2°C for 15 minutes, and the temperature when the weight fell was measured.

In addition, "parts" in one example means "parts by weight."

Examples 1-4. Comparative Examples 1 to 4 95 mol of dimethyl terephthalate, 5 mol of hydrogenated dimer acid (Versadime 52, manufactured by Henkerlo Inc.).

■, 0.01 zinc acetate in 150 mol of 4-butanediol
5. mol as a catalyst and heated at 200° C. for 1 hour under nitrogen atmosphere. A transesterification reaction was performed. Next, a hydrogenated product of polybutadiene glycol having an average molecular weight of about 1500 (
N15so-PBG [-1000) manufactured by Nippon Soda Co., Ltd. 5 mono I/ and 1-0.02 mol of tetramethyl titanate were added and heated under vacuum at 270°C for 4 hours to polycondense. A single polyester elastomer having the component ratio shown in Table 1 and having a softening point of 200°C or more and a maximum of 86° and 0.80 was prepared (Example 1). In addition, acid components and
Shima Mi 7if except for changing the amount of nokol ingredients etc.
In the same manner as i+VllIL, copolymerized polyester elastomers having different copolymerization ratios of hydrogenated dimer acid and hydrogenated V1J fictene glycol were prepared. J Hiro et al.] 1. Component L of saw copolymerized polyester elastomer
Table 1 shows the L, soft strength, and limiting viscosity.

These copolymerized polyester elastomers.

Each melts at a temperature of 220℃, and has a thickness of Q,
It was sandwiched between two 5 mm aluminum plates and bonded together under pressure. The T-peel strength and shear creep softening temperature of the obtained adhesive samples at 20°C and 20°C were determined (
Table 1 shows the results.

As is clear from the comparison between the example and the comparative example,
In the case of dimer acid alone (Comparative Example 1), the low temperature properties at -20°C are poor, and on the other hand, in the case of hydrogenated polybutadiene glycol alone (Comparative Example 2), the adhesive strength is poor. Even if dimer acid and hydrogenated polybutadiene glycol are used in combination, if the sum is less than 10 mol% (Comparative Example 3), the adhesive strength is low, especially the low temperature adhesive part at -20°C is extremely low, and the amount When the amount exceeds 70 mol % (Comparative Example 4), the heat resistance becomes extremely poor and the adhesive strength is significantly reduced even at high temperatures. On the other hand, the examples are Bottmelts with excellent bonding and heat resistance at low temperatures.Example 5, Comparative Example 5 Dimethyl terephthalate 77.5 mol, dimer acid (manufactured by Henkel Japan Co., Ltd., Versadime 288) 22.5 mol and 1 .0.01 mol of zinc acetate was added as a catalyst to 124.5 mol of 4-butanediol, and 200 mol of zinc acetate was added as a catalyst to 124.5 mol of 4-butanediol.
The mixture was heated at ℃ for 1 hour to perform a transesterification reaction.

In the next step, polytetramethylene glycol with a molecular weight of 1000 (manufactured by Sanyo Chemical Co., Ltd., PTMEG-1000) 16.
8 mol and 1-0.02 mol of tetra-n-butyl titanate were added.

It was polycondensed by heating at 270°C under vacuum for 4 hours, and had the component ratio shown in Table 2, a softening point of 179°C, and an intrinsic viscosity of 0.85.
A copolymerized polyester elastomer was created.

For comparison, 100 moles of dimethyl terephthalate.

124.5 moles of 1,4-butanediol and about 1 mol.
000 polytetramethylene glycol and 30 moles of polytetramethylene glycol under the same conditions as in Example 5, the component ratios shown in Table 2 were obtained.

A copolymerized polyester glass 1-mer having a softening point of 180'C and an intrinsic viscosity of 0.83 was prepared.

Each of these copolymerized polyester elastomers 1' was heated and melted at a temperature of 200°C. It was sandwiched between two aluminum plates with a thickness of 0.5n+n+ and bonded under pressure.

The T-peel strength and shear creep softening temperature of the obtained adhesive sample at 20°C and 20°C were measured.

The results are shown in Table 2.

Furthermore, using these copolymerized polyester elastomers, a polyester kufta fabric with a basis weight of 200 was bonded.
Similarly, the results of measuring the T-type peel strength at 0°C are as follows.
Shown in the table.

Table 2

Claims (1)

[Claims] (1) Aromatic dicarboxylic acid or its ester-forming derivative (1), 50 to 95 mol%, dimer acid or its hydrogenated product or its ester-forming derivative (, II)
5 to 40 mol% and aliphatic dicarboxylic acids other than dimer acid or ester-forming derivatives thereof (■) 0 to 30 mol%
is the acid component. Alkylene glycol (IV) having 2 to 10 carbon atoms 60 to
The glycol component is 97 mol%, 3-40 mol% of long chain glycol (■) with an average molecular weight of about 350-6000, and the sum of the components (U) and (V) is 10-70 mol%, and Viscosity [phenol: tetrachloroethane-
A real-melt adhesive comprising a thermoplastic copolymerized polyester elastomer having an i+s constant of 0.5 to 1.5 at 20°C in a mixed solvent of 1:2 weight ratio).