JPS59215373A - Hot-melt adhesive - Google Patents

Abstract

PURPOSE:To provide a hot-melt adhesive which consists mainly of a thermoplastic segment type copolyester elastomer consisting of specified short-chain ester units and long-chain ester units and exhibits excellent heat-resistant and low-temp. adhesion and thermal stability. CONSTITUTION:The hot-melt adhesive consists mainly of a thermoplastic segment type copolyester elastomer with a limiting viscosity number of 0.5-1.5 which consists of 10-75wt% (A) short-chain ester units consisting of an aromatic dicarboxylic acid and a 2-10C alkylene glycol and 90-25wt% (B) long-chain ester units consisting of an aromatic dicarboxylic acid and alpha,omega-1,2-polybutadiene glycol with an average molecular weight of 350-6,000 and/or long-chain ester units consisting of an alpha,omega-1,2-polybutadiene carboxylic acid with an average molecular weight of 350-6,000 and a 2-10C alkylene glycol.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a polyester elastomer resin adhesive that has excellent heat-resistant adhesion and low-temperature adhesion when adhering various types of plastics, metals, wood, etc., and also has excellent thermal stability. It relates to melt adhesives.

Bot1-melt 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 economical efficiency and convenience, as it does not adhere to a relatively wide range of adherends.

However, there are still many problems when applying hot tart adhesives to the field of one-color structural product assembly. That is, general-purpose hot melt adhesives such as ethylene-vinyl acetate copolymer, polyethylene, etc. have a low softening point and therefore have a problem of poor heat resistance on one side. In recent years, polyester resins and polyamide resins with high softening points 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. ing. As a countermeasure to this problem, it may be possible to lower the glass transition point of the hot melt adhesive to lower the solidification temperature of the adhesive and improve its adhesion at low temperatures, but in many cases, lowering the glass transition point When heated, the softening point of the adhesive is also lowered, so in this case, a problem arises in that the heat resistance after bonding becomes poor.

A copolymerized polyetherester elastomer of polyester and polyalkylene glycol such as polytetramethylene glycol has been proposed as an adhesive with excellent low-temperature properties and heat resistance, but this material has poor thermal stability. The drawback is that when melted, the viscosity decreases significantly due to decomposition, making it difficult to use as a true melt adhesive.

Therefore, it has excellent adhesion from low to high temperatures,
Furthermore, there has been a desire to develop a true melt adhesive that has excellent thermal stability during nano 1-melt melting.

The present inventors conducted various intensive studies with the aim of providing an adhesive with the above-mentioned excellent performance, and as a result, the present inventors discovered that a thermoplastic segmented copolymerized polyester elastomer using a specific soft segment was used. - The present invention was achieved by discovering that a melt adhesive achieves the intended purpose.

That is, the present invention comprises: (A) 10 to 75% of short chain ester units consisting of an organic dicarboxylic acid whose main component is an aromatic dicarboxylic acid or an ester-forming derivative thereof and an alkylene glycol having 2 to 10 carbon atoms; B) (
i) A polymer consisting mainly of an aromatic dicarboxylic acid or its ester-forming derivative and α,ω-1,2-polybucudiene glycol or its hydrogenated product having an average molecular weight of about 350 to 6,000. chain ester units and/or (ii) α with an average molecular weight of about 350-6000
, ω-1,2-polybutadiene dicarboxylic acid or its hydrogenated product or its ester-forming derivative and carbon number 2
It consists of 90-25% by weight of long-chain ester units consisting of ~10 alkylene glycols, and has an intrinsic viscosity of 0.5-25% by weight.
1.5 [phenol:tetrachloroethane-1:1 (
Measured at 20°C in a mixed solvent of (weight ratio). Same below. The thermoplastic segmented copolymerized polyester elastomer in the present invention consists of a hard segment consisting of a short-chain ester unit and a soft segment consisting of a long-chain ester unit.
・It is composed of. )＼Door segments raise the softening point of the adhesive. Contributes to imparting heat resistance and
・Segments lower the glass transition point of the adhesive and contribute to maintaining excellent adhesion even at low temperatures. Soshi-
B The hot-nod melt adhesive of the present invention, which is made of a thermoplastic segment-shaped copolymer elastomer obtained by copolymerizing these hard segments and rough 1-segments, has the advantages of both hard segments and soft segments. It has excellent performance. In addition, it has favorable performance such as excellent thermal stability.

The ratio of short chain ester units to long chain ester units in the thermoplastic segment I type copolymerized polyester elastomer is in the range of 10:90 to 75:25,17 or 30:0 to 60:40 by weight. be. When the proportion of short-chain conistel units is less than 10% by weight, resistance! 1) The retention rate of the hard segment becomes poor, and the effect of copolymerizing the hard segment into segments becomes difficult to produce.On the other hand, if it exceeds 75% by weight, the low-temperature properties deteriorate, and the adhesive becomes hard and brittle. Adhesion at room temperature also decreases.

The short chain ester unit constituting the hard segment of the segmented copolymerized polyester elastomer in the present invention is combined with an organic dicarboxylic acid containing an aromatic dicarboxylic acid as a main component or an ester-forming derivative thereof, and a carbon number of 2 to 10.
It consists of alkylene glycol. Examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, phthalic acid, and knack dicarboxylic acid.

Although two or more of these can be used, terephthalic acid or a mixture of terephthalic acid and isophthalic acid is particularly preferably used. Examples of organic dicarboxylic acids include saturated aliphatic dicarboxylic acids having a methylene group of 4 to 2 carbon atoms such as succinic acid, adipic acid, azelaic acid, cehatic acid, and dodecanedioic acid, or ester-forming derivatives thereof such as methyl esters. One or more of these can be used.

In particular, 90 to 50% by weight of aromatic dicarboxylic acid and 10 to 5% of saturated aliphatic dicarboxylic acid whose methylene group has 7 to 2 carbon atoms.
Particularly preferred for the present invention are short-chain ester units containing 1% of Oi[11i as the organic dicarboxylic acid component.

As an alkylene glycol having 2 to IO carbon atoms.

For example, ethylene glycol, trimethylene glycol,
1.4-butanediol, 1.5-pencunediol,
Examples include alkylene glycols such as 116-hexanediol and neopentyl glycol.

The long chain ester unit constituting the soft segment 1- is composed of an organic dicarboxylic acid component or a glycol component constituting the short chain ester unit, and an elastomer component formed into an ester with the organic dicarboxylic acid component or glycol component. The elastomer component is approximately 35
0~6000. α,ω-1,2-polybutadiene glycol or its hydrogenated product preferably having an average molecular weight of about 600 to 4000; or α,ω having an average molecular weight of about 350 to 6000, preferably about 600 to 4000;
-1,2-polybutadiene dicarboxylic acid, hydrogenated products thereof, or ester-forming derivatives thereof are used. In the present invention, by using such a 1,2-polybutadiene component as an elastomer component, a hot melt adhesive having particularly excellent adhesive properties and thermal stability can be obtained.

The thermoplastic segmented copolyester elastomer in the present invention has an intrinsic viscosity in the range of 0.5 to 1.5. If the intrinsic viscosity is less than 0.5, there is a tendency for the adhesive strength to decrease, while if it exceeds 1.5, the melting surface and viscosity become too high, making it unsuitable for use.

The method for producing the thermoplastic segmented copolymerized polyester elastomer in the present invention is not particularly limited, and can be carried out according to any known conventional method. For example, the organic dicarboxylic acid component, alkylene glycol component, α, ω-1,2-polybutadiene glycol component and/or α.

It is possible to employ a method in which the ω-1,2-polybutadiene dicarboxylic acid component is directly esterified simultaneously or in stages, or in which the ω-1,2-polybutadiene dicarboxylic acid component is subjected to a transesterification reaction and then polymerized. In addition, when a high molecular weight or low molecular weight copolymerized polyester is transesterified with an α,ω-1,2-polybutadiene glycol component and/or an α,ω-1,2-polybutadiene dicarboxylic acid component, Depending on the situation, it is also possible to adopt a method in which polymerization is carried out thereafter. Any known catalysts, stabilizers, modifiers or additives may be used during these polymerization or transesterification reactions.

The hot melt adhesive of the present invention can be applied to a general hot melt i-applicator or roll coater in a molten state.
In addition to being used by applying it onto an adherend, for example, it can be used in powder, nitrogen, or tape form.

It is also possible to form the adhesive into various forms such as a string, film, or wave, and then to fuse the adherend by placing scissors 9 on the adherend and heating at a temperature higher than the softening point of the adhesive.

The present invention will be explained in more detail below using Examples.

Note that the characteristic values in the two examples were measured by the following method.

fl) Softening point (”c) It was measured by the ring and ball method according to JIS JA 1-7.

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

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

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

In addition, "1 part" in one example means "1 part by weight".

Examples 1-4. Comparative Examples 1 to 2 77.4 mol of dimenal ralephthalate, 22.6 mol of dimethyl isophthalate, 160 mol of 4-butanediol, and 0,00 mol of dibutyl titanate as a catalyst.
Polycondensation was carried out using a 3θ polymer to obtain a copolymerized polyester having a melting point of 180°C (measured by differential thermal analysis).

70 parts of this copolymerized polyester and an average molecular weight of about 15 (1
0 α,ω-Hydrogenated product of 1,2-polybutadiene glycol (Nippon Soda fil) M, Njsso-! 'B G
I4000) was taken and subjected to a transesterification reaction in the presence of a zinc acetate catalyst at 270°C for 2 hours in a nitrogen atmosphere, resulting in a mixture consisting of 67% by weight of short-chain ester units and 33% by weight of long-chain Nissdale units, with an extremely 1v A segmented copolymerized polyester elastomer having a viscosity of 0.85 was prepared (Example 1).

Similarly, the blending ratio of hydrogenated copolyester and α, ω-1,2 polybutadiene glycol was 8.
5/15.50150.38/62.25/75.17
/83, and the composition ratio of the short chain ester unit and the long chain ester unit is 83/+7 (comparative example 1).
) 46154 (Example 2), 30/70 (
Example 3).

15/85 (Example 4), 5/95 (Comparative Example 2
) polyester elastomer was created using the dinotation method.

Table 1 shows the composition ratio and softening point of each segmented polyester elastomer.

The segmented copolymerized polyvarnish 1-mer was heated and melted at a temperature of 200"C to give a temperature of 20.5 cm.
It was sandwiched between mm-thick aluminum plates and bonded under pressure.

Table 1 shows the results of measuring the 1'' type peel strength and shear creep softening temperature at 20° C. and 20° C. of the obtained adhesive sample.

/'- Table 1 also shows that these adhesives were heated to 24 degrees below 180"C
The rate of decrease in melt viscosity when left for a long time is 10!
'fi or less, and the thermal stability was good.

Example 5 83 mol of dimethyl terephthalate, l100C (C11
2) ζm condensation was carried out using 1117 mol of +aCOO, 160 mol of 4-bucundiol, and 0.003 mol of te(-butyl titanate) to give a melting point of 176°C.
(Measured by differential thermal analysis.)
,r,J, ,lko.

50 parts of this copolymerized foraester and average molecular weight #'J20
(Hydrogenated product of α,ω-1,2-polybutadiene glycol of 10 (Nippon Soda (41+, Nisso
-January 3 G1-2000) 50 parts were taken and transesterified in the presence of a tetrabutyl rapeseed l-catalyst at 270"C in a nitrogen atmosphere for 2 hours to obtain 45% by weight of short-chain ester units and 45% by weight of long-chain ester units. A segment consisting of 55% by weight of chain ester l"1, with a softening point of 161°C (according to the T3 FJ, I'? method) and an intrinsic viscosity of 0.78! --shaped copolymer I
J Ester Ex 1-M were created.

This segmented co-polymerized polynis herring, I-
The mer was heated in a container at a temperature of 2 (2) 0°C in the same manner as in Example 1, and then placed between 0.5 mm thick aluminum plates and bonded under pressure. 11 strength?
Measure C/l::. Furthermore, at a temperature of 180'C, 2
The stability of the bonding process was determined by the rate of decrease in the melt viscosity of the adhesive for 41Jf in total by 1+lIi. The results are shown in Table 2.

Example 6 α, ω ~ 1.2 ~ Instead of hydrogenated polybutadiene glycol, α, ω-1,2-polybutadiene glycol (Nippon Soda (1st offense, former 5SO1) with an average molecular weight of about 2000
18G-2000) was used in the same manner as in Example 5, consisting of 45% by weight of short ↑fi ester units and 55% by weight of long chain ester units, with a softening point of 158°C (according to the B&R method), and an extreme A segmented copolymer polyester with a viscosity of 0.78 [stell elastomer was used as f-1, and the strength and stability of the "1" type peeling block 1 and F', J) were measured in the same manner as in Example 5 (+lI
i Shita. The results are shown in Table 2.

IL comparative example, 4 α, ω-1,2=Jζ reflex diene glycol ylc
iK item f wrinkles) 6 pieces 7-H1 approx. 28 (10)
o: , +77-1.4-. 1; Liptan glycol 71 additive (commercially available α, ω-1,4-polybutane glycol is hydrogenated (tL, J: nM)) or polybutane glycol with a molecular weight of about 2000
-L (Sanyo 1B Sei (nl, PTMG 2000)
The short-chain ester El! On segmented copolymerized polyester, the structural composition ratio of position and long chain ester unit is 4615 in terms of weight ratio, A5/J5+4, zetaization point is 169°C, and intrinsic viscosity at 153°C is 0.75.0.80. As with Example 5, the sternyl elastomer was evaluated for its 'f' type peeling resistance and thermal stability. The results are shown in Table 2.

Table 2 Example 7 70 mol of dimethyl terentalate, l100C (C11
2) +eCOOtl 15 mol, C4-7 Kundio Jl/160 mol and hydrogenated product of α, ω-1,2-polybutadiene dicarboxylic acid having an average molecular weight of about 1500 (To1 Soda f+1), N15so-PB Cl4
000) Take 15 mol of tetraphthyl chickne-1.
Polymerization is carried out in the presence of a catalyst, consisting of 41% by weight of chain esters and 59% by weight of chain esters.

A segmental copolyester elastomer 1-mer having a softening point of 16 Fc and an intrinsic viscosity of 0.68 was prepared.

This Cefmen l-shaped copolymerized polyester elastomer was placed on a polyvinyl chloride film with a thickness of 35 mm.
! After washing the melted surface with 1 O'c for 11J, another polyvinyl chloride film was pressure-bonded to the coated surface. 20 of this glue
The F-type peel strength at °C is 15.2 kg/25 m
It was m.

It is clear from comparing the examples and comparative examples.
, 5: Hi chain varnish (11th position ratio is 75mm)
% (Comparative Example 1), only an adhesive with poor adhesiveness is obtained, especially at low temperatures. Furthermore, when the proportion of short-chain ester units is less than 10 mm% (Comparative Example 2), the adhesiveness becomes poor, especially at high temperatures. In addition, the elastomer component is a, ω-1,,
, l-polybutadiene glycol hydrogenated product (Comparative Example 3) or polytetramethylene glycol (Comparative Example 4), when bonded, only those with poor adhesive properties were used. It can be seen that the adhesive of the present invention has very low stability, especially those using polynatramenalene glycol.On the other hand, the adhesive of the present invention has a short chain ester (11-position; 10 to 75% by weight of long chain ester units, 90 to 25% by weight of long chain ester units, and long chain ester units
i (>2.-1 When α,ω-1,2-polyphtadiene glycol and/or α,ω-1,2-polybutadiene dicarboxylic acid or their hydrogenated products are used as one component of the nilastomer Hora 1-Mel 1, which has excellent adhesion at low temperatures and high temperature adhesion (has excellent thermal stability during summer and melting).
- Provides an adhesive.

Patent applicant: Uniti 11 Co., Ltd.

Claims (1)

Scope of Claims: (11(A) 10 to 75% by weight of short chain stellate units consisting of an organic dicarboxylic acid whose main component is an aromatic dicarboxylic acid or an ester-forming derivative thereof and an alkylene glycol having 2 to 10 carbon atoms. (B) (i) An autologous dicarboxylic acid whose main component is an aromatic dicarboxylic acid or an ester-forming derivative thereof, and α.ω-1,2-polybutadiene glycol having an average molecular weight of about 350 to 6,000. or a long chain ester unit consisting of a hydrogenated product thereof and/or (11) α having an average molecular weight of about 350 to 6000. ω-1,2-polybutadiene dicarboxylic acid or a hydrogenated product thereof or an ester-forming SM and 90 to 25 wt. 'Measured in C. [065-1.5] A hot tart adhesive comprising a thermoplastic segmented copolymerized polyester elastomer of 065 to 1.5. (2) The organic dicarboxylic acid whose main components are aromatic dicarboxylic acid is 90 to 50% by weight of aromatic dicarboxylic acid and 10 to 50% by weight of saturated aliphatic dicarboxylic acid whose methylene group has 7 to 20 carbon atoms.
A bottle-melt adhesive according to claim 1, comprising 50% by weight.