JPH02248486A - Hot-melt adhesive composition - Google Patents

Abstract

PURPOSE:To obtain the title composition excellent in dry cleaning resistance and useful as an adhesive for bonded interlining for clothing by adding a compound having a plurality of isocyanato groups to a specified polyester for chain lengthening. CONSTITUTION:A compound having at least two isocyanato groups (e.g. 1,6- hexamethylene diisocyanate) is added for chain lengthening to a polyester obtained by polycondensation of a dicarboxylic acid (e.g. terephthalic acid or isophthalic acid) and 1,3-propanediol substituted by alkyl groups at the 2-position (e.g. 2-butyl-2-ethyl-1,3-propanediol).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel hot-melt adhesive composition. More specifically, the present invention provides a hot melt adhesive composition useful in electrical parts assembly, automobile parts assembly, textiles, shoe manufacturing, can manufacturing, building materials, food packaging, and the like. In particular, it can provide adhesive interlining for clothing with outstanding adhesion properties that are extremely durable and unattainable with other adhesives.

[Conventional technology]

Traditionally, EVA and polyamide adhesives have been used as hot melt adhesives for adhesive interlining, but the mainstream fiber material has changed to PET fibers, and polyester adhesives with good adhesion to PET fibers are now being used. .

Many of the polyester hot melt adhesives currently on the market are made by copolymerizing terephthalic acid and 1,4-butanediol as main raw materials with other third and fourth components. The above-mentioned copolymerized components are intricately intertwined (JP-A-5EI-133380, JP-B-82-56911). However, it is almost impossible to develop an adhesive that satisfies all the required properties, and no results have been achieved yet.

[Problem that the invention seeks to solve]

Physical properties that are problematic for polyester hot-melt adhesives include adhesion to fibers, dry IJ-ing resistance, washing resistance, texture, processing characteristics, and the like. In particular, there is a need for something that can improve the durability of adhesive strength after dry cleaning.

However, a well-balanced product that satisfies all of these conditions has not yet been obtained, and the current situation is that molecules are designed while sacrificing some of the characteristics.

The object of the present invention is to provide a polyester hot melt adhesive that can provide a good balance of the above physical properties and excellent dry cleaning resistance, particularly as an adhesive for adhesive interlining for clothing. The present invention provides a drug composition.

[Means for solving problems]

The present inventors investigated various polyester compositions from this point of view, and as a result, discovered an adhesive composition capable of achieving the above-mentioned object and arrived at the present invention. That is, the present invention uses dicarboxylic acids and 1,3-substituted alkyl groups at the 2-position.
This is a hot melt adhesive composition obtained by adding a compound having at least two isocyanate groups to a polyester derived from N-condensation with a diol containing propanediol and elongating the chain.

The dicarboxylic acid for obtaining the copolymerized polyester used in the adhesive of the present invention includes aromatic, aliphatic, and alicyclic dicarboxylic acids, and among them, terephthalic acid or isophthalic acid is preferred. In this case, terephthalic acid and isophthalic acid include their condensable derivatives such as lower alkyl esters, and other aliphatic and alicyclic dicarboxylic acids used in combination include oxalic acid, malonic acid, dimethylmalonic acid, succinic acid, etc. Acid, glutaric acid, adipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, itaconic acid,! , 3-cyclopentanedicarboxylic acid,
1.2-cyclohexanedicarboxylic acid, ! , 3-cyclohexanedicarboxylic acid Nt.

Mention may be made of dicarboxylic acids such as 4-cyclohexanedicarboxylic acid or condensable derivatives of these dicarboxylic acids. At least 50 mol% of the acid component is preferably terephthalic acid or a mixture of terephthalic acid and isophthalic acid,
This range is for the purpose of satisfying the melting point and elastic properties of the resulting polymer. If it is outside this range, the softening temperature will be extremely low and the dry cleaning resistance will also tend to be low. More preferably, the ratio of terephthalic acid or a mixture of terephthalic acid and isophthalic acid to the acid component is 7.
It is 0 mol% or more.

The 2-position used in the present invention is substituted with an alkyl group! , 3-propanediol is -forming (where R++
At least one of Ra is an alkyl group, and examples thereof include 2 to 4 carbon atoms. ). Specific 1.
3-propanediol is 2-butyl-2-ethyl-
! , 3-propanediol (hereinafter abbreviated as DMH), 2
．． 2-diethyl-! .

Examples include 3-propanediol (hereinafter abbreviated as DMP). The 1,3-propanediol whose 2-position is substituted with an alkyl group preferably accounts for 20 to 60 mol % in the diol.

The crystallization rate is a factor that affects coating work, such as open time, but 4-butanediol tends to have a fast crystallization rate, and ethylene glycol has a slow crystallization rate. This is because 1,3-propanediol substituted with an alkyl group controls the crystallization rate appropriately.

On the other hand, the degree of crystallinity affects heat resistance, solvent resistance, and adhesiveness, and as the degree of crystallinity increases, the adhesive strength decreases significantly, but the 2-position is substituted with an alkyl group! .

3-Propanediol appropriately balances the degree of crystallinity and provides outstanding weldability with extremely excellent durability.

As the glycol component, in addition to the above-mentioned 1,3-propanediol substituted with an alkyl group at the 2-position, ethylene glyfur, propylene glyfur, and 1,4-butanediol have better adhesive strength.

Still other glycols such as 1,8-hexanediol, cyclohexane dimetatool, cyclohexanediol, 2,2-dimethyl-1,3-propanediol, polyethylene glycol, polytetramethylene glycol, 2,2-bis(hydroxyphenyl) Propane, 2.
2-bis(hydroxyethoxyphenyl)propane, bis(hydroxyphenyl)sulfone, bis(hydroxyethoxyphenyl)sulfone, etc. may be used in an amount of 30 mol% or less.

The production of polyester in the present invention is carried out by methods already known in the art. That is, the above-mentioned acid component and the above-mentioned glycol component are heated in an inert gas atmosphere in the presence of a catalyst if necessary to carry out an esterification reaction or transesterification reaction, and then, if necessary, a heavy reaction is carried out under reduced pressure. prepared by proceeding with condensation.

The copolymerized polyester used in the adhesive of the present invention has an acid value of 1
0 gKOII/g or less, the hydroxyl value is preferably in the range of 10 to 100 g to OH/g, and when the acid value of the copolyester is higher than 10 mgKOR/g, or the hydroxyl value is higher than 100 gKOH/g In both cases, the amount of "compound having at least two isocyanate groups" used in the next step increases, and the melting point of the adhesive increases significantly, or partially gelled products, etc. are generated in the adhesive. Moreover, it is not preferable because it is not possible to obtain a durable adhesive force.

In the present invention, a compound having at least two isocyanate groups is added to the obtained copolyester. As a compound having this isocyanate group,
Any of the various diisocyanate compounds used as raw materials for producing polyurethane resins can be used. Typical examples of compounds having isocyanate groups include: 2.4-tolylene diisocyanate; ll-
) lylene diisocyanate, diphenylmethane, 4.4
'Diisocyanate, 1. B-hexamethylene diisocyanate, 1,4-teiramethylene diisocyanate,
Xylylene diisocyanate, inphorone diisocyanate, cyclohexane! , 4-diisocyanate and the like. Particularly preferably used for fiber processing are aliphatic or alicyclic diisocyanate compounds that do not cause yellowing of the resin when irradiated with ultraviolet rays.

The reaction between the hydroxyl groups in the copolymerized polyester and the isocyanate compound progresses easily even at relatively low temperatures;
The isocyanate compound can be uniformly mixed at a temperature higher than the melting temperature of the polyester, and the reaction can be carried out at 130°C to 160°C. The amount of the isocyanate compound used is preferably in a ratio of NGO1011=0.4 to 1.0 with respect to the copolymerized polyester. When the ratio of IIcoloH to the copolymerized polyester is greater than 1, the melting point of the resulting adhesive may become significantly high due to the IL1 reaction of the excess isocyanate compound, or It is not suitable because a partially gelled product is formed and it is not possible to obtain a durable adhesive force.

The reaction product of polyester and isocyanate compound preferably has a softening temperature of 80°C to 150°C, and a melt index at 160°C of 1 to 50 g, 710 minutes.

When the softening temperature of the reaction product is lower than 80° C., when an adhesive interlining is prepared, the surface coated with the adhesive tends to become sticky, which reduces workability, which is not preferable. Furthermore, if the softening temperature is higher than 150° C., it is not suitable as an extremely high temperature is required to impart good adhesive strength as an adhesive interlining, which may cause embrittlement and discoloration of the fibers.

A more preferable softening temperature is 80°C to 130°C. The melt index of the reaction product resin at 160℃ is 1g/
If the melting time is shorter than 10 minutes, sufficient adhesive strength cannot be obtained under short-time melting conditions. Conversely, if the melt index at 160°C is greater than 50g710min, the adhesive will easily penetrate into the fiber structure during applied processing. More preferably, the melt index of the reaction product resin at 160° C. is 5 to 30 g/10 minutes.

The hot-melt adhesive of the present invention is used in the form of powder, film or thread, or dispersed in water as a liquid dispersion for adhesion. As a film forming method, a melt film forming method is preferable, and softening extrusion is performed using an ordinary extruder to form a film. The obtained film-like hot melt adhesive is sandwiched between woven fabrics of the same or different types, and the adhesive is heated and softened by ironing using a hot press, a hot roller, or the like. In addition, the powdering method involves cooling with a refrigerant such as liquid nitrogen, then pulverizing it with a pulverizer and turning it into powder, which is then coated using a dotting machine, scattering machine, etc. and made into an adhesive interlining. . The dispersion is prepared by stirring at high speed in a pressure cooker, and is coated by spray knife knitting or the like to form an adhesive interlining. Woven fabrics include synthetic fibers such as polyester, polyamide and acrylic, natural fibers such as wool and cotton, and blends thereof, and can also be used to adhere patches, marks, etc. It is possible to obtain adhesives and adhesive cores that are particularly suitable for polyester fibers and have excellent hot water washing resistance and dry cleaning resistance. Incidentally, it is possible to add appropriate amounts of an antioxidant, a slip agent, an antiblock agent, and a tackifying agent to the adhesive of the present invention, if necessary.

〔Example〕

Examples are given below to explain the present invention more specifically, but the present invention is of course not limited to the same extent by the Examples.

Example 1 49.7 g of ethylene glycol in a 1 L four-neck flask
(0,8 mol), 11192.4 g (1,2
mol) and terephthalic acid az,tg (0,5 mol),
83.1 g (0.5 mol) of inphthalic acid and calcium acetate hydrate @ 132 gl 77% dioxide 70.
148 g was charged, heated to 180 to 240 °C in a nitrogen stream, held for 6 hours while distilling the produced water out of the system, heated to 255 °C, and reacted for 4 hours under reduced pressure of % 10 mi + I1 g, Acid value 1, OmgKOH/g s
A polyester with a hydroxyl value of 22 mgKOII/g O) was obtained.

While melting and maintaining 100 parts by weight of this polyester at 150°C, 1.8-hexamethylene diisocyanate 2.
Chain elongation was carried out by gradually dropping 8 parts by weight.

The resulting resin has a softening temperature of 116°C and
The melt index at 0° C. was 15 g/10 minutes.

Examples 2 to 3 Resins were obtained in the same manner as in Example 1 using the acid components, glycol components, and organic diisocyanates shown in Table 1. These physical property values are shown in Table 1.

Comparative Example A resin was obtained in the same manner as in Example 1 using the acid component, glycol component, and organic diisocyanate shown in Table 1. These physical property values are shown in Table 1.

Application Processing Example The obtained adhesive was cooled and then pulverized by freeze pulverization. To create the interlining, apply adhesive to the polyester spun interlining at a rate of 15 g/m'' using a powder coating method on the polyester spun interlining.
Heating was performed at 0° C. for 30 seconds to adhere the adhesive onto the polyester spun interlining to create an adhesive interlining. The obtained adhesive interlining was made of polyester/cotton = 85/35 blended broadcloth at a pressing temperature of 150°C and a pressing pressure of 0.20 kg/c+.
Press bonding was performed under the conditions of 1', press steaming for 1 second, and pressing for 8 seconds. The adhesive strength of the obtained adhesive fabric was examined.

The adhesive strength was measured using an Autograph P-1OO model (manufactured by Shimadzu Corporation), a tensile speed of 100 cm/min, and 180 degree pricking. (Unit: kg/2.5 cm) The adhesive strength is the same at the initial stage, after dry cleaning, and after washing.
Those with a weight of 1.2 kg/2.5 Cm or more are passed.

The above results are shown in Table 2.

〔Effect of the invention〕

According to the present invention, it has become possible to impart outstanding adhesiveness with extremely excellent durability to polyester hot melt adhesives, particularly adhesives for adhesive interlining for clothing.

No. table that's all hand Continued Supplementary Positive book (spontaneous)

Claims (1)

[Claims] (1) Dicarboxylic acid and 1 substituted with an alkyl group at the 2-position
A hot melt adhesive composition obtained by adding a compound having at least two isocyanate groups to a polyester derived from polycondensation with a diol containing , 3-propanediol and elongating the chain.