KR20190065943A - Composition of the hot-melt adhesive - Google Patents

Abstract

The present invention relates to a hot-melt adhesive composition, which, by the combination of two propylene elastomers having different melt viscosity characteristics at the specific temperature, improves low-temperature flowability while having no odor, improves adhesion and cohesion, and improves low-temperature coating processability, and to a hot-melt adhesive comprising the same.

Description

COMPOSITION OF THE HOT-MELT ADHESIVE [0002]

Cross-reference with related application (s)

This application claims the benefit of priority based on Korean Patent Application No. 10-2017-0165283, filed on Dec. 4, 2017, the disclosure of which is incorporated herein by reference in its entirety.

The present invention relates to a hot melt adhesive composition.

Hotmelt adhesive is an adhesive which is applied by melting by heat and very little volatile organic solvent is discharged. Conventional general-purpose hot-melt adhesives are generally composed of a thermoplastic (thermoplastic) polymer such as an olefin-based copolymer as a base polymer and various waxes as a tackifier or a viscosity adjuster. Olefin copolymers such as ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer and ethylene vinyl acetate, which have excellent flexibility of the base polymer and low cost, have been widely used.

Natural adhesives such as rosin-based resins and terpene-based resins, and derivatives thereof and petroleum resins are widely used as the tackifier for improving the adhesion. Examples of waxes for lowering viscosity include petroleum waxes, mineral waxes such as coal, , Low molecular weight polyethylene wax, and the like are widely used.

Although hot-melt adhesives are widely used in various fields such as automobiles, packaging containers, structural materials, and electronic materials, when an olefin copolymer having a low polarity is used as a base polymer or when surface coating is performed with silicone or wax, And the hot-melt adhesive using the thermoplastic rubber as the base polymer is excellent in heat resistance and cold resistance, but the viscosity is high and the workability is reduced.

In addition, when the plasticizer is excessively used to reinforce the cold resistance and the elasticity, the compatibility with the base resin is poor so that phase separation occurs at the use temperature, bleeding phenomenon occurs, and the adhesive strength is decreased. It does not exhibit sufficient strength and flexibility.

On the other hand, in the case of a hot-melt adhesive for sanitary materials, a hot-melt adhesive composed of an amorphous polyalphaolefin or a styrene copolymer is generally used, but such an adhesive has a disadvantage in that the adhesive strength is poor or low-temperature flowability is poor. In particular, styrene copolymer-based adhesives have an odor problem and are replaced by olefins. However, amorphous polyalphaolefins have drawbacks in terms of their cohesion and sprayability.

Therefore, efforts have been made to develop adhesives for sanitary materials composed of a propylene-ethylene copolymer in order to develop an adhesive having an excellent adhesive force without odor and improved processability.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a propylene-based elastomer composition which, by combining two propylene elastomers having different melt viscosity characteristics at a specific temperature, improves low temperature flowability without odor, A hot-melt adhesive composition having improved low-temperature coating processability and a hot-melt adhesive containing the same.

In the present specification, a first amorphous propylene elastomer having a melt viscosity of less than 50,000 cPs at 190 DEG C and a crystallinity of less than 5%; And a crystalline second propylene elastomer having a melt viscosity of more than 500,000 cPs at 190 DEG C and having a crystallinity of more than 5%; Wherein the hot-melt adhesive composition is a thermosetting adhesive composition.

The present invention also provides a hot-melt adhesive comprising the hot-melt adhesive composition.

The present invention also provides a molded article comprising an adhesive layer containing the hot-melt adhesive.

Hereinafter, the hot-melt adhesive composition and the hot-melt adhesive according to a specific embodiment of the present invention will be described in detail.

As described above, according to one embodiment of the present invention, in the case of a hot-melt adhesive composition comprising two kinds of propylene-based elastomers having different melt viscosity characteristics at a specific temperature, the low-temperature flowability is improved without smell, Cohesion is improved and the processability of the low temperature coating is improved, and the present invention has been completed.

The hot-melt adhesive composition according to an embodiment of the present invention includes two kinds of propylene-based elastomers having different melt viscosity characteristics at a specific temperature. Specifically, one kind has a melt viscosity of less than 50,000 cPs at 190 ° C, or a melt viscosity of 10.000 to 40,000 cPs, or 15.000 to 30,000 cPs, and a crystallinity of less than 5%, or 0 to 4%, or 1 to 3.5% Amorphous propylene elastomer (hereinafter referred to as "first propylene elastomer"), and the other one has a melt viscosity of more than 500,000 cPs at 190 ° C, or 550,000 to 900,000 cPs, or 550,000 to 800,000 cPs (Hereinafter referred to as "second propylene elastomer") having a crystallinity of more than 5%, or 5.05 to 20%, or 5.1 to 15%. It should be understood, however, that the terms "first" and "second" used throughout this specification and claims are used to arbitrarily order them.

In the case of the first propylene elastomer contained in the hot-melt adhesive composition according to an embodiment of the present invention, an amorphous propylene elastomer having a melt viscosity of less than 50,000 cPs at 190 ° C and a crystallinity of less than 5% And the elastomer can improve the low-temperature flowability of the hot-melt adhesive composition. However, when the elastomer contains only the amorphous elastomer, the cohesive force of the hot-melt adhesive composition may deteriorate.

In the prior art, polypropylene wax is added to solve the problem of poor cohesive strength in the hot-melt adhesive composition containing amorphous propylene-based olefin as described above. However, the melting of the polypropylene wax Point of 140 ° C or higher, and thus there is a problem that the processability of coating is lowered at a low temperature of 140 ° C or lower.

However, according to one embodiment of the present invention, a semi-cystalline propylene elastomer (second propylene elastomer) having a melt viscosity of higher than 500,000 cPs at 190 DEG C and having a crystallinity of more than 5% Can be combined with the first propylene-based elastomer at a specific weight ratio so that the cohesive force of the hot-melt adhesive composition can be improved and the low-temperature coating processability can be maintained and improved without using the polypropylene-based wax.

Specifically, in the hot-melt adhesive composition according to an embodiment of the present invention, the second propylene elastomer may be contained in an amount of 10 to 20 parts by weight, more preferably 10 to 20 parts by weight, based on 100 parts by weight of the first propylene- 15 parts by weight. When the second propylene-based elastomer is contained in the hot-melt adhesive composition at less than the above-described weight, it is difficult to effectively solve the problem of poor adhesion and cohesive force, and when the above- There is a problem that can get too high.

Meanwhile, the propylene elastomer according to an embodiment of the present invention may be a propylene-ethylene copolymer, a propylene-butylene copolymer, and an ethylene-propylene-butylene terpolymer (ethylene-propylene-butylene-terpolymer). More specifically, it may be a propylene-ethylene copolymer, and the propylene-ethylene copolymer may be amorphous or semi-crystalline.

In a more specific example, the first propylene elastomer has a melt viscosity of less than 50,000 cPs at 190 占 폚, or 10.000 to 40,000 cPs, or 15.000 to 30,000 cPs, and has a crystallinity of less than 5%, or 0 to 4% Or an amorphous propylene-ethylene copolymer in an amount of 1 to 3.5%, wherein the second propylene-based elastomer has a melt viscosity at 190 DEG C of more than 500,000 cPs, or 550,000 to 900,000 cPs, or 550,000 to 800,000 cPs, crystallinity of greater than 5%, or 5.05 to 20%, or 5.1 to 15%.

The use of such amorphous and semi-crystalline propylene-ethylene copolymers enables the adhesion and cohesion of the hot-melt adhesive composition to be further improved without using polypropylene-based waxes used in the prior art, .

The above-mentioned first and second propylene elastomers may be prepared by copolymerizing propylene, alpha-olefins or the like by a well-known method, or commercially available elastomers having the above-mentioned physical properties may be commercially available.

Meanwhile, according to one embodiment of the present invention, a hot-melt adhesive including the hot-melt adhesive composition may be provided.

Specifically, in the hot-melt adhesive, in addition to the hot-melt adhesive composition described above, an adhesive resin, a plasticizer, a wax, an antioxidant, an elastomer, a pigment, a dye, a filler, an ultraviolet blocking agent, an antistatic agent, , At least one additive selected from the group consisting of a slip agent, an inorganic filler, a kneading agent, a stabilizer, a modified resin, a leveling agent, a fluorescent whitening agent, a dispersant, a heat stabilizer, a light stabilizer, an ultraviolet absorber and a lubricant.

Such additives can be suitably employed in the art, and are not particularly limited.

Specifically, a tackifying resin such as dicyclopentadiene, a mineral oil, pentaerythritol tetrakis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate (2,4-ditert-butylphenyl) phosphite (tris (2,4-ditert-butylphenyl) phosphite), pentaerythritol tetrakis ) phosphite, or an antioxidant such as 2- (2H-benzotriazol-2-yl) -p-cresol) .

On the other hand, the additive may be used in an amount of 1 to 80% by weight, more specifically 1 to 70% by weight, based on the total weight of the hot-melt adhesive. It is possible to sufficiently obtain the desired additional effect without hindering the hot-melt adhesive property within the above-mentioned weight range.

The hot-melt adhesive composition described above and the hot-melt adhesive containing the hot-melt adhesive composition are obtained by combining two kinds of propylene-based elastomers having different melt viscosity characteristics at a specific temperature to improve the low-temperature flowability without odor, Cohesion is improved, and the low temperature coating processability is improved.

Accordingly, the hot-melt adhesive can be widely used not only in the fields of automobiles, packaging containers, structural materials and electronic materials, but also sanitary materials such as diapers, napkins, pads and the like. More specifically, a molded article having an adhesive layer containing the hot-melt adhesive can be suitably applied to the various applications described above.

The hot-melt adhesive composition of the present invention improves low-temperature flowability without odor, improves adhesion and cohesion, and improves low-temperature coating processability.

Therefore, the hot-melt adhesive containing the hot-melt adhesive composition of the present invention can be widely used not only in the fields of automobiles, packaging containers, structural materials and electronic materials, but also sanitary materials such as diapers, napkins and pads.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

[Production Example: Production of hot melt adhesive composition]

A hot-melt adhesive was prepared by combining the components shown in Table 1 below. Specifically, the above composition was put into a 1 L reaction vessel and stirred for 2 hours while maintaining the temperature at 150 ° C to prepare a hot-melt adhesive.

Comparative Example  One Comparative Example  2 Example  One Example  2 Propylene-ethylene copolymer A
(Viscosity 20,080 cps at 190 < 0 > C) 31 29 27 26 Propylene-ethylene copolymer B (viscosity 600,000 cps at 190 ° C) 3 3 Tackifier
(DCPD, softening point 100 캜) 54 55 55 55 Polypropylene wax
(Melting temperature 146 [deg.] C) One F-T wax (Melting temperature 112 [deg.] C) One Mineral oil (paraffin 57%) 14 14 14 14 Irganox 1010 0.6 0.6 0.6 0.6 Irgafos 168 0.2 0.2 0.2 0.2 Tinuvin P 0.2 0.2 0.2 0.2 Total 100 100 100 100

In Table 1, Eastman Aerofin 180 was used as the propylene-ethylene copolymer A (first propylene elastomer), and Vistamaxx6202 (ExxonMobil) was used as the propylene-ethylene copolymer B (second propylene elastomer).

The melt viscosity of the first and second propylene elastomers was measured at 190 캜 using a Brookfield viscometer. The melt viscosity measured by this method was as shown in Table 1 above.

Further, the crystallinity of the first and second propylene elastomers was measured by using a DSC25 instrument manufactured by TA Instrument under the nitrogen atmosphere and at a heating rate of 10 ° C / min, the melting enthalpy value (ΔHm) of each of the first and second propylene- And was calculated according to the following formula 1:

[Formula 1]

Crystallinity measurement: Crystallinity (%) = DELTA Hm / DELTA Hm DEG X 100

In the above formula (1), ΔHm ° is a value of 207 J / g as a reference melting enthalpy value of a crystalline propylene elastomer of 100%, and ΔHm represents a melting enthalpy measurement value of the propylene-based elastomer to be measured.

The crystallinity of propylene-ethylene copolymer A (first propylene elastomer) measured by this method was found to be 1.8%, and the degree of crystallization of propylene-ethylene copolymer B (second propylene elastomer) was found to be 5.1%.

[Experiment: Measurement of hot melt adhesive properties]

The properties of the hot-melt adhesives according to the Examples and Comparative Examples obtained in the above-mentioned Production Examples were measured by an experimental method and the results are shown in Table 2.

1) Viscosity : The viscosity of the hot melt adhesive obtained as in the above example was measured using a standard Brookfield viscometer, spindle # 27, 140 占 폚, using ASTM 3236.

2) Softening point : Measured by Ring & Ball test method.

3) Adhesion : First, after heating for about 5 minutes at 160 ° C, it was confirmed that it was liquefied. Then, it was coated on a PET substrate on an applicator heated at 160 ° C and adjusted to a thickness of 30 μm using a blade. , And the same PET substrate was used as a cover film and bonded at the same time to prepare an adhesive force sample.

The thus-prepared sample is subjected to T-peel measurement through a Texture Analyzer (TA). At this time, the measurement conditions were measured at room temperature at a speed of 0.3 mpm, and samples were cut to a length of 100 mm in 1 inch width.

4) Processability : Using a Summit nozzle from Nordson, a hot melt adhesive was applied to the nonwoven substrate at an add-on rate of 0.1 g / m ² and an air pressure of 0.1 Mpa at 140 ° C. Respectively. The dispensing processability was evaluated by confirming spray-ability and adhesion under these conditions.

○: uniform spray formation, nonwoven fabric adhesion of 2N / in or more

?: Spray formation is uniform but nonwoven fabric adhesion is 1.5 N / in or less

X: Spray formation is not uniform and coating pattern or pattern density is not uniform

Comparative Example 1 Comparative Example 2 Example 1 Example 2 Viscosity at 140 ° C (cps) 3,913 3,388 6,188 5,200 Softening point (℃) 91.5 99.7 93.8 96.6 Adhesion (N / in) 8.1 7.8 15.0 15.2 Application Fairness △ X ○ ○

Referring to the results of Table 2, it was confirmed that the hot melt adhesives according to Examples 1 and 2 of the present invention exhibited improved effects compared with the hot melt adhesives according to Comparative Examples 1 and 2 in terms of adhesive force and coating processability.

Claims (10)

An amorphous first propylene elastomer having a melt viscosity of less than 50,000 cPs at 190 DEG C and a crystallinity of less than 5%; And
A semi-crystalline second propylene-based elastomer having a melt viscosity of greater than 500,000 cPs at 190 DEG C and having a crystallinity of greater than 5%; Wherein the hot melt adhesive composition comprises: The method according to claim 1,
Wherein the second propylene-based elastomer is contained in an amount of 10 to 20 parts by weight based on 100 parts by weight of the first propylene-based elastomer. The method according to claim 1,
The propylene-based elastomer may be a propylene-ethylene copolymer, a propylene-butylene copolymer, or an ethylene-propylene-butylene-terpolymer. Wherein the hot melt adhesive composition is one selected from the group consisting of The hot-melt adhesive composition according to claim 1, wherein the first propylene-based elastomer comprises a propylene-ethylene copolymer having a melt viscosity at 190 ° C of 10.000 to 40,000 cPs and a crystallinity of 1 to 3.5%.
The hot-melt adhesive composition of claim 1, wherein the second propylene-based elastomer comprises a propylene-ethylene copolymer having a melt viscosity of from 550,000 to 900,000 cPs at 190 ° C and a degree of crystallinity of 5.1 to 15%.
A hot-melt adhesive comprising the hot-melt adhesive composition of any one of claims 1 to 5. The method according to claim 6,
The hot-melt adhesive may be used in combination with one or more additives selected from the group consisting of a tackifier resin, a plasticizer, a wax, an antioxidant, an elastomer, a pigment, a dye, a filler, an ultraviolet screening agent, an antistatic agent, an antiblocking agent, a slip agent, Wherein the adhesive further comprises at least one additive selected from the group consisting of an optical brightener, a dispersant, a heat stabilizer, a light stabilizer, an ultraviolet absorber and a lubricant. 8. The composition of claim 7 wherein the additive is selected from the group consisting of dicyclopentadiene, mineral oil, pentaerythritol tetrakis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) Ditert-butyl-4-hydroxyphenyl) propionate), tris (2,4-ditert-butylphenyl) phosphite (tris (2,4- butylphenyl) phosphite, and 2- (2H-benzotriazol-2-yl) -p-cresol. Hot melt adhesive. 8. The method of claim 7,
Wherein the additive is contained in an amount of 1 to 80% by weight based on the total weight of the hot-melt adhesive. A molded article comprising an adhesive layer comprising the hot melt adhesive of claim 6.