JPH11323278A - Hot-melt adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a hot-melt adhesive composition excellent not only in flexibility and cold resistance but also in creeping properties at a high temperature. SOLUTION: This hot-melt adhesive composition comprises a base polymer and a paraffin wax having 40-110 deg.C melting point. An ethylene-vinyl acetate copolymer having 15-42 wt.% content of vinyl acetate and 50-2,000 g/10 min melt index can be used as the base polymer. The number average molecular weight of the paraffin wax is about 200-660. The amount of the used paraffin wax is about 10-90 pts.wt. based on 100 pts.wt. base polymer. The hot-melt adhesive composition may contain an adhesion-imparting agent such as a hydrogenated petroleum-based resin and/or an antioxidant such as a phenolic antioxidant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to papers, textiles,
The present invention relates to a hot melt adhesive composition useful for bonding plastics, wood, leather, metal, and the like.

[0002]

2. Description of the Related Art Hot melt adhesives have a solid content of 100%.
Is a non-solvent type adhesive which is solid at room temperature, heated and melted at the time of use, applied and adhered to various adherends, solidified by cooling, and exhibits adhesive strength. The hot melt adhesive has many advantages such as no risk of environmental pollution, a low risk of fire and the like, a short set time for bonding, and easy handling. Moreover, due to the rapid spread of applicators, hot melt adhesives are widely used in various fields such as bookbinding, packaging, and woodworking.

[0003] The hot-melt adhesive is generally used as a base polymer (for example, an ethylene-based copolymer such as an ethylene-vinyl acetate copolymer or an ethylene-acrylate copolymer, polyethylene, thermoplastic rubber, polyamide, or the like).
Thermoplastic polymers such as polyurethane and polyester)
And various waxes as tackifiers and viscosity modifiers. As the base polymer, flexibility,
Ethylene-based copolymers such as an ethylene-vinyl acetate copolymer and an ethylene-acrylate ester are widely used from the viewpoint of a heating stabilizer, price, and the like. As the tackifier, a natural resin such as a rosin-based resin or a terpene-based resin or a derivative thereof, a petroleum-based resin, or the like is often used.

[0004] Such hot melt adhesives include:
(1) In order to improve workability and wettability to a substrate, low melt viscosity, (2) in addition to high adhesive strength, high cold resistance and high flexibility, (3) adhesive strength even at high temperature Various properties such as high heat resistance, (4) short set time, and (5) high heating stability are required for the expression. However, usually, when the melt viscosity is reduced, the heat resistance is reduced and the set time is increased,
Improving the heat creep resistance increases the melt viscosity and decreases the adhesive strength, cold resistance and flexibility. As described above, a hot-melt adhesive is required to have a plurality of contradictory characteristics, and in order to achieve both of these characteristics, various aspects such as constituent components and composition ratios have been studied.

As a method for reducing the melt viscosity, for example, a method using (a) an ethylene-vinyl acetate copolymer having a high melt index as a base polymer,
(B) a method of reducing the content of an ethylene-vinyl acetate copolymer, (c) a method of adding a wax (for example, a mineral wax such as a petroleum wax, a coal wax, or a low-molecular polyethylene wax) and a plasticizer. It has been known.

However, in the method (a), since the melt index is high, the tensile strength and the melting point or the softening point are lowered, and not only the adhesive strength (cohesion) but also the heat creep resistance is lowered. Further, as shown in (b), when the content of the ethylene-vinyl acetate copolymer is reduced, the adhesive strength,
Flexibility and cold resistance are reduced. Furthermore, in the method (c), the waxes are generally brittle and hard and have a low softening point. Therefore, when many waxes are added, the softening point and the heat creep resistance of the hot melt adhesive are lowered, and the flexibility and the adhesiveness are reduced. And cold resistance are also significantly reduced.

As methods for increasing the softening point and improving the heat creep resistance, there are known a method using an ethylene-vinyl acetate copolymer having a low vinyl acetate content, a method using a high melting point additive and a method using a filler. ing. However, contrary to the above, in these methods, the flexibility and the cold resistance are reduced, the melt viscosity is increased, and the workability and the wettability to the substrate are reduced.

Further, when a normal rosin-based resin is added as a tackifier, the adhesive strength and the cold resistance are improved.
A film is formed on the surface during heating and melting, the heating stability is not sufficient, and the set time becomes long. In order to improve the heat stability, a method using a disproportionated or hydrogenated rosin-based resin, a method of adding an antioxidant, and the like are known. However, even if a disproportionated or hydrogenated rosin-based resin is added, not only the setting property is not significantly improved but also the use of a hydrogenated rosin-based resin is not practical in terms of economic efficiency. Terpene-based resins mainly composed of terpene-phenol resins are excellent in heat stability and settability, but deteriorate heat creep resistance and cold resistance and generate odor.

On the other hand, various petroleum resins obtained by polymerizing inexpensive petroleum fractions are used as tackifiers instead of rosin-based and terpene-based resins. Various properties such as compatibility with the base polymer, heat stability, adhesion, and cold resistance are inferior to those of the derivative.

As described above, each component constituting the hot melt adhesive has a great influence on a plurality of properties of the adhesive instead of a single property. Therefore, adhesive strength, setability,
It is extremely difficult to simultaneously satisfy all properties of flexibility, cold resistance and heat resistance. In particular, when the softening point or melt viscosity decreases, the flexibility and cold resistance tend to improve, but since the heat creep resistance decreases, it is difficult to achieve both flexibility and cold resistance and heat resistance adhesion. is there.

[0011]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a hot melt adhesive composition which is excellent not only in flexibility and cold resistance but also in heat creep resistance. Another object of the present invention is to provide a hot melt adhesive composition having high heat creep resistance despite low softening point and low melt viscosity. Still another object of the present invention is to provide a hot melt adhesive excellent in cold resistance, heat creep resistance and high-speed adhesiveness. Another object of the present invention is to
An object of the present invention is to provide a hot melt adhesive composition having further improved adhesive strength and cold resistance. Still another object of the present invention is to provide a hot melt adhesive composition having further improved heat stability.

[0012]

The present inventors have conducted intensive studies to achieve the above object, and as a result, have found that a base polymer such as an ethylene-vinyl ester copolymer or an ethylene-acrylate ester copolymer and a specific paraffin are used. It has been found that when combined with a wax, a hot-melt adhesive having high heat resistance can be obtained in spite of being excellent in flexibility and cold resistance and low in softening point and melt viscosity. Thus, the present invention has been completed.

That is, the hot melt adhesive composition of the present invention contains a base polymer and a paraffin wax having a melting point of 40 to 110 ° C. The base polymer may be an ethylene-vinyl acetate copolymer having a vinyl acetate content of 15 to 42% by weight and a melt index of 50 to 2000 g / 10 minutes. The number average molecular weight of the paraffin wax is, for example, about 200 to 660. The hot melt adhesive composition further comprises a tackifier and / or
Alternatively, it may contain an antioxidant. For tackifiers,
It includes a hydrogenated petroleum-based resin and the like, and examples of the antioxidant include a phenol-based antioxidant, a phosphorus-based antioxidant, and a sulfur-containing antioxidant.

[0014] In the present specification, "melting point" means
JIS K71 using a thermal differential scanning calorimeter (DSC)
21 means the melting peak temperature (Tpm) when measured at a heating rate of 10 ± 1 ° C./min according to the measuring method specified in 21. The “softening point” means a softening point when measured at a heating rate of 5 ° C./min according to the ring and ball drop method defined in JIS K2406. In addition, the ethylene-vinyl ester copolymer and the ethylene-acrylate ester copolymer may be collectively referred to as “ethylene copolymer”. Also, the melt index (melt flow rate)
Means a value measured according to the measurement method specified in JIS K6730.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Base Polymer] As the base polymer, various thermoplastic resins which melt or soften at a relatively low temperature of about 80 to 200 ° C. and exhibit adhesive strength, for example, ethylene-vinyl acetate Ethylene-vinyl ester copolymers such as copolymers, ethylene-acrylate copolymers such as ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, polyethylene, atactic polypropylene, nylon 12, etc. Polyamide, polyurethane, polyester and the like.

Preferred base polymers include ethylene copolymers (ethylene-vinyl ester copolymers, ethylene-acrylate copolymers) having excellent flexibility, toughness, compatibility, fluidity, etc., especially ethylene. -Vinyl acetate copolymer or ethylene-ethyl acrylate copolymer,
Among them, ethylene-vinyl acetate copolymer and the like are included.

The content of the vinyl ester or the acrylate ester in the ethylene copolymer can be selected within a range that does not impair the properties such as adhesive strength and flexibility, and is, for example, 15 to 42% by weight (usually 15 to 35% by weight). %degree),
Preferably 18 to 32% by weight, more preferably 20 to 32% by weight.
It is about 30% by weight, especially about 22 to 28% by weight. If the content is less than 15% by weight, the adhesive strength tends to decrease.
If it exceeds 2% by weight, blocking tends to occur.

The base polymer can be used alone or in combination of two or more of the same or different polymers. For example, two or more types of ethylene having different vinyl ester contents such as vinyl acetate or acrylic ester contents.
A vinyl ester copolymer or an ethylene-acrylate copolymer can be used in combination.

The melt index (MI) of the base polymer, especially the ethylene-vinyl acetate copolymer, is, for example, 5
0 to 2000 g / 10 min, preferably 80 to 1800 g
/ 10 min, more preferably about 100 to 750 g / 10 min. The melt index of the base polymer is
125-500 g / 10 min, especially 150-450 g / 1
It is often about 0 minutes. Melt index is 50
If the viscosity is less than g / 10 minutes, the melt viscosity tends to be high,
If it exceeds 0 g / 10 minutes, the set time may be long.

[Paraffin wax] The feature of the present invention is that
The base polymer and a specific melting point (i.e. 40-110)
C)).

The melting point of paraffin wax is usually from 40 to
106 ° C., preferably 60 to 100 ° C., and more preferably about 65 to 85 ° C. The melting point of paraffin wax is often, for example, about 65 ° C to 80 ° C, particularly about 66 ° C to 78 ° C, and especially about 68 ° C to 76 ° C. If the melting point of the paraffin wax is less than 40 ° C., the heat creep resistance decreases, and if it exceeds 110 ° C., flexibility and cold resistance decrease.
The paraffin wax can be used alone or in combination of two or more.

The number average molecular weight of the paraffin wax is, for example, about 200 to 660, preferably about 300 to 630, and more preferably about 400 to 600. The number average molecular weight of paraffin wax is, for example, about 200 to 600, especially about 400 to 580, and particularly about 450 to 550 in many cases. The carbon number of paraffin wax is, for example, 21
~ 70, preferably 25-60, more preferably 30
About 40. The paraffin wax may contain a branched component such as i-paraffin or a cyclic component as long as it contains n-paraffin as a main component.

When such a paraffin wax is used, the heat-resistant adhesiveness can be increased, and high adhesive strength can be exhibited even at a high temperature, although the softening point and the melt viscosity are reduced. In addition, workability and wettability to the substrate are high, and the flexibility, cold resistance and thermal stability are not impaired.

The amount of the paraffin wax is usually 10 to 90 parts by weight, based on 100 parts by weight of the base polymer.
Preferably 20 to 80 parts by weight, more preferably 30 to 7 parts by weight.
5 parts by weight, especially about 35 to 60 parts by weight. If the amount of paraffin wax used is less than 10 parts by weight based on 100 parts by weight of the ethylene copolymer, the melt viscosity is high, and the workability and wettability to the base material are apt to decrease. It's easy to do. When the use amount of the paraffin wax is 10 to 90 parts by weight, while ensuring sufficient adhesive strength, it is possible to suppress the development of adhesiveness at room temperature, and the melt viscosity is low, and workability and wettability are good. .

[Tackifier] The hot melt adhesive composition of the present invention may further contain a tackifier in order to improve the adhesive strength and increase the initial adhesive strength.

The tackifier includes, for example, terpene resins, cumarone resins, petroleum resins, styrene resins, phenol resins, rosin resins, and the like.

As terpene resins, α-pinene, β
-Terpene resins which are polymers of terpenes such as pinene, dipentel, limonene, myrcene, bornylene, camphene and the like, and phenol-modified terpene resins obtained by modifying these terpenes with phenols. Examples of the coumarone-based resin include a coumarone-indene resin and a phenol-modified coumarone-indene resin.

Examples of the petroleum-based resin include aliphatic petroleum-based resins and alicyclic petroleum-based resins obtained from distillates such as styrene, methylstyrene, vinyltoluene, indene, methylindene, butadiene, isoprene, piperylene and pentylene. Resins or aromatic petroleum resins, homo- or copolymers of cyclopentadiene and the like are included. Petroleum resin C ₅ -C ₉
Resins obtained by hydrogenating the above resins, such as hydrogenated cyclopentadiene resins, are often polymers using a small fraction as the main component (hydrogenated petroleum resins).
It may be.

Examples of the styrene resin include a low molecular weight homopolymer of styrene, and a copolymer of styrene with, for example, α-methylstyrene, vinyltoluene, butadiene rubber, and the like.

Phenol resins include phenol, cresol, xylenol, resorcinol, toluene, pt-
Reaction products of phenols such as butylphenol and p-phenylphenol with aldehydes such as formaldehyde, acetaldehyde and furfural, and rosin-modified phenol resins are included.

As the rosin resin, rosins such as gum rosin and wood rosin, and derivatives thereof (for example,
Disproportionated rosin, hydrogenated rosin, dehydrogenated rosin, rosin esters such as rosin glycerin ester and rosin pentaerythritol ester, maleic acid adducts, and rosin metal salts).

[0032] Preferred tackifiers, and hydrogenated petroleum oil-based resin (particularly, C ₅ fraction or C ₅ -C ₉ fraction aliphatic petroleum resin whose main component, or a C ₉ fraction composed mainly to hydrogenation product, such as an aromatic petroleum resin), among others C ₉ fraction mainly containing petroleum resin (C ₉ petroleum resins) obtained by hydrogenating a hydrogenated petroleum oil-based resin (C ₉ Hydrogenated petroleum resin). The tackifiers can be used alone or in combination of two or more.

The softening point of the tackifier is, for example, 80 to 15
0 ° C., preferably about 100 to 140 ° C., and more preferably about 120 to 140 ° C. The softening point of the tackifier is 8
If the temperature is lower than 0 ° C., the heat creep resistance is poor, and the set time tends to be long.
Cold resistance tends to decrease. When such a tackifier is combined with the paraffin wax, low-temperature properties such as adhesion and cold resistance are further improved while maintaining a low softening point and melt viscosity.

The amount of the tackifier used is, for example, 20 to 150 parts by weight, preferably 40 to 130 parts by weight, and more preferably 60 to 130 parts by weight, based on 100 parts by weight of the base polymer.
It is about 120 parts by weight. The amount of the tackifier used is often 70 to 130 parts by weight, particularly about 80 to 120 parts by weight, based on 100 parts by weight of the base polymer. If the amount of the tackifier to 100 parts by weight of the base polymer is less than 20 parts by weight, the initial adhesiveness, cold resistance and settability tend to decrease, and if it exceeds 150 parts by weight, the heating stability tends to decrease. As the cohesive strength decreases, the adhesive strength tends to decrease.

The ratio of the tackifier to the paraffin wax can be selected within a range that does not impair the heat creep resistance, heat stability, cold resistance, flexibility, etc. For example, the amount of the tackifier is 1 part by weight of paraffin wax. For 0.5 to 5
Parts by weight, preferably about 1 to 3 parts by weight, more preferably about 1.5 to 2.5 parts by weight. When used in such a ratio, an adhesive having a low melt viscosity and high adhesive strength and heat resistance can be obtained.

[Antioxidant] In general, a hot melt adhesive is industrially put into a device equipped with an applicator, heated and melted at a certain temperature, stored in that state, and then put through a nozzle into a certain amount. It is used for bonding after flowing out in a small amount. When stored by heating for a long time in this manner, the hot melt adhesive itself is oxidized, colored, odored, gelled, and the like, and thermally deteriorated.

In order to suppress such thermal deterioration and improve the heat stability, the hot melt adhesive composition preferably contains an antioxidant. An antioxidant may be used in combination with the base polymer and paraffin wax, or may be used in combination with the base polymer, paraffin wax and tackifier. Antioxidants include:
For example, phenolic antioxidants, amine antioxidants, phosphorus antioxidants, sulfur-containing antioxidants, hydroquinone antioxidants, quinoline antioxidants, hydrazines, urea antioxidants, and other oxidants And an inhibitor.

Examples of the phenolic antioxidant include 2,6-di-tert-butyl-p-cresol (BH
T), 2,2'-methylenebis (4-methyl-6-t-
Butylphenol), 4,4'-butylidenebis (3-
Methyl-6-t-butylphenol), stearyl-β
-(3,5-di-t-butyl-4-hydroxylphenol) propionate, tetrakis [methylene-3-
(3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-4-hydroxy Benzyl) benzene, 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenol) butane, 1,1-bis (4-oxyphenyl) cyclohexane, dialkylphenol sulfide, alkylphenol condensate, styrene Phenol and the like. Preferred phenolic antioxidants include cresol derivatives having a t-butyl group, such as BHT.

As the amine-based antioxidant, for example,
N, N′-di-2-naphthyl-p-phenylenediamine, phenyl-α-naphthylamine, phenyl-β-naphthylamine, 4,4′-dimethoxydiphenylamine, N, N′-diphenyl-p-phenylenediamine,
N-phenyl-N′-cyclohexyl-p-phenylenediamine, N-isopropyl-N′-phenyl-p-phenylenediamine, aldol-α-naphthylamine,
Examples thereof include 4,4'-diaminodiphenylmethane, acetaldehyde aniline, and a reaction product of diphenylamine and acetone.

Examples of the phosphorus-based antioxidant include triisodecyl phosphite, diphenyl isodecyl phosphite, triphenyl phosphite, and trinonyl phenyl phosphite.

Examples of the sulfur-containing antioxidant include, for example,
2,2'-thiobis (4-methyl-6-t-butylphenol), 4,4'-thiobis (6-t-butyl-m-
Thioethyls such as cresol); dilauryl thiodipropionate, distearyl thiodipropionate,
Thiopropionic esters such as lauryl stearyl thiodipropionate and dimyristyl thiodipropionate; 2-mercaptobenzimidazole; dibutyl-
Nickel dithiocarbamate and the like. Preferred sulfur-containing antioxidants include thioethers and the like.

Hydroquinone-based antioxidants include, for example,
2,5-di-t-amylhydroquinone, 2,5-di-t
-Butylhydroquinone, hydroquinone monobenzyl ether, etc., and quinoline-based antioxidants include trimethyldihydroquinoline polymer, 6-ethoxy-2,2,2
4-trimethyl-1,2-dihydroquinoline, 1,2-
Dihydro-2,2,4-trimethyl-6-phenylquinoline, 1,2-dihydro-2,2,4-trimethylquinoline and the like are included. Hydrazines include N-salicyloyl-N'-acetylhydrazine, N-salicyloyl-
N'-acetylhydrazine and the like are included, and urea-based antioxidants include, for example, o-phenylenethiourea.

Other antioxidants include, for example,
N, N'-diphenyloxamide, N-N'-di- (2
-Hydroxyphenyl) oxamide; phenol-nickel complex; dibenzo-18-crown-6, 18-crown-6, cryptand [2.2], cryptand
Crown ethers such as [2.2.2]; cyclodextrin;

In a preferred embodiment of the present invention, the antioxidant contains at least one selected from phenolic antioxidants, phosphorus-based antioxidants and sulfur-containing antioxidants. It is preferable to use at least a phenolic antioxidant.

The antioxidants can be used alone or in combination of two or more. In particular, when two or more different types of antioxidants are used in combination, the heat stability may be greatly improved. Preferred combinations of antioxidants include at least two or more combinations selected from phenolic antioxidants, phosphorus antioxidants, and sulfur antioxidants. Further, the combination of antioxidants preferably contains at least a phenolic antioxidant, for example, a combination of a phenolic antioxidant and a phosphorus-based antioxidant, a phenolic antioxidant and a sulfur-containing antioxidant. And a combination of a phenolic antioxidant, a phosphorus antioxidant, and a sulfur antioxidant.

When a plurality of antioxidants are used in combination, the amount of each antioxidant can be appropriately selected within a range where thermal deterioration can be suppressed and heating stability can be increased. For example, when using two kinds of antioxidants,
The amount of each antioxidant used is one antioxidant / the other antioxidant (weight ratio) = 10-90 / 90-10, preferably 25-75 / 75-25, and more preferably 30-90.
It is about 70 / 70-30. When three types of antioxidants, for example, a phenolic antioxidant, a phosphorus antioxidant, and a sulfur-containing antioxidant are combined, the amount of each antioxidant used is 100% of the total amount of the antioxidant.
5 to 50% by weight, preferably 10 to 45% by weight
%, More preferably about 15 to 40% by weight.

The total amount of the antioxidant is, for example, 0.1 to 1 with respect to 100 parts by weight of the total amount of the hot melt adhesive composition.
0 parts by weight, preferably 0.3 to 5 parts by weight, more preferably about 0.5 to 2.5 parts by weight. When the total amount of the antioxidant is less than 0.1 part by weight, the heat resistance deterioration and heating stability are not significantly improved, and when the total amount exceeds 10 parts by weight, the cost becomes high and it is not economical. When a plurality of antioxidants are used, the amount of each antioxidant used is, for example, 0.05 to 5 with respect to 100 parts by weight of the total amount of the hot melt adhesive composition.
Parts by weight, preferably 0.1 to 2 parts by weight, more preferably 0.2 to 1.5 parts by weight, especially about 0.25 to 0.9 parts by weight.

[Other Additives] The hot melt adhesive composition of the present invention may contain, if necessary, a stabilizer such as an ultraviolet absorber, as long as it does not impair heat creep resistance, flexibility and cold resistance. Inorganic fillers such as calcium, clay, silica, magnesium carbonate, titanium, zinc oxide, and carbon black; thermoplastic resins other than base polymers such as polyethylene and polypropylene; lanolin, dibutyl phthalate, liquid polybutene, liquid polyisobutylene, mineral oil, etc. Thermoplastic rubbers such as styrene-isoprene-based block copolymers and styrene-butadiene-based block copolymers; asphalt; microcrystalline wax, animal wax, plant wax, mineral wax, synthetic wax, hydrogen-based Waxes other than the paraffin wax It may contain a box class.

[Production of Hot Melt Adhesive Composition] The hot melt adhesive composition of the present invention can be produced by a conventional method, for example, by heating and melting and mixing the components. Heat melting mixing is usually performed at normal pressure in many cases,
It may be performed under pressure or under reduced pressure. The heat melting temperature may be affected by the high melting point component,
The temperature is in the range of 300 ° C, preferably about 90 to 200 ° C.

The apparatus for heating and melting and mixing is not particularly limited as long as heating and mixing are possible. Usually, a tank with a stirrer is often used. In addition, an intensive mixer, a Banbury mixer, a super mixer, a Hensiel mixer, or the like can also be used. Also,
The components constituting the hot-melt adhesive composition are heated and melt-mixed using an extruder equipped with a screw, extruded from a mold and cooled, thereby bonding in a desired shape such as a pellet, a rod, and a string. It may be an agent.

The thus obtained hot melt adhesive composition of the present invention is excellent in flexibility and cold resistance, and has high heat creep resistance despite its low softening point and low melt viscosity. For example, in the hot melt adhesive composition of the present invention, the softening point according to the ring and ball drop method (JIS K2406) is about 70 to 100 ° C, and the melt viscosity at 180 ° C is 5
00 to 2000 cps (preferably 700 to 1850 c
ps), and the heat-resistant creep temperature described later (see Examples) is often 60 ° C. or higher (for example, about 60 to 85 ° C.) in many cases.

The hot bonding temperature when using the hot melt adhesive composition of the present invention can be appropriately selected according to the softening point, melt viscosity, type of adherend and the like of the composition.
The temperature is about 90 to 250C, preferably about 140 to 220C.

The hot-melt adhesive composition of the present invention can be used not only for various adherends such as plastics and metals having a smooth surface but also for porous adherends such as paper and wood products. It can also be used for thermal bonding. More specifically, examples of the adherend include cellulosic adherends (eg, paper, board, cardboard, cellophane, etc.), plastics (eg, polyester, polyvinyl chloride, polyurethane, polypropylene, ABS resin, polymethacrylate) , Polycarbonate, etc.), textiles (eg, woven, knitted, non-woven, etc.), wood, leather, metal (eg,
Stainless steel, aluminum, etc.), and glass.

The hot melt adhesive composition of the present invention can be used in a wide range of fields, for example, packaging, shoemaking, textile processing, metal industry,
It can be used for various applications in fields such as electric and electronic industries. For example, paper-to-paper, production of packaging materials by adhesion of plastic films or sheets, bookbinding, production of footwear, production of laminates, production of plywood, adhesion of paper to metal or plastic, adhesion of metal to plastic,
It can be used for applications such as coating of paper, fiber, plastic film or sheet, as well as for use as sealing agents and building materials. In particular, since the hot melt adhesive composition of the present invention has both high heat creep resistance and cold resistance, various members in which a decrease in adhesive strength at high or low temperatures becomes a problem, for example, interior materials for automobiles And various adhesives for building materials.

[0055]

The hot-melt adhesive composition of the present invention comprises:
Since the base polymer is combined with a specific paraffin wax, it has not only flexibility and cold resistance, but also excellent heat creep resistance and high-speed adhesion.
In addition, heat resistance is high despite its low softening point and melt viscosity. Furthermore, when a tackifier (particularly, a hydrogenated petroleum resin) is used, the adhesive strength and cold resistance can be further improved. When an antioxidant is used, the heating stability can be further improved.

[0056]

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 An ethylene-vinyl acetate copolymer (Tosoh Corporation, trade name: Ultracene 72) was placed in a stainless steel flask.
2, vinyl acetate content 28% by weight, MI = 400 g / 10
40 parts by weight, hydrogenated petroleum resin (Arakawa Chemical Co., Ltd.)
Trade name: Archon M-135, softening point 135 ° C) 40 parts by weight, paraffin wax (Nippon Seiro Co., Ltd., trade name:
20 parts by weight of paraffin HNP-9) are melted at 180 ° C., and as an antioxidant, a phenolic antioxidant (Adeka Argus Chemical Co., Ltd., trade name: AO-37) 0.3
Parts by weight, 0.3 parts by weight of a phosphorus-based antioxidant (Adeka Argus Chemical Co., Ltd., trade name: HP-10) and a thioether-based antioxidant (Adeka Argus Chemical Co., Ltd., trade name: AO-412S) ) 0.3 part by weight was added little by little and mixed to obtain a hot melt adhesive.

Example 2 An ethylene-vinyl acetate copolymer (Tosoh Corporation, trade name: Ultracene 72) was placed in a stainless steel flask.
5, vinyl acetate content 28% by weight, MI = 1000 g / 1
0 minutes) 40 parts by weight, hydrogenated petroleum resin (Arakawa Chemical Industry Co., Ltd., trade name: Archon M-135, softening point 135)
C.) 45 parts by weight and 15 parts by weight of paraffin wax (Nippon Seiro Co., Ltd., trade name: Paraffin HNP-9) are melted at 180 ° C., and as an antioxidant, a phenolic antioxidant (Ciba Geigy Co., Ltd.) 0.2 parts by weight of Irganox 1010) and 0.2 parts by weight of a phosphorus-based antioxidant (Adeka Argus Chemical Co., Ltd., trade name: HP-10) are added and mixed little by little, and then hot melt bonded. Agent was obtained.

Example 3 An ethylene-vinyl acetate copolymer (trade name: Ultracene 72, manufactured by Tosoh Corporation) was placed in a stainless steel flask.
2, vinyl acetate content 28% by weight, MI = 400 g / 10
40 parts by weight, hydrogenated petroleum resin (Arakawa Chemical Co., Ltd.)
Brand name: Archon M-115, softening point 115 ° C) 40 parts by weight, paraffin wax (Nippon Seiro Co., Ltd., trade name:
Paraffin HNP-9) 10 parts by weight and paraffin wax (Nippon Seiro Co., Ltd., trade name: Paraffin 155F)
10 parts by weight were melted at 180 ° C., and as an antioxidant, a phenolic antioxidant (Adeka Argus Chemical Co., Ltd.)
Trade name: AO-37) 0.3 parts by weight, thioether antioxidant (Adeka Argus Chemical Co., Ltd., trade name: AO
-412S) 0.3 parts by weight were added little by little and mixed to obtain a hot melt adhesive.

Example 4 An ethylene-vinyl acetate copolymer (trade name: Ultracene 72, manufactured by Tosoh Corporation) was placed in a stainless steel flask.
2, vinyl acetate content 28% by weight, MI = 400 g / 10
35 parts by weight, 5 parts by weight of ethylene-vinyl acetate copolymer (Tosoh Corporation, trade name: Ultracene 680, vinyl acetate content 20% by weight, MI = 160 g / 10 minutes), hydrogenated petroleum resin (Arakawa Chemical Industry Co., Ltd., product name: Archon P
-140, softening point 140 ° C) 40 parts by weight, paraffin wax (Nippon Seiro Co., Ltd., trade name: Paraffin HNP-
9) 10 parts by weight and 10 parts by weight of paraffin wax (Nippon Seiro Co., Ltd., trade name: Paraffin 155F)
The mixture was melted at 80 ° C., and 0.5 parts by weight of a phenolic antioxidant (Ciba Geigy Co., Ltd., trade name: Irganox 1010) was added and mixed little by little as an antioxidant to obtain a hot melt adhesive.

Example 5 An ethylene-vinyl acetate copolymer (Tosoh Corp., trade name: Ultracene 72) was placed in a stainless steel flask.
2, vinyl acetate content 28% by weight, MI = 400 g / 10
20 parts by weight, ethylene-vinyl acetate copolymer (Tosoh Corporation, trade name: Ultracene 680, vinyl acetate content 20% by weight, MI = 160 g / 10 minutes) 15 parts by weight,
40 parts by weight of hydrogenated petroleum resin (Arakawa Chemical Industry Co., Ltd., trade name: Alcon M-135, softening point 135 ° C.), paraffin wax (Nippon Seiro Co., Ltd., trade name: paraffin HNP)
-9) 25 parts by weight were melted at 180 ° C., and 0.5 part by weight of a phenolic antioxidant (Ciba Geigy Co., Ltd., trade name: Irganox 1010) was added and mixed little by little as an antioxidant, A melt adhesive was obtained.

Comparative Example 1 An ethylene-vinyl acetate copolymer (Tosoh Corporation, trade name: Ultracene 72) was placed in a stainless steel flask.
2, vinyl acetate content 28% by weight, MI = 400 g / 1
0 minutes) 40 parts by weight, hydrogenated petroleum resin (Arakawa Chemical Industry Co., Ltd., trade name: Archon M-135, softening point 135)
C) 40 parts by weight and 20 parts by weight of polyethylene wax (Yasuhara Chemical Co., Ltd., trade name: Neowax L)
Melted at 80 ° C and used as an antioxidant as a phenolic antioxidant (Adeka Argus Chemical Co., Ltd., trade name: AO-
37) 0.3 parts by weight, 0.3 parts by weight of a phosphorus-based antioxidant (Adeka Argus Chemical Co., Ltd., trade name: HP-10) and a thioether-based antioxidant (Adeka Argus Chemical Co., Ltd., product) (Name: AO-412S) 0.3 part by weight was added and mixed little by little to obtain a hot melt adhesive.

Comparative Example 2 An ethylene-vinyl acetate copolymer (Tosoh Corp., trade name: Ultracene 72) was placed in a stainless steel flask.
2, vinyl acetate content 28% by weight, MI = 400 g / 10
40 parts by weight, hydrogenated petroleum resin (Arakawa Chemical Co., Ltd.)
Trade name: Alcon M-115, softening point 115 ° C) 40 parts by weight, Sasol wax (Kato Yoko Co., Ltd., trade name: H
1) 20 parts by weight were melted at 180 ° C., and 0.01 part by weight of a thioether-based antioxidant (Adeka Argus Chemical Co., Ltd., trade name: AO-412S) was added and mixed little by little as an antioxidant. Thus, a hot melt adhesive was obtained.

Comparative Example 3 An ethylene-vinyl acetate copolymer (Tosoh Corporation, trade name: Ultracene 53) was placed in a stainless steel flask.
0, vinyl acetate content 6% by weight, MI = 75 g / 10 min)
30 parts by weight, rosin-based tackifier (Arakawa Chemical Industries, Ltd., trade name: Superester A125, softening point 1)
25 parts by weight) and 40 parts by weight of polypropylene wax (Mitsui Petrochemical Co., Ltd., trade name: NP105) are 18 parts by weight.
Melting was performed at 0 ° C. to obtain a hot melt adhesive.

Evaluation of Characteristics The melt viscosity, set time, open time, heat-resistant creep temperature, cold-resistant adhesiveness and thermal stability of the hot melt adhesives obtained in the above Examples 1 to 5 and Comparative Examples 1 to 3 were as follows. It was measured and evaluated by the method. Table 1 shows the results.
Shown in

(1) Melt viscosity (cps / 180 ° C.): Measured with a rotational viscometer. (2) Set time: A hot melt adhesive was linearly applied to a K liner cardboard B flute (220 g / m ² ) at an application temperature of 180 ± 2 ° C. and an application amount of 3 ± 0.3 g / m. Then, a corrugated cardboard was adhered with an open time of 2 seconds, and five test pieces of a plurality of types were produced with a load of 2 kgf and a different pressing time (elapsed time from the start of compression). The plurality of types of test pieces were peeled off, and the pressing time when the material destruction rate was 80% or more in four or more test pieces out of five test pieces of the same type was defined as a set time. In addition,
If the set time is within 2 seconds, the high-speed adhesion is excellent.

(3) Open time: The hot melt adhesive was applied at an application temperature of 180 ± 2 ° C. and an application amount of 3 ± 0.3 g / m.
Under the conditions of (2), the corrugated cardboard B flute of K liner,
g / m ² ). The time elapsed after the application of the adhesive was changed, the corrugated cardboard was adhered and pressed with a load of 2 kgf for 2 seconds to peel. Such an operation,
The test was performed on five test pieces under the same conditions, and the elapsed time after the application when the material destruction rate was 80% or more in four or more test pieces was defined as the open time.

(4) Heat-resistant creep temperature: hot melt adhesive was applied at an application temperature of 180 ± 2 ° C. and an application amount of 3 ± 0.3 g /
m, applied to kraft paper in a 25 mm wide line,
A test piece was prepared by laminating with another kraft paper with an open time of 2 seconds and pressing with a load of 2 kgf for 2 seconds. The test piece was left at room temperature for 12 hours or more,
After leaving for 0 minutes, 100 g of
When a load of f / 25 mm was applied and the temperature was raised at a rate of 1 ° C./min, the temperature at which the adhesive layer was broken and the kraft paper fell was defined as the heat-resistant creep temperature. The numerical values in Table 1 are the average values of five test pieces. If the heat-resistant creep temperature is 60 ° C. or higher, there is no problem in practical use.

(5) Cold-resistant adhesiveness: A hot-melt adhesive was applied at a coating temperature of 180 ± 2 ° C. and a coating amount of 3 ± 0.3 g / m under the conditions of a K-liner cardboard B flute (220 g /
m ² ), a K liner corrugated cardboard B flute was adhered with an open time of 2 seconds, pressed under a load of 2 kgf for 2 seconds, and left at room temperature for 12 hours or more to prepare a test piece. Under the same conditions, five test pieces were left in a thermostat at different temperatures for 24 hours, then peeled off, and the temperature of the thermostat at the time when the material destruction rate became 50% with four or more test pieces was changed to cold resistance. It was used as an index of adhesiveness.

(6) Thermal stability: The hot melt adhesive was placed in a container (100 ml), heated at a temperature of 180 ° C., and the formation of carbide and the occurrence of phase separation were visually observed and evaluated according to the following criteria. ：: Carbide and phase separation do not occur △: Carbide and phase separation slightly occur ×: Carbide and phase separation are remarkable

[Table 1] As is evident from Table 1, the hot melt adhesive compositions of the examples have higher cold adhesion resistance and heat creep resistance than the hot melt adhesive compositions of comparative examples, and are excellent in high-speed adhesion. .

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Claims (11)

[Claims] 1. A base polymer having a melting point of 40 to 110 ° C.
A hot melt adhesive composition comprising paraffin wax. 2. The base polymer having a vinyl acetate content of 15
~ 42% by weight, melt index 50 ~ 2000g /
2. An ethylene-vinyl acetate copolymer for 10 minutes.
The hot melt adhesive composition according to the above. 3. The paraffin wax having a number average molecular weight of 2
The hot melt adhesive composition according to claim 1, wherein the number is from 00 to 660. 4. A method according to claim 1, wherein 100 parts by weight of the base polymer is
The hot melt adhesive composition according to claim 1, comprising 10 to 90 parts by weight of paraffin wax. 5. An ethylene copolymer having a vinyl acetate content of 15 to 35% by weight and a melt index of 50 to 2000 g / 10 min.
Melting point of 60 to 100 parts by weight of vinyl acetate copolymer
The hot melt adhesive composition according to claim 1, comprising 20 to 80 parts by weight of paraffin wax having a number average molecular weight of 300 to 630 at 100 ° C. 6. The hot melt adhesive composition according to claim 1, further comprising a tackifier and / or an antioxidant. 7. The hot melt adhesive composition according to claim 6, wherein the tackifier is a hydrogenated petroleum resin. 8. The hot melt adhesive composition according to claim 6, wherein the antioxidant is at least one selected from a phenolic antioxidant, a phosphorus antioxidant, and a sulfur-containing antioxidant. 9. The composition according to claim 9, wherein the weight of the base polymer is 100 parts by weight.
7. The hot melt adhesive composition according to claim 6, comprising 20 to 150 parts by weight of a tackifier. 10. A vinyl acetate content of 15 to 35% by weight,
Melt index 50 to 2000 g / 10 min, 100 parts by weight of ethylene-vinyl acetate copolymer, melting point 6
A hot melt adhesive composition containing 20 to 80 parts by weight of paraffin wax at 5 to 80 ° C, 40 to 130 parts by weight of a hydrogenated petroleum resin as a tackifier, and an antioxidant. 11. An ethylene-vinyl acetate copolymer having a vinyl acetate content of 15 to 35% by weight, based on 100 parts by weight,
Oxidation containing 30 to 75 parts by weight of paraffin wax having a melting point of 65 to 80 ° C., 80 to 120 parts by weight of a C ₉ hydrogenated petroleum resin having a softening point of 100 to 140 ° C. as a tackifier, and at least a phenolic antioxidant. A hot melt adhesive composition containing an inhibitor in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the total amount of the composition.