JPH08269417A - Hot melt adhesive composition - Google Patents

Abstract

PURPOSE: To obtain a hot melt adhesive having a long open time, does not cause a moisture-permeable olefin resin film to undergo exudation and has a low melt viscosity. CONSTITUTION: This composition comprises 100 pts.wt. butene-1 homopolymer and/or butene-1 copolymer, 40-300 pts.wt. tackifying resin, and 10-100 pts.wt. unsaturated hydrocarbon oligomer having a flow point of -80 to 30 deg.C and desirably having 4-14 carbon atoms.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot melt type adhesive composition suitable for adhering a moisture-permeable olefin resin film.

[0002]

2. Description of the Related Art As an adhesive used to bond a breathable olefin resin film used in disposable diapers, sanitary napkins, bed pad components, etc. to other components such as nonwoven fabric and paper For example, a hot melt adhesive containing a base polymer composed of an amorphous ethylene-propylene random copolymer having a number average molecular weight of 500 to 20,000 and an ethylene content of 10 to 80% by weight and waxes or a tackifying resin. An agent has been proposed (JP-A-5-148465).

In the above-mentioned hot melt type adhesive, when waxes are blended, the solidification rate after application is fast (open time is short), so that it is difficult to bite into nonwoven fabric or paper and the adhesive strength is weak. It also has a drawback that when a tackifying resin is blended, the effect of preventing seepage from the fine pores of the moisture-permeable olefin resin film is not sufficient.

As one method for solving the above problems,
As a hot melt adhesive having a long open time and suitably used for bonding non-woven products, a hot melt adhesive containing a homopolymer of butene-1 or a copolymer thereof as a base polymer (Japanese Patent Laid-Open No. 2-196878). Is proposed.

[0005]

However, Duraflex 8910 (trade name; current trade name is polybutylene D) disclosed in Japanese Patent Laid-Open No. 2-196878.
If P-8910) is used, the melt viscosity becomes too high and the coating operation becomes difficult. If the compounding amount of the tackifying resin is increased to lower the melt viscosity, the solidification after coating becomes too fast and the nonwoven or paper is applied. The adhesiveness is weak, and there is exudation from the fine pores of the moisture-permeable olefin resin film.

Further, when the molecular weight of the butene-1 polymer is lowered, the polymer itself becomes sticky, and when the pellets are formed into pellets, the pellets adhere to each other. It is necessary to attach an anti-adhesion agent such as wax, which shortens the open time.

Further, with process oils such as Shelf Rex 371 (trade name) exemplified in Japanese Patent Laid-Open No. 2-196878, the melt viscosity can be lowered, but the fine pores of the moisture-permeable olefin resin film can be reduced. There is a bleed from.

The present invention has been made in view of the above problems, and an object thereof is a hot melt having a long open time, no exudation from a moisture-permeable olefin resin film, and a low melt viscosity. A mold adhesive is provided.

[0009]

The hot melt adhesive composition of the present invention comprises a butene-1 homopolymer and / or its copolymer, a tackifying resin, and a pour point of -80 to 30.
It consists of unsaturated hydrocarbon oligomers at ° C. Butene above
The monomer of No. 1 and / or the copolymer thereof are used as a base polymer, and the copolymer of butene-1 includes butene-1 and other α-olefins (ethylene,
And a copolymer with propylene). When the content of butene-1 in the above-mentioned copolymer is small, solidification becomes fast and the open time becomes short when the adhesive is cooled. The butene-1 monomer and its copolymer are
Each can be used alone or in combination of two or more.

When the number average molecular weight of the butene-1 monomer or its copolymer is small, not only the adhesive strength of the resulting adhesive decreases and the desired adhesive strength is not obtained, but also the polymer itself. When it is formed into pellets because it becomes tacky, it becomes easy for the pellets to adhere to each other, and when the pellets become large, the melt viscosity becomes high, so 1 to 500,000 is preferable, and more preferably 2 to 100,000.

Examples of the tackifying resin include aliphatic petroleum resins and hydrogenated products thereof, aromatic petroleum resins and hydrogenated products thereof, alicyclic petroleum resins and hydrogenated products thereof, aliphatic and aromatic petroleum resins and their products. Hydrogenated products, aliphatic / alicyclic petroleum resins and their hydrogenated products, terpene resins and their hydrogenated products, aromatic modified terpene resins and their hydrogenated products, rosins, disproportionated rosins, rosin esters, hydrogenated rosins Examples thereof include esters and disproportionated rosin esters.

Of these, hydrogenated petroleum resins such as aliphatic hydrogenated petroleum resins and aliphatic hydrogenated petroleum resins are preferably used because they are unlikely to be colored when heated. In the case of petroleum resin which is not hydrogenated, it is advisable to use an antioxidant. The tackifying resins may be used alone or in combination of two or more.

Further, if the softening point of the above tackifying resin is lowered, the cohesive force of the adhesive is reduced and it becomes difficult to obtain a sufficient adhesive force. On the other hand, if the softening point is increased, the melt viscosity becomes high and the coating operation becomes difficult. Therefore, it is preferably in the range of 60 to 155 ° C. as measured by the ring and ball softening point measuring method defined in JIS K2207.

When the blending amount of the above tackifying resin is small, the melt viscosity becomes high and the coating work becomes difficult, and when it is large, the solidification after coating becomes fast and the required open time becomes difficult to obtain, so that the base polymer is obtained. 40 to 300 parts by weight with respect to 100 parts by weight of the butene-1 monomer and / or its copolymer.

When the pour point of the unsaturated hydrocarbon oligomer is low, the amount of low molecular weight substances is large, and exudation easily occurs from the fine pores of the permeable olefin resin film. When the pour point is high, the softening effect is high. Because it is difficult to obtain-
It is 80 to 30 ° C. The unsaturated hydrocarbon oligomer having 4 to 14 carbon atoms can be preferably used, and examples thereof include polymers such as butene, butadiene, isoprene, pentene, pentadiene, hexene, heptene, octene and decene, and the number average molecular weight. It is preferably about 100 to 500.

The pour point of the unsaturated hydrocarbon oligomer is a value measured according to JIS K 2269.

When the amount of the unsaturated hydrocarbon oligomer added is small, the softening effect is difficult to be obtained, and when it is large, the cohesive force is insufficient and the adhesive strength is difficult to be obtained, so that the moisture-permeable olefin resin film has fine pores. Since exudation is likely to occur, it is 10 to 100 parts by weight of the butene-1 monomer of the base polymer and / or its copolymer.
It is 100 parts by weight.

The hot melt adhesive composition of the present invention contains the above-mentioned components as essential components, and may further contain antioxidants, ultraviolet absorbers, waxes, oils and the like, if necessary. As the antioxidant, 2,4-bis-
(N-octyl neo) -6- (4-hydroxy-3,5
-Di-t-butylanilino) -1,3,5-triazine, pentaerythrityl-tetrakis [3- (3,5-
Di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, and other hindered phenol compounds, tris (2,4-di) -T-
Examples thereof include phosphorus compounds such as butylphenyl) phosphite.

If the amount of the above-mentioned antioxidant added is small, it becomes difficult to obtain the antioxidant effect, and even if it is increased, it is not economical. Therefore, the monomer of butene-1 of the base polymer or / and its 0.1-5 per 100 parts by weight of polymer
Parts by weight are preferred.

Examples of the ultraviolet absorber include 2- (5-methyl-methyl-hydroxyphenyl) benzotriazole and dimethyl-1- (2-hydroxyethyl) succinate.
-4-Hydroxy-2,2,6,6-tetramethylpiperidine polycondensation product and the like can be mentioned. If the amount of the ultraviolet absorber added is small, it becomes difficult to obtain the ultraviolet absorption effect, and even if the amount is increased, it is not economical. Therefore, the monomer of butene-1 of the base polymer and / or its copolymer 100 is used.
0.01 to 2 parts by weight is preferable with respect to parts by weight.

Examples of the waxes include polyethylene wax, acid-modified polypropylene wax, paraffin wax, microcrystalline wax and the like.

Examples of the above oils include paraffin-based, naphthene-based, aroma-based process oils, aromatic oils,
Liquid paraffin such as polybutene can be used.

Further, talc, clay, calcium carbonate or the like may be added as a filler.

[0024]

The hot melt adhesive composition of the present invention can secure a sufficient open time by using a butene-1 (co) polymer having a slow crystallization rate as a base polymer. Further, by blending a specific amount of the tackifying resin and the unsaturated hydrocarbon oligomer, good adhesiveness and coatability can be obtained. The unsaturated hydrocarbon oligomer has better compatibility with the butene-1 (co) polymer as compared with other plasticizers, and thus it is considered that bleeding into the moisture-permeable olefin resin film does not easily occur.

[0025]

Embodiments of the present invention will be described below.
In the following, "parts" means "parts by weight". (Examples 1 to 4 and Comparative Examples 1 to 5) Copolymers of ethylene and butene-1 (DP) according to the blending compositions shown in Tables 1 and 2.
-8910 "Brand name": manufactured by Shell Chemical Co., ethylene content of about 5%, number average molecular weight of about 70,000, copolymer of ethylene and propylene (Ubetack 2585 "Brand name": manufactured by Ube Lexen Co., ethylene content About 15%, number average molecular weight about 7,000, alicyclic hydrogenated petroleum resin (Alcon P-10)
0 “Brand name”: Arakawa Chemical Co., Ltd., softening point 100 ° C.), isobutylene-based oligomer (Polybutene 300R “Brand name”: Idemitsu Petrochemical Co., Ltd., pour point about 0 ° C.), Penten-based oligomer (Marca Clear H “commercial item” Name: Maruzen Petrochemical Co., Pour point approx. 0 ° C, Decane oligomer (PAO)
-5010 "Product name": Idemitsu Petrochemical Co., Ltd., pour point -5
3 ° C.) and Irganox 1010 (“trade name”: manufactured by Ciba Geigy, hindered phenolic acid inhibitor) are charged into a sigma blade mixer preheated to 180 ° C., heated and melt mixed for 50 minutes, and hot melt type. An adhesive composition was obtained.

With respect to each of the obtained hot-melt type adhesive compositions, melt viscosity, adhesive strength, breaking state, bleeding, and thermal stability were measured as follows, and the results are also shown in Tables 1 and 2. It was

[0027]

[Table 1]

[0028]

[Table 2]

Melt viscosity According to JIS K-6862, the viscosity at 160 ° C was measured using a BM type viscometer.

Adhesive Strength A hot melt type adhesive is applied at 160 ° C., and the coating amount is about 0.07 g.
/ M, a beat-like coating was applied to a moisture-permeable polyethylene film, and 10 seconds after the coating, a polypropylene fiber nonwoven fabric was pressure bonded to obtain a test piece. This test piece was cut into a strip shape with a width of 15 mm so that the bead was located in the center in the direction parallel to the bead, and the T-type peel strength was measured at a peeling speed of 300 mm / min to obtain the adhesive strength.

Destructed state The test piece after the measurement of the adhesive strength was visually judged in what state it was peeled off.

The same test piece as in the case of measuring the exudation adhesive strength was left to stand in a hot air dryer at 60 ° C. for 24 hours, left at 20 ° C. for 10 minutes, and the shape of the bead of the adhesive was measured from the moisture permeable polyethylene film side. The appearance was evaluated by visually judging whether it looks like. Those with no bead shape were marked with ⊚, those with almost no distinction were marked with ◯, and those with distinction were marked with x.

[0033]

EFFECT OF THE INVENTION The hot melt adhesive composition of the present invention facilitates coating work and has good adhesive strength,
Does not cause defective appearance due to seepage from the moisture-permeable olefin resin film.

Claims (1)

[Claims] 1. Butene-1 homopolymer and / or copolymer thereof 100 parts by weight, tackifying resin 40 to 300 parts by weight,
And a hot melt adhesive composition comprising 10 to 100 parts by weight of an unsaturated hydrocarbon oligomer having a pour point of −80 to 30 ° C.