JPH0629395B2 - Hot melt adhesive composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a low-crystalline to non-crystalline thermoplastic saturated polyester resin-based hot melt adhesive having improved adhesive strength.

[Conventional technology and its problems]

A low-melting or non-crystalline thermoplastic haiku polyester resin alone or a hot-melt adhesive composition obtained by mixing it with an epoxy resin or the like is known. I had it, but there were many cases where the adhesive strength was insufficient.

On the other hand, a butadiene-acrylonitrile copolymer (JP-A-56-157424) and polyvinyl acetate (JP-A-56-157424) are used in the thermosetting resin composition containing the polyfunctional cyanate ester which is the component B of the present invention as an essential component. The inventors have previously described and filed a method for obtaining an adhesive composition by blending a dimer acid-based polyamide (JP-A-58-198563), thermoplastic polyurethane and the like. However, all of these methods are aimed at a thermosetting adhesive mainly composed of a component B, and require a cross-linking curing reaction of the component B and have extremely excellent performance. However, since it is a thermosetting type, it has the problems of storage stability in the case of long-term storage and higher cost.

[Means for solving problems]

The present inventors have conducted extensive studies to eliminate the drawbacks of low crystalline to non-crystalline thermoplastic saturated polyester resin (hereinafter referred to as “LPES”) hot melt adhesives, and as a result,
Monofunctional or polyfunctional cyanate ester compound,
By blending with LPES, the adhesive strength was improved,
The hot melt adhesive composition excellent in workability and processability was found.

That is, the present invention provides a low-crystalline to non-crystalline thermoplastic saturated polyester resin (A) containing a monofunctional or polyfunctional cyanate ester compound (B) 1 containing at least one cyanato group in the molecule. It is a hot melt adhesive composition containing about 30% by weight.

The configuration of the present invention will be described below.

The LPES of the component A of the present invention is an aromatic or aliphatic dicarboxylic acid and an aliphatic or alicyclic diol or a prepolymer thereof, particularly terephthalic acid as an acid component, ethylene glycol, propylene glycol or butanediol as a diol component. Is used as a main component, and a polycondensation is performed by controlling the melting point, flow characteristics, crystallinity, etc. of the target substance by using several other acids or diols together.
Its softening point is below 150 ° C, preferably 140-40 ° C, especially
It is in the range of 120-60 ° C. In the present invention, the average molecular weight calculated from the number of terminal functional groups is usually 1500 to 2
Those having a compatibility of 5,000, preferably 5,000 to 22,000, are more preferred because of their compatibility. Further, when LPES has an excess of free hydroxyl groups or carboxyl groups, these groups and the cyanite group of the component B gradually react even at room temperature, resulting in poor storage stability of the composition. Therefore, the smaller the amount, the more preferable the crystallinity is.

Examples of the aromatic or aliphatic dicarboxylic acid include terephthalic acid, isophthalic acid, malonic acid, succinic acid, adipic acid, pimelic acid, speric acid, azelaic acid, sebacic acid, and their lower alkyl esters and acid anhydrides. And a low molecular weight pyrolyzate of a carboxyl group-terminated saturated polyester resin.

Further, as the aliphatic or non-alicyclic diol or its prepolymer, ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol,
1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, polybutylene glycol, polycaprolactone diol, 2,2-dimethylpropanediol, 2,2-
Bis (4-hydroxycyclohexyl) propane, 1,4-dihydroxymethylcyclohexane, trimethylolpropane, 1,2,3-trihydroxypropane, tetramethylolmethane, etc., for low crystallinity or non-crystallinity It is better to use one having a low molecular weight.

Examples of such LPES include "Polyester" manufactured by Nippon Synthetic Chemical Industry Co., Ltd. and "PES manufactured by Toa Synthetic Chemical Industry Co., Ltd."
Commercial products with trade names such as "Series", "Byron" manufactured by Toyobo Co., Ltd., and "KODAR PET" manufactured by Eastman Chemical Co. are suitable and suitable.

The LPES of the present invention is as described above, but it is a mixture with known plastics such as vinyl chloride, polyethylene, polycarbonate, ethylene propylene rubber, ethylene vinyl acetate copolymer, rosin, paraffin, chlorinated diphenyl, neoprene. Adhesives such as rubber and nitrile rubber, as a mixture with waxes, calcium carbonate, aluminum hydroxide, calcium hydroxide, talc, clay, mica, cobalt, nickel, chromium, manganese, aluminum, or alloys of these metals Powder, fiber, flakes, etc., powder of copper oxide, iron oxide, lead oxide, etc., fiber, thin shoulder, etc., organometallic compound pigment such as copper phthalocyanine (= phthalocyanine blue), yellow lead, mineral violet, carbon Black, red iron oxide, ultramarine blue, cobalt blue Cobalt violet, inorganic pigments, plasticizers, flame retardants such as titanium white, UV absorbers, may be used as a composition prepared by adding a stabilizer and the like.

Suitable as the monofunctional or polyfunctional cyanate ester compound which is the component B of the present invention is a compound represented by the following general formula (1) R (OCN) m (1) (m in the formula is 1 or more, usually It is an integer of 5 or less, R is an aromatic organic group, and the cyanato group is a compound represented by (bonded to the aromatic ring of the organic group). Illustrative examples are monocyanatobenzene, 1,3- or 1,
4-dicyanatobenzene, 1,3,5-tricyanatobenzene,
1,3-, 1,4-, 1,6-, 1,8-, 2,6- or 2,7-dicyanatonaphthalene, 1,3,6-tricyanatonaphthalene, 4,4'-dicyanato Biphenyl, bis (4-dicyanatophenyl) methane,
2,2-bis (4-cyanatophenyl) propane, 2,2-bis (3,5-diloro-4-cyanatophenyl) propane, 2,2-bis (3,5-dibromo-4-dianato) Phenyl) propane, bis (4-cyanatophenyl) ether, bis (4-cyanatophenyl) thioether, bis (4-cyanatophenyl)
Examples thereof include sulfone, tris (4-cyanatophenyl) phosphite, tris (4-cyanatophenyl) phosphate, and cyanate ester obtained by the reaction of novolac with cyanogen halide. In addition to these
41-1928, 43-18468, 44-4791, 45-11712, 46
-41112, 47-26853, and cyanate esters described in JP-A-57-63149 and the like can also be used.

Further, it can be used as a prepolymer obtained by polymerizing the above-mentioned polyfunctional cyanate ester in the presence of a mineral acid, a Lewis acid, a salt such as sodium carbonate or lithium chloride, or a phosphate ester such as tributylphosphine. it can. These prepolymers are formed by the trimerization of the cyan groups in the cyanate ester s
The ym-triazine ring generally has in the molecule. In the present invention, it is preferable to use the prepolymer having a number average molecular weight of 300 to 6,000.

Furthermore, the polyfunctional cyanates mentioned above can also be used in the form of prepolymers with amines. Examples of amines that can be preferably used include meta or para-phenylenediamine,
Meta or para-xylylenediamine, 1,4- or 1,3-cyclohexanediamine, hexahydroxylylenediamine, 4,4'-diaminobiphenyl, bis (4-aminophenyl) methane, bis (4-aminophenyl) ether , Bis (4-aminophenyl) sulfone, bis (4-amino-3-
Methylphenyl) methane, bis (4-amino-3,5-dimethylphenyl) methane, bis (4-aminophenyl) cyclohexane, 2,2-bis (4-aminophenyl) propane, 2,
2-bis (4-amino-3-methylphenyl) propane, 2,2-
Bis (4-amino-3-chlorophenyl) propane, bis (4-amino-3-chlorophenyl) methane, 2,2-bis (4-
Amino-3,5-dibromophenyl) propane, bis (4-aminophenyl) phenylmethane, 3,4-diaminophenyl-4-aminophenylmethane, 1,1-bis (4-aminophenyl) -1-phenylethane Etc.

Of course, the abovementioned polyfunctional cyanates, their prepolymers, and prepolymers with amines can be used in the form of mixtures.

The blending amount of the component B described above is usually 1 to 30 parts by weight,
It is preferably 5 to 25 parts by weight. If it exceeds 30 parts by weight, a curing reaction becomes essential, and there is an engagement that the cured product becomes hard, which is not preferable, and if it is less than 1 part by weight, the effect of improving the adhesive force is insufficient.

The mixing method of both components A and B is not particularly limited,
Usually, a method of melt-mixing each component without a solvent, a method of forming a solvent-free mixture into a solution, and if desired, a solvent-free liquid or paste form using a reactive diluent among the compatible components described below. The method of preparing the composition of

The hot melt adhesive composition of the present invention contains the above-mentioned components as essential components, but replaces a part of the above cyanate ester compounds with another thermosetting resin monomer or prepolymer; It is possible to add a curing catalyst as appropriate. As such a thermosetting resin monomer or prepolymer, bis (4-maleimidophenyl) methane or another molecule containing an N-maleimide group is used.
Monofunctional or polyfunctional maleimides having two or more; bisphenol A type, phenol novolac type, cresol novolac type, other epoxy resins; (meth) acrylate, polyfunctional (meth) acrylate, alkyl (meth) acrylate , Poly (meth) acrylates such as epoxy (meth) acrylate; polyallyl compounds such as diallyl phthalate, divinylbenzene, diallylbenzene, trialkenyl isocyanurate and their prepolymers; dicyclopentadiene and its prepolymers; known phenolic resins Resins of are exemplified. Among these, maleimides, epoxy resins, alkyl (meth) acrylates and alkyl-
Poly- (meth) acrylate or the like is preferably used from the viewpoint of improving the adhesive strength. Examples of the curing catalyst include organic peroxides such as benzoyl peroxide, lauroyl peroxide, capryl peroxide, acetyl peroxide, parachlorobenzoyl peroxide, and di-tert-butyl-di-perphthalate; naphthenic acid. Examples of organic metal salts include lead, lead stearate, zinc naphthenate, zinc octylate, tin oleate, dibutyltin malate, manganese naphthenate, cobalt naphthenate, and iron acetylacetone.

The conditions for bonding using the hot melt adhesive composition of the present invention vary depending on the type of composition components used, etc., but are usually selected at 90 to 250 ° C. for 5 seconds to 30 minutes,
It is preferable to apply pressure at the time of adhesion, and generally speaking, it is appropriately selected within the range of 0.1 to 500 kg / cm ² , preferably 5 to 150 kg / cm ² .

〔Example〕

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. The parts in the examples and comparative examples are parts by weight unless otherwise specified.

Examples-1 to 6 and Comparative Examples 1 to 3 As LPES (trade name; PES 110H or PES 170, manufactured by Toa Gosei Chemical Industry Co., Ltd., or trade name; Polyester
LP 035 Number average molecular weight calculated from terminal hydroxyl groups 16,000
Hydroxyl value 6 mg KOH / g, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., simply described as "110H", "170" and "035" in the table), and 2,2-bis (4-cyclo- Anatophenyl) propane (hereinafter referred to as "BPCN"), BPCN90
Parts and bis (4-maleimidophenyl) methane 10 parts with 130 parts
Pre-react for 30 minutes at ℃, prepolymer (hereinafter referred to as “BT31”, molecular weight about 300) or 80 parts of 1,4-dicyanatobenzene and bis (4-maleimidophenyl) methane 20 at 150 ℃ for 3 hours A prepolymer (hereinafter referred to as “BT22”, a molecular weight of about 2,000) was used by reaction, and other dicumyl peroxide (hereinafter referred to as “DCPO”) and rosin were appropriately used as shown in Table 1. 1 to 4, 6 and Comparative Example-2 are at 80 ° C. for 30 minutes, and Example-5 is 100 and 30.
A hot melt adhesive composition was manufactured by mixing with a kneader under the condition of 1 minute.

Using the above-prepared hot melt adhesive composition and the above LPES alone for comparison, the cutting adhesive strength (σ _T , unit: kg / cm ² ) was measured using a soft iron plate with a thickness of 2 mm and a width of 25 mm. Using a test piece that was formed so that the thickness of the adhesive layer was 100 μm on the edge 15 mm and adhered under the conditions of 180, 3 minutes, 5 kg / cm ² , and peeling strength (σ _T , unit kg / cm
For the measurement, an adhesive layer was formed between aluminum foil with a thickness of 100 μm to a thickness of 150 μm, 160 ° C, 30 minutes, 5 kg
Using a test piece adhered under the condition of / cm ^2, the measurement was performed by a method of peeling off both ends of the adhered foil.

The results are shown in Table 1.

[Operation and Effect of the Invention] As is clear from the above detailed description of the invention and Examples and Comparative Examples, the hot melt adhesive composition of the present invention is extremely excellent without any special surface treatment for adhesion. It is understood that the hot melt adhesive composition exhibits excellent adhesiveness, and that the hot melt adhesive composition has storage stability because it does not require catalysts, and that it is extremely excellent in practical use.

Claims (3)

[Claims] 1. A low-crystalline to non-crystalline thermoplastic saturated polyester resin (A) containing a monofunctional or polyfunctional cyanate ester compound (B) having 1 or more cyanato groups in the molecule. Hot melt adhesive composition containing 30% by weight 2. The number average molecular weight calculated from the number of terminal functional groups of the low-crystalline to non-crystalline thermoplastic saturated polyester resin (A) is 5,000 to 22,000.
Adhesive composition according to item 3. The adhesive composition according to claim 1 or 2, wherein the low-crystalline to non-crystalline thermoplastic saturated polyester resin has a softening point of 40 to 140 ° C.