JPH07228856A - Hot-melt type adhesive - Google Patents

Abstract

PURPOSE:To obtain a polyamide-based hot-melt type adhesive, excellent in resistances to chemical, water, calcium chloride, heat, adhesion to metal and lightweight properties, etc., remarkably improved as compared with those of a conventional adhesive and further adhesion, strength and toughness. CONSTITUTION:This hot-melt type adhesive contains a polyamide, comprising a dicarboxylic acid component, 60-100mol% of which is terephthalic acid, and a diamine component, 60-100mol% of which is 1,9-nonanediamine, and having 0.3-2.0dlg [eta] measured in concentrated sulfuric acid at 30 deg.C.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel hot melt adhesive. Specifically, it has excellent adhesion performance in a wide temperature range, strength, toughness, etc., and in particular, metal adhesion, chemical resistance, water resistance, calcium chloride resistance, heat resistance,
The present invention relates to a novel hot melt type adhesive excellent in lightness.

[0002]

2. Description of the Related Art In recent years, adhesives, especially hot-melt adhesives for metals, have become more important in the fields of aircraft, automobiles, construction machinery and machine assembly. In addition to excellent adhesive performance over a wide temperature range, the adhesive has excellent chemical resistance, water resistance, calcium chloride resistance, and heat resistance in terms of adhesive performance, as well as excellent adhesion speed and workability. High reliability is required for various performances.

Further, conventionally, various proposals have been made that a semi-aromatic polyamide composed of an aromatic dicarboxylic acid component unit and an aliphatic diamine component unit can be used as a hot melt adhesive. For example, JP-B-45-6825, JP-B-54-3767, and JP-A-51-413.
78, JP-A-46-1342, JP-A-58.
-120681, JP-A-59-126483, JP-A-59-126484, US Pat. No. 37
No. 90423 and the like describe that various semi-aromatic polyamides can be used as hot-melt adhesives and can be used.

[0004]

However, in the polyamides described in these prior art documents, the adhesive performance,
Water resistance, chemical resistance, calcium chloride resistance, etc. were not sufficient, and they were not always satisfactory when used in the above-mentioned fields of use. The object of the present invention is excellent in significantly improved chemical resistance, water resistance, calcium chloride resistance, heat resistance, lightness and adhesion to metal, etc., as compared with conventional polyamide hot melt adhesives. Another object of the present invention is to provide a polyamide-based hot melt adhesive having excellent adhesiveness, strength and toughness.

[0005]

As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention showed that the above-mentioned performance was excellent for the first time in a polyamide containing terephthalic acid and 1,9-nonanediamine as main components. The present invention has been completed by finding that a polyamide hot melt adhesive can be obtained.

According to the present invention, the above object is to provide a dicarboxylic acid component in which 60 to 100 mol% of the dicarboxylic acid component is terephthalic acid, and 60 to 100 mol% of the diamine component.
Of 1,9-nonanediamine is a diamine component, and [η] measured at 30 ° C in concentrated sulfuric acid is 0.3 to 2.0.
This is accomplished by providing a hot melt adhesive containing polyamide which is dl / g.

The present invention will be specifically described below. The polyamide serving as the base resin of the hot melt adhesive of the present invention has a terephthalic acid component of 60 mol% or more, preferably 75 mol% or more, more preferably 90 mol% or more, of the dicarboxylic acid components used. is there. When the content of the terephthalic acid component is less than 60 mol%, various properties such as heat resistance and chemical resistance of the obtained polyamide are deteriorated, which is not preferable. Other dicarboxylic acid components other than the terephthalic acid component include malonic acid, dimethylmalonic acid, succinic acid,
Aliphatic dicarboxylic acids such as glutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, 3,3-diethylsuccinic acid, azelaic acid, sebacic acid and suberic acid; 1,
Alicyclic dicarboxylic acids such as 3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid; isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1 , 4-phenylenedioxydiacetic acid, 1,3-phenylenedioxydiacetic acid, diphenic acid, dibenzoic acid, 4,
4'-oxydibenzoic acid, diphenylmethane-4,4 '
-Dicarboxylic acids, diphenyl sulfone-4,4'-dicarboxylic acids, aromatic dicarboxylic acids such as 4,4'-biphenyldicarboxylic acid, or any mixture thereof. Of these, aromatic dicarboxylic acids are preferably used. Further, polyvalent carboxylic acids such as trimellitic acid, trimesic acid and pyromellitic acid can be used within the range where melt molding is possible.

As the diamine component used in the polyamide that is the base resin of the hot melt adhesive of the present invention, the 1,9-nonanediamine component is 60 mol% or more, preferably 75 mol% or more, more preferably 90 mol%. It is at least mol%. When the 1,9-nonanediamine component is in the above range, various properties of the obtained hot melt adhesive are particularly excellent, which is preferable.

As diamine components other than the 1,9-nonanediamine component, ethylenediamine, propylenediamine, 1,4-butanediamine, 1,6-hexanediamine, 1,8-octanediamine, 1,10-decanediamine. , 1,12-dodecanediamine, 3-methyl-
1,5-pentanediamine, 2,2,4-trimethyl-
1,6-hexanediamine, 2,4,4-trimethyl-
Aliphatic diamines such as 1,6-hexanediamine, 2-methyl-1,8-octanediamine, 5-methyl-1,9-nonanediamine; alicyclic diamines such as cyclohexanediamine, methylcyclohexanediamine and isophoronediamine; p -Aromatic diamines such as phenylenediamine, m-phenylenediamine, xylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone and 4,4'-diaminodiphenylether, or any mixture thereof. be able to. Among them, 2-methyl-1,8-octanediamine is preferable.

The polyamide as the base resin of the hot-melt adhesive of the present invention preferably comprises 10% or more, more preferably 40% or more, and even more preferably 70% or more of the monocarboxylic acid of the terminal groups of its molecular chain. It is desirable that the endcapping agent is a monofunctional compound having reactivity with an amino group or a carboxyl group at the terminal of the polyamide, such as or monoamine. By performing end-capping, a composition having further excellent properties such as melt stability and hot water resistance can be obtained.

The amount of the end-capping agent that can be used in the production of the base resin polyamide for the hot-melt adhesive of the present invention depends on the reactivity, boiling point,
Although it varies depending on the reaction apparatus, reaction conditions, etc., it is usually 0.1 to 15 relative to the total number of moles of dicarboxylic acid and diamine.
Used within the range of mol%.

The polyamide as the base resin of the hot melt adhesive of the present invention can be produced by any method known as a method for producing a crystalline polyamide. For example, the polymerization can be carried out by a solution polymerization method using an acid chloride and a diamine as raw materials or an interfacial polymerization method, a melt polymerization method using a dicarboxylic acid and a diamine as raw materials, a solid phase polymerization method, a melt extruder polymerization method and the like. Below, an example of the polymerization method of polyamide is shown.

According to the research conducted by the present inventors, a catalyst and, if necessary, an end-capping agent were first added all at once to a diamine and a dicarboxylic acid to prepare a nylon salt, which was once heated to 200 to 250 ° C. 30 ℃ in concentrated sulfuric acid at the temperature of
Viscosity [η] at 0.15 to 0.25 dl / g
The polyamide of the present invention can be easily obtained by subjecting the prepolymer of (1) to solid phase polymerization or performing polymerization using a melt extruder. When the intrinsic viscosity [η] of the prepolymer is in the range of 0.15 to 0.25 dl / g, the deviation of the molar balance between the carboxyl group and the amino group and the decrease in the polymerization rate are small in the post-polymerization stage, and the molecular weight is further reduced. A polyamide with a small distribution and excellent performance and moldability can be obtained. When the final stage of the polymerization is carried out by solid phase polymerization, it is preferably carried out under reduced pressure or under the flow of an inert gas, and if the polymerization temperature is in the range of 200 to 250 ° C., the polymerization rate is large and the productivity is excellent. It is preferable because coloring and gelation can be effectively suppressed. When the final stage of polymerization is carried out by a melt extruder, the polymerization temperature is 370 ° C.
It is preferable for it to be less than that the polyamide is hardly decomposed and a polyamide without deterioration can be obtained.

In producing the above-mentioned polyamide, in addition to the above-mentioned end-capping agent, for example, as a catalyst, phosphoric acid, phosphorous acid, hypophosphorous acid or a salt or ester thereof,
Specifically, potassium, sodium, magnesium, vanadium, calcium, zinc, cobalt, manganese, tin,
Metal salts such as tungsten, germanium, titanium and antimony, ammonium salts, ethyl ester, isopropyl ester, butyl ester, hexyl ester, isodecyl ester, octadecyl ester, decyl ester, stearyl ester, phenyl ester and the like can be added. Further, a copper compound as a stabilizer, further, if necessary, a colorant, an ultraviolet absorber, a light stabilizer, an antioxidant, an antistatic agent, a flame retardant, a crystallization accelerator,
Other additives such as a plasticizer and a lubricant may be added during or after the polycondensation reaction.

In the hot melt type adhesive of the present invention,
In addition to the above-mentioned polyamide, which is an essential component, a case where a powdery inorganic filler is included can be given as a preferable example of use. Examples of powdered inorganic fillers include silica, alumina, talc, clay, dolomite, glass powder, quartz powder, red iron oxide, titania, carbon black, iron powder,
Aluminum powder, stainless powder, calcium carbonate,
Examples thereof include barium sulfate, zinc oxide, titanium oxide and magnesium oxide. These powdered fillers can be used without modification, but those modified with a coupling agent such as silane or titanate can also be used. These fillers may be used alone or in combination of two or more. The use of these fillers further improves the performance of the adhesive such as heat resistance, mechanical strength, water resistance, chemical resistance and low shrinkage.

The hot melt type adhesive of the present invention is
Paraffin wax, tackifier resins, plasticizers, stabilizers, lubricants and the like can be used as its constituents for the purpose of increasing the tackiness and improving the low temperature plasticity.

Further, the hot melt adhesive of the present invention is a conventionally known adhesive such as ethylene or ethylene copolymer system, polyester system, depending on the use or purpose.
A polypropylene-based, epoxy-based, urethane-based, polycarbonate-based, acrylic-based hot melt adhesive can also be added and used.

Examples of the method of blending the above-mentioned respective components include a method of dry blending and a method of melt kneading and blending using an extruder.

The hot-melt adhesive of the present invention may be used in a melt-kneaded state, or may be formed into a film, a sheet, a filament, a granular material, or a powder, and may be used between the materials to be adhered. It is also possible to employ a method in which the sheet is placed on the substrate and is heated and pressed by a press.

The hot-melt adhesive of the present invention can be used for bonding fibers, stones, porcelain, glass, etc. in addition to metals. When using the hot-melt adhesive of the present invention for adhesion of metal, on the adhered metal surface according to the purpose,
Surface treatment such as mechanical polishing, chemical treatment, and solvent cleaning is preferable.

When the hot-melt type adhesive of the present invention is used for the adhesion by the thermocompression bonding method, the heat treatment condition varies depending on the melting point of the adhesive used, but is usually the melting point or the melting point plus 100 ° C., preferably the melting point. Melting point or melting point plus 50 ° C. Pressurization at the time of adhesion is suitable for increasing the adhesive strength and making it uniform, but usually 0.1
kg / cm ² or more, preferably 0.2 to 10 kgkg / c
It is in the range of m ² .

[0022]

EXAMPLES The hot-melt adhesive of the present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. The terminal sealing rate, intrinsic viscosity, tensile shear strength, and resistance to various environments in the examples were measured by the following methods.

End capping ratio: ¹ H-NMR (500 MH
z, measured in deuterated trifluoroacetic acid at 50 ° C.) to measure the number of carboxyl group end, amino group end and capped end respectively from the integrated value of the characteristic signal for each end group, The terminal sealing rate was calculated from (1). The chemical shift values of typical signals used for measurement are shown below. Sealing rate (%) = [(A−B) ÷ A] × 100 (1) [In the formula, A is the total number of end groups of molecular chain (this is usually equal to twice the number of polyamide molecules). And B represents the total number of carboxyl group terminals and amino group terminals.]

[0024]

[Table 1]

Intrinsic viscosity [η]: in concentrated sulfuric acid at 30 ° C.
The intrinsic viscosity (ηinh) of the samples having the concentrations of 0.05, 0.1, 0.2 and 0.4 g / dl was measured, and the value obtained by extrapolating this to the concentration of 0 was defined as the intrinsic viscosity [η]. ηinh = [ln (t ₁ / t ₀ )] / c [wherein, ηinh represents an intrinsic viscosity (dl / g), t ₀ represents a solvent flowing time (second), and t ₁ represents a sample solution flowing down. Time (second), c is the concentration of the sample in the solution (g / dl)
Represents ]

Tensile shear strength: A press film having a thickness of about 200 μm was produced by compression molding at a temperature about 20 ° C. higher than the melting point of polyamide by a press molding machine. These press films are 100 mm long, 10 mm wide, and 1 m thick.
m stainless steel plate (SUS304, 2B finish, acetone degreasing treatment) sandwiched between the tips (1 cm ² ), put a backing plate and crimp at a temperature 20 ° C. higher than the softening point under a pressure of 5 kg / cm ² for 5 minutes. , Then 5 kg at a temperature of 30 ° C
Under a pressure of / cm ² , the protruding portion was scraped off by cooling for 5 minutes to prepare a tensile shear strength test piece. And 23
The test piece was left to stand in a room at 50 ° C and 50% RH for 30 minutes, and the tensile shear strength of the test piece was measured at that temperature at a tensile speed of 50 mm / min.

Resistance to various environments: Tensile shear test pieces were immersed in a specified chemical at a specified temperature for 7 days and then taken out, and the surface was wiped with a dry cloth.
It was held for a minute, and at that temperature, the shear strength was measured at a tensile speed of 50 mm / min, and the chemical resistance was evaluated by the retention rate for the tensile shear strength of the sample piece not treated with the chemical.

Reference Example 1 3272.9 g (19.70 mol) of terephthalic acid,
3165.8 g (20.0 mo) of 1,9-nonanediamine
1), benzoic acid 73.27 g (0.60 mol), and sodium hypophosphite monohydrate 6.5 g (0.
1% by weight) and 6 liters of distilled water were placed in an autoclave having an internal volume of 20 liters and purged with nitrogen. The mixture was stirred at 100 ° C for 30 minutes, and the internal temperature was raised to 210 ° C over 2 hours. At this time, the pressure in the autoclave was increased to 22 kg / cm ² . After continuing the reaction for 1 hour, 230 ℃
The temperature to 230 ° C for 2 hours,
The reaction was carried out while gradually removing the steam to maintain the pressure at 22 kg / cm ² . Next, the pressure is 10 kg / c over 30 minutes.
Lower to m ² and react for 1 hour, then [η] = 0.2
A prepolymer of 5 dl / g was obtained. This was dried at 100 ° C. under reduced pressure for 12 hours and pulverized to a size of 2 mm or less. This was solid-phase polymerized at 230 ° C. and 0.1 mmHg for 10 hours to obtain a white polyamide having a melting point of 317 ° C., [η] 1.35 dl / g, a terminal sealing rate of 90%.

Reference Examples 2 to 5 Using the dicarboxylic acid component and the diamine component shown in Table 2, a polyamide was produced by the method described in Reference Example 1.

Examples 1 to 5 and Comparative Examples 1 to 2 The above-mentioned test pieces were prepared using the polyamide alone or the composition containing the additive, and the various performances described above were evaluated. The results are shown in Table 2.

[0031]

[Table 2]

[0032]

The polyamide hot-melt adhesive of the present invention has remarkably improved chemical resistance, water resistance, calcium chloride resistance and heat resistance as compared with conventional polyamide hot-melt adhesives. Excellent in lightness and adhesion to metal, and also excellent in adhesion, strength and toughness.

Front page continuation (72) Inventor Hiroshi Hayashibara 1 4545 Sakata, Kurashiki City, Okayama Prefecture Kuraray Co., Ltd.

Claims (1)

[Claims] 1. 60 to 100 mol% of the dicarboxylic acid component
Is a terephthalic acid dicarboxylic acid component, and a diamine component in which 60 to 100 mol% of the diamine component is 1,9-nonanediamine, and the intrinsic viscosity [η] measured in concentrated sulfuric acid at 30 ° C. is 0.3 to A hot melt adhesive containing a polyamide of 2.0 dl / g.