KR950002245B1 - Hot melt adhesive composition - Google Patents

Abstract

The heat melt-fusing adhesive composition comprises polyamide resin; organic phosphoric acid ester of formula (I) (pref. 5-15wt.%); diglycidyl ether of polypropylene glycol of 175-335 epoxy equivalence (pref. 0.5-5wt.%); adhesive agent which is hydrogen esterified cpd. of rosin derivs (pref. 3-15wt.%); and inorganic filler. In the formula, R1,R3 and R3 are same or not C1-8 alkyl or a functional gp. e.g. benzene to be substd. in para position with C1-8 alkyl. The obtd. adhesive compsn. has good adhesiveness at high temp., and improved workability, heat-stability.

Description

Hot Melt Adhesive Composition

The present invention relates to a hot melt adhesive composition, and in particular, to a hot melt adhesive, which maintains excellent adhesion at high temperatures, and has improved processability, workability, and thermal stability of the adhesive.

Compared to solvent adhesives, hot melt adhesives have no problems such as fire, poisoning, air pollution, etc., and the shortening of the solidification time enables mechanization and the like. .

Conventional hot melt adhesives have been prepared by combining ethylene copolymers, tackifiers, waxes, antioxidants, and the like, and have been widely used in wood processing, bookbinding, and packaging. As the hot melt adhesive has gradually expanded its application range, a hot melt adhesive based on a polyamide resin has been used in a field with strict requirements.

In the case of using polyamide resin as a base for maintaining the properties at high temperatures, the polyamide resin has polar functional groups such as amino groups, carboxyl groups, and imide groups in the molecule, and thus, it can be used with steel sheet, aluminum, copper, wood, fiber, plastic and plastic materials. It also exhibits high adhesion (Japanese Patent Publication No. 53-48238, US Pat. No. 4207217, and the like).

Polyamide-based adhesives for wood processing, furniture, etc. are generally added in an amount of 20 to 55% by weight as inorganic fillers, and the viscosity of the resin used as a base when imparting improved properties by adding inorganic fillers or If the softening point is high, there may be a problem in working due to the poor flow characteristics during melting due to the inorganic filling.In the case of using a gas having a low softening point of low viscosity, workability can be improved, but poor adhesion and adhesive durability at high temperatures There is a risk of loss.

In addition, the hot melt adhesive may have a deterioration in characteristics such as long elapsed in the molten state during the process, repeated melt-solidification in the applicator several times depending on the working condition, or partial overheating that may occur in the applicator. It should not come.

Therefore, the present invention solves various problems of the conventional inorganic filler type hot melt adhesive, suppresses the change in the adhesion force due to the change of temperature to the maximum, and has excellent adhesion to various adherends such as plastic, wood, ceramic, furniture, It is devised to provide a hot melt adhesive that can be used for industrial purposes such as assembly of electronic components.

That is, in the present invention, it is designed to meet the various demanded properties by improving the properties of the hot-melt adhesive based on polyamide, (1) polyamide resin, (2) diglycidyl ether of polypropylene glycol ( 3) Organic Phosphoric Acid Ester (4) Tackifier (5) An inorganic material-filled hot melt adhesive composition formed by blending an inorganic filler.

The polyamide resin used as a substrate of the present invention is generally a reaction of an unsaturated fatty acid called dimer acid by reaction of fatty acids containing 70 to 80% of dimers with amines such as ethylene diamine. As the obtained fatty acid polyamide resin, one having a softening point in the range of 120 to 180 ° C is used.

In the present invention, the organic phosphate ester has the following general formula

(Here, R1, R2, R3 may be the same or different, and means a functional group such as a benzene group in which an alkyl group having 1 to 8 carbon atoms or an alkyl group having 1 to 8 carbon atoms is added to the para position.)

Specific examples thereof include tricresyl phosphate, triisopropyl phenyl phosphate, tributyl phosphate, triethyl phosphate, trimethyl phosphate, trioctyl phosphate, octyl diphenyl phosphate, and the addition amount is 5 to 15% by weight of the total composition. The range is reasonable.

When a small amount is added in the above range, the workability, thermal stability, etc. may be lowered. In the case where the amount is added in an excessive amount, the adhesion durability may be lowered.

In the present invention, diglycidyl ether of polypropylene glycol contributes to improvement of workability as well as heat resistance and durability of the adhesive surface after work, and specific examples thereof include epoxy equivalents in the range of 175 to 335, and the amount of the diglycidyl ether is A range of 0.5 to 5% by weight of the composition is suitable.

In case of less than 0.5% by weight, the improvement of durability and heat resistance is insufficient, and in the case of 5% by weight or more, it may adversely affect the uniformity of the product, initial adhesive strength, and the like.

In the present invention, the tackifier contributes to improvement of workability, improvement of initial adhesive strength, and improvement of flexibility of the adhesive layer, and has excellent usability with other additives, does not have high melt viscosity, does not cause blocking, and requires a softening point of the adhesive. It is suitable to maintain it, and specific examples include rosin, tall oil rosin, hydrogenated rosin, and polymerized rosin. Among the modified rosin, glycerol esterified rosin, hydrogenated rosin glycerol ester, polymerized rosin glycerol ester, polytelphen, phenol modified The ester compound of the hydrogenated derivative of rosin in telphen or the like shows the most excellent property in terms of heat resistance, and a softening point of 90 to 140 ° C is appropriate. The addition amount is suitably in the range of 3 to 15% by weight based on the total composition. In the case of less than 3% by weight, there is a fear that the initial adhesive strength, flexibility is poor, and in the case of 15% by weight or more, the adhesion durability may be poor.

In the present invention, the inorganic filler reduces the shrinkage of the adhesive to prevent the problem of adhesion failure, to prevent breaking, to reduce the internal stress of the adhesive surface after solidification, to facilitate the work, the dimensional stability and adhesion durability of the product used In this example, calcium carbonate, barium sulfate, titanium oxide, talc powder, cray, and the like may be used. Depending on the performance, it is generally used in the range of 1.5 to 10㎛.

The addition amount is suitable in the range of 15 to 45% by weight based on the total composition, less than 15% can not be expected the effect of the above-mentioned inorganic fillers, in the case of more than 45% by weight, the workability may be poor due to the increase in viscosity There is.

In the present invention, in order to prevent deterioration of properties caused by a long time in a molten state or a partial overheating that may occur in an applicator, sometimes an antioxidant is added to a molecular structure, Phenol or polyfunctional phenolic compounds containing sulfur and phosphorus are used.

Specific examples thereof include 1, 3, 5-trimethyl-2, 4, 6-tris (3, 5- dietary butyl-4-hydroxy benzyl) benzene, n-octadecyl 3- (3, 5-diter Shari butyl-4-hydroxy phenyl) propionate, 4, 4'-methylene bis (2, 6-diterary butylphenol), 2, 2'-methylene bis (4-methyl-6-tertiary butylphenol) , 2, 6-tertary butylphenol 6- (4-hydroxy phenoxy) -2, 4-bis (n-octylthio) 1, 3, 5-triazine, di-n-octadecyl 3, 5- Dietary butyl-4-hydroxy benzoate, 2, 4, 6-tris (4-hydroxy-3, 5- dietary butylphenoxy) 1, 3, 5-triazine, 4, 4'-thiobis (6-tertiary butyl-O-gresol), 2- (n-octylthio) ethyl-3, 5-diterary butyl-4-hydroxy-benzoate, sorbitol hexa [3- (3,5-diter Shari butyl hydroxy phenyl) propionate].

The method for producing the hot melt adhesive of the present invention is not limited to a specific method, and conventional mixed kneading techniques can be applied. That is, a heatable two-roll roll, a high-speed impeller type disperser with a heatable closed container, a closed kneader, a high speed mixer, a continuous kneader, etc. may be used, and if necessary, work in an inert gas atmosphere such as nitrogen. have. Depending on the order of raw materials, the uniformity and thermal stability of the composition may be influenced.In general, the order of loading is to melt the compound with a low melting point first and completely melt it, and then to add the antioxidant and raise the temperature. Add high raw materials and mix. At this time, the temperature may vary depending on the type of the additive, but usually in the range of 130 to 220 ℃ is appropriate.

In the following examples, specific application methods and effects of the present invention will be described in detail. However, the scope of the present invention is not limited by the following example.

Example 1-5

According to the composition of Table 1 below, a heat-melt adhesive was manufactured using a continuous training apparatus at about 155 ° C., and applied to an adhesive at 175 ° C. to prepare a specimen for measuring adhesive force, and the adhesive force was measured at each temperature. It was.

Comparative Example 1-3

The composition was carried out in the same manner as in Example 1 except that the tackifiers, the diglycidyl ether of the polypropylene glycol, and the organic phosphate ester components, which are important components of the present invention, were prepared as shown in Table 1, and the results are shown in Table 2 below. Marked on.

TABLE 1

* (1) Viscosity 1700 cps at 125 ° C and 200 ° C softening point

* (2) glycerol esters of hydrogenated rosin

* (3) A 50:50 (weight ratio) mixture of calcium carbonate and barium sulfate having an average particle diameter of 1.7 to 2.5 탆.

* (4) epoxy equivalents in the range of 230 to 250

* (5) using triphenyl phosphate

TABLE 2

Exam conditions

* Room temperature: Measured at the same temperature after 24 hours at 23 ℃ and 65% relative humidity after the adhesion test specimen.

* Thermal Stability: Viscosity rise rate after standing at 200 ℃ for a certain time (initial viscosity is calculated as 1)

* Workability: The number of occurrences per minute of poor adhesion state in the adhesive specimens when the automatic application of the metal plate of the plate at 150 / min speed.

Claims (2)

A hot melt adhesive composition comprising a polyamide resin, an organic phosphate ester, a diglycidyl ether of polypropylene glycol, a tackifier, and an inorganic filler. The compound according to claim 1, wherein the tackifier is a hydrogenated ester compound in a derivative of rosin, the addition amount of which is 3 to 15% by weight of the total composition, and the organic phosphate ester has the following general formula (Here, R1, R2, R3 may be the same or different, and means a functional group such as a benzene group in which an alkyl group having 1 to 8 carbon atoms or an alkyl group having 1 to 8 carbon atoms is added to the para position.) The addition amount is 5 to 15% by weight of the total composition, the diglycidyl ether of polypropylene glycol is epoxy equivalent of 175-335, the addition amount is 0.5 to 5% by weight, the hot melt adhesive composition.