JPH11181386A - Hot-melt adhesive composition and production of automotive interior material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot-melt adhesive compsn. which is excellent in heat resistance and is used for bonding lowly polar adherends to each other or a lowly polar adherend to a highly polar adherend and to provide an automotive interior material produced by using the same. SOLUTION: This hot-melt adhesive compsn. contains, as essential ingredients, (A) 100 pts.wt. crystalline polybutylene having a melt index (190 deg.C, 2.16 kgf/cm<2> ) of 20-2,000 g/10 min, (B) 20-200 pts.wt. hydrogenated tackified resin, (C) 20-200 pts.wt. at least one nonhydrogenated tackified resin selected from among terpene-modified phenol resins, arom. petroleum resins, styrenic resins, and rosin-base resins, and (D) 0.1-100 pts.wt. polypropylene-based wax, and amt. of ingredient A accounting for 10-60 wt.% of the compsn.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot-melt adhesive composition and a method for producing an automotive interior material using the adhesive composition. In particular, using a hot-melt adhesive composition having excellent heat resistance used for bonding between low-polarity adherends such as polyolefins or a high-polarity adherend such as an essential material or a fabric, and using the adhesive composition The present invention relates to a method for manufacturing an automotive interior material.

[0002]

2. Description of the Related Art Hot melt adhesives are used in various industries because of their simplicity that they are applied in a molten state and completed when they are cooled, and that they are environmentally friendly due to the elimination of solvents and the like. . As the base polymer, ethylene-based copolymers such as ethylene-vinyl acetate copolymer, polyethylene, amorphous polypropylene, crystalline polypropylene, crystalline polybutylene, styrene-based block copolymer, polyamide, polyester and the like are mainly used. A hot-melt adhesive is obtained by adding various kinds of tackifier resins, oils, waxes and other various additives. However, when an ethylene-based copolymer, polyethylene, amorphous polypropylene, or a styrene-based block copolymer is used as a base polymer, adhesion between low-polarity adherends such as polypropylene or between them and high-polarity substances such as wood or cloth is considered. Although it is possible to exhibit performance, it has a drawback of poor heat resistance.

[0003] On the other hand, when crystalline polypropylene, polyamide, polyester, or the like is used, the heat resistance of the hot melt itself can be obtained. Adhesion of highly polar materials is insufficient. There is also known an example in which crystalline polybutylene is used as a base polymer of a hot melt adhesive (technical data of Shell Japan Co., Ltd.). Specifically, an example using a composition comprising polybutylene and a tackifier is shown.

However, crystalline polybutylene has not been practically used since it has not been known how to use a tackifier resin and how to control the crystallinity and balance the adhesiveness with other compounding agents. there were.

On the other hand, when manufacturing interior materials for automobiles by bonding a fabric surface material to a polyolefin molded article such as polypropylene, for example, a solvent-type adhesive mainly containing chloroprene rubber is applied by spraying or the like. After drying the solvent, a method has been adopted in which a fabric-made skin material is attached and formed and adhered.

However, in such a manufacturing method,
Since the solvent is volatilized in the atmosphere, there is a possibility of causing environmental pollution, and this is not preferable in terms of work environment. In addition, solvent-based adhesive is not only low workability because it takes a long time to complete the bonding, when sticking to the recess,
Since it is necessary to press the skin material until the bonding is completed, the workability is further reduced. Further, the solvent type adhesive has a disadvantage that the initial creep characteristics are inferior due to the presence of a trace amount of the residual solvent for several hours after the molding and bonding.

On the other hand, when the hot melt adhesive is used, the above-mentioned problems of environmental pollution and working environment can be solved. However, the conventionally proposed hot melt adhesive has a sufficient adhesiveness to polypropylene. However, it was difficult to satisfy the heat resistance of about 80 ° C. required for the present application.

[0008]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a novel hot melt adhesive composition and a method for producing an automotive interior material using the adhesive composition.

Another object of the present invention is to provide a hot-melt adhesive composition having excellent heat resistance used for bonding low-polarity adherends such as polyolefins or high-polarity adherends such as essential materials and fabrics. It is an object of the present invention to provide a method of manufacturing an interior material for an automobile using the article and the adhesive composition.

[0010]

These objects are achieved by the following (1) to (7).

(1) (A) Melt index 20 to
2,000 g / 10 minutes (190 ° C., 2.16 kgf / c
m ² ) 100 parts by weight of crystalline polybutylene
(B) 20 to 200 parts by weight of a hydrogenated tackifier resin,
(C) at least one unhydrogenated tackifier resin selected from the group consisting of terpene-modified phenolic resins, aromatic petroleum resins, styrene resins and rosin resins;
200 parts by weight and 0.1 to 100 parts by weight of (D) polypropylene wax are essential components, and the compounding amount of the crystalline polybutylene (A) is 10 to 60% by weight of the whole composition. Hot melt adhesive composition.

(2) Among the hydrogenated tackifier resin (B) and / or unhydrogenated tackifier resin (C), at least one of resins having a ring-ball method softening point of 120 ° C. or higher has the crystalline property. The hot melt adhesive composition according to the above (1), which is contained in an amount of 20 to 200 parts by weight per 100 parts by weight of the polybutylene (A).

(3) The hot melt adhesive composition according to (1) or (2), wherein the crystalline polybutene has a crystallinity of 30 to 80% by an X-ray diffraction method.

(4) The above-mentioned (1), which is used for bonding between low-polarity adherends or between the low-polarity adherend and the high-polarity adherend.
The hot melt adhesive composition according to any one of (1) to (3).

(5) In the step of bonding a fabric-made skin material to an automobile polyolefin molded article,
The hot-melt adhesive according to any one of (1) to (4) is applied to the surface of the polyolefin molded article and / or the surface material of the fabric, and the hot-melt adhesive composition is cooled and solidified immediately after or after the application. Thereafter, the hot melt adhesive composition is activated by reheating, and is activated by reheating, and bonding the polyolefin molded body and a fabric skin material in a state where the adhesive force is manifested. Production method.

(6) The method according to the above (5), wherein the coating amount of the hot melt adhesive composition is 20 to 500 g / m ² .

(7) The method according to (5) or (6), wherein the activation temperature is 90 to 150 ° C.

[0018]

DETAILED DESCRIPTION OF THE INVENTION The crystalline polybutylene of the present invention has a melt index of 20 to 2,000 g / 10.
Min (190 ° C., 2.16 kgf / cm ² ), preferably 50 to 1000 g / 10 min. When the crystallinity is less than 30%, sufficient heat resistance is not obtained, and when it is more than 90%, a sufficient open time cannot be obtained. If the melt index is less than 20, the fluidity is low, and the workability is reduced due to the high viscosity. If the melt index is more than 2,000, sufficient heat resistance is not exhibited. Such crystalline polybutylene can be obtained by an X-ray diffraction method (Polymer Encyclopedia, published by Maruzen Co., Ltd. in 1994, p11
Crystals having a degree of crystallinity of from 30 to 80%, preferably from 40 to 60%, are used. That is, if the crystallinity is less than 30%, sufficient heat resistance may not be exhibited, while if it exceeds 80%, a sufficient open time may not be obtained.

The compounding amount of the crystalline polybutylene in the present invention is 10 to 60% by weight of the whole system. That is, if the content is less than 10% by weight, sufficient heat resistance is not exhibited, while if it exceeds 60% by weight, the fluidity is low and the workability is reduced.

Further, the hot-melt adhesive composition of the present invention contains polyethylene, polypropylene, ethylene-propylene copolymer for the purpose of viscosity control, crystallization rate control, and improvement of adhesive properties at low temperature. And polymers such as ethylene-butylene copolymer, styrene-ethylene-butylene copolymer rubber, and styrene-ethylene-propylene copolymer rubber. The amount used is 50% by weight or less, preferably 30% by weight, based on the whole adhesive composition.
% By weight or less.

The hydrogenated tackifier resin in the present invention comprises:
It is used to improve the adhesiveness with low polar substances such as polypropylene. Examples, C ₅ based, C ₉ system and C ₅ -C ₉ copolymer based petroleum resin hydrogenated products can include terpene, a modified terpene the hydrogenated product or the like. The compounding amount of the hydrogenated tackifier resin is crystalline polybutylene 100
20 to 200 parts by weight, preferably 30 to 5 parts by weight per part by weight
0 parts by weight. That is, if the amount is less than 20 parts by weight, sufficient adhesiveness to a low-polarity material such as polypropylene cannot be obtained, while if the amount exceeds 200 parts by weight, sufficient adhesiveness to a high-polarity material such as wood or cloth can be obtained. I can't get it.

The unhydrogenated tackifier resin in the present invention comprises:
It is used in combination to improve the adhesiveness to highly polar materials such as wood and cloth. Such unhydrogenated tackifier resins include terpene-modified phenolic resins, aromatic petroleum resins,
There are styrene-based resins, rosin-based resins and the like, and a single system or a combination of two or more systems can be used, and it is used in an amount of 20 to 200 parts by weight, preferably 30 to 150 parts by weight based on 100 parts by weight of crystalline polybutylene. . That is, 20
If the amount is less than part by weight, the adhesiveness to a highly polar substance such as a wooden material or a cloth is insufficient when the amount is small, while the adhesiveness to a low polar substance such as a polypropylene is insufficient if the amount exceeds 200 parts by weight.

In the present invention, one or more resins having a softening point in the ring and ball method of 120 ° C. or higher, preferably 120 to 150 ° C., are added to the crystalline polybutylene in the hydrogenated tackifier resin and / or the unhydrogenated tackifier resin. 20 to 2 for 100 parts by weight
It is preferably contained in an amount of 00 parts by weight. That is, when only the resin having a ring and ball method softening point of less than 120 ° C. is used, or when the addition amount is less than 20 parts by weight, it is difficult to obtain sufficient heat resistance. On the other hand, if the addition amount is more than 200 parts by weight, solidification is fast, and it is difficult to obtain a sufficient open time.

The hot-melt adhesive composition of the present invention contains various tackifier resins such as terpene resins, aliphatic petroleum resins, and hydrogenated resins thereof in order to control the adhesiveness to various adherends. Can be mixed.

The hot-melt adhesive composition of the present invention further comprises a polypropylene wax in an amount of 0.1 to 100 parts by weight, preferably 100 parts by weight of crystalline polybutylene, for the purpose of accelerating crystallization of polybutylene and improving heat resistance. It is obtained by melting and mixing 1 to 50 parts by weight. Such a wax has a melting point of 140 ° C. or more, preferably a melting point of 140 to 16.
It is a crystalline wax at 0 ° C. When other waxes are used, the melting point is low and sufficient heat resistance is not exhibited. The effect of the polypropylene wax on the solidification rate is extremely remarkable, and the solidification time is drastically reduced from the minimum value of 0.1 part by weight. The mechanism of action is presumed to be such that polypropylene wax, which has a high degree of crystallization, serves as a nucleating agent for accelerating the crystallization of polybutylene, and induces the overall crystallization by starting peripheral crystallization. Therefore, the minimum blending amount of the polypropylene wax is 0.1 part by weight. If the amount is less than 0.1 part by weight, the crystallization speed of polybutylene is low, and a sufficient solidification speed cannot be obtained. On the other hand, if the amount is more than 100 parts by weight, the solidification rate is high and a sufficient open time cannot be obtained.

The hot melt adhesive composition used in the present invention may further contain various additives such as an antioxidant, an inorganic filler and a coloring agent, if necessary. The hot melt adhesive composition used in the present invention is, for example, the above-mentioned materials are charged into a melt-stirring / mixing apparatus,
℃, preferably at a temperature of about 160-170 ℃
Obtained by heating and mixing for 3 hours.

In the present invention, as a method of applying the hot melt adhesive composition to one or both of a low-polarity substance such as polypropylene and a high-polarity substance such as a wood material and a fabric, atomizing spray, spiral spray, curtain, and the like can be used. spray,
A method using a roll coater or the like can be used.

Therefore, the hot melt adhesive needs to have a melt viscosity suitable for these application methods. Specifically, in the case of spray or curtain spray, 100 ~
50,000 mPa · s, preferably 500 to 20,000
00 mPa · s. If it is lower than 500, scattering occurs during coating, and if it is higher than 50,000, a sufficient amount of coating cannot be secured. The melt viscosity in the case of roll coater coating is 100 to 100,000 mPa · s,
Preferably it is 500-50,000 mPa * s. 1
If it is lower than 00, sagging occurs, and if it is higher than 100,000, a sufficient amount of coating cannot be secured.

The amount of the hot melt adhesive applied is 2
0 to 500 g / m ² , preferably 100 to 200 g / m
² If it is less than 20 g / m ² , the adhesive strength is not sufficient,
If it exceeds 500 g / m ² , the hot melt adhesive may ooze onto the surface of the fabric skin material during lamination.

In the present invention, activating the hot-melt adhesive composition means that the composition is heated to melt or soften to make the adhesive force apparent, and the heating means is hot air, infrared rays, hot press or the like. Can be used, and the temperature is, for example, 100 to 4 in the case of hot air.
Hot air of 00 ° C, preferably 200 to 300 ° C is used.

A low-polarity adherend such as polypropylene and a high-polarity material such as a wood material or a cloth, in which the hot melt adhesive composition of the present invention is used, are those parts of the automobile interior material or the like where heat resistance is required. The low-polarity material includes polyethylene, polypropylene, ethylene-propylene copolymer and the like. Examples of the high-polarity material include wood, paper, metal, and plastics and fibers mainly made of nylon, polyester, polycarbonate, acrylic, and the like. These are usually woven fabrics, nonwoven fabrics, knitted fabrics, and the like. Used in the form of a fabric.

The interior material for a vehicle in the present invention includes an inner panel of a vehicle door, a door ornament ceiling material,
There are cushioning materials in the trunk, carpets in the trunk, floor carpets, seats, etc., which are woven, knitted,
It is formed by bonding a fabric such as a nonwoven fabric or felt.

In the present invention, activating the hot-melt adhesive means that the adhesive is exposed by heating to melt and soften, and hot air, infrared rays, hot press or the like is used as a heating means. You. Upon activation, the hot melt adhesive needs to be heated above its melting point. If the temperature is much higher than the melting point, the hot melt adhesive may sag, and the hot melt applied polypropylene molding material or fabric skin material may be deformed.

Therefore, the hot melt temperature required for activation is 90 to 150 ° C., preferably 100 to 140 ° C. When using any heating means such as hot air, infrared ray or hot press, it is necessary to adjust the heat source temperature and the heating time so that the hot melt adhesive falls within this temperature range.

When the heating method is hot air or infrared rays,
Lamination needs to be performed in a state where the hot melt adhesive is activated, that is, when the heated hot melt bonding is not completely cooled, the surface temperature is 60 ° C. or more, and the surface tack remains.

When the heating method is hot air or infrared rays, it is necessary to perform pressure bonding at the time of bonding, and in the case of hot pressing, it is necessary to perform pressure bonding while the temperature of the hot melt adhesive is 60 ° C. or higher after pressing. For the pressure bonding, a pressing method using a mold is usually used, and the pressing pressure is 0.001 to 1 kgf.
/ Cm ² , preferably 0.01 to 0.5 kgf / cm ²
It is. No sufficient adhesion can be obtained is less than the press pressure of 0.001kgf / cm ^2, there is a possibility that deformation occurs polypropylene molding material exceeds 1 kgf / cm ^2. Crimping time is 10 to 3 when the mold and the ambient temperature are 20 ° C.
0 seconds. If the time is less than 10 seconds, the hot melt adhesive is not sufficiently solidified, and since the solidification is completed within 30 seconds, no further press bonding is required.

The hot-melt adhesive composition of the present invention can be prepared by using crystalline polybutylene, a tackifier having a high softening point, and a polypropylene wax for adjusting the crystallization rate and the melt viscosity to obtain a polypropylene or the like. Adhesive and heat-resistant properties of low-polarity substances or high-polarity substances such as wood agent and fabric can be provided.

[0038]

The present invention will be described below with reference to examples.
The present invention is not limited to these examples.

Examples 1 to 4 and Comparative Examples 1 to 4 Mixtures 1,000 in the ratios shown in Tables 1 and 2
g was charged into a heating kneader having an internal volume of 2 liters, and the mixture was stirred and mixed at 160 ° C. for 2 hours to obtain a desired hot melt adhesive composition. Table 2 also shows Comparative Examples 1 to 4. The content of the materials used in the examples and comparative examples and the method for testing the properties of the hot melt adhesive composition are shown below.

[Contents of Material] (1) Polybutylene (1) DC8910 (manufactured by Shell Japan KK) Melt index = 1000 g / 10 min (190 ° C., 2.160)
kgf / cm ² ), melting point = 90 ° C. (2) polybutylene (2) DP0800 (manufactured by Shell Japan Co., Ltd.) melt index = 200 g / 10 min (190 ° C., 2.160 k)
gf / cm ² ), melting point = 125 ° C. (3) polybutylene (3) DP0300 (manufactured by Shell Japan KK) melt index = 4 g / 10 min (190 ° C., 2.160 kgf)
/ Cm ² ), melting point = 125 ° C. (4) Hydrogenated tackifier resin (1) Alcon P125 (Arakawa Chemical Industries, Ltd., fully hydrogenated petroleum resin) Ring and ball method softening point = 125 ° C. (5 ) Hydrogenated tackifier resin (2) Alcon P85 (Arakawa Chemical Industries, Ltd., aromatic completely hydrogenated petroleum resin) Ring and ball softening point = 85 ° C (6) Unhydrogenated tackifier resin (1) YS Polystar T130 (terpene-phenol copolymer resin manufactured by Yasuhara Chemical Co., Ltd.)
130 ° C. (7) Unhydrogenated tackifier resin (2) YS Polystar T100 (terpene-phenol copolymer resin manufactured by Yashara Chemical Co., Ltd.)
100 ° C (8) Aromatic petroleum resin Petcol 140 (manufactured by Tosoh Corporation, unhydrogenated aromatic tackifier resin) Ring and ball softening point = 135 ° C (9) Polypropylene wax Viscol 550P (manufactured by Sanyo Chemical Industries, Ltd.) ) Ring and ball method softening point = 150 ° C (10) Antioxidant Irganox 1010 (manufactured by Nippon Ciba Geigy Co., Ltd.) Hindered phenolic antioxidant [Method for testing properties of hot melt adhesive composition] (1) Melt viscosity JIS K The melt viscosity at 180 ° C. was measured according to the method for measuring the melt viscosity of a −6862 hot melt adhesive.

(2) Ring and Ball Method Softening Point The ring and ball method softening point was measured in accordance with the ring and ball method softening point measuring method of JIS K-6863 hot melt adhesive.

(3) Heat-resistant creep A hot-melt adhesive composition was coated on a polypropylene plate having a thickness of 2 mm, a width of 25 mm and a length of 120 mm by about 100 μm.
, And immediately bonded to a nylon cloth having a width of 25 mm and a length of 150 mm, and pressed and bonded with a hand roller to obtain a test piece. After curing this test piece in a 20 ° C. atmosphere for 24 hours, 20
A load of 0 g was hung and left under a temperature condition of 80 ° C. for 24 hours, and the peel length of the bonded portion was measured.

(4) Peeling strength The same test piece as in the above (9) was tested at a temperature of 20 ° C. and 80 ° C. using a tensile tester at 200 ° / 180 ° in a 180 ° direction.
A peel test was performed at a speed of min.

(5) Open time The hot melt adhesive composition was applied to a thickness of about 100 μm on a polypropylene substrate, cooled to room temperature, and then heated to 130 ° C. with hot air.

After the heating was stopped, the longest time during which the nylon cloth could be bonded was defined as the open time.

(6) Solidification time After the same test piece as in the above (3) was prepared, the shortest time during which the cohesive failure of the hot melt adhesive composition did not occur in the heat creep test was defined as the solidification time.

The results are shown in Tables 1 and 2.

[0048]

[Table 1]

[0049]

[Table 2]

It will be apparent that the foregoing examples are for illustrative purposes and may be varied in proportions, procedures and materials without departing from the scope of the invention as set forth in the appended claims.

As is clear from the results shown in Tables 1 and 2, in Examples 1 to 4, since at least one tackifier resin having a ring and ball method softening point of 120 ° C. and a polypropylene wax were used, heat-resistant creep was observed. , 80 ° C. and excellent adhesive strength. On the other hand, in Comparative Example 1 in which the unhydrogenated tackifier 1 was not blended, the adhesiveness to the nylon cloth was insufficient, so that interfacial destruction occurred in the heat creep test and the peel strength was low. I have. Also,
In Comparative Example 2 using a hydrogenated tackifier 2 (softening point: 85 ° C.) and an unhydrogenated tackifier (softening point: 110 ° C.), cohesive failure of the hot melt adhesive occurs in heat-resistant creep, Also, it was recognized that the 80 ° C. peel strength was significantly inferior to the examples. Further, in Comparative Example 3 in which no polypropylene wax was used, the solidification time was 3 hours.
It was extremely late in the day and it was confirmed that it lacked practicality. In Comparative Example 4, as a result of using polybutylene of MI4, it was confirmed that the viscosity was high and lacked practicality.

Examples 5 to 7 and Comparative Examples 5 to 9 Mixtures of 1,000 mixed at the ratios shown in Tables 3 and 4.
g was charged into a heating kneader having an internal volume of 2 liters, and the mixture was stirred and mixed at 160 ° C. for 2 hours to obtain a desired hot melt adhesive composition. The contents of the materials used in Examples and Comparative Examples and the methods for testing the physical properties of the hot melt composition are shown below.

[Contents of Material] (1) Polypropylene S-13B (manufactured by Ube Lexen Co., Ltd.) melt index 700 g / 10 min (230 ° C., 2.160 kgf /
cm ² ), melting point = 157 ° C. (2) Polybutylene (2) DP0800 (manufactured by Shell Japan KK) melt index 200 g / 10 min (190 ° C., 2.160 kg)
f / cm ^2), mp = 125 ° C. (3) hydrogenation system tackifier resin (3) ARKON P140 (Arakawa Chemical Industries, Ltd., C ₉ aromatic fully hydrogenated petroleum resin) ring and ball softening point = 140 ° C (4) Hydrogenated tackifier resin (2) Alcon P85 (C ₉ aromatic completely hydrogenated petroleum resin manufactured by Arakawa Chemical Industries, Ltd.) Ring and ball softening point = 85 ° C (5) Rosin ester Superester A -125 (Arakawa Chemical Industries, Ltd., unhydrogenated rosin ester-based tackifier resin) Ring and ball method softening point = 125 ° C (6) Antioxidant NORGANOX 1010 (Nippon Ciba Geigy Co., Ltd.) Hindered phenolic antioxidant [Solvent-based adhesive] (1) Hybon XA223-10 (manufactured by Hitachi Chemical Co., Ltd.) Chloroprene-based adhesive [Method for preparing hot-melt adhesive composition] It was charged and the mixture 1kg which engages the heating kneader having an inner volume of 2 liters which was stirred for 2 hours mixing at 160 ° C..

[Method of Testing Properties of Hot Melt Adhesive] (1) Melt Viscosity The same method as in Examples 1 to 4 was used.

(2) Ring and Ball Method Softening Point The same method as in Examples 1-4 was used.

(3) Heat-resistant creep A test was performed in the same manner as in Examples 1-4.

(4) Peeling Strength The peeling strength was the same as in Examples 1-4.

[Heat resistance test of bonded product] 100 g of hot melt adhesive having the composition shown in Table 3 was applied to a molded polypropylene article having irregularities for an automobile door by using curtain spray.
/ M ² , the hot-melt adhesive applied surface is heated to a surface temperature of 120 ° C. by blowing hot air of 200 ° C. for 10 seconds, and the hot-melt adhesive surface temperature is 70 ° C. after an open time of 10 seconds. A skin material made of polyester-based woven fabric is stuck, and pressure is 0.1 kg using a mold at 20 ° C.
Cold pressing was performed under the conditions of f / cm ² and 20 seconds to obtain a test piece. However, in Comparative Example 8, the hot melt surface temperature was reduced to 80 seconds by reducing the hot air blowing time to 8 seconds.
° C, and immediately after heating, a polyester woven skin material was bonded at a hot melt adhesive temperature of 70 ° C. In Comparative Example 9, the open time was set to 20 seconds, so that the surface temperature of the hot melt adhesive at the time of bonding was set to 50 ° C.

The solvent-based adhesive shown in Comparative Example 7 was applied by spraying at a coating amount of 100 g / m ² , and after one minute, a polyester-based cloth material was adhered thereto, and a mold at 20 ° C. was used. The sample was cold-pressed under the conditions of a pressure of 0.1 kgf / cm ² and 20 seconds to obtain a test piece. These specimens are
Five minutes after the bonding, the substrate was left in an atmosphere at 80 ° C. for one hour, and the presence or absence of floating of the bonded portion was confirmed.

Table 3 shows the results.

[0061]

[Table 3]

As is clear from the results in Table 3, Example 5
In the case of No. 7 to 7, the tackifier resin having a ring and ball method softening point of 120 ° C. or more is used in an amount of 120 to 100 parts by weight of the crystalline polyolefin.
Since it is used in an amount of 150 parts by weight, it exhibits excellent properties in heat creep and peel strength.

On the other hand, in Comparative Example 5 using a tackifier resin having a softening point of 85 ° C. in the ring and ball method, cohesive failure occurred in a heat creep test, and the peel strength at 80 ° C. was a low value. In addition, even in the heat resistance test immediately after laminating, the uneven portions are lifted. In Comparative Example 6, since the tackifier resin having a softening point of the ring and ball method of 120 ° C. or more was used in excess of 300 parts by weight with respect to 100 parts by weight of the crystalline polyolefin, the adhesiveness was not sufficient, and the heat resistance test immediately after lamination was performed. However, there is a floating on the uneven portion.

On the other hand, in Comparative Example 7 which is the prior art, although the heat resistance creep and the peeling strength were good, it was confirmed in the heat resistance test immediately after lamination that floating occurred due to the effect of the residual solvent.

In Comparative Examples 8 and 9, the same formulation as in Example 5 was used. However, in Comparative Example 8, the activation temperature of the hot melt adhesive was low, and in Comparative Example 9, the temperature at the time of lamination was low. Due to the low temperature, even in the heat resistance test immediately after laminating, the uneven portions are lifted.

[0066]

Since the hot melt adhesive composition according to the present invention has the above-mentioned constitution, there is no problem of the contamination due to the evaporation of the solvent into the air during the bonding operation unlike the solvent type adhesive. Also, the health of workers is not impaired. In addition, excellent adhesion and heat resistance can be satisfied in bonding low-polarity adherends such as polyolefins or high-polarity objects such as wood materials and fabrics. Further, since the bonding time is extremely short, not only the workability is good, but also the pressing time in the bonding work of the skin material to the concave portion is extremely short.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification code FI C09J 161/14 C09J 161/14 191/06 191/06 193/04 193/04 201/02 201/02 (72) Inventor Yamaguchi Susumu Daihatsu Industry Co., Ltd. 2-1-1 Taoyuan, Ikeda-shi, Osaka

Claims (7)

[Claims] (A) a melt index of 20 to 2.0
00g / 10 minutes (190 ° C, 2.16 kgf / cm ² )
(B) 20 to 200 parts by weight of a hydrogenated tackifier resin, (C) a terpene-modified phenol resin, an aromatic petroleum resin, a styrene resin and a rosin resin with respect to 100 parts by weight of crystalline polybutylene 20 to 200 parts by weight of at least one unhydrogenated tackifier resin selected from the group consisting of (D) and 0.1 to 100 parts by weight of a polypropylene wax (D) as essential components, and the compounding amount of the crystalline polybutylene (A) Is from 10 to 60% by weight of the whole composition. 2. At least one of the hydrogenated tackifier resin (B) and / or the unhydrogenated tackifier resin (C) having a ring-ball method softening point of 120 ° C. or higher is the crystalline polybutylene. (A) The hot melt adhesive composition according to claim 1, which is contained in an amount of 20 to 200 parts by weight per 100 parts by weight. 3. The hot melt adhesive composition according to claim 1, wherein the crystalline polybutene has a crystallinity of 30 to 80% as determined by an X-ray diffraction method. 4. The hot-melt adhesive composition according to claim 1, which is used for bonding low-polarity adherends to each other or between the low-polarity adherend and the high-polarity adherend. . 5. The step of bonding a fabric skin material to an automobile polyolefin molded article, wherein the hot melt adhesive according to claim 1 is applied to the polyolefin molded article and / or the fabric. After being applied to the surface of the skin material and immediately after application or after the hot-melt adhesive composition is cooled and solidified, the hot-melt adhesive composition is activated by reheating, and the adhesive force is manifested in a state where it is activated. A method for producing an interior material for automobiles, comprising bonding the polyolefin molded body and a skin material made of fabric. 6. The method according to claim 5, wherein the coating amount of the hot melt adhesive composition is 20 to 500 g / m ² . 7. The method according to claim 5, wherein the activation temperature is 90 to 150 ° C.