JP2005097360A - Hotmelt composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that although hotmelt adhesives are widely used in various applications, those hotmelt adhesives which adhere to polyolefin-based resin materials, have an appropriate debonding feature from bonded state and leave a small compression set when compressed under heat have not been developed. <P>SOLUTION: The hotmelt composition is obtained by mixing a hydrogenated paraffin-based process oil, a high molecular styrenic block polymer, a polyphenylene ether resin or a modified polyphenylene ether resin, an antioxidant and an amorphous polyalphaolefin. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a hot melt composition, and more specifically, a hot melt composition having sufficient adhesiveness even to difficult-to-adhere polyolefin-based resin materials, excellent in adhesion, sealing properties, etc., and having disassembly properties. About.

In various industrial fields such as electricity, automobiles, and construction, polyolefin resin materials that do not emit harmful dioxins at the time of incineration are widely adopted, but as is well known, polyolefin resin materials lack adhesiveness, Reliability has not been obtained for adhesion between polyolefin resins or between polyolefin resins and other materials.
In addition to the method using an adhesive, there is a method of heat-sealing as a reliable joining method when the polyolefin resin material is used as an adherend, but the work cannot be done easily because heating equipment is required. Is only employed in special fields due to the complexity of the process.

On the other hand, in recent years, from the viewpoint of effective use of resources and environmental measures, it has been widely practiced to recycle each member, part, etc. as a resource when dismantling equipment and devices after use.
However, when members and parts are assembled, if they are firmly joined and bonded, disassembly is difficult and inconvenient for recycling. Desired.

In addition, in order to increase the confidentiality of equipment that incorporates electronic components as a dust-proof measure and waterproof measure, a method of assembling with a sealant interposed at the joint of the equipment has been adopted, but the components and members are strong. If they are joined together, the equipment will break down and cannot be easily disassembled for inspection and repair.
Even in such a case, an adhesive and a sealing material having both proper adhesiveness and dismantling properties are required.

However, in the adhesive work and assembly work such as parts and members processed from the polyolefin resin material lacking the adhesiveness as described above, the adhesive and the sealing material having appropriate adhesiveness and dismantling properties, It often happens that the set is removed or displaced.
For this reason, problems such as inability to smoothly perform operations such as bonding and sealing and poor work efficiency have occurred.

Furthermore, in automobiles, various production facilities, and other various facilities, the digitization has progressed and the degree of mounting of electronic devices such as microcomputers has increased. However, if the device is kept under heating, the seal portion deteriorates over time. In some cases, gaps occur due to volume shrinkage, etc., and confidentiality is lost and dust, moisture, etc. get in, causing malfunction of electronic devices.
For this reason, performance that does not deteriorate even under heating is required.

JP 4-110381 A JP-A-10-265719

  The present invention has the above-mentioned problems, that is, defects such as conventional adhesives and hot-melt type sealing materials, and improves the adhesion to polyolefin-based resin materials, adhesion, and improves thermal degradation, Parts that were assembled at the time of repair of various equipment and devices can be easily removed, or materials that were used when disposing of various equipment and devices can be easily separated. The object is to develop a hot melt composition that can be recovered for each material as a resource.

  As a result of earnest research and development to solve the above problems, hydrogenated paraffin process oil, high molecular weight styrene block copolymer and polyphenylene ether resin or modified polyphenylene ether resin, antioxidant and amorphous polyalphaolefin With the blended hot melt composition, a predetermined object could be achieved.

Conventionally, in the case of bonding or sealing parts and members processed from polyolefin resin materials, there has been a concern about adhesion and adhesion, but the hot melt composition according to the present invention is a polyolefin resin. Adhesion and sealing can be performed without any problem because of excellent adhesion to the material or the polyolefin-based primer-treated substrate.
In addition, since it does not deteriorate even when placed under high temperature, it is an adhesive for various devices and parts assembly parts, joints, etc. used in the fields of electricity, automobiles, other heating devices, heat treatment devices, etc. When used as a sealing material, stable sealing performance, bonding performance, etc. can be maintained for a long period of time.
Furthermore, since it is excellent in the dismantling property in the joint part, the seal part, etc., it has become possible to easily dismantle each member and part for repair, disposal or resource recycling. For this reason, the convenience could be remarkably improved as compared with the case where dismantling was difficult.

Hydrogenated paraffinic process oil is blended to ensure softening, viscosity adjustment, kinematic viscosity, pour point, etc., and has a pour point of -20 to -5 ° C, a viscosity index of 100 or more, and a kinematic behavior at 100 ° C. A viscosity of 5 to 35 mm ² / S is suitable.
The blending amount of the hydrogenated paraffinic process oil is preferably 40 to 90 parts by weight from the viewpoint of hardness, viscosity, fluidity and the like. If it is 40 parts by weight or less, the composition becomes hard and the viscosity increases, which is not suitable for use. On the other hand, if it is 90 parts by weight or more, the amount of oil blits becomes large, which is not preferable.
Oils other than hydrogenated paraffin process oils are not suitable for use because of their poor heat aging resistance.

  The high molecular weight styrene block copolymer preferably has a number average molecular weight of 100,000 or more. Specific examples include styrene-isoprene-styrene (SIS) block copolymers and styrene-butadiene-styrene (SBS) blocks. Copolymer, styrene-ethylene-1 butene-styrene (SEBS) block copolymer, styrene-isobutylene-styrene (SIBS) block copolymer, styrene-ethylene-propylene-styrene (SEPS) block copolymer, poly ( [alpha] -methyl-styrene) -polybutadiene-poly ([alpha] -methyl-styrene), poly ([alpha] -methyl-styrene) -polyisoprene-poly ([alpha] -methyl-styrene), and hydrogenated modifications thereof such as poly ( α-methyl-styrene) -poly (ethylene-1butene) -Poly (α-methyl-styrene), poly (α-methyl-styrene) -poly (ethylene-propylene) -poly (α-methyl-styrene). Commercially available products include Kuraray Septon 4055.

  The compounding quantity of a high molecular weight styrene-type block polymer can be suitably selected in the range of 5-20 weight part with respect to the whole. 5 parts by weight or less is not suitable because rubber elasticity cannot be obtained in the blend. On the other hand, if it is 20 parts by weight or more, the melt viscosity becomes too high, which is not suitable.

As the polyphenylene ether resin, known ones having a number average molecular weight of 1000 or more can be used. For example, poly (2,6-dimethyl-1,4 phenylene ether), poly (2-methyl-6-ethyl-1,4 phenylene) Ether), poly (2,6 diphenyl-1,4-phenylene ether), poly (2-methyl-6-phenylene-1,4-phenylene ether), poly (2,6-dichloro-1,4 phenylene ether) A polyphenylene ether copolymer such as a copolymer of 2,6-dimethylphenol and monovalent phenols can also be used.
The modified polyphenylene ether resin is a blend of styrene resin, nylon resin, etc. for processability and other reasons for the polyphenylene ether resin. Commercially available products are Zylon 500H manufactured by Asahi Kasei Kogyo Co., Ltd., SA- manufactured by Japan GE Plastics. There are 120 mag.

By adding the polyphenylene ether resin or the modified polyphenylene ether resin, the non-adhesive polyphenylene ether resin or modified polyphenylene ether resin is compatible with the styrene phase of the high molecular weight styrene block copolymer. While reducing wettability with respect to a dressing and imparting peelability, the temperature at which the styrene phase that determines the heat resistance of the styrenic block copolymer is softened can be increased to impart heat resistance.
Therefore, if the heat distortion temperature or glass transition point of the polyphenylene ether resin or modified polyphenylene ether resin to be added is higher than 90 to 100 ° C., which is the glass transition temperature of the styrene resin, the purpose of imparting heat resistance can be achieved.
However, in order to easily obtain heat resistance with a small addition amount, it is desirable that the heat distortion temperature is 120 ° C. or higher. Especially when heat resistance of 80 ° C. or higher is desired, the heat distortion temperature is 150 ° C. or higher. By using those, it is possible to easily obtain peelability and heat resistance with a small addition amount. A commercially available polyphenylene ether resin or modified polyphenylene ether resin can be relatively easily obtained as a type having a heat distortion temperature of 120 ° C. or higher.
Moreover, a compounding quantity can be suitably selected in the range of 0.5-10 weight part. If it is 0.5 parts by weight or less, the desired heat resistance cannot be obtained even when the heat distortion temperature or glass transition point is 200 ° C. or more, and at the same time, the peelability from each substrate is remarkably lowered. On the other hand, if it exceeds 10 parts by weight, the softening point of the composition becomes too high, and it is not suitable for the purpose of melting and using it as a hot melt composition.

  In addition to the above, styrene block copolymers having a number average molecular weight Mn of less than 100,000, such as styrene-isoprene-styrene (SIS) block copolymers, styrene-butadiene-styrene (SBS) block copolymers, styrene-ethylene-1 Butene-styrene (SEBS) block copolymer, styrene-isobutylene-styrene (SIBS) block copolymer, styrene-isoprene-styrene (SEPS) block copolymer, poly (α-methyl-styrene) -polybutadiene-poly ( α-methyl-styrene), poly (α-methyl-styrene) -polyisoprene-poly (α-methyl-styrene), and hydrogenated modified products thereof such as poly (α-methyl-styrene) -poly (ethylene- 1-butene) -poly (α-methyl-styrene), poly (α-methyl) Ru-styrene) -poly (ethylene-propylene) -poly (α-methyl-styrene) other butyl synthetic rubber, ethylene-propylene rubber, acrylic rubber, polyester elastomer, ethylene-vinyl acetate copolymer, ionomer resin, ethylene -A thermoplastic elastomer such as an acrylic acid copolymer or a polyamide resin alone or a mixture thereof may be appropriately blended as necessary for the purpose of adjusting the viscosity.

In addition, a tackifying resin is blended as necessary to give the hot melt composition appropriate adhesiveness and adhesion to the adherend. As specific examples of the tackifying resin, terpene resin, terpene phenol resin, rosin and hydrogenated rosin resin, petroleum resin and hydrogenated petroleum resin are used alone or as a mixture.
Moreover, as fillers, general fillers used for paints and adhesives such as talc, clay, silica, calcium carbonate, and titanium oxide are appropriately used for the purpose of adjusting hardness and reducing costs.
Further, an olefinic or paraffinic wax or the like is appropriately blended for adjusting the viscosity of the hot melt.

Amorphous polyalphaolefin (hereinafter abbreviated as APAO) blended for the purpose of imparting adhesion to olefin resin material is a comparison obtained by copolymerizing propylene alone or propylene with ethylene or butene-1 using a special catalyst. A low molecular weight amorphous polyolefin having a high degree of freedom by copolymerization composition and molecular weight adjustment and stable quality can be obtained.
The APAO has a melt viscosity at 190 ° C. of 0.4 to 9 Pa · s, a ring and ball method softening point of 80 to 160 ° C., a penetration of 10 to 45 dmm by a penetration meter, and a glass by dynamic viscoelasticity measurement. Some have a transition temperature (Tg) of −40 to 0 ° C., and are appropriately selected from these.
A compounding quantity can be suitably selected in the range of 1-10 weight part. If it is 1 part by weight or less, the adhesion to the olefin resin is weak and the desired adhesion cannot be obtained. Even if it exceeds 10 parts by weight, there is no room for improvement in adhesion to the olefin resin, but it is not suitable because it causes a decrease in heat resistance.

In this invention, antioxidant is mix | blended in order to ensure heat resistance.
Antioxidants include copper-based antioxidants, copper salt-based antioxidants, copper halide-based antioxidants, phosphorus-based antioxidants, phenol-based antioxidants, hindered amine-based antioxidants, sulfur-based antioxidants Those selected from an inhibitor, a lactone antioxidant, an aromatic amine, a metal deactivator comprising a chelating agent, etc. are used, preferably a phenol antioxidant, a phosphorus antioxidant, a hindered amine It has been confirmed that the use of a mixture of antioxidants is preferred.

  As phenolic antioxidants, 2,6-di-t-butylphenol derivatives, 2-methyl-6-t-butylphenol derivatives, octadecyl 3 (3,5-dibutyl-4-bitoxyphenyl) propionate, 4,4- Butylidene-bis (6-t-butyl-m-cresol), pentaerythrityl tetrakis {3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate}, 2 {1- (2-hydroxy -3,5-di-t-pentylphenyl) -ethyl} -4,6 di-t-pentylphenyl acrylate.

  Examples of phosphorus-based antioxidants include tris (2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetrabis (2,4-di-t-butylphenyl phosphite), dostearylpentane erythritol diphos. Phyto, sodium dihydrogen phosphate, and disodium monohydrogen phosphate.

  Examples of the sulfur-based antioxidant include 3,3-thiobispropionic acid didodecyl ester, 3,3-thiobispropionic acid dioctadecyl ester, pentaerythritol tetrakis- (3-laurylpropionate), and the like.

  Examples of hindered amine antioxidants include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1,2,3. 4-tetrakis (2,2,6,6) tetramethyl-4-piperidyloxycarbonyl) butane, dimethyl succinate-1- (2-hydroxylethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine heavy Condensate, 1- (3,5, -di-t-butyl-4-hydroxyphenyl) -1,1-bis (2,2,6,6-tetramethyl-4-piperidyloxycarbonyl) pentane, N, N-bis ( 3-aminopropyl) ethylenediamine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, bis (octylone-2,2,6, 6-tetramethyl-4-pipentyl) sebacate and the like.

It has been confirmed that when these antioxidants are used in these mixed systems, performances such as tensile strength retention, viscosity retention, and tensile elongation are easily obtained. The antioxidant is preferably blended in an amount of 0.5 to 5 parts by weight.
In addition, when used for a long time in a state of being pressed somewhat under heating as described above, the volume of the sealing material shrinks, and if a gap is generated in the seal portion, confidentiality is impaired and dust and moisture are removed from the device. Intruding inside the equipment may cause malfunction of electronic equipment.
For this reason, in accordance with the compression set measurement method defined in JISK6262, the blending is determined with a compression set of 70% or less after 100 hours at 100 ° C. in a state of 50% compression.

In addition, a hollow filler may be mix | blended for the following purposes.
The hollow filler is blended in a timely manner to prevent settlement as well as adjusting the filling property, weight reduction, fluidity, etc. As a specific example to be used, the average particle size is 100 μm or less and the apparent specific gravity is 1.0 or less. Glass microballoons, pearlite, silica balloons, alumina balloons, carbon balloons, aluminosilicate balloons and the like are mentioned, and among these, silica balloons are preferable in terms of availability and cost.
When the average particle size is 100 μm or more, the appearance is deteriorated, so that it is not suitable. On the other hand, if the apparent specific gravity is 1.0 or more, the filler tends to sink during melting, which is not suitable.

  The method for producing a hot melt composition of the present invention can be obtained by kneading the above-mentioned blending components with a Banbury mixer, a heating kneader, a uniaxial or biaxial extruder, and the like.

The hot melt composition according to the present invention includes polyolefin resins such as polyethylene resin and polypropylene resin, those obtained by blending them with inorganic fillers such as glass powder, polyolefin resin materials such as alloys with other resins, polystyrene The present invention can be applied to various materials such as various resins such as resin, polycarbonate resin, and acrylic resin, metals, inorganic materials, and organic-inorganic composite materials. Moreover, depending on the case, it can apply also to what apply | coated and dried the olefin type primer beforehand on the surface of these raw materials.
As a specific application example, it can be effectively used at the joining location, assembly seal location, adhesion location, etc. of various members, parts, equipment, etc. processed from the polyolefin resin materials as described above. it can.
Especially because of its good heat aging properties, equipment and devices installed around electric furnaces, incinerators, heat treatment furnaces, equipment around automobile engines, household water heaters, bathroom kettles, etc. It is suitable for use in adhesives and sealing materials such as parts placed in a moderately pressed state in order to ensure confidentiality under heating, assembly parts and assembly equipment installed in these places.

As an example, the method of applying the hot melt composition according to the present invention to a connecting part such as a part is described. In addition to the method of applying a seal to the gap of the connecting part after assembling the part, assembling one part before assembling the part. It is possible to adopt a method in which the coating is applied to the periphery of the part and other parts are brought into contact with and connected to the periphery.
Accordingly, in addition to processing procedures applied at assembly factories for various products, it is possible to adopt processing procedures that carry in what is applied to one part at other factories and abut the parts applied with the other parts for assembly.

  For the application of the hot melt composition according to the present invention, a hand gun type, a block melt type, a bulk type and a foam type can be used. and so on.

  In addition, when mass-manufacturing processed parts at factories, etc., if the head part of the hot melt composition coating device is attached to an industrial robot, etc., it can be applied quickly even to complicated shapes, greatly A significant improvement in production efficiency can be expected.

Hereinafter, the present invention will be described with reference to examples and comparative examples.
In addition, the number in a table | surface represents each weight part and naturally this invention is not restrict | limited to an Example.
Examples and Comparative Examples The following materials were blended as shown in Tables 1 and 2 to prepare hot melt compositions of Examples 1 to 7 and Comparative Examples 1 to 9. The formulation was dissolved and prepared using a double arm heating kneader heated to 200 ° C. until evenly dispersed.
1 Hydrogenated paraffin process oil: Idemitsu Kosan Co., Ltd., product number PW-90, pour point -15 ° C, viscosity index 108, kinematic viscosity at 100 ° C 11.25 mm ² / S
2 high molecular weight styrenic block copolymer: Kuraray's product number Septon 4055,
SEPS type 3 polyphenylene ether resin having a number average molecular weight of about 250,000: manufactured by Nippon GE Plastics, SA-120,
Number average molecular weight about 2,000
4 Tackifying resin 1: Eastman Chemical Co., Endex 155,
Styrene-based 5 tackifying resin 2: manufactured by Tonex, E-5320, DPCD-based 6APAO 1: manufactured by Huntsman, RT-2730, propylene / butene-1 co-weight
Combined type, R & B softening point 107 ° C
7APAO2: manufactured by Huntsman, RT-2115, propylene homotype, R &
B softening point 152 ° C
8Phenol-based anti-aging agent: manufactured by Kyodo Pharmaceutical Co., Ltd., GA-80
9 Phosphorus anti-aging agent: Ciba Geigy, Irgafos 168
10 amine anti-aging agent: manufactured by Asahi Denka Kogyo, LA-63P

The physical properties of the examples and comparative examples were evaluated by the following methods.
1. Observation of destruction state Failure state Melt in advance in a hot gun heated to 200 ° C and 5 mm thick polypropylene
A resin (hereinafter abbreviated as PP) plate is applied in the form of a bead of φ 3 mm, and another 5
After superposing mm-thick PP plates, the bead is forcibly peeled off from the test specimen cured for 24 hours in an atmosphere at 23 ° C., and the fracture state is observed.
The fracture at the hot melt part is called cohesive fracture, and the fracture at the surface of the adherend is called interfacial fracture.
Fracture state After applying 100g / cm2 of olefin-based water primer (Nippon Paper Chemical Co., Ltd., Supercron S-750) to the concrete surface with a moisture content of 7% or less, it was cured at 23 ° C for 48 hours and then heated to 200 ° C After being melted in advance in a hot gun and coated in a φ3 mm bead shape, after curing in a 23 ° C. atmosphere for 24 hours, the bead is forcibly peeled off by hand and the state of destruction is observed.
The fracture at the hot melt part is called cohesive fracture, and the fracture at the surface of the adherend is called interfacial fracture.
2. Dismantling property A hot melt molded product formed into a cylindrical shape having a diameter of 27 mm and a height of 20 mm is sandwiched between a PP plate having a thickness of 10 mm and a polycarbonate resin plate, and kept in a compressed state up to a thickness of 10 mm. After leaving in the dryer for 30 days, release the compressed state and observe whether both plates and the hot melt molded product can be easily disassembled when both plates are forced open by hand. The case where it could be easily disassembled was marked with ◯, and the case where it could not be disassembled was marked with ×.
3. In order to confirm the sealing property, each compound was mixed with a Nordson bulk melter (discharge temperature setting 200 ° C.), and a bead having a diameter of 5 mm along the periphery of a glass plate having a thickness of 3 mm × width of 100 mm × length of 100 mm. After coating in the shape, a glass plate of the same size is pressure-bonded and compressed and fixed to 2.5 mm.
After leaving at 80 ° C. for 5 days, taking out, returning to 3 mm, immersing in water and observing the presence or absence of water leakage.
4). Compression set The compression set after 24 hours at 100 ° C. was measured in a state of 50% compression according to the provisions of JISK6262 for various compounds molded into a cylindrical shape of φ27 × 20 mm in height.
5). Oil bleed Various shaped compounds formed into a cylindrical shape of φ27 × 20 mm in height are 75% compressed and left in a 100 ° C. atmosphere for 168 hours, then the compression is released and the bleed oil is wiped off with a waste cloth. The weight was measured.
The case where the weight of the bleed oil was less than 1% with respect to the weight of the sealing material before compression was rated as ◯, and the case where it was 1% or more was marked as x.
6). Heat aging property After putting 100g of various compounds into a 200ml steel can with lid, after standing for 48 hours in a 220 ° C atmosphere with the lid closed, the hot melt composition was extracted from the steel can and hot melt composition at 200 ° C. The melt viscosity of the product is measured. The case where the viscosity reduction rate was less than 30% with respect to the viscosity before heat aging was rated as ○, and the case where it was 30% or more as x.
7). Applicator Dischargeability Using a block type applicator HM-3900M manufactured by Nordson, a sufficient amount of hot melt composition was introduced into the tank, and it was investigated whether discharge was possible after 4 hours of energization at a set condition of 200 ° C.
Judgment criteria were 3 g / second or more ejection possibility, ○ when possible, and x when impossible.

The hot-melt composition according to the present invention can be applied to members and parts using polyolefin resin materials or polyolefin primer-treated substrates, or to bonding and sealing parts and members made of various other materials without problems. it can.
Also, adhesives and seals for various devices and parts assembly parts and joints used in fields such as electrical field, automobile field, other heating devices, heat treatment devices, etc. Can be used as a material.
Furthermore, since there is disassembly at the joints and seals, each member and part can be easily disassembled, making it a great use in fields where repairs are expected to be required, or where disposal or resource recycling is required. can do.

Claims (4)

A hot melt composition comprising a hydrogenated paraffinic process oil, a high molecular weight styrene block copolymer, a polyphenylene ether resin or a modified polyphenylene ether resin, an antioxidant and an amorphous polyalphaolefin.   The amount of the hydrogenated paraffin process oil is 40 to 90 parts by weight, the amount of the high molecular weight styrene block copolymer having a number average molecular weight of 100,000 or more is 5 to 20 parts by weight, and the polyphenylene ether resin or the modified polyphenylene ether resin is 0. The hot melt according to claim 1, wherein the amount of the antioxidant is 0.5 to 5 parts by weight, and the amount of the amorphous polyalphaolefin is 1 to 10 parts by weight. Composition.   3. The hot melt composition according to claim 1, wherein a combination of a phenolic antioxidant, a phosphorus antioxidant and a hindered amine antioxidant is blended as the antioxidant. The hot melt composition according to claim 1, 2 or 3, wherein the compression set by a measuring method according to JISK6262 is 70% or less after 100 hours at 100 ° C in a state of 50% compression. .