JP4104611B2 - Hot melt composition for sealing - Google Patents

Description

  The present invention relates to a hot-melt composition for sealing, and more particularly, to a hot-melt composition for sealing excellent in adhesion between different materials such as glass and a metal frame, and excellent in coating property, heat resistance and elasticity. .

  As a hot-melt water-proof sealant, a sealing material that is coated and sealed using a bulk melter that melts the surface portion of a butyl rubber-based hotmelt sealant placed in a pail tube and discharges it to the outside while applying pressure. Although generally used, the used waste pail can becomes industrial waste, and because it contains a large amount of inorganic filler, the gear pump is worn and the load on the coating equipment is large, so the coating workability is high. In addition, there is a problem that it is not able to sufficiently meet the demands of the market where heat resistance and adhesive performance are becoming stricter.

  When a sealing material is filled between an adherend that is easily damaged, such as glass, and other adherends, a large stress is likely to occur due to the difference in the expansion coefficient between the adherends. When the size is large, the generated distortion increases when the temperature changes suddenly. However, when the sealing material cannot absorb the stress, there is a problem that the adherend such as glass is damaged.

  For example, in solar cells, window materials, etc., when the sealing material is filled and sealed for sealing between glass and aluminum materials, the glass plate is damaged because the expansion coefficient differs greatly between them. . In order to avoid such breakage of the glass plate which is easy to break, a sealing material capable of absorbing the stress due to the difference in dimensional change due to the temperature of both is required.

  Naturally, it is required that no significant deformation such as protrusion of the sealing material occurs even at high temperatures in summer, and heat resistance is required. This is a problem especially when a heavy product such as a solar battery panel is transported by ship, and needs to be improved.

However, in a normal case, if the heat resistance of the sealing material is improved, the sealing material becomes hard and contrarily decreases in cold resistance. Therefore, there is a problem that cracking cannot be suppressed with a glass plate that is easily damaged.
JP 4-110381 A Japanese Patent Laid-Open No. 9-193865

  The present invention has been made as a result of research and development to solve the above-mentioned problems, and is an improvement of the drawbacks of conventional hot-melt type sealing materials, and has coating filling properties, heat resistance, and adhesive performance. Another object of the present invention is to provide a hot melt composition for sealing which is elastic and can be stably applied even with a tank type hot melt applicator.

In order to solve the above problems, at least 3 to 15% by weight of a styrenic block copolymer and 20 to 35% by weight of butyl rubber are contained relative to the entire hot melt composition, and the melt viscosity is 10 Pa.s. s / 180 ° C. to 50 Pa. It is a hot melt composition for sealing excellent in coating filling property, heat resistance, cold resistance and elasticity with a creep at 100 ° C. of less than 10 mm in a heat resistant creep test by the test method described in (1) below at s / 230 ° C. .
(1) Adhering to a vertically supported aluminum plate with a 10mm sq. Rectangular parallelepiped, hot melt weighing 1g so as not to cause interfacial breakage with a vertically-adhered substrate, in an atmosphere of 100 ° C The vertical variation (mm) after standing for 24 hours is evaluated as creep.
The hot melt composition for sealing, which has an elastic modulus at −20 ° C. of 150 MPa to 50 MPa, excellent heat filling, heat resistance, cold resistance and elasticity, can absorb large-size or large stress due to a dimensional change due to temperature. A hommel composition for sealing could be completed.

According to the present invention, it is a hot melt composition containing the styrene block copolymer and butyl rubber, and can be handled by a tank type hot melt applicator, has heat resistance, and can be used in a wide range of applications. Can be applied as a hot melt composition for sealing between dissimilar materials which are large in size such as solar cells and have different linear expansion coefficients.

Hereinafter, the hot melt composition according to the present invention and its melt viscosity, elastic modulus, characteristics and materials to be blended will be described.
A feature of the present invention is that stable coating can be performed with a tank-type hot melt applicator. The melt viscosity suitable as a seal-type hot melt is 10 Pa. At 10 rpm. s / 180 ° C. to 50 Pa. If it exceeds s / 230 ° C and exceeds the upper limit, heat resistance can be obtained, but deterioration in the tank occurs in a short time, and continuous use is not possible. If it is less than the lower limit, the sealing performance in normal use cannot be maintained. As a supplement to the lower limit, creep at 100 ° C. is performed by a heat-resistant creep test method. If it is less than 10 mm, the sealing performance at 100 ° C. can be maintained. Moreover, it is a hot melt composition containing a styrene block copolymer and butyl rubber, and normal sealing performance will be sufficient if the following formulation is followed. As a further feature, the hot melt composition has an elastic modulus at −20 ° C. of 150 MPa to 50 MPa. In the present invention, the elastic modulus at −20 ° C. can be used for an accelerated test imitating use conditions or a large object. If the pressure is 150 MPa or less, the stress between different types of materials can be relieved even with a size of 2 m, for example, without damaging the glass and airtightness. If it is 50 MPa or more, it depends on the weight and displacement of the material. There is no loss of airtightness and poor appearance.

The blending materials and the like will be described below.
Butyl rubber is compounded for the purpose of imparting sealability, weather resistance, water resistance, heat resistance, impact absorption, etc. to a hot melt composition for sealing, has a Mooney viscosity of 20 to 90, and has zero degree of unsaturation. A commercially available product such as 065 from Nippon Butyl Co., Ltd. can be used.

  The styrenic block copolymer is blended in the sealing material to ensure elasticity, cohesion and adhesion to the substrate, and the average molecular weight is 30000 to ensure elasticity and cohesion. 500,000 are compatible.

  Specific examples thereof include SBS (styrene-butadiene-styrene block copolymer), SIS (styrene-isoprene-styrene block copolymer), SEBS (styrene-ethylene-butylene-styrene block copolymer), SEB ( Styrene-ethylene-butylene block copolymer), SEPS (styrene-ethylene-propylene-styrene block copolymer), SEP (styrene-ethylene-propylene block copolymer) SIBS (styrene-isobutylene-styrene block copolymer) Copolymer) and the like. Among these, SEBS is preferable in terms of cohesion and adhesion, and can be used alone or mixed with other styrenic block copolymers. As for the composition of SEBS, a polystyrene / polyolefin blending ratio of 10/90 to 40/60 is desirable from the viewpoint of heat resistance and elastic modulus. If it is 10/90 or less, the heat resistance is low, which is not preferable, and if it exceeds 40/60, problems such as low elasticity and hardening occur. Commercial products include Clayton G manufactured by Shell Chemical Co., Septon manufactured by Kuraray Co., Ltd. and the like.

  The blending amounts of butyl rubber and styrene block copolymer are preferably selected in the range of 10 to 50% by weight and 2 to 30% by weight with respect to the entire hot melt for sealing, respectively, from the viewpoint of melt viscosity and heat resistance. If the blending amount is less than the above, sufficient elasticity cannot be obtained, and if it is too much, the melt viscosity increases, so that coatability cannot be obtained. In addition, when using a large product with a large coating amount or a high line speed, it is necessary to lower the melt viscosity in order to maintain sufficient hot melt supply capability. However, there is a concern that it deteriorates in the tank and lowers the quality of the product. For this reason, it is not preferable to increase the blending amount of the butyl rubber and the styrenic block copolymer, and if it is too small, the heat resistance and elasticity are lowered, and the performance as a sealing agent cannot be maintained. For this reason, using a general applicator and considering the application to large-scale adherents at a temperature at which there is no concern about extreme deterioration of hot melt, the blending amounts of butyl rubber and styrene block copolymer are each sealed. It is preferable to select in the range of 20 to 35% by weight and 3 to 15% by weight with respect to the entire hot melt. In addition to butyl rubber and styrenic block copolymers, terpene resins, terpene phenol resins, rosin resins, petroleum resins and their modified resins, hydrogenated resins and other tackifying resins for the purpose of imparting and improving tackiness, melting Atactic polypropylene, amorphous polyalphaolefin, paraffin wax, low molecular weight polyethylene, low molecular weight polypropylene, oils such as paraffin oil and naphthene oil, liquid polybutadiene and liquid for the purpose of controlling fluidity and non-stickiness A liquid polymer such as polybutene is blended.

Moreover, generally used fillers such as talc, clay, silica, calcium carbonate, and titanium oxide may be blended for the purpose of adjusting heat resistance, fluidity, and filling properties. Alternatively, hollow fillers such as shirasu balloons and glass foams may be blended for the purpose of preventing sedimentation when these fillers are melted, suppressing dimensional changes, and improving heat insulation. Furthermore, adhesion to an adherend such as glass or metal can be greatly improved by blending a silane coupling agent such as amino, vinyl or epoxy.

In particular, an antioxidant is appropriately blended for sealing applications requiring heat aging resistance.
Antioxidants include copper-based antioxidants, copper salt-based antioxidants, copper halide-based antioxidants, phosphorus-based antioxidants, phenol-based antioxidants, hindered amine-based antioxidants, and sulfur-based antioxidants. , A lactone-based antioxidant, an aromatic amine, a metal deactivator comprising a chelating agent, etc. are used, preferably a phenol-based antioxidant, a phosphorus-based antioxidant, a hindered amine-based antioxidant. Use of a combination is desirable from the standpoints of viscosity retention and airtight performance.

  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-tert-butyl-m-cresol), pentaerythrityl tetrakis {3- (3,5-di-tert-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. Examples thereof include phyto, sodium dihydrogen phosphate, and sodium dihydrogen 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 polycondensate 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-piperidyl) sebacate and the like. These may be used alone or in combination.

The hot melt composition for sealing according to the present invention can be prepared by kneading each of the above compounded materials while heating them with a Banbury mixer, a heating kneader, a uniaxial or biaxial extruder, and the like.
The material kneaded under heating is molded into a string shape, an irregular shape, etc. by an extruder, or cast into a mold and molded into each shape. As a coating filling.
In addition, what is kneaded and melted under heating can be directly applied and filled at the target seal position.

  The hot-melt composition for sealing according to the present invention is a seal at a connection portion between a glass plate and a frame, for example, a connection portion between an aluminum sash and a glass plate in a window material for construction, a metal opening of a vehicle body in a vehicle, and a glass plate. It is suitable for sealing a connection part or a connection part of a frame made of aluminum or stainless steel and a glass plate in a solar cell.

The method of applying and filling the hot melt composition for sealing according to the present invention to various connecting portions is, for example, a method of applying and filling the connecting portion such as a frame and a glass plate or the connecting portion of an assembled part, or the like, Apply to the edge of the assembly part on one side, and directly or reheat immediately before installation or just before assembly, and then contact the glass plate and other parts by contacting the edge where the hot-melt composition for sealing is applied. Can be used.
Therefore, in addition to processing procedures to be applied at the assembly plant for various products, processing is carried out in which parts applied to one part at another factory are brought in and brought into contact with the part where other parts are applied directly or after reheating. Procedures can also be adopted.

  For application and filling of the hot melt composition for sealing according to the present invention, hand gun type, block melt type, bulk type and foam type applicator equipment is used, and as a specific example of the applicator equipment, a bulk melter BM-505 manufactured by Nordson. And a commercial product such as a tank type applicator MX-4412 for applying a melted product in a tank manufactured by the same company.

  In addition, when manufacturing processed parts in large quantities at factories, etc., if the discharge part of the hot-melt composition coating and filling device for sealing is attached to a numerically controlled industrial robot, etc., it will be able to speed up even complex shapes. It can be applied to the surface, and significant improvement in production efficiency can be expected.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
Examples and Comparative Examples Sealing hot melt compositions of Examples and Comparative Examples were produced as follows. In addition, the compounding numerical value in a table | surface shows a weight part, and describes it only as a part.
As butyl rubber, butyl rubber with a degree of unsaturation of 0.8% (Nippon Butyl, Butyl 065), SEBS as a styrenic block copolymer (Kuraray, Septon 2063, average molecular weight), hydrogenated petroleum resin (TONEX as a tackifier) Manufactured by Escoretz 235E, melting point 125 ° C., polybutene as liquid resin (manufactured by Nippon Oil, HV-300, average molecular weight 1400), polyolefin wax as WAX (manufactured by Sanyo Chemical Industries, Viscol 550-P, melting point 152 ° C.), silane cup 1,3-bis (aminopropyl) tetramethyldisiloxane (manufactured by Chisso, hereinafter abbreviated as APDS) as a ring agent, and a phenolic antioxidant, Sumitizer GA-80 (manufactured by Sumitomo Chemical Co., Ltd.) as a heat aging inhibitor CAS No 90498-90-1 / 3, 9-bis [ 2- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5/5] undecane, phosphoric antioxidant Irgafos 168 (manufactured by Ciba Geigy, CAS No 31570-04-4 / tris (2,4-di-tert-butylphenyl) phosphide)), etc., were mixed by heating with a sigma blade type kneader. A hot melt composition for sealing was obtained.

Table 1, Table 1 shows the results of creep (heat resistance) of the hot melt compositions for sealing in Examples and Comparative Examples, the fracture state when the test piece having a glass plate bonded to an aluminum frame was forcibly destroyed, and the evaluation of the cycle test. Two streets.

The physical properties of the examples and comparative examples were evaluated by the following methods.
1. Elastic modulus (MPa)
The measurement was carried out in the compression mode of “FT-Leospectra DVE-V4” manufactured by Rheology Co., Ltd. The sample size is 2 mm × 5 mm × 5 mm in thickness, compressed in the thickness direction, the measurement starts from −70 ° C., and the temperature rising rate is 1 ° C./min.
2. Viscosity (Pa.s)
Brookfield's thermosel system Brookfield's digital viscometer (model: DVI-I +), thermo controller (model: 75), thermo container (HT-60DP), etc. No. 29. The rotation speed is 10 rpm. The spindle is inserted 10 minutes after the start of heating of the hot melt, and the measurement is started after another 10 minutes. The measured value is 20 minutes after the start of spindle rotation.
3. Creep (mm)
The specimen to be tested is a rectangular parallelepiped with a 10mm square bonding surface on a vertically supported aluminum plate (3mm thick), so that no interfacial breakage occurs between the metal surface and the hot-melt metal with a weight of 1g. The creep (mm) is evaluated as creep when allowed to stand in a 100 ° C. atmosphere for 24 hours. In order to prevent interfacial fracture between the metal surface and the test, the material under test is heated to such an extent that it does not deform and adheres to the metal surface. Fig. 1 shows the front and side images before and after the test, and the creep values. Reference numeral 4 denotes creep as a vertical difference between the lowermost part before the test (on the support plate) and the lowermost part after the test 5 (usually a part away from the aluminum plate).
4). An aluminum frame having a substantially U-shaped cross-sectional shape in the length direction of a fractured state thickness of 1 mm, groove width of 5 mm × groove height of 5 mm × length of 50 mm is filled with a hot melt composition for sealing melted at 200 ° C. After solidification, the sample is reheated at 100 ° C. for 10 minutes, and a glass piece having a thickness of 3 mm × width 25 mm × height 50 mm is inserted into the groove in the thickness direction up to 3 mm within 30 seconds, and cooled to obtain a test piece. After assembling, curing is performed in an atmosphere at 23 ° C. for 3 days, and the fracture state is confirmed by performing forced fracture at a tensile speed of mm / min. cf: Cohesive failure A state where there is no failure at the interface is expressed as 100%.
5. An aluminum frame having a substantially U-shaped cross-sectional shape in the glass crack length direction, a thickness of 1 mm, a groove width of 5 mm × a groove height of 5 mm, a bottom portion in the length direction of 392 mm, and an upper portion in the length direction of 387 mm; An aluminum frame having the same width and groove height and an upper part of 262 mm and a bottom part of 257 mm is placed facing each other, and the hot melt melted at 200 ° C. is filled in the grooves of the two aluminum frames, and cooled and solidified. Furthermore, after reheating at 100 ° C. for 10 minutes, it was assembled so that each side of a rectangular glass plate having a thickness of 3 mm × length of 390 mm × width of 260 mm was inserted into the groove to a depth of 3 mm within 30 seconds. Restrain the frame.
After curing for 3 days, 50 cycles of -50 ° C. for 1 hour and 110 ° C. for 1 hour were carried out, and the glass was broken.
However, when hot melt flowed out of the aluminum frame when heated at 110 ° C., the test was interrupted as NG. FIG. 2 shows an image of the frame.

The hot-melt composition for sealing according to the present invention has elasticity, is excellent in coating properties and heat resistance, has good adhesion to a member made of glass, metal, etc., and has good sealing properties. It can be used greatly for applications such as solar cells, architectural and window materials for vehicles, ships, etc., where the size is used. In particular, when a large glass plate is mounted on an aluminum frame or the like, it absorbs stress resulting from dimensional changes due to the difference in expansion coefficient between them, making it possible to avoid breakage of the glass. Can be used with confidence for any application.

It is a creep test explanatory drawing. It is frame explanatory drawing of a glass crack.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Aluminum plate 2 Test object 3 Vertical variation | change_quantity 4 Test object bottom imaginary line before test 5 Test material bottom imaginary line after test 6 Sheet glass 7 Metal frame 8 Upper length Indicator line 9 Bottom length Indicator line

Claims (2)

A hot melt composition containing at least 3 to 15% by weight of a styrene block copolymer and 20 to 35% by weight of butyl rubber with respect to the entire hot melt composition, and having a melt viscosity at 10 rpm of 10 Pa.s. s / 180 ° C. to 50 Pa. A seal characterized by an elastic modulus at s / 230 ° C. and −20 ° C. of 150 MPa to 50 MPa, and a creep at 100 ° C. by a heat-resistant creep test method according to the measurement method described in (1) below is less than 10 mm. Hot melt composition.
(1) Adhering to a vertically supported aluminum plate with a 10mm sq. Rectangular parallelepiped, hot melt weighing 1g so as not to cause interfacial breakage with a vertically-adhered substrate, in an atmosphere of 100 ° C The vertical variation (mm) after standing for 24 hours is evaluated as creep. A solar cell, wherein the hot melt composition according to claim 1 is used as a sealing material.

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