JPH11236553A - Water stop seal material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water stop seal material having excellent sealability by forming a layer comprising a pressure-sensitive adhesive composition containing a polymer having a specified polycarbonate structure on at least either surface of a foam structure through a base material. SOLUTION: A foam structure having closed cells or both closed cells and open cells is used, and a pressure-sensitive adhesive composition containing a polymer having repeating units of the formula (R is a 2-20C hydrocarbon group) is used. The molecular weight of the polymer is suitably 10,000 or above in terms of a weight-average molecular weight. The polymer used is a polyester synthesized from a polycarbonate diol and a dicarboxylic acid, a polyester synthesized from a polycarbonate dicarboxylic acid and a diol, or a polyurethane synthesized from a polycarbonate diol and a diisocyanate, and is particularly desirably a polyester synthesized from a polycarbonate diol and a dicarboxylic acid. The water stop seal material is prepared by forming a pressure-sensitive adhesive composition layer having a thickness of, usually, 2-100 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixed watertight seal material using a foamed structure having closed cells or both closed cells and open cells.

[0002]

2. Description of the Related Art Rubber foams have excellent cushioning properties and are useful for applications such as cushioning materials and padding materials. Comparing closed cells and open cells in the foamed structure, the former has a structure in which the cells are separated by partitions in a three-dimensional lattice, whereas the latter removes the partitions between the series of separated cells. The latter is easier to deform mechanically. However, while open cells cannot expect a water stopping effect at all, closed cells can expect a water stopping effect due to repulsive stress due to the partition between the cells.

A foamed structure having both closed cells and open cells (hereinafter sometimes referred to as a semi-semi-open cell structure) is used to fill complicated gaps due to easy deformation based on open cells. It is suitable as a standard waterproof sealing material to be used by filling in complicated gaps because it can be expected to have both easy easiness and waterproofness based on closed cells.

However, when a closed-cell foamed structure or a half-semi-sealed foamed structure is used as a water-sealing material, the repulsive stress of the foamed structure is reduced with the passage of time. As a result, the contact surface pressure between the foamed structure and the interface of the adherend decreases, and water leaks along this interface, whereby the water stop function may not be achieved. To solve this problem,
There has been proposed a method in which an adhesive layer is provided on both sides of a foamed structure, and the interface of the adherend is sealed with an adhesive. However, if an acrylic or rubber-based general adhesive is used as the adhesive layer, these adhesives will develop an adhesive force at the time of assembly, making it difficult to align and reposition, which hinders sealing work. Easy to come.

Therefore, the present inventors have proposed a pressure-sensitive adhesive layer provided on a closed-cell foamed structure or a semi-semi-sealed foamed structure.
By using a polymer having a polycarbonate structure as a main component, the pressure-sensitive adhesive layer does not have tack, so that it does not immediately adhere to the adhesive layer, so that the alignment,
The repositioning is easy and the sealing operation can be performed without any trouble. After assembly, the foam structure gradually adheres due to the repulsive force, and the seal between the surface of the foam structure and the interface between the water blocking portion. -Learned that the resilience was significantly increased, and
It has already been proposed as the invention according to No. 232108.

[0006]

However, according to subsequent studies by the present inventors, even with the above proposed waterproofing seal material, even under the severe conditions of long-term use at high temperatures, the water-sealing material cannot be used under the severe conditions. I learned that the sealability may gradually decrease. The present invention has been made in view of such circumstances,
It is an object of the present invention to further improve the waterproof seal material proposed above to obtain a fixed waterproof seal material having further improved sealing properties.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies on the above-mentioned objects, and as a result, under severe conditions of long-term use at high temperatures, depending on the type of foamed structure, A phenomenon in which certain components migrate to the pressure-sensitive adhesive layer containing a polymer having a polycarbonate structure as a main component has been observed, and as a result, the pressure-sensitive adhesive layer has deteriorated and the adhesiveness has decreased. , And found that the sealability was reduced.

The inventors of the present invention have made further studies based on this finding. As a result, when providing a specific pressure-sensitive adhesive layer mainly composed of a polymer having a polycarbonate structure on a foamed structure, When the base material is provided inside the pressure-sensitive adhesive layer, that is, when the pressure-sensitive adhesive layer is provided on the foamed structure via the base material, the sealing work is improved by the non-tacky property of the pressure-sensitive adhesive layer. On the other hand, the migration of the foamed structure is prevented by the base material, and the deterioration of the pressure-sensitive adhesive layer can be avoided.
It has been found that the sealing property is improved as compared with the case where the pressure-sensitive adhesive layer is directly provided on the foamed structure, and that high sealing property can be obtained especially under severe conditions such as long-term use at high temperature. It was completed.

That is, the present invention provides the following formula on at least one surface of a foamed structure having closed cells or both closed cells and open cells: (R is a linear or branched hydrocarbon group having 2 to 20 carbon atoms)
A water-sealing material (Claim 1), wherein a layer comprising a pressure-sensitive adhesive composition containing a polymer having a bone structure is provided via a base material; A layer made of a pressure-sensitive adhesive composition containing a polymer having a polycarbonate structure is provided on one surface of the foamed structure via a base material, and the pressure-sensitive adhesive composition is formed on the opposite surface. The present invention relates to a water-blocking seal material having the above-mentioned structure provided with a pressure-sensitive adhesive layer different from a material (claim 2).

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The pressure-sensitive adhesive composition used in the present invention has the following formula: (R is a linear or branched hydrocarbon group having 2 to 20 carbon atoms)
A polymer having a bone structure.
The molecular weight of the polymer is preferably 10,000 or more, preferably 30,000 or more, more preferably 50,000 or more (usually up to 300,000) by weight average.

The above-mentioned polymers include polyester synthesized from polycarbonate (or a derivative thereof) and dicarboxylic acid, polyester synthesized from polycarbonate dicarboxylic acid and diol, Examples include polyurethane synthesized from polycarbonate and diisocyanate. Particularly preferred is polyester synthesized from polycarbonate and dicarboxylic acid.

This polyester is required to have a diol component essentially comprising polycarbonate and a dicarboxylic acid having a molecular skeleton of an aliphatic or alicyclic hydrocarbon group having 2 to 20 carbon atoms. It is obtained by subjecting the obtained dicarboxylic acid component to an esterification reaction according to a conventional method without using a catalyst or using an appropriate catalyst. In this reaction, the diol component and the dicarboxylic acid component are desirably subjected to an equimolar reaction so that the molecular weight of the obtained polyester falls within the above range.However, in order to promote the esterification reaction, any May be used in excess.

The polycarbonate used herein is
The formula is: Wherein R is a linear or branched hydrocarbon group having 2 to 20 carbon atoms, and has a number average molecular weight of 400 or more, preferably 900 or more (usually 1 to 20). Up to 10,000). Specifically, polyhexamethylene carbonate di-diol, poly (3-methylpentene carbonate di-diol), polypropylene carbonate di-diol, mixtures and copolymers thereof, and the like can be used. is there. Commercially available products include “PLACCEL CD205PL” and “CD208” manufactured by Daicel Chemical Industries, Ltd.
PL "," CD210PL "," CD220P "
L "," CD205HL "," CD208HL ",
"CD210HL" and "CD220HL".

The diol component may be ethylene glycol, propylene glycol, butanediol, if necessary.
Linear or branched diols such as diol, hexanediol, octanediol, decanediol and octadecandiol may be used in combination. These diols are used in an amount of 50% by weight or less, preferably 30% by weight or less of the whole diol component. In order to increase the molecular weight of the polymer, a small amount of a tri- or higher functional polyol component may be added.

The dicarboxylic acid component has 2 to 2 carbon atoms.
It has 20 aliphatic or alicyclic hydrocarbon groups as its molecular skeleton, and the above-mentioned hydrocarbon groups may be linear or branched. Specifically, succinic acid, methyl succinic acid, adipic acid, pimelicic acid, azelaic acid,
Sebacic acid, 1,12-dodecandioic acid, 1,14-tetradecandioic acid, tetrahydrophthalic acid, endomethylenetetrahydrophthalic acid, acid anhydrides and lower alkyl esters thereof, and the like can be mentioned.

In the present invention, a polymer having a polycarbonate structure, such as polyester, is usually used.
Can be cross-linked by an appropriate means to obtain a tack-free adhesive composition having excellent durability such as heat resistance.
The method of crosslinking may be any method, but generally a method using a so-called crosslinking agent, in which a compound having a functional group capable of reacting with a hydroxyl group and / or a carboxyl group contained in a polymer such as polyester is added and reacted. Examples of the crosslinking agent include a polyisocyanate compound, an epoxy compound, an aziridine compound, a metal chelate compound, and a metal alkoxide compound, and a polyisocyanate compound is particularly preferably used.

As the polyisocyanate compound, lower aliphatic polyisocyanates such as ethylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate, cyclopentylene diisocyanate,
Alicyclic polyisocyanates such as cyclohexylene diisocyanate and isophorone diisocyanate, 2,4
-Aromatic polyisocyanates such as tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate and xylylene diisocyanate; and tolylene diisocyanate of trimethylolpropane. Ne-
Adducts and hexamethylene diisocyanate adducts are also used.

These crosslinking agents can be used alone or in a mixture of two or more. The amount used depends on the balance with the polymer such as polyester to be crosslinked.
It is appropriately selected according to the purpose of use of the pressure-sensitive adhesive composition.
In general, the ratio is preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of a polymer such as polyester, thereby facilitating the adhesiveness for exhibiting the sealing property and facilitating the mounting operation. Good results are obtained in the balance characteristics with tack free.

The above-mentioned pressure-sensitive adhesive composition may contain various conventionally known tackifiers. The blending of the tackifier may make it easier to balance adhesion and durability. In addition, various known additives such as inorganic or organic fillers, powders such as metal powders and pigments, particles, and foils can be arbitrarily added. Further, the durability may be improved by adding an antioxidant.

As the base material used in the present invention, those widely used as base materials for adhesive sheets can be used. For example, porous base materials such as non-woven fabrics, plastic films, metal foils and the like can be used. Can be Among these, plastic films and metal foils, particularly plastic films, are preferably used from the viewpoint of preventing migration components from the foamed structure. The thickness of the base material is appropriately selected according to the above-mentioned material, but in the case of plastic films, it is usually 5 to 5.
The thickness is preferably 100 μm.

As the foamed structure used in the present invention, various known structures can be used as long as they have closed cells or both open cells and closed cells. To manufacture the foamed structure, natural rubber or synthetic rubber (chloroprene rubber, ethylene propylene terpolymer, etc.), a vulcanizing agent, a foaming agent, a filler and the like are mixed using a Banbury mixer or a pressurized needle.
After kneading with a kneading machine such as a kneader, the mixture is continuously kneaded by a calendar, an extruder, a conveyor belt casting, etc., formed into a sheet shape, a rod shape, and then heated, vulcanized and foamed. If necessary, the vulcanized foam may be cut into a predetermined shape, or natural rubber or synthetic rubber, a vulcanizing agent, a foaming agent, a filler, and the like may be kneaded with a mixture of mixin and the like. According to the formula, a method of vulcanization, foaming and molding in a mold can be used.

The water-sealing material of the present invention is obtained from the above-mentioned pressure-sensitive adhesive composition comprising a polymer having a polycarbonate structure on such a foamed structure via the above-mentioned substrate. Is provided so that the thickness of the layer is usually 2 to 100 μm. The layer made of the above-mentioned pressure-sensitive adhesive composition provided via the base material may be provided not only on one side of the foamed structure but also on both sides as necessary. The method of providing the adhesive sheet may be arbitrary, but generally, an adhesive sheet in which a layer comprising the above-mentioned adhesive composition is formed on a base material is prepared in advance, and the foamed structure is formed with the base material inside. What is necessary is just to laminate on top. At this time, lamination may be performed using an appropriate adhesive (adhesive), or lamination may be performed by heat fusion. When laminating using an adhesive (adhesive), this adhesive (adhesive) may be previously applied to the opposite surface side of the above-mentioned adhesive sheets.

[0023] The water-sealing seal material thus configured has high strength (strain) as a whole seal material due to the presence of the above-mentioned base material, is easily punched and formed, and is easy to handle during assembly. Also, since the layer made of the above-mentioned pressure-sensitive adhesive composition has no tack and is easy to align and reposition, the sealability is remarkably excellent. Moreover, after assembling, the foamed structure is gradually adhered by the repulsive force to enhance the sealing property between the surface of the foamed structure and the interface between the water blocking portion, and the base material is made of the above-mentioned adhesive composition. In order to hold the layer made of the material and prevent its deterioration, especially deterioration due to the migration component from the foamed structure, it exhibits high sealing properties even under severe conditions such as long-term use at high temperature.

In the case where the layer made of the above-mentioned pressure-sensitive adhesive composition is provided only on one side of the foamed structure via the base material in the water-sealing material of the present invention, the layer on the opposite side of the foamed structure is provided. As a pressure-sensitive adhesive layer different from the above-mentioned layers, a general-purpose pressure-sensitive adhesive layer such as a rubber-based pressure-sensitive adhesive or an acrylic pressure-sensitive adhesive can be provided. According to this type of waterproof sealing material, in addition to the above-described functions and effects, the characteristics of the general-purpose pressure-sensitive adhesive layer can be utilized.

[0025]

EXAMPLES Next, examples of the present invention will be described in more detail. In the following, “parts” means “parts by weight”.

Example 1 The following composition was kneaded with a mixture of mixins, and the kneaded product was heated in an oven at 160 ° C. for 30 minutes to form a vulcanized foam, taken out of the oven, and After cooling, some of the air bubbles were broken by a pressurization method to obtain a half-semi-half-cell foamed structure. The specific gravity of this foamed structure was 0.11 g / ml.

<Composition of foamed structure> Ethylene propylene terpolymer 100 parts Zinc flower 5 parts Stearic acid 1 part Carbon 40 parts Polyethylene 20 parts Heavy calcium carbonate 180 parts Polybutene 40 parts Sulfur 2 parts Mercapto Benzothiazole 1 part Zinc diethyldithiocarbamate 2 parts Azodicarboxylic acid amide 13 parts

On the other hand, 2-ethylhexyl acrylate 90
And 10 parts of acrylic acid were subjected to radical polymerization at 60 ° C. for 5 hours using 0.2 parts of azobisisobutyronitrile and 200 parts of toluene to obtain a solution containing an acrylic polymer. To 100 parts of the acrylic polymer, 2 parts of a hexamethylene diisocyanate adduct of trimethylolpropane (“Coronate HL” manufactured by Nippon Polyurethane Co., Ltd.) was blended as a cross-linking agent, and the mixture was thoroughly stirred and mixed. Thus, an acrylic pressure-sensitive adhesive was prepared.

Separately, a four-neck separable flask was equipped with a stirrer, a thermometer and a water separation tube, and this was equipped with polycarbonate [Diocel Chemical Industries, Ltd. "PLACCEL CD220PL"]. , Hydroxyl value: 5
5.4 KOH mg / g], 500 g of sebacic acid, and 123 mg of dibutyltin oxide as a catalyst.
In the presence of a small amount of toluene as a solvent for discharging reaction water, the temperature was raised to 180 ° C. while stirring was started, and the temperature was maintained at this temperature. After a while, water separation was observed, and the reaction began to proceed. The reaction was continued for about 50 hours to obtain a polyester having a weight average molecular weight of 47,000. To 100 parts (solid content) of this polyester, trimethylo-
Hexamethylene diisocyanate adduct of lupropane (“Coronate HL” manufactured by Nippon Polyurethane Co., Ltd.) was added in an amount of 2 parts (solid content) and mixed well with stirring to prepare a polyester-based pressure-sensitive adhesive.

Using the above semi- and semi-continuous foam structure, acrylic pressure-sensitive adhesive and polyester-based pressure-sensitive adhesive, a waterproof sealing material was produced in the following manner. First, an acrylic pressure-sensitive adhesive was applied to the release liner using an applicator and dried to form two types of acrylic pressure-sensitive adhesive layers having a thickness of 50 μm and 150 μm. In the same manner as described above, a polyester-based pressure-sensitive adhesive was applied to a 25 μm-thick polyethylene terephthalate film (hereinafter referred to as a PET film) as a base material, and dried to form a 30 μm-thick film.
A μm-based polyester pressure-sensitive adhesive layer was formed to obtain a pressure-sensitive adhesive sheet. Next, an acrylic pressure-sensitive adhesive layer having a thickness of 50 μm is adhered to one side of the half-semi-sealed foam structure, and the above-mentioned pressure-sensitive adhesive sheet is placed on the base material inside. Pasted like so. Further, the acrylic pressure-sensitive adhesive layer having the above-mentioned thickness of 150 μm was stuck on the side opposite to the pressure-sensitive adhesive sheet to prepare a water-sealing seal material.

Example 2 A polyester adhesive prepared in Example 1 was applied on a PET film having a thickness of 25 μm as a substrate and dried to form a polyester adhesive layer having a thickness of 5 μm. To make an adhesive sheet. A water-blocking seal material was produced in the same manner as in Example 1 except that this adhesive sheet was used.

Example 3 The following composition was kneaded with a mixture of mixin, and the kneaded product was heated in an oven at 160 ° C. for 30 minutes for vulcanization and foaming to form a closed-cell foamed structure. Obtained. The specific gravity of this foamed structure was 0.10 g / ml. Next, in the same manner as in Example 1 except that this closed-cell foamed structure was used instead of the semi-semi-semi-opened foamed structure of Example 1,
Waterproof seal material was produced.

<Composition of foamed structure> Ethylene propylene terpolymer 40 parts Butyl rubber 60 parts Zinc white 5 parts Stearic acid 3 parts Carbon 50 parts Heavy calcium carbonate 50 parts Process oil 20 parts Sulfur 0. 5 parts Mercaptobenzothiazole 1 part Zinc diethyldithiocarbamate 1 part Quinone dioxime 0.5 parts Quinone monooxime 0.5 parts Azodicarboxylic acid amide 20 parts

For each of the water seal materials of Examples 1 to 3, a U-shaped water stop test and a high-pressure water stop test were carried out as a water stop test by the following methods. The results of these tests were as shown in Table 1 below.

<U-shaped water stoppage test>
Sample A was formed into a cord having a rectangular cross section of 0 mm and a width of 10 mm. This sample A is U-shaped as shown in FIGS. 1 and 2 and is sandwiched between two acrylic plates 1 and 1. Fastened with bolts and nuts 3. The compressibility in the thickness direction of the sample A was adjusted by the thickness of the spacer 2.

After fastening with the bolts and nuts 3 in this way, as shown in FIG.
Water 4 was added at 00 mm. After fastening the bolts and nuts 3, the sample was left in an atmosphere of 80 ° C. for 168 hours, and then returned to room temperature.
Water 4 was added at 0 mm. Immediately after assembling the former, 80
As a U-shaped water stop test after 168 hours at a temperature of 168 ° C., it was examined whether or not the sample A was able to stop water when the compression ratio in the thickness direction was set to what percentage.

<High-pressure Water-Stopping Test> The water-blocking seal material was processed into a donut shape having a thickness of 10 mm, an outer diameter of 100 mm, and an inner diameter of 80 mm to obtain a sample B. This sample B was prepared as shown in FIGS.
As shown in (1), the acrylic plate 1 and the acrylic molded body 5 were fastened with bolts and nuts 3 while being held between the acrylic plate 1 and the acrylic molded body 5 and maintaining the space by the spacer 2 passed through the bolt portion. . The compressibility in the thickness direction of the sample B was adjusted by the thickness of the spacer 2. After fastening with bolts and nuts 3 in this manner, 80 kgf /
Water was applied for 3 minutes at the pressure of cm ^{2 to} the portion of the waterproof seal material. When the compression ratio in the thickness direction of the sample B was set to what percentage, whether or not the water could be stopped was examined.

[0038]

As is evident from the results in Table 1 above, each of the water-blocking seal materials of Examples 1 to 3 of the present invention can obtain good water-blocking properties at a low compression ratio of the foamed structure. Has been
It can be seen that even if the repulsive stress is relaxed over time, the water stoppage does not decrease, and it shows high water stoppage even with high-pressure running water.

The water-sealing material having a conventional structure in which an acrylic pressure-sensitive adhesive layer is provided on one side of the foamed structure has a higher compressibility than the above, for example, a U-shaped water-proof test (at 80 ° C. × 168 hours later). ) Shows a low sealing property such that water leakage is observed even when the compression ratio is 90%, and the waterproof sealing material provided with an acrylic pressure-sensitive adhesive layer on both sides of the foamed structure is a sealing material. Although the sealability was good (water could be stopped at 10 to 20% compression), repositioning was difficult due to surface tack, and sealing work was often hindered. On the other hand, it was also found that in each of the waterproof sealing materials of Examples 1 to 3, the polyester-based pressure-sensitive adhesive layer did not have tackiness, and thus the assembly work could be performed satisfactorily without such a problem. .

Further, in the waterproof sealing materials of Examples 1 and 3, the adhesive sheet (and the inner thickness thereof was 50 μm).
Water-proof seal for reference having a structure in which a 30 μm-thick polyester-based pressure-sensitive adhesive layer is provided in place of the acrylic pressure-sensitive adhesive layer)
Specimens were prepared and their performance was examined in the same manner as described above. As a result, a closed-cell foamed structure corresponding to Example 3 was used.
It became "water stop at 40% compression", which was inferior to that of the present invention.

Further, as a more severe condition than the U-shaped water stop test after 80 ° C. for 168 hours, after fastening the bolt and nut 3, after leaving in an atmosphere of 80 ° C. for 60 days,
A U-shaped still water test was performed in the same manner as above. as a result,
The above reference water-sealing seal material uses a half-semi-continuous foamed structure corresponding to the first embodiment.
In contrast to the case of using the closed-cell foamed structure corresponding to Example 3 which was able to stop water by 30% compression, the water-stop seal materials of Examples 1 and 3 were all 10% compressed. It was found that the material was sufficiently water-stoppable, and that the water-stopping seal property could be further improved as compared with the above-mentioned reference water-stopping seal material.

[0043]

As described above, the present invention relates to a specific structure containing a polymer having a polycarbonate structure as a main component on a foamed structure having closed cells or both open cells and closed cells. By providing a layer made of the pressure-sensitive adhesive composition via a base material, excellent seal workability, and excellent sealability between the foam structure surface and the adherend interface,
In particular, it is possible to provide a waterproof sealing material that exhibits high sealing properties even under severe conditions such as long-term use at high temperatures. Further, by providing a layer made of the pressure-sensitive adhesive composition on one side of the foamed structure via a base material and providing a general-purpose pressure-sensitive adhesive layer such as a rubber-based or acrylic-based on the other side, the above advantages are provided. It is possible to provide a water-blocking seal material that can make use of the characteristics of the general-purpose pressure-sensitive adhesive layer without losing it.

[Brief description of the drawings]

FIG. 1 is a side view showing an apparatus configuration of a U-shaped water stop test of a water stop seal material.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a cross-sectional view showing a state in which water is poured into a U-shaped sample (water-blocking seal material) in the apparatus configuration of FIGS. 1 and 2;

FIG. 4 is a side view showing an apparatus for a high-pressure running water stoppage test of the watertight seal material.

FIG. 5 is a sectional view taken along line VV in FIG. 4;

[Explanation of symbols]

 A and B samples (water seal material) 1 Acrylic plate 2 Spacer 3 Bolt and nut 4 Water 5 Acrylic molded body

Continuation of the front page (51) Int.Cl. ⁶ Identification code FI B32B 27/00 B32B 27/00 D 27/36 102 27/36 102 C09J 7/02 C09J 7/02 Z 169/00 169/00

Claims (2)

[Claims] 1. The following formula is provided on at least one surface of a foamed structure having closed cells or both closed cells and open cells: (R is a linear or branched hydrocarbon group having 2 to 20 carbon atoms)
A water-blocking seal material, characterized in that a layer comprising a pressure-sensitive adhesive composition containing a polymer having a bone structure is provided via a substrate. 2. A polycarbonate structure is provided on one surface of the foamed structure.
A layer comprising a pressure-sensitive adhesive composition containing a polymer having a heat-resistant structure, and a pressure-sensitive adhesive layer different from the above-mentioned pressure-sensitive adhesive composition on the opposite surface. Item 6. The water-sealing material according to Item 1.