JPH0146543B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an improved water-based pressure sensitive adhesive applied to walls for mortar finishing of the walls of structures. Traditionally, mortar painting on the exterior or interior walls of structures involves pasting lath paper, rubber or resin sheets on the base material, mechanically fixing wood or lath wire mesh, and then spraying green mortar or troweling on top of it. It is carried out by In this method, the woodwork and lath wire mesh are fixed with ordinary nails and staples, so water often flows to the back side through the nail holes and staple holes. Recently, various types of adhesives have been used to bond green mortar and wall surfaces for the purpose of saving labor, but these adhesives have the drawback of being limited by the period of time between applying the adhesive to the wall surface and placing the green mortar. That is,
When an adhesive is applied to a wall and then exposed outdoors, there is a problem in that the adhesion strength of the adhesive with raw mortar decreases significantly due to changes over time. In practice, the green mortar is covered with a black polyethylene sheet, etc., but this requires labor and has problems such as the covering sheet being damaged by wind and rain. In order to solve this problem, the present invention has developed an acrylic resin emulsion in which an acrylic resin with a molecular weight of 300,000 or more is dispersed in water with a nonionic surfactant, and a terpene resin with a softening temperature of 100 to 150°C is dispersed in water with a nonionic surfactant. The present invention provides a water-based pressure-sensitive adhesive characterized in that a dispersed terpene resin emulsion is mixed with the acrylic resin and the terpene resin in a weight ratio of 1:0.5 to 1:2.
The present invention also provides a water-based pressure-sensitive adhesive in which antifoaming agents, thickeners, inorganic fillers, etc. are uniformly mixed and dispersed in the water-based pressure-sensitive adhesive as required. This water-based pressure-sensitive adhesive is applied to organic or inorganic adherends such as plywood, metal plates, cement boards, and gypsum boards. It is possible to bond with In other words, there is significantly less decrease in adhesive strength with raw mortar due to UV deterioration, water resistance deterioration, heat resistance deterioration, etc. due to outdoor exposure, and after the raw mortar hardens, the adherend and mortar layer are completely integrated, and the adhesive layer has the feature that it can be used as a waterproof layer. The acrylic resin of the present invention is a copolymer having the following structural formula (referred to as basic acrylic resin in the present invention). It is. The molecular weight of the acrylic resin must be 300,000 or more, and if the molecular weight is less than 300,000, it will have sufficient cohesive strength, but when used in a water-based pressure-sensitive adhesive, the adhesive strength will be low, which poses a problem. As described above, the acrylic resin of the present invention preferably has good weather resistance and water resistance, high cohesive force and high film strength, and has surface tack because it is a pressure-sensitive adhesive. Types of resins used with acrylic resins include coumaron/indene resin, terpene phenol resin, p-tert-butylphenol/acetylene resin, phenol formaldehyde resin, terpene resin, xylene/formaldehyde resin, petroleum hydrocarbon resin, and hydrogen. There are additive hydrocarbon resins, rosin derivatives, terpene resins, etc., but they have problems with weather resistance, heat resistance, water resistance, etc., as well as cost issues, as well as compatibility with various base materials and compatibility with acrylic resins. Terpene resin is best. In addition, in terms of the softening temperature of terpene resin, since it is used as a base material for mortar, it is estimated that a maximum temperature of about 80°C is required, so a softening temperature of 100°C is necessary. Further, when a water-based pressure-sensitive adhesive is prepared using a resin having a temperature of 100° C. or lower, the cohesive force of the adhesive layer decreases. If a water-based pressure-sensitive adhesive is made using a resin with a softening temperature of 150°C or higher, the adhesive layer will be hard;
Moreover, the brittleness causes interfacial peeling between the mortar layer and the adhesive layer or between the adhesive layer and the base layer. Considering the above points, a terpene resin having a softening temperature of 100 to 150°C is preferable as the resin for the water-based pressure-sensitive adhesive. Both the acrylic resin and terpene resin of the present invention are used in the form of an emulsion in which they are dispersed in water with a nonionic surfactant. The concentration of each resin in the acrylic resin emulsion and the terpene resin emulsion is appropriately selected depending on the conditions when used as a water-based pressure-sensitive adhesive, and is usually 35
~55% by weight is used, typically 50% by weight, but of course the present invention is not limited thereto. A water-based pressure-sensitive adhesive is prepared by mixing an acrylic resin emulsion and a terpene resin emulsion such that the weight ratio of the acrylic resin to the terpene resin ranges from 1:0.5 to 1:2. Furthermore, a water-based pressure-sensitive adhesive in which an antifoaming agent, a thickener, and an inorganic filler are uniformly mixed and dispersed as necessary is also preferable as a water-based pressure-sensitive adhesive.
As the surfactant, it is preferable to use a nonionic surfactant in terms of water resistance, dispersibility, compatibility, and viscosity stability. Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenol ethers,
Polyoxyethylene alkyl esters, sorbitan alkyl esters or polyoxyethylene sorbitan alkyls are used. The amount of surfactant used is an appropriate amount of 10 parts by weight or less per 100 parts by weight of acrylic resin or terpene resin. In this case, the antifoaming agent is preferably a non-silico type since it is used as an adhesive, and includes nonionic surfactants and the like. The amount of antifoaming agent used is usually 0.2 to 3 parts by weight per 100 parts by weight of acrylic resin. Thickeners include sodium cellulose glycolate and potassium salt of vinyl polymer (Modicol).
VE, manufactured by Nopco Chem Co., Ltd. (trade name) in the United States, and bentonite. The amount of thickener used is usually 2 to 10 parts by weight per 100 parts by weight of acrylic resin. Silica sand etc. are available as an inorganic filler. The amount of inorganic filler used is usually 100 to 500 parts by weight per 100 parts by weight of acrylic resin. By using an inorganic filler, drying can be made faster.
That is, water-based adhesives are normally dried at room temperature for a long period of time, but by introducing a filler, it becomes possible to dry them at a temperature of 50 to 80° C. for a short period of time. At the same time, water-based pressure-sensitive adhesives form an adhesive layer with few glue gaps even when applied thickly. The water-based pressure-sensitive adhesive obtained by mixing the above materials not only adheres well to green mortar, but also has the ability to apply the water-based pressure-sensitive adhesive to an adherend and dry it, and then to place the green mortar. It has the advantage that it is not affected by the period of outdoor exposure until the mortar is placed, and the mortar and adherend are completely integrated after the green mortar is placed.
The adhesive layer forms a waterproof layer with suitable moisture permeability. The actual construction according to the present invention is as follows. (B) Composition: Apply water-based pressure-sensitive adhesive to the organic or inorganic adherend surface of plywood, metal plate, cement board, or gypsum board at a rate of 0.8 to 1.2 kg/m ² using a roll brush, roll coater, spray, etc. Apply in proportion and dry thoroughly. One of its features is that it can be dried either naturally or by forced drying. Fresh mortar is sprayed onto the sufficiently dried surface of the water-based pressure-sensitive adhesive, and the green mortar is applied by a method such as troweling, and after the mortar dries, it is completely molded into one piece. (b) Use: It serves as an adhesive layer and waterproof layer for mortar and adherends around the exterior walls of structures, bathrooms, and apartments. A water-type pressure-sensitive adhesive is applied to an organic or inorganic adherend such as plywood, metal plate, cement board, or gypsum board, and the adhesive strength of the dried adhesive layer with mortar is observed to decrease due to subsequent curing conditions. do not have. In other words, its greatest feature is that there is no decrease in adhesive strength with raw mortar caused by UV deterioration, water resistance deterioration, heat resistance deterioration, etc. due to outdoor exposure. Conventional adhesives on the market suffer from a significant drop in adhesive strength due to outdoor exposure, making it difficult to place green mortar in on-site work where exposure to the outdoors can be expected until the time the green mortar is placed.However, the water-based adhesive of the present invention Press-type adhesives pose no problems in use even after being exposed outdoors. In addition, the mortar layer and the adherend are integrated by interposing a water-type pressure-sensitive adhesive layer,
Furthermore, since the adhesive layer also serves as a waterproof layer,
It can be used not only as a base material for the exterior walls of structures, but also as a base material for interior walls around bathrooms and rooms. The present invention will be explained in detail below with reference to Examples and Comparative Examples. Among the materials and chemicals used in these Examples and Comparative Examples, the following were used unless otherwise specified. For acrylic resin emulsions, the molecular weight of the acrylic resin in the emulsion is then shown in parentheses, and the line below that shows the type of acrylic resin and the type of surfactant used in the emulsion. As the acrylic resin, the emulsion using basic acrylic resin is Acronal 81DP (manufactured by Yuka Padishyu Co., Ltd., trade name), and the emulsion using acrylic resin copolymerized with styrene is Acronal 295D (manufactured by Yuka Padishyu Co., Ltd.). (product name),
As an emulsion using an acrylic resin copolymerized with vinyl acetate, Ricabond PS-3000H (manufactured by Chuo Rika Kogyo Co., Ltd., trade name) was used. The concentration of acrylic resin in the acrylic resin emulsion is approximately 50% by weight unless otherwise specified. Terpene resin emulsion indicates the softening temperature of the terpene resin in parentheses below the name, and the chemical structural formula of the resin is as shown in the following formula (). This is a water-dispersed emulsion using a nonionic surfactant, T-130 (manufactured by Yasuyu Kogyo Co., Ltd., trade name). The concentration of terpene resin in the terpene resin mortar is approximately 50% by weight unless otherwise specified. The antifoaming agent used was Nopco NXZ (manufactured by San Nopco Co., Ltd., trade name), and the thickener used was Gelton-50 (manufactured by Shiraishi Kogyo Co., Ltd., trade name). The nonionic surfactant is polyoxyethylene monostearate (Nonion S-6, manufactured by NOF Corporation,
Polyoxyethylene nonyl phenol ether (Nonion NS-206, manufactured by NOF Corporation, trade name) is a polyoxyethylene alkyl phenol ether, and polyoxyethylene stearyl ether (trade name) is a polyoxyethylene alkyl ether. Nonion S-215, manufactured by Nippon Oil & Fats Co., Ltd.
product name) is used in the same way. All amounts used are in parts by weight. Next, examples and comparative examples will be shown. Example 1 Acrylic resin emulsion (molecular weight 1 million) (basic acrylic resin, nonionic surfactant) 100 Terpene resin emulsion (softening temperature 130°C)
100 Calcium carbonate 200 Antifoaming agent 1 Thickener 5 total 406 Comparative example 1 Acrylic resin emulsion (molecular weight 1 million) (50
Acrylic resin copolymerized with styrene (wt%), nonionic surfactant) 100 Terpene resin emulsion (softening temperature 130℃)
100 Calcium carbonate 200 Antifoaming agent 1 Antifoaming agent 5 total 406 Comparative example 2 Acrylic resin emulsion (molecular weight 1 million) (50
Acrylic resin copolymerized with vinyl acetate (wt%), nonionic surfactant) 100 Terpene resin emulsion (softening temperature 130℃)
100 Calcium carbonate 200 Antifoaming agent 1 Thickener 5 total 406 Example 2 Acrylic resin emulsion (molecular weight 1 million) (25
Acrylic resin copolymerized with styrene (wt%), nonionic surfactant) 100 Terpene resin emulsion (softening temperature 130℃)
100 Calcium carbonate 200 Antifoaming agent 1 Antifoaming agent 5 total 406 Example 3 Acrylic resin emulsion (molecular weight 1 million) (25
Acrylic resin copolymerized with vinyl acetate (wt%), nonionic surfactant) 100 Terpene resin emulsion (softening temperature 130℃)
100 Calcium carbonate 200 Antifoaming agent 1 Antifoaming agent 5 total 406 Comparative example 3 Acrylic resin emulsion (molecular weight 250,000) (basic acrylic resin, nonionic surfactant) 100 Terpene resin emulsion (softening temperature 130°C)
100 Calcium carbonate 200 Antifoaming agent 1 Thickener 5 total 406 Example 4 Acrylic resin emulsion (molecular weight 5 million) (basic acrylic resin, nonionic surfactant) 100 Terpene resin emulsion (softening temperature 130°C)
100 Calcium carbonate 200 Antifoaming agent 1 Thickener 5 total 406 Comparative example 4 Acrylic resin emulsion (molecular weight 1 million)*
1 (Basic acrylic resin, anionic surfactant)
100 Terpene resin emulsion (softening temperature 130℃)
100 Calcium carbonate 200 Antifoaming agent 1 Antifoaming agent 5 total 406 *1 Acronal YX8501D (Yuka Badishyu Co., Ltd.)
Comparative example 5 Acrylic resin emulsion (molecular weight 1 million) (basic acrylic resin, nonionic surfactant) 100 Petroleum-based hydrocarbon emulsion *2 (softening temperature
130℃) 100 Calcium carbonate 200 Antifoaming agent 1 Thickener 5 total 406 An emulsion in which Petrosin #130, which has the chemical structure, is dispersed in water with a nonionic surfactant, and the concentration of the resin is approximately 50%. Comparative Example 6 Acrylic resin emulsion (molecular weight 1 million) (basic acrylic resin, nonionic surfactant) 100 Terpene resin emulsion (softening temperature 90℃)
100 Calcium carbonate 200 Antifoaming agent 1 Thickener 5 total 406 Comparative example 7 Acrylic resin emulsion (molecular weight 1 million) (basic acrylic resin, nonionic surfactant) 100 Terpene resin emulsion (softening temperature 160°C)
100 Calcium carbonate 200 Antifoaming agent 1 Antifoaming agent 5 total 406 Comparative example 8 Acrylic resin emulsion (molecular weight 1 million) (basic acrylic resin, nonionic surfactant) 100 Terpene resin emulsion (softening temperature 130°C)
40 Calcium carbonate 200 Antifoaming agent 1 thickener 5 total 346 Comparative example 9 Acrylic resin emulsion (molecular weight 1 million) (basic acrylic resin, nonionic surfactant) 100 Terpene resin emulsion (softening temperature 130°C)
230 Calcium carbonate 200 Antifoaming agent 1 Thickener 5 total 536 The formulations of the above Examples and Comparative Examples are stirred at high speed to obtain a uniform paste-like water-based pressure-sensitive adhesive. The adhesive strength obtained in this manner was measured for adhesive strength over time, water resistant adhesive strength, heat resistant adhesive strength, and moisture permeability, and Tables 1 to 4
Describe it in Test method [1] Adhesive strength over time 1-1 Preparation of specimen Apply water-based pressure-sensitive adhesive at a rate of 1 kg/m ² to 9 mm thick plywood and plasterboard and dry indoors overnight. This is then exposed outdoors. After that, green mortar was poured to a thickness of 10 mm and cured indoors for two days, covered with polyethylene film.
Thereafter, the polyethylene film was removed and the samples were aged indoors for 8 days and then measured. 1-2 Measurement method Make a cut in the mortar surface so that the sample area is 16cm ² (4 x 4cm ² ). Next, attach the attachment with epoxy resin adhesive and measure at a tensile speed of 200 mm/min. There are 3 samples and the value is the average of the 3 samples. [2] Water-resistant adhesive strength 2-1 Preparation of specimen Apply a water-based pressure-sensitive adhesive at a rate of 1 kg/m ² to 9 mm thick plywood and gypsum board, and after drying for a day and night, pour green mortar to a thickness of 10 mm. After curing the raw mortar in the same manner as in 1-1, cover the exposed parts of the plywood and plasterboard with a low-viscosity type epoxy resin adhesive. After the epoxy resin adhesive has hardened, it is immersed in water at room temperature. When measuring, take it out of the water 2
Measure after hours. 2-2 Measurement method Same as 1-2 [3] Heat-resistant adhesive strength 3-1 Preparation of specimen A water-based pressure-sensitive adhesive was applied to 9 mm thick plywood and plasterboard at a rate of 1 kg/m ² and dried for a day and night. Place mortar to a thickness of 10mm. After curing the raw mortar in the same manner as in 1-1, cure it in a constant temperature bath at 80℃. When measuring, take it out from the thermostat 4
Measure after leaving it in the room for an hour. 3-2 Measurement method Same as 1-2 [4] Measurement of moisture permeability (according to JIS-Z-0208) 4-1 Preparation of specimen Apply 1 kg of water-based pressure-sensitive adhesive to a 5.5 mm thick waterproof plywood board. The specimen was applied at a ratio of m ² and dried at room temperature for one week. 4-2 Measurement method Cut the specimen to 70 mm diameter and fill an aluminum cup with anhydrous calcium chloride. The sample is then embedded with the adhesive layer facing up and sealed with wax.
Leave this in a constant temperature bath at 40℃ and humidity 90±10% for 24 hours, and calculate the moisture permeability using the following formula. Moisture permeability (g/m ² , 24H) = 240×m/tS S: Moisture permeability area t: Total time between two weighing intervals during which the test was conducted
(h) m: 〃 〃 Total increased mass (mg) The composition of mortar used in the above tests [1] to [3] was as follows. Portland cement 100 Standard Sand 200 Water 60 Total 360

【table】

【table】

【table】

【table】

【table】

【table】

【table】

[Table] From the above Examples and Comparative Examples, the following things were found. The type of acrylic resin is preferably a basic acrylic resin, styrene within 30% by weight, or an acrylic resin copolymerized with vinyl acetate. If the content of styrene, vinyl acetate, or the total of both exceeds 30% by weight, problems will arise in weather resistance and water resistance. In other words, if a water-based pressure-sensitive adhesive is made using an acrylic resin copolymerized with styrene in an amount exceeding 30% by weight, the adhesive strength with green mortar will decrease if the outdoor exposure period after the adhesive is applied and dries becomes longer. descend. When a water-based pressure-sensitive adhesive is prepared using an acrylic resin copolymerized with vinyl acetate in an amount exceeding 30% by weight, water resistance is poor. If the molecular weight of the acrylic resin is less than 300,000, the cohesive force after application of the water-based pressure-sensitive adhesive will be low.
There is no problem if the molecular weight is 300,000 or more. As a surfactant for dispersing acrylic resin in water,
When comparing nonionic surfactants and anionic surfactants, nonionic surfactants have better water resistance. When using a cationic surfactant, the dispersibility, compatibility with other formulations,
Since the viscosity stability of water-based pressure-sensitive adhesives is poor, nonionic surfactants are considered to be better. When comparing terpene resins and petroleum-based hydrocarbon resins, terpene resins are preferable because they have higher adhesive strength values. Furthermore, if the softening temperature of the terpene resin is lower than 100°C, the adhesive force value will be low. On the other hand, the softening temperature
If the temperature is higher than 150°C, the adhesive layer after coating and drying of the water-based pressure-sensitive adhesive becomes brittle, causing interfacial peeling between the adhesive layer and the mortar. The weight ratio of acrylic resin and terpene resin is 1:
When it is larger than 0.5, interfacial peeling occurs between the base material and the adhesive layer. The weight ratio of acrylic resin and terpene resin is 1:2
When it is smaller, water resistance and heat resistance are poor. In particular, there is an extreme drop in water resistance. Based on the above, acrylic resins include basic acrylic resins, styrene, vinyl acetate, or acrylic resins with a total content of up to 30% by weight, with a molecular weight of 30%.
Preferred is an acrylic resin emulsion that is water-dispersed using a nonionic surfactant of 10,000 or more. As the terpene resin, a terpene resin emulsion having a softening temperature of 100 to 150°C and water-dispersed with a nonionic surfactant is preferable. The water-based pressure-sensitive adhesive obtained in this way adheres well to fresh mortar regardless of the curing conditions and curing days after application and drying, and is also excellent in water resistance and heat resistance. . Another feature is that it can be used in a wide range of materials, including organic or inorganic plywood, metal plates, cement plates, and gypsum plates. Furthermore, after the raw mortar has hardened, the water-based pressure-sensitive adhesive layer not only integrates the adherend and the mortar layer, but also has the feature of forming a waterproof layer with appropriate moisture permeability. .

Claims (1)

[Claims] 1. An acrylic resin emulsion in which an acrylic resin with a molecular weight of 300,000 or more is dispersed in water with a nonionic surfactant, and a terpene resin with a softening temperature of 100 to 150°C is dispersed in water with a nonionic surfactant. A water-based pressure-sensitive adhesive characterized in that a terpene resin emulsion is mixed in a weight ratio of the acrylic resin and the terpene resin in a range of 1:0.5 to 1:2. 2. An acrylic resin emulsion in which an acrylic resin with a molecular weight of 300,000 or more is dispersed in water with a nonionic surfactant, and a terpene resin emulsion in which a terpene resin with a softening temperature of 100 to 150°C is dispersed in water with a nonionic surfactant. A water-based pressure-sensitive adhesive characterized by blending an antifoaming agent, a thickener, and an inorganic filler into a mixture of the acrylic resin and the terpene resin in a weight ratio of 1:0.5 to 1:2. . 3 As the antifoaming agent, one or more selected from nonionic surfactants are added to the acrylic resin 100.
3. The water-based pressure-sensitive adhesive according to claim 2, wherein the water-based pressure-sensitive adhesive is blended in an amount of 0.2 to 3 parts by weight. 4. The thickener is blended with one or two selected from sodium cellulose glycolate and bentonite in an amount of 2 to 10 parts by weight based on 100 parts by weight of the acrylic resin. A water-based pressure-sensitive adhesive according to Scope 2. 5 Using silica sand as the inorganic filler with acrylic resin
The water-based pressure-sensitive adhesive according to claim 2, wherein the water-based pressure-sensitive adhesive is blended in an amount of 100 to 500 parts by weight per 100 parts by weight. 6 An acrylic resin emulsion in which an acrylic resin with a molecular weight of 300,000 or more is dispersed in water with a nonionic surfactant, and a terpene resin emulsion in which a terpene resin with a softening temperature of 100 to 150°C is dispersed in water with a nonionic surfactant, To a mixture of the acrylic resin and the terpene resin in a weight ratio of 1:0.5 to 1:2, 0.2 to 3 parts by weight of an antifoaming agent and 2 parts by weight of a thickener are added to 100 parts by weight of the acrylic resin. 2. The water-based pressure-sensitive adhesive according to claim 2, which contains 100 to 500 parts by weight of silica sand as an inorganic filler.