JPH0471110B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a water-based resin composition that provides a film with excellent elasticity. The resin composition of the present invention is useful as a waterproof and heat-insulating paint for concrete buildings, a coating material for adjusting the degree of expansion and contraction, a soundproof and vibration-proofing paint for automobile bodies, an undercoat paint for wood, and a carpet packing material. In addition, a thick wall (1
~20mm) film is useful as a heat insulation sheet and a sound insulation sheet. As a coating composition made of a resin emulsion containing cement, its use as a soundproof and anti-vibration paint for vehicles is described in Japanese Patent Application Laid-Open No. 11562/1983, and is used as a waterproof coating composition for base coating, intermediate coating, and top coating of buildings, metals, wood, etc. , as anti-corrosion paints, Special Publication No. 50-29731 and No. 56-33334.
No. 58-1698, JP-A No. 54-66938, No. 55-
No. 10433, No. 55-104955, No. 48-44327, No. 52
It is publicly known from publications such as No.-81331 and No. 56-164048. These aqueous resin emulsions containing cement generally contain aggregates such as silica powder, silica sand, calcium carbonate, kaolin, titanium oxide, and zinc oxide, and since cement is hydraulic, the resin and cement partner are Since it acts as a binder for materials, it has the advantage of being able to incorporate a large amount of aggregate, and has the advantage of being able to be coated in a thick film. Furthermore, as a sound-proofing and vibration-proofing paint, asphalt is roll-kneaded with aggregates such as asbestos powder, silica powder, calcium carbonate, and talc, and then made into a 2-3 mm sheet, which is applied to the upper surface of the interior floor of the car body during the painting process. Compared to the conventional method of spreading and baking and fusing at a temperature of 140°C or higher, it has the advantage of being able to coat uneven surfaces easily. However, in these coating compositions, inorganic fine powder with a bulk specific gravity (JISK-5400) of 2.5 to 4.5 is used as aggregate, so the specific gravity of the coating composition itself becomes large and the aggregate scatters during painting. There is a drawback. In addition, since the aggregate itself is hard, it is difficult to cut the thick film obtained. In order to make the film easier to cut and to improve the dispersibility of the aggregate, inorganic bones with a bulk specific gravity (apparent specific gravity) of 0.4 or less, such as pearlite, shirasu burlun, foamed glass spheres, and vermiculite, are used as aggregates. An undercoat paint for wood boards was proposed using the following compounding ratio (Japanese Patent Application Laid-Open No. 1983-66937). (a) Aqueous emulsion of thermoplastic or thermosetting resin (b) Cement 25-60% pigment volume concentration (PVC) (c) Mixture of (a) and (b) inorganic aggregate with a bulk specific gravity of 0.4 or less 30 parts per 100 volume parts of paste
~300 parts by volume, with the apparent volume of cement x 25 x 60/100 or more. This coating composition has excellent aggregate dispersibility and forms a homogeneous film. It also has the advantage that the resulting film can be easily cut. However, it is easily broken by stirring of the inorganic aggregate, and destruction reduces its heat insulation and soundproofing effects. In addition, the resulting coating has a high water absorption rate and a large proportion of cement and lightweight aggregate in the coating, resulting in a drawback that the adhesive strength of the coating to base materials such as wood boards and concrete is low. The inventors have determined that the apparent density of the aggregate is 0.015.
When foamed resin particles of ~0.5 were used, the foamed resin particles, which were aggregates, moved upward in the film while the film-forming composition was dried to form a film after being applied to the base material. , the density of the foamed resin particles is extremely low near the surface of the base material, or a film is formed in which the foamed resin particles are not visible at all;
Moreover, they discovered that the small presence of foamed resin particles in the film near the base material surface is a cause of improving the adhesive strength of the film to the base material and the bending strength of the film, and thus arrived at the present invention. . That is, the present invention provides (A) an aqueous resin emulsion with a film-forming temperature of 10°C or less (B) hydraulic senmet (the sum of the solid content of (A) and the volume of (B), with a volume concentration of 10°C or less).
Amount accounting for ~60% (C) Resin foam particles with an apparent specific gravity of 0.015 to 0.5 (A) 100 to 100% of the solid content of the aqueous resin emulsion
600% by volume The present invention provides a resin composition for forming an elastic film, characterized in that the above components (A), (B), and (C) are blended in the above proportions. In the present invention, the film forming temperature (MFT) of component (A)
Examples of aqueous emulsions of resins with a temperature of 10°C or less, preferably 5°C to -40°C include 2-ethylhexyl acrylate (Tg -85°C), n-butyl acrylate (-54°C), and ethyl acrylate (- 22℃), vinylidene chloride (-18℃), isopropyl acrylate (-5℃), 2-ethylhexyl methacrylate (-
5℃), n-propyl acrylate (8℃), n-butyl methacrylate (20℃), vinyl acetate (30℃),
Acrylic acid (87℃), n-propyl methacrylate (Tg81℃), styrene (100℃), acrylonitrile (100℃), methyl methacrylate (105℃), methacrylic acid (130℃), maleic anhydride, itaconic acid Obtained by emulsion polymerization of one or more vinyl monomers selected from (130℃), acrylamide (153℃), ethyl methacrylate (65℃), vinyl chloride (79℃), ethylene, and butadiene. It is an emulsion of a homopolymer or a copolymer, or a mixture thereof. In addition, Tg shown in parentheses is
This is the glass transition point of a homopolymer of these vinyl monomers. The amount of these vinyl monomers is selected so that the resulting resin emulsion has an MFT of 10°C or less. The film forming temperature (MFT), which is the temperature that marks the boundary between continuous film formation, is mainly determined by the glass transition point (Tg), although it varies depending on the particle size, water absorption, surface tension, and drying conditions of the polymer.
Tg is shown as a guideline for MFT. Specific examples are as follows. Styrene (20% by weight)/n-butyl acrylate (80% by weight) copolymer (-35°C), styrene (17% by weight)/n-butyl acrylate (80% by weight)/acrylic acid (3% by weight) ) copolymer (-35℃), n-butyl acrylate (85% by weight)/styrene (12% by weight)/itaconic acid (3% by weight) copolymer, etc. (-
45℃). Note that a material with a high MFT is not preferable because it impairs the flexibility of the film. These aqueous emulsions have a solids concentration of 15~
It is generally prepared to be 65% by weight. Next, the hydraulic cement of component (B) is ordinary Portland cement called boltland cement, white cement, early strength cement, ultra early strength cement, etc., and mixed cement such as blast furnace cement and silica cement. , fly ash cement, etc. can be used, but boltland cement and white cement are generally used. This component (B) cement has a solid content of 10 to 60% of the solid content of the resin aqueous emulsion of component (A) and the volume of component (B).
It is used as a percentage by volume (volume concentration (PVC)). If the amount is less than 10% by volume, the film obtained will be highly adhesive even if it is flexible, which is not preferable. On the other hand, if it exceeds 60% by volume, the flexibility of the film will be significantly impaired.
In addition, when the compounding ratio of resin and cement in the emulsion is expressed as a weight ratio, the solid content of the former is 100 parts by weight, while the latter is 40 to 500 parts by weight. The foamed resin particles of component (C), which is a lightweight aggregate, have an apparent specific gravity of 0.015 to 0.5 and a particle size of 0.3 to 5 mm, preferably 0.5 to 2 mm. in particular,
expanded polystyrene particles, expanded polyethylene particles,
Examples include hydrophobic resin particles such as foamed polypropylene particles, ethylene/vinyl acetate copolymer flakes, and foamed polystyrene/ethylene copolymer.
These are preferably spherical, but may also be crushed foam products. Spherical foam particles are relatively easily available with a narrow particle size distribution. These resin foam particles are 100 to 600% by volume, preferably 160% by volume of the resin aqueous emulsion solid content of component (A).
Used at a rate of ~400% by volume. If the amount is less than 100% by volume, the heat insulation and sound insulation effects of the resulting film will be small and the cuttability will also be poor. On the other hand, if it exceeds 600% by volume, the film becomes brittle. While the film is being formed, the foamed resin particles move upwards in the film because their apparent specific gravity is
In addition to being small at 0.015 to 0.5, this is presumed to be due to the fact that it is hydrophobic compared to inorganic lightweight aggregate, which is hydrophilic. In addition, this hydrophobicity gives a better result to the water absorption rate of the coating film than that of a coating film whose main component is an inorganic lightweight aggregate. In addition to these (A), (B) and (C) components, zinc oxide,
Pigments such as titanium oxide, antifoaming agents, reinforcing fibers, plasticizers, thickeners, etc. may be added. Furthermore, inorganic lightweight aggregates and aggregates such as calcium carbonate, silica sand, talc, clay, mica, diatomaceous earth, kaolin, and aluminum hydroxide may be blended within a range that does not impair the purpose of the present invention. These inorganic aggregates usually account for 0 to 300%, preferably 50 to 200%, of the weight of the cement. The composition of the present invention may be prepared by simultaneously mixing and stirring components (A), (B), and (C), or by mixing resin foam particles in cement slurry in advance and stirring. This mixture may be blended into the aqueous resin emulsion of component (A) and stirred. The composition of the present invention is applied as a covering material onto a base material such as metal, concrete, wood, etc. and, when dried, provides a film that is highly waterproof, flexible, sound insulating, heat insulating, and cuttable. In addition, a thick film is applied on a metal plate whose surface is coated with polyfluoroethylene resin, and a thickness of 1
The sheets obtained by peeling ~20mm sheets from metal plates can be used as soundproofing sheets and heat insulating sheets at construction sites or as indoor paving materials. Additionally, the compositions of the present invention can be used as carpet backing materials. Hereinafter, the present invention will be explained in more detail with reference to Examples. Example 1 (A) n-butyl acrylate (80%)/styrene (20%) copolymer resin aqueous emulsion “ABE”
−SM” (solids concentration 50% by weight, MFT0℃
(below) 200 parts by weight (B) 100 parts by weight of ordinary Portland cement manufactured by Mitsubishi Mining Cement Co., Ltd. (specific gravity approximately 3.7) (C) Spherical polystyrene foam particles with a particle size of 0.5 to 0.8 mm [apparent specific gravity 0.21, oil-based bardate cement] Special grade IBE (product name) foam product from Co., Ltd.
42 parts by weight The aqueous resin coating composition having the above composition was applied onto a Teflon resin-coated steel plate using a bar coater, left at 20° C. for 96 hours to remove moisture, and dried to form a film. Next, the film was peeled off from the Teflon resin coated steel plate to obtain a film having a wall thickness of approximately 7 mm and a specific gravity of 0.77. The tensile elasticity (JISA-6021) of this product is 57Kg/
^cm2 , and the tensile elongation (JISA-6021) was 230%. Further, in the cross section of this sheet, as shown in FIG. 1, there were no or only a few foam particles present in the approximately 1 mm thick portion of the film facing the steel plate side. Examples 2 to 5, Comparative Examples 1 to 3 The aqueous resin coating composition shown in Table 1 was applied onto a slate board to a thickness of 2 mm (after drying), and
A film was obtained by standing at ℃ for 48 hours. A sheet-like film was also obtained according to "Example 1". The performance of this film was measured by the following method, and the results are shown in the same table. In addition, the resin aqueous emulsion is
The thickener was adjusted to about 10,000 cps using the thickener Latecol D (trade name, manufactured by Yuka Verdice Co., Ltd.), and the flow value of the composition was adjusted to about 300 mm with water. 1) Non-adhesiveness of the film surface: If it is sticky to the touch with your finger, it is bad (×), if it is not sticky, it is good (〇)
And so. 2) Elasticity: 100 times of 180-degree bending test of the sheet-like film, and if there is no abnormality in the state of the film returned after the test, it is evaluated as good (〇), abnormal (damage,
Those with occurrence of cracks were marked as defective (x). 3) Adhesive strength to slate board: JISA-6910
It was measured using the method. 4) Heat insulation coefficient: Measured by the method of JISA-1412. 5) Water absorption rate: After curing at 20° C.-60% RH for 7 days, a sheet with a thickness of about 2 mm was punched out to a length of 50 mm and a width of 50 mm, and this was used as a test specimen. This was heated to 48℃ at 20℃.
The rate of change in weight when immersed in water for a period of time was defined as the water absorption rate. 6) Water permeability: Measured according to the method of JISA-1404. The test specimens were prepared by applying polymer mortar paste of each composition to a thickness of about 2 mm on the test specimen used in JISA-1404, and curing at 20° C. and 60% RH for 7 days. The measurement conditions were 1 kg pressure/1 hour in accordance with the polymer cement standard.

【table】

【table】 [Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view of an elastic sheet obtained according to Example 1 of the present invention.

Claims (1)

[Claims] 1 (A) Aqueous resin emulsion with a film-forming temperature of 10°C or less (B) Hydraulic Cenmeth (A) The sum of the solid content of (A) and the volume of (B), with a volume concentration of 10
Amount accounting for ~60% (C) Resin foam particles with an apparent specific gravity of 0.015 to 0.5 (A) 100 to 100% of the solid content of the aqueous resin emulsion
600% by volume A resin composition for forming an elastic film, characterized in that the above components (A), (B) and (C) are blended in the above proportions.