JPS6273944A - Waterproof structure - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a waterproof structure comprising a polyurethane resin waterproof material layer having a protective layer with excellent weather resistance.

[Prior Art] Hitherto, coating film waterproofing has been widely used as a method for waterproofing layers of buildings such as roofs and outer walls.

A waterproof structure obtained by coating waterproofing is usually a multilayer structure. For example, on the surface of a substrate such as concrete or mortar, there is first a thin layer of primer, then an undercoat layer, then an overcoat layer, and in some cases a protective layer, also called a finishing layer, on the overcoat layer. There are layers. The first layer of primer is 1. L has the function of adhesion between the substrate and the waterproof layer -H, the F coating layer mainly functions as a buffer layer to prevent destruction of the waterproof layer due to the small size of the substrate, etc., and -L- The coating layer mainly serves the waterproof function. The base coat layer may be reinforced with U & male receipt etc. There may also be an intermediate layer, particularly a layer of insulation material such as a 7 ohm sheet between the substrate and the undercoat layer.

As mentioned above, the waterproof material layer is -L, and consists of an L coating layer and an undercoat layer, and is made of a highly elastic synthetic resin. For example, acrylic resins made of polymers of acrylic acid esters and methacrylic acid esters, synthetic resins such as chloroprene rubber, and polyurethane resins are often used, with polyurethane resins containing or not containing ethanol being the most widely used. It is being

These synthetic resins usually have insufficient weather resistance, and deteriorate in a short period of time, resulting in a decrease in waterproof performance. Therefore, a protective layer with high weather resistance is often provided on the surface of these synthetic resin layers.

Alkyd paints and acrylic urethane paints are often used as materials for the protective layer. ! .

However, these materials also usually undergo 4-J-king after 1 to 3 years, and therefore it becomes necessary to scrape off the protective layer and reinstall a new protective layer every 1 to 3 years. In particular, waterproof materials made of polyurethane resin tend to have weather resistance problems, and for polyurethane resin waterproof materials that can be attached outside d, it is almost essential to provide a protective layer.

On the other hand, it is often a problem that the elasticity of the protective layer tends to decrease at low temperatures. Particularly in cold regions, the waterproof layer is easily damaged during the winter, and one of the reasons for this is that the elasticity of the protective layer decreases, making it more likely to cause cracks and scratches due to external stress. Therefore, the protective layer
Along with weather resistance, retention of elasticity at low temperatures is also required.

[Problems to be Solved by the Invention] In order to improve the weather resistance of the protective layer, it is necessary to develop a coating material with high weather resistance. So-called fluororesin paints are known as paints with high weather resistance, but ordinary fluororesin paints have low elasticity and are not suitable as materials for forming protective layers that require high elasticity. Conventional acrylic urethane resins, which have relatively good weather resistance, are insufficient as protective layer forming materials having high elasticity.

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems, and relates to a waterproof structure using a highly elastic fluorine-containing polyurethane resin paint as a material for the protective layer. This invention is as follows.

It consists of a waterproof layer provided on a substrate and having a polyurethane resin surface, and a fluorine-containing polyurethane resin protective layer that protects the polyurethane resin surface, and the fluorine-containing polyurethane resin of the protective layer has a hydroxyl value of about 160 F or more. fluoroolefin copolymer polyol, hydroxyl value approximately 20
It is a fluorine-free polyurethane resin obtained by reacting a high molecular weight polyol with a molecular weight of 0 or less and a polyincyanate compound! Waterproof structure with T5 characteristics.

The waterproof structure in the present invention has a waterproof material layer made of various highly elastic synthetic resin materials as an essential component as described in +iii, but it may also have a fiber sheet, a heat insulating material layer, etc. good. The synthetic resin material may contain tar, carbon black, colorants, fillers, ultraviolet absorbers, light stabilizers, flame retardants, plasticizers, and other additive components. Further, the waterproof material layer may have a single layer structure or a multilayer structure, and in the latter case, the materials of each layer may be different. In addition, as waterproof materials, curable liquid synthetic resin materials,
It is preferable to use a so-called coating film waterproofing material, which is formed by applying a synthetic resin emulsion, solution, or other liquid material, but it is not limited to this. It may be a so-called sheet waterproof material formed by pasting a film.

In the present invention, the surface of the waterproof material layer is made of polyurethane resin. That is, the outermost layer of the waterproof material layer must be made of polyurethane resin. Compared to surfaces made of other synthetic resins, the polyurethane resin surface has good compatibility with fluorine-containing polyurethane resins, and is relatively compatible with fluorine-containing polyurethane resins that can be cured at room temperature or at relatively low temperatures. Another advantage is that it can be applied to polyurethane resins with low heat resistance. Preferably, all of the synthetic resin material of the waterproof material layer including the inner layer (for example, 2 above J-,
Both the coating layer and the undercoat layer are preferably made of polyurethane resin.

G. The protective layer that protects the surface of the waterproofing material layer is made of a fluorine-containing polyurethane resin obtained by reacting a polyol having a fluorine atom, a polyol not having a fluorine atom, and a polyisocyanate compound. Two or more of these polyols and polyisocyanate compounds can be used in combination, and other reactive raw material components can also be used if necessary. Furthermore, stabilizers such as ultraviolet absorbers, light stabilizers, and antioxidants, colorants, viscosity modifiers, leveling agents, and other auxiliary raw materials can also be blended with the fluorine-containing polyurethane resin. In addition, these raw material components are
It is usually used as a coating composition dissolved or dispersed in a solvent, and this coating composition is applied to the surface of the waterproofing agent layer and dried and hardened to form a protective layer.

A fluoroolefin copolymer polyol, which is one of the essential raw material components, is a polyol containing a fluorine raw material and is an important factor for improving weather resistance. Several types of polyols with different hydroxyl values are known as this polyol, but in order to obtain a fluorine-containing polyurethane resin with high elasticity, it is necessary to have a hydroxyl group with a hydroxyl value of about 160 or less and a relatively high molecular weight. Must be a polyol. In particular, the hydroxyl value is about 30 to 120, and even about 40.
-80 polyols are preferred. Further, this fluoroolefin copolymer polyol must be soluble in a solvent. Otherwise, a good coating composition cannot be obtained.

The fluoroolefin copolymer polyols that can be dissolved in the above-mentioned solvents are basically known polyols. This polyol has a basic structure of a copolymer of a fluoroolefin such as tetrafluoroethylene or trifluorochloroethylene and a vinyl ether monomer, and by using a hydroxyl group-containing vinyl ether monomer as part or all of the vinyl ether monomer, hydroxyl groups are added to the copolymer. be introduced. The ratio of fluoroolefin units and vinyl ether monomer units in the fluoroolefin copolymer is about 40 to 60 mol% for the former and about 60 to 40 for the latter.
Preferably it is mol%. Copolymers outside this ratio range and copolymers with a large ratio of units of the third type of monomer other than both types of monomers have low solvent solubility. Further, in the present invention, in order to lower the hydroxyl value, it is usually necessary to use a vinyl ether monomer having no hydroxyl group in combination with a vinyl ether monomer containing a hydroxyl group.

As the hydroxyl group-containing vinyl ether monomer, hydroxyalkyl vinyl ethers and hydroxycycloalkyl vinyl ethers are preferable, and vinyl ethers having a vitroalkyl group having about 6 or less carbon atoms are particularly preferable. Specifically, for example, 3-hydroxypropyl vinyl ether.

Examples include 4-hydroxybutyl vinyl ether and 4-hydroxy-2-methylbutyl vinyl ether. As the vinyl ether monomer having no hydroxyl group, vinyl ethers having an alkyl group or cycloalkyl group having 8 or less carbon atoms are preferred, such as ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, and cyclohexyl vinyl ether. Furthermore, fluorine-containing alkyl vinyl ethers such as 2,2,3,3-tetrafluorobrobyl vinyl ether and other vinyl ether monomers can also be used. The intrinsic viscosity of the fluoroolefin copolymer-based polyol (measured in tetrahydrofuran at 30° C.) is about 0.05 to 2.0 dl/g, especially 0.05 to 0.0 dl/g.
7 dl/g is preferred. If the intrinsic viscosity is too low, the mechanical strength of the polyurethane-based polyurethane resin will decrease, and if the intrinsic viscosity is too high, it may cause difficulties in construction.

The second polyol, a high molecular weight polyol with a hydroxyl value of about 200 or less, is necessary to increase the elasticity of the fluorine-containing polyurethane resin and maintain its elasticity at low temperatures. Too high a hydroxyl value causes a decrease in elasticity. On the other hand, if the hydroxyl value is too low, the viscosity of the paint composition will increase,
The lower limit of the water base value is preferably about 30, since this may cause difficulties in construction. More preferably,
A polyol having a hydroxyl value of about 40 to 160 is employed, and a polyol having a hydroxyl value of about 60 to 140 is particularly preferred. The average number of hydroxyl groups per molecule of this polyol is suitably about 2 to 8, but if it is too high, the elasticity tends to decrease, so it is preferably about 2 to 4. In particular, polyols mainly composed of about 2 to 2,4 diols are preferred. This polyol is a polyether polyol.

Polyester polyols, hydrocarbon copolymer polyols (for example, polybutadiene polyols), acrylic polyols (for example, copolymers of acrylates or methacrylates having hydroxyalkyl groups and other acrylates or methacrylates), polycarbonate polyols, and the like can be used.

Specifically, polyether polyols obtained by adding ethylene oxide, propylene oxide, butylene oxide, and other alkylene oxides to polyfunctional initiators such as polyhydric alcohols, polyhydric phenols, alkanolamines, and polyamines; Polyether polyols made of ring polymers and polyoxytetramethylene polyols such as ring-opened combinations of tetrahydrofuran and alkylene oxide, polybutadiene polyols made of butadiene and copolymers of it with acrylonitrile, styrene, etc., hydroxyethyl acrylate, etc. Acrylic polyols consisting of copolymers of hydroxyalkyl (meth)acrylate and alkyl (meth)acrylate, polyester polyols such as polyethylene adipate diol and polybutylene adipate diol, poly(l,6-hexylene carbonate) ) There are polycarbonate polyols such as diols. Particularly preferred high molecular weight polyols are polyether polyols, and polyether diols are particularly preferred. More preferred are polyoxypropylene diols or polyoxytetramethylene diols containing a high proportion of oxypropylene groups or oxytetramethylene groups (approximately 70% by weight or more).

If the amount of the high molecular weight polyol used is too large, the weather resistance will be reduced, and if it is too small, the elasticity will be reduced. Therefore,
The amount thereof is about 5 to 50 parts by weight, particularly about 8 to 50 parts by weight, based on 100 parts by weight of the fluoroolefin copolymer-based polymer.
30 parts by weight is preferred.

As the polyisocyanate compound that reacts with the polyols to form a polyurethane resin, a compound having two or more incyanates 5 or a modified product thereof can be used. Examples of the polyisocyanate compound include aliphatic, alicyclic, and aromatic polyinsyanate compounds.

Aromatic polyisocyanate compounds having an incyanate group directly bonded to an aromatic nucleus are called modified polyisocyanates, and it is known that polyurethane resins obtained using the same are susceptible to yellowing. Since the fluorine-containing polyurethane resin used in the present invention is required to have weather resistance, the polyincyanate compound is preferably a polyincyanate other than yellowing polyisocyanate (non-yellowing polyisocyanate) or a modified product thereof. Examples of non-podally modified polyisocyanates include hexamethylene diisocyanate, octamethylene diisocyanate, lysine diisocyanate, other aliphatic polyisocyanates, inphorone diisocyanate, methylene bis(cyclohexyl isocyanate), bis(isocyanate methyl) cyclohexane, and other alicyclic polyisocyanates. isocyanate and xylylene diisocyanate.

Examples include α, α, α', α'-tetramethylxylylene diisocyanate, and other non-yellowing aromatic polyinsyanates. Furthermore, polymers and copolymers of vinyl monomers having an incyanate group such as 2-incyanate ethyl methacrylate can also be used. The polyisocyanate compound may be a modified product of these polyisocyanates, such as a prepolymer type modified product modified with a polyhydric alcohol such as trimethylolpropane, a carbodiimide modified product, a urea modified product, a biuret modified product, a trimerized ( There are modified products such as isocyanurate modified products and dimerized modified products.

The amount of the polyisocyanate compound to be used is 1 equivalent in total of the two types of polyols, or 1 equivalent in total of the two types of polyols and a raw material component that can be used optionally such as the chain extender described below.
about 0.4 to 1.2 equivalents per equivalent. If the equivalence ratio is more than this, there is a risk that elasticity and surface performance will be lowered, and if it is less than this, there is a risk that mechanical strength will be low. A more preferred equivalent ratio is about 0.7-1
．． It is 0 duty welfare.

The fluorine-containing polyurethane resin is formed by mixing the above two polyols and a polyisocyanate compound, or by producing a prepolymer or quasi-prepolymer, adding a chain-preventing agent or a crosslinking agent thereto, and curing the mixture through a reaction. be done. As the chain extender and crosslinking agent, low molecular ψ polyols and polyamines are suitable. These can also be used together with the two polyols mentioned above. However, these low molecular weight compounds often reduce the elasticity of the fluorine-containing polyurethane resin and are not normally used. Then, a coating composition obtained by adding a polyisocyanate compound to this is applied to the surface of the waterproof material layer, and is dried and cured at room temperature or at low temperature (preferably about 60°C or less) to form a protective layer. . The thickness of this protective layer is suitably about 10° or more; if it is thinner than this, it will be difficult for the protective layer to fully exhibit its function. Furthermore, if the thickness is too large, the elasticity of the protective layer is likely to be insufficient. The thickness of the protective layer is preferably about 20-200μ.

The waterproof structure of the present invention has excellent properties as a waterproof structure for a base made of an inorganic material such as concrete, mortar, or metal, particularly for a base exposed outdoors such as a roof or an outer wall. However, the application is not limited to this, and can be used as a waterproof structure constructed especially on the outdoor surface of a building or structure. Furthermore, the base material is not limited to inorganic materials, and may be organic materials such as wood materials and bunsnack materials.

EXAMPLES The present invention will be specifically explained below using Examples, but the present invention is not limited to these Examples.

(Example) A coating composition was manufactured using the following raw materials.

Coating composition fluoroolefin copolymer 100 i♀:81! −
10 parts by weight of high molecular weight polyol (PTMG
or PPG)” Xylene IEi 5 parts by weight Toluene 165 parts by weight Colorant
58 parts by weight modified polyisocyanate 22.5 parts by weight water fluoroolefin copolymer polyol Copolymer of nitrifluorochloroethylene, ethyl vinyl ether, and 4-hydroxybutyl vinyl ether (mol% of each unit is 50.40.10 in order) It has a hydroxyl value of 57 and an intrinsic viscosity of 0.21 dl/g.

$tPTNG: polyoxytetramethylene diol with a hydroxyl value of O ppc: polyoxybrobylene diol with a hydroxyl value of 110 modified polyisocyanate ditrimerized modified hexamethylene diincyane) (contains NGO 21.3% by weight) ) About 250 g/a29 of a commercially available polyurethane brimer was applied to the concrete substrate-L on the roof of the building, and after drying and curing, a commercially available glass cloth was fixed with an adhesive. Next, apply 2.5 kg of commercially available polyurethane waterproofing material for undercoating.
g/m2 was applied and cured, and then a commercially available polyurethane waterproofing material for HI was applied at 2.5 kg/m2 and cured. After 24 hours, add 250 g of the above coating composition.
/m2 by roll coating and curing.

In order to evaluate the physical properties of the waterproof structure, the following tests were conducted. 400 g of the base material and 400 g of the curing agent for the polyurethane waterproof material for top coating were accurately weighed into a 1Q container, and stirred slowly for 5 minutes using a metal spatula to avoid entraining bubbles. 600 g of this mixture was cast onto a 50 cm square glass plate coated with a mold release agent, and smoothed with a rubber spatula to form a layer with a thickness of 2 mm. After leaving it at room temperature for 24 hours, apply a low lambda recorder to a thickness of 40 g with 1 ml of paint.
・It was coated with a method and cured for 10 minutes at 20°C and 60g of humidity. After that, see from the glass plate! (I 12
, the following evaluation tests were conducted. In the coating composition,
An example using a composition containing PTNG is referred to as Test Example 1,
Test Example 2 is an example in which a composition containing PPG was used. In addition, a sheet was prepared by the above method using the same coating composition except that no high molecular weight polyol was blended and the amount of modified polyisocyanate was 25% by weight. Comparative example 1
shall be.

Further, a sheet was prepared by the above method using a commercially available acrylic urethane paint for top coat of waterproof materials instead of the paint composition. This example is Comparative Example 2. Four types of 6L sheets were used to measure the elongation at break at 20° C. and -20° C. using a Tensilon testing device (tensile speed 500 mm/min). On the other hand, an accelerated weathering test was conducted on the coated surface using a Sunshine Weatherometer. After 3000 poems, the elongation at break was similarly measured at 20°C. The results of each test are shown in Table 1 below. Furthermore, in an accelerated weathering test, the gloss retention rate of the coated surface was measured after 500 hours, 1500 hours, and 300 hours. The results of each test are listed below.
Shown in the table. In Comparative Example 2, chalking had already occurred after 500 hours.

Table 1 [Effects of the Invention] The material for the protective layer of the present invention not only has extremely high weather resistance, but also has high elasticity even at low temperatures, and has a superior surface protection function for waterproof materials than conventional materials. It also has extremely excellent properties.

Claims (1)

[Claims] 1. Consisting of a waterproof layer provided on a substrate and having a polyurethane resin surface, and a fluorine-containing polyurethane resin protective layer that protects the polyurethane resin surface, the fluorine-containing polyurethane resin of the protective layer is a fluorine-containing polyurethane resin obtained by reacting a fluoroolefin copolymer polyol with a hydroxyl value of about 160 or less, a high molecular weight polyol with a hydroxyl value of about 200 or less, and a polyisocyanate compound. 2. The waterproof structure according to claim 1, wherein the protective layer has a thickness of about 20 to 200 μm. 3. The fluoroolefin copolymer polyol is a copolymer of at least three monomers: a fluoroolefin consisting of tetrafluoroethylene or trifluorochloroethylene, a hydroxyl group-containing vinyl ether monomer, and a vinyl ether monomer having no hydroxyl group. Waterproof structures in scope 1.