JPS6235414B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a primer for acrylic modified urethane sealants. In recent years, technological advances and diversification of needs in the construction industry have been remarkable, and the Japanese Industrial Standard JIS A5758-1979 regarding architectural sealants has been revised, and five types of durability classes are defined: 9030, 8020, 7020, 7010, and 7005. , as well as polyurethane sealants.
It is now possible to apply 9030 as a durable sealant. However, conventional polyurethane sealants have poor heat resistance, and in reality, acrylic-modified polyurethane sealants are the most JIS
It can be said that it meets the durability classification of A5758-1979. Although the acrylic modified urethane sealant has various advantages and is therefore in practical use, the present inventor believes that, although the acrylic modified urethane sealant has various advantages and is therefore in practical use, the primer used when applying the sealant is of the same quality as the sealant. The present invention was developed based on the realization that acrylic-modified urethane resins are being used in a conventional manner, and are not necessarily used in a way that immediately meets the needs of customers. In other words, it is generally considered appropriate to use a primer for sealants that is similar to the sealant, taking into consideration its adhesion to the sealant.
When it is decided to mix urethane resin as a primer, the target material can be used within a limited range of conditions that do not expose the general drawbacks of urethane resins, such as poor heat resistance and susceptibility to photodeterioration. Good conditions must be set for each material to be sealed, and a high degree of skill is required.
From this point of view, the present inventor sought to provide a sealant primer that is fully applicable to acrylic modified urethane sealants without incorporating a urethane resin.

A methacrylate compound represented by [Formula] (wherein R ¹ means an alkyl group having 1 to 4 carbon atoms), ha styrene or the general formula

[Formula] (In the formula, n is an integer from 1 to 3 indicating the number of methyl groups substituted on the benzene nucleus.) A styrene derivative represented by the following general formula:

[Formula] [In the formula, R ² is H or a methyl group, X is COOH,

【formula】

[Formula] (m is an integer of 2 to 4) or CO-Y {Y is NH ₂ , NHCH ₂ OR ³ (R ³ is H or an alkyl group having 1 to 4 carbon atoms) or (CH ₂ ) _l -N
(R ⁴ ) ₂ (l is an integer of 1 to 4, R ⁴ is an alkyl group having 1 to 4 carbon atoms)}. 70% by weight of the compound represented by ] and phototriallylisocyanuric acid.
A primer for an acrylic modified urethane sealant whose main component is a copolymer obtained by copolymerization from a monomer mixture containing the above, and (a) acrylonitrile or methacrylonitrile (b) General formula

A methacrylate compound represented by [Formula] (wherein R ¹ means an alkyl group having 1 to 4 carbon atoms), ha styrene or the general formula

[Formula] (In the formula, n is an integer from 1 to 3 indicating the number of methyl groups substituted on the benzene nucleus.) A styrene derivative represented by the following general formula:

[Formula] [In the formula, R ² is H or methyl group, X is COOH,

【formula】

[Formula] (m is an integer of 2 to 4) or CO-Y {Y is NH ₂ , NHCH ₂ OR ³ (R ³ is H or an alkyl group having 1 to 4 carbon atoms) or (CH ₂ ) _l -N
(R ⁴ ) ₂ (l is an integer of 1 to 4, R ⁴ is an alkyl group having 1 to 4 carbon atoms)}. ], phototriallylisocyanuric acid, and the general formula

[Formula] [In the formula, Z is (CH ₂ ) _p or

[Formula] (p is an integer of 1 to 4, q is an integer of 1 to 10), R ⁵ is H or a methyl group, and R ⁶ is an alkyl group having 1 to 10 carbon atoms. ] A primer for an acrylic modified urethane sealant is provided, the main component being a copolymer obtained by copolymerizing a monomer mixture containing 70% by weight or more of a silane compound represented by the following. Here, the second compound is more specifically acrylic acid, methacrylic acid, derivatives thereof such as hydroxymethyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate,
Hydroxyalkyl acrylate or hydroxyalkyl methacrylate such as hydroxymethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, derivatives thereof Yes, N-methoxymethylacrylamide, N-ethoxymethylacrylamide, N-propoxymethylacrylamide, N
-N-alkoxymethylacrylamide or N-alkoxymethylmethacrylamide such as butoxymethylacrylamide, N-methoxymethylmethacrylamide, N-ethoxymethylmethacrylamide, N-propoxymethylmethacrylamide, N-butoxymethylmethacrylamide, and glycidyl acrylate , glycidyl methacrylate, etc. Among these, 2-hydroxyethyl methacrylate in particular showed good results in the water resistance test described below. In addition, specific examples of the silane compounds include γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-acryloxypropyltripropoxysilane, γ-acryloxypropyltributoxysilane, γ-methacryloxypropyltrismethoxyethoxysilane, γ-methacryloxypropyltrisethoxyethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropyltributylsilane, δ-methacryloxy Examples include butyltrimethoxysilane, trimethoxyvinylsilane, triethoxyvinylsilane, and the like. When mixing the compounds corresponding to a), b), c), d), e), and f) to form a monomer mixture, ), select one or more compounds corresponding to (a) component, b)
component, c) component, d) component, e) component, and f) component), according to the following mixing ratio. In other words, the mixing ratio of each component cannot be determined unconditionally because it depends on the type of acrylic modified sealant to which the target primer is applied, but in general, Similarly, component (b) should account for 20-70% by weight, preferably 40-60% by weight of the total monomers.
c) component is 2 to 30% by weight, preferably 5 to 20% by weight, and d) component is 3 to 40% by weight, preferably 5 to 20% by weight.
Mix together so that they each account for 30% by weight. In addition, the amount of component e) does not exceed 100 parts by weight per 100 parts by weight of the total amount of components a) to d);
Preferably, an amount of 50 parts by weight or less is added, and similarly when adding component f), an amount not exceeding 100 parts by weight, preferably 50 parts by weight, based on 100 parts by weight of the total amount of components a) to d). Add the following amount. b) If the amount of the component is too small, the heat resistance, hot water resistance, and oil resistance will be insufficient, and if the amount is too large, the weather resistance and normal state adhesion will be insufficient. Furthermore, if the amount of component (b) is too small or too large, the normal adhesiveness will be insufficient. Furthermore, if the amount of the component is too low, the heat resistance and boiling water resistance will be insufficient; if the component is too high, the oil resistance and normal adhesion will be insufficient; and if the component is too low, the adhesion with the sealant will be poor. Hot water resistance becomes insufficient. Addition of component e) and component f) is effective in improving the adhesion and hot water resistance of the target product, but if the amount of the former component e) is too large, gelation may occur during copolymer synthesis. In addition, the solution viscosity of the copolymer increases, resulting in a decrease in workability and also in the normal state adhesion of the target product. On the other hand, if the amount of the latter component (f) is too large, the affinity for the target sealant will decrease and the adhesiveness will also tend to decrease. Monomers other than components a) to f) should not be added if possible, but include alkylene compounds such as ethylene, propylene, butene, butadiene, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, octyl acrylate, stearyl acrylate, lauryl Acrylic acid esters such as acrylate, long chain alkyl methacrylates such as 2-ethylhexyl methacrylate, lauryl methacrylate, and stearyl methacrylate, vinyl compounds such as vinyl acetate, vinyl propionate, and vinyl chloride, maleic acid, fumaric acid, and itaconic acid. Unsaturated carboxylic acids such as esters and esters thereof are permissible as long as they do not exceed 30% by weight of the total monomers. In preparing the sealant primer of the present invention, the monomers mixed as described above are first subjected to bulk polymerization, solution polymerization, or gas phase polymerization in the presence of heat, light, electron beams, or a catalyst such as a peroxide. Alternatively, a copolymer may be obtained by emulsion polymerization, and then this copolymer may be dissolved in an appropriate organic solvent to form a solution with an appropriate viscosity. Solution polymerization is most advantageous for polymerizing the above monomers, and the organic solvent used during polymerization can remain in the final product without being removed. For solution polymerization, for example, benzoyl peroxide, t-butyl peroxide, lauroyl peroxide, methyl ethyl ketone peroxide,
A commonly used polymerization initiator such as cumene peroxide, dicumene peroxide, dicumene hydroperoxide, azobisisobutyronitrile, etc. may be used in a proportion of 0.05 to 5 parts by weight per 100 parts by weight of the monomer. In this case, a chain transfer agent such as butyl mercaptan, dodecyl mercaptan, trichloroacetic acid, or tetrawarmed carbon is added to the monomer.
It can be used in a proportion of 0.05 to 10 parts by weight per 100 parts by weight. The solvent used in solution polymerization may be any solvent as long as it dissolves the copolymer, but alcohols, amines, and the like containing active hydrogen should preferably be avoided. The thus obtained copolymer was heated in DMF at 30°C.
Intrinsic viscosity in solution [η] is 0.07 to 0.50 dl/
g, especially those exhibiting 0.1 to 0.3 dl/g are good; the smaller the intrinsic viscosity, the lower the adhesiveness and heat resistance; conversely, if it becomes too large, the adhesiveness will decrease and the workability will also decrease. Deteriorate. Finally, the sealant primer of the present invention is
The copolymer is provided by dissolving it in an appropriate solvent so that the solution viscosity in the environment of use is 200 cps or less, preferably 100 cps or less. In this case, the solvent may be the same as the solvent for solution polymerization. You can use . The sealant primer can also contain commonly used additives such as colorants, viscosity modifiers, and storage stability improvers. As is clear from the above, the present invention provides a primer that can be applied to acrylic modified urethane sealants without incorporating urethane resin, and the present invention is aimed at cement mortar, where adhesion is most likely to be a problem. Even in this case, as shown in the Examples and Test Examples described later, it exhibits good performance within a relatively wide composition range. Hereinafter, the present invention will be explained in more detail with reference to Examples, Test Examples, etc. Example 1 20 parts of acrylonitrile, 45 parts of butyl methacrylate, 10 parts of styrene, 25 parts of 2-hydroxyethyl methacrylate, triallylisocyanuric acid
10 parts of toluene, 80 parts of toluene, and 30 parts of acetone were uniformly mixed, 3 parts of azobisisobutyronitrile was added thereto, and the mixture was heated under stirring and reflux for 16 hours while maintaining the liquid temperature at 85°C, until it became non-volatile. A colorless and transparent copolymer solution with a concentration of 49.9% was obtained. This copolymer was precipitated with petroleum benzine, diluted with a small amount of acetone, precipitated again with petroleum benzine, separated and dried under reduced pressure at room temperature, and the intrinsic viscosity at 30°C was determined using dimethylformamide. ,0.243
It was hot. Next, toluene was further added to the toluene/acetone solution of the copolymer synthesized as described above to make a 30% solution, and a primer for an acrylic-modified urethane sealant was prepared. Example 2 25 parts of acrylonitrile, 50 parts of butyl methacrylate, 10 parts of styrene, 15 parts of 2-hydroxyethyl methacrylate, triallylisocyanuric acid
25 parts, 20 parts of γ-methacryloxypropyltrimethoxysilane, 100 parts of toluene, and 45 parts of acetone.
3.5 parts of azobisisobutyronitrile was added to this, and the temperature of the solution was brought to reflux while stirring.
Heated for 18 hours while maintaining at 80℃, non-volatile content 48.5%
A colorless and transparent copolymerization solution was obtained. This copolymer was precipitated with petroleum benzine, diluted with a small amount of acetone, precipitated again with petroleum benzine, the separated product was dried under reduced pressure at room temperature, and the intrinsic viscosity at 30°C was determined using dimethylformamide. It was 0.261. Next, toluene was added to the toluene and acetone solution of the copolymer synthesized as above to give a 30%
The solution was used as a primer for acrylic modified urethane sealant. Examples 3 to 11, Comparative Examples 1 to 6 Example 1 except that the type and amount of monomers were changed.
and 2, the primer of the present invention (30% copolymer solution) and the comparative primer (30%
A copolymer solution) was obtained. The types and amounts of monomers and the intrinsic viscosity [η] of the produced copolymers in these Examples are shown in Table 1 together with those of Examples 1 and 2.

【table】

[Table] Test Examples The following tests were conducted using the sealant primers obtained in the Examples and Comparative Examples. The results were as shown in Table 2. <Adhesion test> 50mm prepared in accordance with JIS A5758 Section 5.12.2
Apply the primer composition to each side of two cement mortar blocks measuring 50 mm x 25 mm, leave it for 30 minutes at room temperature, and then apply the top layer to the center using a spacer in accordance with JIS A5758, Section 5.12.3. Sealer
Au (manufactured by Yamauchi Rubber Industries Co., Ltd., product name, acrylic modified sealing material) is extruded and 50mm x 12mm x 12
A tensile adhesion test piece was prepared by adhering to the cement mortar in the form of a column of mm and hardening it, and curing it at room temperature for 7 days and then at 50°C for 7 days. Using three test pieces obtained in this way, the collective failure rate and tensile adhesive strength were measured using a tensile tester. <Hot Water Resistance Test> Three test pieces prepared in the same manner as in the adhesion test were immersed in warm water at 50°C for 2 days, and then a tensile test was conducted in the same manner as in the adhesion test. <Heat resistance test> Using three test pieces prepared in the same way as the adhesion test,
In accordance with JIS A5758 Section 5.12.3, at 80℃ or 90℃
After heating for 14 days, a tensile test similar to the adhesion test was conducted. <Durability test> Using three test pieces prepared in the same way as the adhesion test,
A durability test (durability classification 8020 and 9030) was conducted in accordance with JIS A5758 Section 5.12.3.

[Table] In Table 2, CF is a simultaneous failure (failure at the sealant part), TL is a thin layer failure (failure at the boundary between the sealant and primer), and AF is an interfacial failure (between the primer and the target material). CF,
The numbers after TL and AF mean the area ratio.

Claims (1)

[Scope of Claims] 1) acrylonitrile or methacrylonitrile, b) a methacrylate compound represented by the general formula [formula] (wherein R ¹ means an alkyl group having 1 to 4 carbon atoms), c styrene or A styrene derivative represented by the formula [formula] (wherein n is an integer from 1 to 3 indicating the number of methyl groups substituted on the benzene nucleus), D General formula [formula] [in the formula R ^{2 is} H or _{a methyl} group ^, alkyl group) or (CH ₂ ) _l -N
(R ⁴ ) ₂ (l is an integer of 1 to 4, R ⁴ is an alkyl group having 1 to 4 carbon atoms)}. ] A compound represented by
A monomer mixture containing 70% by weight or more of triallylisocyanuric acid and phototriallylisocyanuric acid, in which the proportions of the components (a), (b), (c), and (d) in the total monomers are in order, respectively. , 10-40
Weight%, 20-70% by weight, 2-30% by weight, 3-40
The main component is a copolymer obtained by copolymerizing a monomer mixture in the range of % by weight and in which the weight of the component e) does not exceed the total weight of the components a) to d). Primer for acrylic modified urethane sealant. 2 a acrylonitrile or methacrylonitrile, b methacrylate compound represented by the general formula [formula] (in which R ¹ means an alkyl group having 1 to 4 carbon atoms), ha styrene or the general formula [formula] (formula n is an integer from 1 to ³ indicating the number of methyl groups substituted on the benzene nucleus. X is COOH [Formula] [Formula] (m is an integer of 2 to 4) or CO-Y {Y is NH ₂ , NHCH ₂ OR ³ (R ³ is H or an alkyl group having 1 to 4 carbon atoms) or (CH ₂ ) _l -N
(R ⁴ ) ₂ (l is an integer of 1 to 4, R ⁴ is an alkyl group having 1 to 4 carbon atoms)}. ] A compound represented by the general formula [Formula] [wherein Z is (CH ₂ ) _p or [Formula] (p is an integer of 1 to 4, q is an integer of 1 to 10), integer), R ⁵ is H or a methyl group,
R ⁶ each represents an alkyl group having 1 to 10 carbon atoms. A monomer mixture containing 70% by weight or more of a silane compound represented by ], in which the proportions of the component (a), component (b), component (c), and component (d) in the total monomers are, respectively, in order:
10-40% by weight, 20-70% by weight, 2-30% by weight, 3
~40% by weight, containing the above components (e) and (e)
A primer for an acrylic-modified urethane sealant, the main component of which is a copolymer obtained by copolymerizing a monomer mixture in which the weight of none of the components (a) to (d) exceeds the total weight of the components (a) to (d).