JP3467065B2 - Curable resin composition - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a curable resin composition which cures in the presence of moisture.

[0002]

2. Description of the Related Art Reactive silicon groups are condensed after being hydrolyzed in the presence of water. This polymer having a reactive silicon group is crosslinked and cured in the presence of moisture and can be used as a curable resin composition. Among these polymers, those whose main chain skeleton is polyoxyalkylene are generally known as modified silicones. A curable composition using this is liquid at room temperature and has a property of becoming a rubber elastic body when cured, and is widely used for a sealant for construction and the like. However, this curable composition, depending on the compounding composition and the curing conditions, impairs the appearance by contaminating the surface of the cured product due to adhesion of dust or the like, which is an unfavorable state (hereinafter,
(Abbreviated as "polluting").

Therefore, various compositions have been proposed so far in order to improve this drawback. For example, JP-A-55-3
No. 6241, a photocurable compound was added to an oxyalkylene polymer containing a reactive silicon group.
In 85 1, adding liquid diene polymer, JP-A-3 -1
60053 discloses a curable composition in which the stain resistance of the surface of a cured product is improved by adding a photocurable compound and an unsaturated compound.

[0004]

However, although these compositions have certain antifouling effects,
In long-term exposure, or in harsh, polluted areas with a lot of dust and fine powdery soil, many of them are not effective enough. Further, even when the effect of improving the stain resistance is observed, a remarkable crack is generated on the surface of the cured product to impair the appearance, and an unfavorable state (hereinafter,
"Surface crack") may occur. These phenomena are thought to be related to film formation on the surface of the cured product of the added photocurable resin or unsaturated compound. Contamination is poor film formation, surface cracks are film hardness, shrinkage, etc. It can be caused by. Therefore, in view of these circumstances, the present invention aims to provide a curable resin composition having not only stain resistance but also improved surface cracks.

[0005]

[Means for Solving the Problems] As a result of examining the effects of various additives for the above problems, the present invention has been accomplished. That is, the present invention includes (a) 100 parts by weight of an oxyalkylene polymer containing at least one reactive silicon group in one molecule (b) 0.01 to 20 parts by weight of a photocurable compound (c) 1 A polyester compound having at least two allyloxy groups in the molecule and capable of reacting with oxygen in the air.
It relates to a curable resin composition comprising 1 to 20 parts by weight. This curable resin composition is particularly suitable for the unsaturated group of a polyester compound.
It has been clarified that not only the staining property but also the surface cracks are improved by having two or more groups in one molecule.

The main chain skeleton of the oxyalkylene polymer containing at least one reactive silicon group in one molecule (a) contained in the present invention is essentially the repeating structure represented by the general formula (1). It has a unit. —R ¹ —O— (1) (In the formula, R ¹ is a divalent organic group and is preferably a linear or branched alkylene group having 1 to 14 carbon atoms.) As a specific example of the general formula (1) _{is, -CH 2 O -, - CH} 2 CH 2 O -, - CH 2 CH (C
_{H 3) O -, - CH} 2 CH (C 2 H 5) O -, - CH 2
_{C (CH 3) 2 O -} , - (CH 2) 4 O- , and the like. The main chain skeleton of the oxyalkylene polymer may be composed of only one kind of repeating unit or may be composed of two or more kinds of repeating units.

Typical examples of the reactive silicon group contained in the component (a) include groups represented by the general formula (2).

[0008]

[Chemical 1]

In the formula, R ² and R ³ are each an alkyl group having 1 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or (R ⁴ ) ₃ S.
iO- [R ⁴ is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and three R ⁴ may be the same or different] and represents a triorganosiloxane group, R
^{When 2} or R ³ there are two or more, they may be the same or may be different. X represents a hydrolyzable group or a hydroxyl group, and when two or more X are present, they may be the same or different. a represents 0, 1, 2 or 3 and b represents 0, 1 or 2.

Further, m general formulas (3)

[0011]

[Chemical 2]

B in does not have to be the same. m represents 0 or an integer of 1 to 19. However, a + (sum of b)
It is assumed that ≧ 1 is satisfied. The hydrolyzable group represented by X is not particularly limited, and includes conventionally known hydrolyzable groups, specifically, for example, a hydrogen atom, a halogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group. Group, amide group, acid amide group, aminooxy group, mercapto group, alkenyloxy group and the like. Among these, a hydrogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an aminooxy group, a mercapto group and an alkenyloxy group are preferable, and an alkoxy group is preferable from the viewpoint of mild hydrolyzability and easy handling. Particularly preferred.

The hydrolyzable group or hydroxyl group can be bonded to one silicon atom in the range of 1 to 3, and (sum of a + b) is preferably in the range of 1 to 5. When two or more hydrolyzable groups or hydroxyl groups are bonded to the reactive silicon group, they may be the same or different. The number of silicon atoms forming the reactive silicon group may be one, and
The number may be more than one, but in the case of silicon atoms connected by a siloxane bond or the like, it may be up to about 20. Especially the general formula (4)

[0014]

[Chemical 3]

A reactive silicon group represented by the formula (wherein R ³ and n represent an integer of 1, 2 or 3) is preferable from the viewpoint of easy availability. Specific examples of R ² and R ³ in the general formula (1) include, for example, alkyl groups such as methyl group and ethyl group, cycloalkyl groups such as cyclohexyl group, aryl groups such as phenyl group, and aralkyl such as benzyl group. And a triorganosiloxy group represented by (R ⁴ ) ₃ SiO— in which R ⁴ is a methyl group, a phenyl group or the like. Of these, a methyl group is particularly preferable.

The reactive silicon group may be introduced by a known method. That is, for example, the following methods can be mentioned. (1) An oxyalkylene polymer having a functional group such as a hydroxyl group in the molecule is reacted with an organic compound having an active group and an unsaturated group reactive with the functional group to contain an unsaturated group. An oxyalkylene polymer is obtained. Alternatively, an unsaturated group-containing oxyalkylene polymer is obtained by copolymerization with an unsaturated group-containing epoxy compound. Then, the obtained reaction product is subjected to hydrosilylation by reacting hydrosilane having a reactive silicon group.

(2) The unsaturated group-containing oxyalkylene polymer obtained in the same manner as in the method (1) is reacted with a compound having a mercapto group and a reactive silicon group. (3) An oxyalkylene polymer having a functional group such as a hydroxyl group, an epoxy group or an isocyanate group (hereinafter referred to as a Y functional group) in the molecule, and a functional group and a reactivity which are reactive with the Y functional group. A compound having a silicon group is reacted.

Among the above methods, the method (1) or the method (3) of reacting a polymer having a hydroxyl group at the terminal with a compound having an isocyanate group and a reactive silicon group is preferable. The component (a) may be linear or branched and has a molecular weight of 500 to 50,000.
It is about 0, more preferably 1,000 to 30,000. At least one reactive silicon group is preferably present in one molecule of the polymer, and preferably 1.1 to 5 reactive silicon groups are present. When the number of reactive silicon groups contained in the molecule is less than 1, the curability becomes insufficient, and when the number is too large, the network structure becomes too dense and good mechanical properties are not exhibited. Specific examples of the component (a) include JP-B-45-363.
19, JP-B-46-12154, JP-A-50-1565.
99, JP-A-54-6096, JP-A-55-1376.
7, JP-A-55-13468, JP-A-57-16412
3, Japanese Patent Publication No. 3-2450, USP 3,632,557,
USP 4,345,053, USP 4,366,30
7, USP 4,960,844 and the like are listed, and these are effectively used, but the invention is not particularly limited thereto.

The photocurable compound (b) contained in the present invention is a compound in which the molecular structure undergoes a chemical change due to the action of light to cause a change in physical properties such as curing. Many compounds such as organic monomers, oligomers, resins or compositions containing them are known as compounds of this type, and any commercially available compounds can be adopted. As a typical example, a photopolymerizable resin, a photosensitive resin that is cured by a photodimerization reaction, or the like can be used.

The photopolymerizable resin is a monomer, an oligomer or a mixture thereof containing 1 to several reactive groups which can be polymerized by light irradiation such as an acryloyl group and / or a methacryloyl group, and is propylene glycol,
Special acrylates obtained from glycols such as trimethylolpropane, pentaerythritol, dipentaerythritol and acrylic acid and / or methacrylic acid,
Such as an epoxy acrylate obtained from an epoxy resin and acrylic acid and / or methacrylic acid, a urethane acrylate having an acryloyl group and / or a methacryloyl group introduced into a urethane resin, and a polyester acrylate having an acryloyl group and / or a methacryloyl group introduced into a polyester. Monomer or molecular weight 1000
The oligo acrylate of 0 or less is illustrated.

The photosensitive resin which is cured by a photodimerization reaction is a photosensitive resin containing a cinnamoyl group, a furan acrylate group or the like which causes a photodimerization reaction, in which polyvinyl alcohol is esterified with cinnamic acid, Many polyvinyl cinnamates are exemplified. The addition amount of the component (b) is 0.01 to 20 parts with respect to 100 parts of the component (a) (parts by weight, the same applies hereinafter). When it is 0.01 part or less, the effect on the stain resistance is small, and when it is 20 parts or more, the mechanical properties of the cured product may be adversely affected, which is not preferable. The effect may be enhanced by adding a sensitizer such as an aromatic carbonyl compound or an accelerator such as an amine compound.

An ant is contained in one molecule (c) contained in the present invention.
The polyester compound containing at least two loxy groups and capable of reacting with oxygen in the air is a compound that can be crosslinked and cured by the reaction between an allyloxy group and oxygen in the air, and is particularly effective against surface cracks. is there.

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

The structure of component ( c) is based on polyester resin
The thing which introduced the allyloxy group is illustrated. The number of allyloxy groups contained in one molecule of the component (c) is preferably 2 or more. As the particularly preferable component (c),
Having A Rirokishi group include those having a polyester as the main chain structure. Such an allyloxy group-containing polyester is obtained, for example, by polycondensation of an allyloxy group-containing glycol and a polyvalent carboxylic acid, and those generally used as air-drying unsaturated polyesters are exemplified. .

The amount of component (c) added is 100 parts of component (a).
It is 0.1 to 20 parts with respect to parts. If it is 0.1 part or less, the effect on the stain resistance is small, and if it is 20 parts or more, the mechanical properties of the cured product may be adversely affected, which is not preferable. The effect may be enhanced by adding a dryer such as an organic acid metal salt of cobalt, manganese, calcium or the like, which promotes the oxidation reaction.

The method for preparing the curable resin composition containing the components (a), (b) and (c) is not particularly limited. For example, the components (a), (b) and (c) may be used. Conventional methods such as blending and kneading using a mixer, roll, kneader, or the like, and dissolving and mixing each component using a suitable solvent can be employed. It is also possible to prepare a one-pack type and a two-pack type mixture by appropriately combining the respective components.

The composition of the present invention may contain a silanol condensation catalyst which accelerates the reaction of the reactive silicon group. Such silanol condensation catalysts include titanic acid esters such as tetrabutyl titanate and tetrapropyl titanate; dibutyltin dilaurate, dibutyltin maleate, dibutyltin diacetate, tin octylate, tin naphthenate, dibutyltin oxide and phthalic acid. Reaction products with ester, organotin compounds such as dibutyltin diacetylacetonate; organoaluminum compounds such as aluminum trisacetylacetonate, aluminum trisethylacetoacetate, diisopropoxyaluminumethylacetoacetate; zirconium tetraacetylacetonate Chelate compounds such as titanium tetraacetylacetonate; organolead compounds such as lead actylate;
Organic vanadium compounds; butylamine, octylamine, dibutylamine, monoethanolamine, diethanolamine, triethanolamine, diethylenetriamine, triethylenetetramine, oleylamine, cyclohexylamine, benzylamine, diethylaminopropylamine, xylylenediamine, triethylenediamine, guanidine, diphenyl Guanidine, 2,4,6
-Tris (dimethylaminomethyl) phenol, morpholine, N-methylmorpholine, 2-ethyl-4-methylimidazole, 1,8-diazabicyclo (5,4,0)
Undecene-7 (DBU) and other amine compounds, or salts thereof with carboxylic acids and the like; low molecular weight polyamide resins obtained from excess polyamine and polybasic acid; reaction products of excess polyamine and epoxy compound, etc. However, the condensation catalyst is not limited thereto, and a commonly used condensation catalyst can be used. These silanol condensation catalysts may be used alone or in combination of two or more. Of these silanol condensation catalysts,
Organometallic compounds or a combination system of organometallic compounds and an amine compound is preferable from the viewpoint of curability.

The composition of the present invention may further contain, if necessary.
Dehydrating agent, compatibilizing agent, adhesion improving agent, physical property adjusting agent, storage stability improving agent, filler, antioxidant, ultraviolet absorber, metal deactivator, ozone deterioration preventing agent, light stabilizer, amine-based agent Various additives such as a radical chain inhibitor, a phosphorus-based peroxide decomposer, a lubricant, a pigment, and a foaming agent can be appropriately added. For example, when using a filler as an additive, wood powder, walnut shell powder, chaff powder, pulp, cotton chips, mica, graphite, diatomaceous earth, clay, kaolin, clay, talc,
Fumed silica, precipitated silica, silicic acid anhydride, quartz powder, glass beads, calcium carbonate, magnesium carbonate, titanium oxide, aluminum powder, zinc powder, asbestos, glass fiber, carbon fiber and the like can be used. These fillers may be used alone or in combination of two or more.

In addition to (a) an oxyalkylene polymer containing at least one reactive silicon group in one molecule, another polymer having a reactive silicon group such as polydimethylsiloxane is added. Good.

[0035]

EXAMPLES The present invention will be described more specifically based on examples. Examples 1-9 and Comparative Examples 1-15 Average of 2 methyldimethoxysilyl groups per molecule

[0036]

[Chemical 7]

100 parts by weight of a propylene oxide polymer having an average molecular weight of 10500 (hereinafter referred to as a methyldimethoxysilyl group-containing propylene oxide polymer) containing 10 parts by weight (parts by weight; hereinafter the same) together with the compounding agents shown in Table 1 The photo-curable compound and the unsaturated compound capable of reacting with oxygen in the air were added and sufficiently kneaded, and then passed through a small three-piece paint roll three times to obtain a curable resin composition.

Outdoor exposure test This curable resin composition was spread to a thickness of 5 mm to give 23
It was cured at 60 ° C. and 60% RH to obtain a sheet-shaped cured product. This was used as a test piece and attached to an exposure table with a 15 ° inclination on the south surface installed in the Takasago Plant of Kanegafuchi Chemical Industry, and the contamination of the surface of the cured product after about 23 months and the state of occurrence of surface cracks were visually evaluated. The results are shown in Table 2. The contamination property in the table is the degree of adhesion of dust on the surface, which is 5: almost no adhesion to 1: the base is not visible due to adhesion. The surface crack is the number of cracks on the surface and the degree of depth. 5: Almost no cracks-3: Some cracks are partially observed-1: Deep cracks are entirely observed.

The photocurable compound in Table 2 is a special acrylate manufactured by Toa Gosei Co., Ltd. and has the following structure. Aronikusu _{M309 (CH 2 = CHCOOCH 2)} 3 C-CH 2 CH 3 Table unsaturated compound capable of reacting with oxygen in the air in the 2, Examples 1 to 9 and Comparative Examples 1 to 9 Nippon Synthetic Chemical (Co. ), An air-drying unsaturated polyester resin containing two or more allyloxy groups in one molecule, Gosselac 500B, 50
0E and 400. In Comparative Examples 10 to 12, 1,2-polybutadiene NISSO-PB B3000 having a molecular weight of about 3000 manufactured by Nippon Soda Co., Ltd. is used.

[0040]

[Table 1]

[0041]

[Table 2]

From Table 2, the effects of stain resistance and surface cracks of the cured products obtained from the curable resin composition of the present invention are shown only in the air-drying unsaturated polyester resin containing the allyloxy group of Comparative Examples 1-9. It is obvious in comparison with the addition and the use of 1,2-polybutadiene as the unsaturated compound in Comparative Examples 10 to 12.

[0043]

EFFECTS OF THE INVENTION The curable resin composition of the present invention is liquid at room temperature, has excellent properties of becoming a rubber elastic body by curing, and has excellent stain resistance even when exposed outdoors for a long period of time. A cured product having a surface with improved surface cracks and excellent appearance can be obtained. Therefore, it can be suitably used for adhesives, sealants, coatings, etc. that require appearance.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-160053 (JP, A) JP-A-5-295248 (JP, A) JP-A-7-70425 (JP, A) JP-A-6- 57173 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08L 71/02-71/03 CA (STN)

Claims (2)

(57) [Claims] 1. An oxyalkylene polymer containing (a) at least one reactive silicon group in one molecule.
0 parts by weight (b) photocurable compound 0.01 to 20 parts by weight (c) polyester compound containing at least two allyloxy groups in one molecule and capable of reacting with oxygen in the air.
A curable resin composition comprising 1 to 20 parts by weight. 2. The curable resin composition according to claim 1, wherein the photocurable compound (b) is a compound containing an acryloyl group and / or a methacryloyl group.