JPS6284134A - Thermosetting resin composition - Google Patents

Abstract

PURPOSE:A curable resin composition that is composed of an organic rubber polymer bearing reactive silicon groups and a phenolic resin, thus giving cured products with improved flexibility, shock resistance and toughness or strength. CONSTITUTION:The objective curable resin composition contains (A) a phenolic resin and (B) a rubber organic polymer bearing at least one of reactive silicon group in the molecule (preferably alkoxysilyl group), preferably a vinyl polymer- modified polyether polymer bearing 1.2-6 reactive silicon groups on its terminals, which is obtained by polymerizing vinyl monomers, preferably ethyl acrylate or butyl acrylate in a polyether polymer bearing recurring units of the formula: -R-O-(R is 2-4C divalent alkylene) as the major chain where A/B ratio is 1/100-100/1 by weight.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is directed to improved flexibility, impact resistance, toughness, or strength of a rubber-based organic polymer having reactive silicon groups and a phenolic resin. The present invention relates to a curable resin composition that provides a cured product.

[Problems to be solved by conventional technology/invention] Conventionally,
Phenolic resins are used in a wide variety of applications, including various molding materials, adhesives, paints, plywood, and laminates, but a common problem with these applications is that the cured product is brittle.

On the other hand, rubber-based organic polymers having reactive silicon groups have the interesting property of curing even at room temperature and becoming rubber elastic bodies, but have the disadvantage that the strength of the cured product is low. Uses are limited.

The present invention has been made in view of the above-mentioned circumstances in order to improve the brittleness of cured products of phenolic resins and the lack of strength of cured products of rubber-based organic polymers having reactive silicon groups.

[Means for Solving the Problems] The present invention comprises (A) a phenolic resin and (B) a rubber-based organic polymer having at least one reactive silicon group in the molecule; (B) component is 1/10Q
-10 (1/I (weight ratio)).

[Example] There is no particular limitation on the phenolic resin that is component (A) used in the present invention, and any commonly used phenolic resin can be used. Specific examples of such phenolic resins include phenolic compounds such as phenol, cresol, xylenol, resorcinol, alkylphenols, modified phenols (e.g. cashew oil modified phenol, tall oil modified phenol, etc.), and aldehyde compounds such as formalin and paraformaldehyde. Resol type or novolak type phenolic resin obtained by condensation reaction with a compound, or nitrogen obtained by condensation using ammonia or an amine compound as a catalyst during the reaction of the phenol compound and an aldehyde compound. Examples include phenolic resins containing atoms, and these may be used alone or in combination of two or more.

In addition, when a novolak type product is used as component (A), it is preferable to use a curing agent generally known as a curing agent for phenolic resins such as aldehyde or hexamethylenetetramine during curing.

Although component (B) in the composition of the present invention is cured by moisture, component (A) also ultimately causes a curing reaction.B)
Coexists with the ingredients.

At least 1 in the molecule of component (B) used in the present invention
Examples of rubber-based organic polymers containing two reactive silicon groups include polyester polymers obtained by condensation of a dibasic acid such as adipic acid with glycol or ring-opening polymerization of lactones, and ethylene-propylene copolymers. , polyisobutylene, copolymers of imbutylene and isoprene, etc., polychloroprene, polyisoprene, copolymers of isoprene and butadiene, acrylonitrile, styrene, etc.
Polybutadiene, copolymers of butadiene with styrene, acrylonitrile, etc., polyolefin polymers obtained by hydrogenating polyisoprene, polybutadiene, copolymers of isoprene or butadiene with acrylonitrile, styrene, etc., ethyl acrylate, butyl acrylate, etc. Polyacrylic esters obtained by radical polymerization of monomers, acrylic ester copolymers of acrylic esters such as ethyl acrylate or butyl acrylate, and vinyl acetate, acrylonitrile, methyl methacrylate, styrene, etc., the rubber organic polymers mentioned above. A graft polymer obtained by polymerizing vinyl monomers during coalescence, a chemical whose main chain is essentially -R-0- (wherein R represents a divalent alkylene group having 2 to 4 carbon atoms) polyethers with repeating units that are linked together, such as propylene oxide, ethylene oxide,
Obtained by polymerizing vinyl monomers such as acrylic esters, methacrylic esters, vinyl acetate, acrylonitrile, and styrene with alcohols having 1 to 12 carbon atoms in polyether polymers obtained by polymerizing cyclic ethers such as tetrahydrofuran. Examples include vinyl polymer-modified polyether polymers, polysulfide polymers, and the like, which have at least one reactive silicon group in their polymer molecules. Among these, in particular, vinyl polymer-modified polypropylene oxide polymers obtained by polymerizing vinyl monomers such as ethyl acrylate and butyl acrylate in polypropylene oxide polyethers, polyacrylic esters or acrylic esters, and vinyl acetate, A copolymer with acrylonitrile, methyl methacrylate, styrene, etc., with at least one
Polymers with two reactive silicon groups are preferred.

Examples of the reactive silicon group contained in the rubber-based organic polymer include a hydrolyzable silicon group and a silanol group.

The term "hydrolyzable silicon group" as used herein means a group in which a hydrolyzable group that undergoes hydrolysis with moisture is bonded to a silicon atom in the presence or absence of a silanol condensation catalyst.

Examples of reactive silicon groups include the general formula: (wherein, X is a hydroxyl group or a hydrolyzable group, and R1 is a
valent hydrocarbon group or siloxy group such as (R')3S1-0- group, a is 0°1.2 or 3, b is 0.1 or 2, 1≦a+b, m is O or 1418) The groups represented are shown. The reactive silicon groups and the polymer chain are bonded via silicon-carbon bonds. A preferred reactive silicon group is a group represented by the general formula: (wherein, X is the same as above, R2 is a monovalent hydrocarbon group having 1 to 18 carbon atoms, and n is 1.2 or 3).

Specific examples of the hydrolyzable group include a hydrogen atom, a halogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amido group, an aminooxy group,
Examples include commonly known groups such as mercapto group and alkenyloxy group. Among these, alkoxy groups are particularly preferred because they are mildly hydrolyzable and easy to handle. One to three hydrolyzable groups are bonded to one silicon atom.

Silanol groups can also be removed by hydrolyzing hydrolyzable silicon groups.

The number of silicon atoms forming the hydrolyzable silicon group may be one or two or more, but in the case of silicon atoms connected by siloxane bonds etc., up to 20 silicon atoms may be used. Can be used freely.

Specific examples of methods for introducing a hydrolyzable silicon group, which is a type of reactive silicon group, into a rubber-based organic polymer include the following method.

(1) A monomer having a copolymerizable unsaturated group and a hydrolyzable silicon group in the molecule, such as vinyltrialkoxysilane, methacryloxypropylmethyldialkoxysilane, methacryloxypropyltrialkoxysilane, etc., is added to ethylene, Copolymerization with polymerizable monomers such as propylene, imbutylene, chlorobrene, isoprene, butadiene, acrylic ester, or γ-
Copolymerizing monomers with copolymerizable epoxy and hydrolyzable silicon groups in the molecule, such as glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, etc., with propylene oxide, ethylene oxide, etc. Method.

These methods allow the introduction of hydrolyzable silicon groups into molecular side chains.

(Silicon compounds that have a mercapto group, disulfide group, etc. and a hydrolyzable silicon group in the molecule, such as mercaptopropyltrialkoxysilane, mercaptopropylmethyldialkoxysilane, etc., which can cause a chain transfer reaction in two-radical polymerization) A method of polymerizing radically polymerizable monomers using them as chain transfer agents.

(3) Azobis-2-(6-methyljethoxysilyl-
A method of polymerizing radically polymerizable monomers using an azo initiator or peroxide initiator containing a hydrolyzable silicon group such as 2-cyanohexane).

In addition, in the methods (2) and (3), a hydrolyzable silicon group can be introduced at the end of the polymer molecule.

(4) Using a polymer having a functional group (hereinafter referred to as a Y functional group) such as a hydroxyl group, a carboxyl group, a mercapto group, an epoxy group, or an isocyanate group in the side chain and/or the terminal of the polymer, the Y functional group is used. A method in which a silicon compound containing a Y functional group capable of reacting with a group in its molecule and having a hydrolyzable silicon group is reacted with the Y functional group. Specific reaction examples are shown in the following table, but are not limited thereto.

[Left below] Preferred specific examples of polymers having a Y functional group used as starting materials or intermediate materials in the table above include:
polypropylene polyol, polyethylene polyol,
Polyalkylene polyols whose main chain is essentially -R-0- (in the formula, R represents a divalent alkylene group having 2 to 4 carbon atoms) such as polyoxytetramethylene diol, adipic acid, etc. Polyester polyols obtained by condensation of dibasic acid and glycol or ring-opening polymerization of lactones, polyisobutylene polyols or polycarboxylic acids, polybutadiene or copolymer polyols or polycarboxylic acids of butadiene and styrene, acrylonitrile, etc. , polyols such as polyols of polyolefins obtained by hydrogenating polyisoprene or polybutadiene, or isocyanate functional foundations obtained by reacting polycarboxylic acids with polyisocyanates, the above polymers: the polyols with polyvalent halogen compounds and the above-mentioned polymers containing a vinyl-type unsaturated group, which are obtained by reacting with a halogen compound containing a vinyl-type unsaturated group, and it is more preferable that the Y functional group is located at the end of the polymer molecule.

In addition, as a silicon compound having a Y° functional group, γ-
(2-aminoethyl)propyltrimethoxysilane, γ
- Aminosilanes such as (2-aminoethyl)aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, etc.; Mercaptosilanes such as γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, etc.; γ-glycidoxypropyltrimethoxysilane, β-(3,4-
Epoxysilanes such as epoxycyclohexyl)ethyltrimethoxysilane; vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane,
Vinyl-type unsaturated group-containing silanes such as γ-acryloxypropylmethoxysilane; chlorine atom-containing silanes such as γ-chloropropyltrimethoxysilane;
γ-Isocyanatepropyltriethoxysilane, γ-
Specific examples include incyanate silanes such as incyanate propylmethyldimethoxysilane; hydrosilanes such as methyldimethoxysilane, trimethoxysilane, methyljethoxysilane, etc., but are not limited to these. isn't it.

At least 1 in the molecule of component (B) used in the present invention
The molecular weight of the rubber-based organic polymer having reactive silicon groups, preferably 1.2 to 6, is about 500 to 50,000,
Particularly preferred is a liquid material having molecules of about 1,000 to 20,000 m, since it is easy to handle. If the number of reactive silicon groups contained in the molecule is less than one, curing may be insufficient and no clear modification effect can be obtained.

In the rubber-based organic polymer having at least one reactive silicon group in the molecule used in the present invention, the reactive silicon group is preferably present at the end of the molecule. When a reactive silicon group is present at the end of the molecule, the amount of effective network chains of component (B) contained in the cured product increases, making the rubber elasticity more likely to deteriorate, thus reducing the brittleness of the phenol resin. On the other hand, in the case of a cured rubber product mainly consisting of component (B), it becomes easier to obtain a high-strength product.

As a specific example of the component (B) as mentioned above,
-15951, JP-A-57-179210, JP-A-58
-191703, 59-78220, 59-7
No. 8221, No. 59-78222, No. 59-188
No. 014, No. 80-23405, No. 80-32871
No. 59-78223, Go-4575, Go-80-4576, Patent Application No. 59-84848, Go-59
-84849, 59-158873, 59-1
5611i74 and the like are useful, but are not limited thereto.

In the present invention, the phenol resin as component (A),
A curable resin composition is prepared using component (B), a rubber-based organic polymer having at least one reactive silicon group in its molecule, as an active ingredient.

Ratio of (A) component to (B) component ((A) component/(B)
component) is used in a weight ratio of 1/100 to 100/l. The ratio of component (A)/component (B) is t7io.

(weight ratio, the same applies hereafter) If it is smaller, the improvement effect on the low strength, which is a drawback of cured rubber-based organic polymers, will be insufficient, and the ratio of component (A)/component (B) will be 100/l. The larger the size, the more difficult it is to improve impact strength and toughness. The preferred ratio of component (A)/component (B) cannot be determined unconditionally as it varies depending on the use of the curable resin composition, but for example, , when improving peel strength etc., component (A)/component (B) - 100/1 to 507100, more preferably 10
It is best to use a ratio of 0/2 to 100/100.

On the other hand, when modifying the strength of the cured product of the rubber-based organic polymer having at least one reactive silicon group in the molecule as component (B), component (A)/component (B)-1001
50-1/100, preferably 100/100-5/
It is best to use 100.

There is no particular limitation on the method for preparing a curable resin composition containing component (A) and component (B) as active ingredients.
) and (B) are blended together and kneaded under heat using a roll or kneader, or by using a small amount of a suitable solvent to dissolve and mix both components. can be used. Furthermore, by appropriately combining these components, one-pack type or two-pack type formulations can be created and used.

The curable resin composition of the present invention contains (A) which is an active ingredient.
In addition to component (B), various fillers, plasticizers, silanol condensation catalysts commonly used to cure component (B), anti-aging agents, ultraviolet absorbers, lubricants, aminosilane, mercaptosilane, and epoxy. Commonly used silane coupling agents such as silane, pigments, blowing agents, etc. may be added as necessary.

For example, when using fillers as additives,
Wood flour, pulp, cotton chips, asbestos, glass fiber,
Fillers commonly used for phenolic resins, such as mica, walnut shell powder, rice flour, graphite, diatomaceous earth, and white clay, can be effectively used. In addition, other fillers such as hume silica, precipitated silica, silicic anhydride,
carbon black, calcium carbonate, clay, talc,
Titanium oxide, magnesium carbonate, quartz, aluminum,
Fine powder, flint powder, zinc dust, etc. may also be used.

These fillers may be used alone or in combination of two or more.

The curable resin composition of the present invention can be cured at low temperatures such as room temperature, and can also be rapidly cured at high temperatures, so it can be cured in a wide temperature range from low to high temperatures depending on the purpose. I can do it.

There are no particular limitations on the method of molding the curable resin composition of the present invention, but if the amount of component (A) is greater than component (B),
It is preferable to mold by a method commonly used as a molding method for phenolic resin, such as compression molding, transfer molding, or injection molding. Molding by such a method improves impact resistance, flexibility, Molded products with improved toughness and laminated molded products such as copper-clad laminates and reinforced wood can be used. In addition, in the case of the above composition,
Adhesives with improved peel strength, phenolic foams with improved flexibility, binders for fiberboard or particleboard, paints, binders for shell molds, binders for brake linings, binders for grinding wheels. It can also be suitably used as a binder for glass fibers.

On the other hand, if the amount of component (B) is greater than component (A), it is preferable to mold by a method commonly used for molding solid rubber such as natural rubber or rubber-based liquid polymer such as polyurethane. When molded using this method, rubber molded products and rubber-like foams with improved strength and the like can be obtained. Furthermore, when the amount of component (B) is greater than component (A), it can be suitably used as a rubber adhesive, a sealant, etc.

Next, the curable resin composition of the present invention will be explained based on Examples.

Production Example 1 Polypropylene oxide 1 with an average molecular m of 8000 in which 90% of all terminals are C112-CHClI20- groups
00f in a reaction vessel and dimethoxymethylsilane 1
．． 77g, chloroplatinic acid (H2Pt C2a ・6H20
After adding 0.013 g of a 10% by weight isopropanol solution of ), the temperature was raised to 80° C. and reacted for 4 hours.

Take an IR spectrum and find 5 around 2100CI11-'
After confirming the disappearance of L-11 absorption, the reaction was terminated.

The iodine value of the reactant is 2°O, and when calculated from this value, there are on average 1.2 reactive silicon functional groups and 0.6 polymerizable unsaturated groups per molecule of the reactant obtained. was contained.

100 g of the reactant was placed in a reaction vessel, devolatilized under reduced pressure,
After nitrogen substitution, heating to 90°C and stirring,
Separately prepared n-butyl acrylate 95.4.
[,) Lis(2-hydroxyethyl)incyanuric acid triacrylate L, 8g.

γ-methacryloxypropyldimethoxymethylsilane
A mixed solution consisting of 1.5 g of γ-mercaptopropyldimethoxymethylsilane, 2.3 g of γ-mercaptopropyldimethoxymethylsilane, and 0.5 g of 2,2°-azobisisobutyronitrile (hereinafter referred to as AIBN) was heated under a nitrogen atmosphere for 2 hours. dripped. AIBN after 15 minutes and 30 minutes after completion of dropping, respectively.
25 g each of O was dissolved in 4 times the weight of acetone and added. After the addition was completed, stirring was continued for 30 minutes to complete the polymerization reaction.

The resulting reaction product was a pale yellow, transparent, viscous liquid with a residual monomer ffl of 0.8% as determined by gas chromatography analysis (hereinafter referred to as GC analysis), and a viscosity of 460 poise (at 23°C).
Production Example 2 Butyl acrylate 80g, vinyl acetate 20g.

γ-methacryloxypropylmethyljethoxysilane
2゜3g: Mix 1.8g of γ-mercaptopropylmethyldimethoxysilane and LOg of azobis-2-(6-methyljethoxysilyl-2-cyanohexane).
Stir to ensure uniform dissolution. 25 g of the mixture was placed in 14 200 m flasks equipped with a stirrer and a cooling bone, and heated to 80° C. in an oil bath while passing nitrogen gas. After a few minutes, polymerization started and generated heat, but after the heat generation became mild, the remaining mixed solution was gradually added dropwise using a dropping funnel over a period of 3 hours to cause polymerization. Polymerization was terminated when no heat generation was observed.

When the obtained liquid polymer was analyzed by gel permeation chromatography (CPC), the average molecular weight was approximately 1.
It was 1000.

Example 1 and Comparative Example 1 Sumilight Resin I'! In a solution in which 50 parts (parts by weight, the same shall apply hereinafter) of R-12887 (manufactured by Sumitomo Bakelite ■, hexamethylenetetramine-containing Casigny-modified novolak phenol resin) was dissolved in 50 parts of methyl ethyl ketone,
Polymer 1 having reactive silicon groups obtained in Production Example 1
00 parts, 2,2-methylenebis(4-methyl-8-t-
butylphenol) and 2 parts of dibutyltin dilaurate were added and mixed well to prepare a solution.

Pour the obtained solution into a polyethylene mold, and
After curing for 10 days at ℃, a cured sheet with a thickness of 2 mm was obtained. The obtained cured product sheet was heat-treated at 150°C for 1 hour, and then 3-bow dumbbells were punched out in accordance with JIS K 6301, and the breaking strength (
T), and the elongation at break (EB) was measured, and it was found that T
A high-strength cured rubber material with a weight of 52 kg/cd and an EB of 230% was used instead.

Using the above system, a cured product sheet was prepared in the same manner except that the phenol resin was not used, and the TB was measured.
I could only get something with a low value of kg/cd.

Examples 2 to 6 Cured sheets were prepared in the same manner as in Example 1 using the phenolic resins and polymers having reactive silicon groups shown in Table 1, and their properties were measured. The results are shown in Table 1.

In addition, PR-50775 in Table 1 is a hexamethylenetetramine-containing alkylphenol-modified novolac type phenol resin manufactured by Sumitomo Bakelite ■, PI? -175 is an alkylphenol-modified resol-type phenolic resin manufactured by Sumitomo Bakelite Oki.

[Margin below]

Example 7 and Comparative Example 2 Polymer 5 having reactive silicon groups obtained in Production Example 2
0 parts, 2,2°-methylenebis(4-methyl-6-1-
butylphenol) 0.5 part, Sumilight Resin PR-
100 parts of 12687 and 80 parts of white birch wood flour (particle size: 100 mesh) were mixed and kneaded with a heated roll at 95° C. to obtain a blend. The powder obtained by pulverizing the mixture with a pulverizer was put into a mold with a depth of LO mm set at a temperature of 150°C and plasticized, and then 100 kg of 150°C
Press molding was performed under the following conditions: / d x 1 hour.

A test piece with a cross-sectional area of 10 mm x 12 mm was cut out from the obtained molded product, and a U-notch was cut to meet JIS K 691.
An Izot impact test was conducted in accordance with 1, and the impact strength was measured to be 3.7 kg(7)/cd.

A test piece was prepared in the same manner as above except that the polymer having a reactive silicon group was not used, and the Izod impact strength was measured and found to be 1.5 kgcm/ci.

Example 8 and Comparative Example 3 100 parts of the polymer having reactive silicon groups obtained in Production Example 1, 2
, 1 part of 2-methylenebis(4-methyl-6-t-butylphenol), methylhydrodiene polysiloxane (
5 parts of tsF 484) manufactured by Toshiba Silicone ■ and 5 parts of silicic acid anhydride were added and stirred well. After that, 2 parts of dibutyltin dilaurate and 1 part of laurylamine were added, mixed well, and cured in a dryer at 50°C for 3 days to produce a foam, and then heat treated in a dryer at 150°C for 1 hour. As a result, a bendable, flexible and strong foam with a specific gravity of about 0.3.90'' was obtained.

When a foam was produced in the same manner as described above except that the polymer with reactive silicon groups was not used, the result was a very brittle foam with no flexibility that easily broke when attempting to bend it.

〔Effect of the invention〕

By using the composition of the present invention, a cured product can be obtained that does not have the disadvantages of phenolic resins and rubber-based polymers having reactive silicon groups, such as brittleness and low strength of the cured product, respectively.

Claims (1)

[Scope of Claims] 1 (A) a phenolic resin and (B) a rubber-based organic polymer containing at least one reactive silicon group in the molecule, wherein the ratio of component (A)/component (B) is 1/ 100-10
A curable resin composition having a weight ratio of 0/1. 2. The curable resin composition according to claim 1, wherein the reactive silicon group in component (B) is an alkoxysilyl group. The main chain of component 3(B) is essentially -R-O- (wherein R
represents a divalent alkylene group having 2 to 4 carbon atoms) A polymer obtained by polymerizing a vinyl monomer in a polyether having chemically bonded repeating units represented by Curable resin composition according to item 1. 4. The curable resin composition according to claim 1, wherein the main chain of component (B) is an acrylic ester polymer or an acrylic ester copolymer.