JPH10158471A - Curable resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a curable resin composition which, when used as a treating agent for a cellulosic substrate, can give improved surface hardness, moisture resistance and water resistance thereto without detriment to its flexibility by using a hydroxyalkyl-containing vinyl compound and an amino resin as the essential components. SOLUTION: The vinyl compound is represented by the formula (wherein R1 is hydrogen, a 1-18C alkyl, a 3-10C cycloalkyl, an aryl, a 1-8C hydroxyalkyl, -(CH2 )n NR2 R3 or -(C2 H4 O)n R4 ; R2 and R3 are each a 1-8C alkyl; R4 is a 1-18C alkyl; R5 is hydrogen, a 1-12C alkyl, a 3-10C cycloalkyl, an aryl, a 1-12C alkyl, a 3-10C cycloalkyl, an aryl, a 1-12C hydroxyalkyl or a 2-8C oxirane group; m is an integer of 2-5; and n is an integer of 1-80). The amino resin is desirably a triazine-ring-containing one such as a melamine resin from the viewpoint of the strengths of a cured product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a curable resin composition which can be used as a treatment agent for a cellulose-based substrate.

[0002]

2. Description of the Related Art Amino resins such as melamine resins are used to improve the surface hardness, moisture resistance and water resistance of cellulosic laminated substrates used for decorative laminated paper used for decorative boards and insulating laminates for electric parts. , Impregnation processing and coating processing.

[0003]

The amino resin such as melamine resin which is generally used is used in the form of an aqueous solution or a solvent because of its handling problem, and is impregnated or coated on a cellulose base such as paper and dried. After that, it is cured by heating. An air drying method or a heat drying method is used for this drying step. However, the former has a problem that the treatment step becomes longer, and the latter has a problem that the resin may peel off due to deterioration of the base material or foaming.

In addition, when a cellulose-based substrate is treated with an amino resin having a triazine ring such as a melamine resin, the rigidity of the cellulose-based substrate results in poor flexibility and poor punching workability and impact resistance. there were. In order to improve this problem, an alkyd resin or a polyester resin containing a hydroxyl group or a carboxyl group in an amino resin having a triazine ring such as a melamine resin, an unsaturated polyester resin,
It is known to incorporate a vinyl ester resin. However, in this case, since these resins have low affinity with the cellulosic base material, the improvement in moisture resistance and water resistance becomes insufficient.

Accordingly, an object of the present invention is to improve the surface hardness of a cellulose-based substrate without impairing the flexibility of the cellulose-based substrate after treatment when used as a treatment agent for the cellulose-based substrate, An object of the present invention is to provide a curable resin composition capable of improving moisture resistance and water resistance.

[0006]

Means for Solving the Problems To solve the above problems, the curable resin composition according to the present invention comprises (A) a compound represented by the general formula (1),

[0007]

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(Wherein R ₁ is a hydrogen atom, having 1 to 18 carbon atoms)
An alkyl group, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group, a hydroxyalkyl group having 1 to 8 carbon atoms,-
(CH ₂ ) _m NR ₂ R ₃ or — (C ₂ H ₄ O) _n R
Shows ₄ groups. R ₂ and R _{3 each} represent a linear or branched alkyl group having 1 to 8 carbon atoms. R ₄ has 1 carbon atom
-18 represents a linear or branched alkyl group. R ₅ represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group, a hydroxyalkyl group having 1 to 12 carbon atoms, an oxirane group having 2 to 8 carbon atoms. m is an integer of 2 to 5, and n is an integer of 1 to 80. ) (B) Amino resin is an essential component.

The compound (A) preferably contains a compound in which R ₅ is a hydrogen atom in the general formula (1). In the present invention, the curable resin composition means not only a final product as a curable resin composition, but also an intermediate product not containing various additives which are added as necessary.

The present invention is characterized in that the compound (A) represented by the general formula (1) and the amino resin (B) are essential components. The compound represented by the general formula (1) is a vinyl compound having a hydroxyalkyl group. General formula (1)
The hydroxyalkyl group of the compound represented by is a relatively easy condensation reaction with the amino resin to form a cross-link,
Since it has a strong affinity for hydroxyl groups of cellulose, it greatly contributes to improvement of moisture resistance and water resistance. In particular, when R ₅ in the general formula (1) is a hydrogen atom, that is, when the hydroxyalkyl group is a methylol group, the effect is remarkable. Further, the vinyl group of the compound represented by the general formula (1) has high polymerizability, and can easily form a polymer by heat or light. Further, when a reactive functional group such as a hydroxyalkyl group is provided in the portion of R ₁ , various chemical modifications are possible and coloring and the like are facilitated.

According to the above arrangement, when the curable resin composition is used as a treating agent for a cellulose-based substrate, the flexibility of the cellulose-based substrate is not impaired after the treatment. The surface hardness can be improved, and the moisture resistance and water resistance can be improved.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The curable resin composition according to the present invention is a resin composition comprising a compound (A) represented by the general formula (1) and an amino resin (B) as essential components. The resin composition can be easily obtained by mixing the compound represented by the general formula (1) and an amino resin.

The compound (A) represented by the general formula (1) will be described.

[0014]

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In the general formula (1), R ₁ is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group, a hydroxyalkyl group having 1 to 8 carbon atoms,-( CH ₂ ) _m NR ₂ R ₃ or — (C ₂ H)
₄ O) _n R ₄ represents a group. R ₂ and R ₃ have 1 to 8 carbon atoms
Represents a linear or branched alkyl group. R ₄
Represents a linear or branched alkyl group having 1 to 18 carbon atoms. R ₅ is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group, a hydroxyalkyl group having 1 to 12 carbon atoms, and 2 carbon atoms.
８8 is an oxirane group. m is an integer of 2 to 5, n is 1
Is an integer of 80. The method for producing the compound represented by the general formula (1) is not particularly limited, and for example, as disclosed in JP-A-7-285906,

[0016]

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[0017] (R ₁ is the same as in the general formula (1).) And a vinyl compound represented by, and a method of reacting a compound having an aldehyde group. Examples of the compound represented by the general formula (2) include: (a) acrylic acid in which R ₁ is a hydrogen atom; (b) alkyl acrylate in which R ₁ is an alkyl group having 1 to 18 carbon atoms: for example, methyl Acrylate,
Ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate,
n- octyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, stearyl acrylate and the like; cycloalkyl acrylate (c) R ₁ is a cycloalkyl group having 3 to 10 carbon atoms: for example, cyclopentyl acrylate, cyclohexyl (D) aryl acrylate wherein R ₁ is an aryl group: for example, phenyl acrylate, o-methoxyphenyl acrylate, p-methoxyphenyl acrylate, p-nitrophenyl acrylate, o-methylphenyl acrylate, p-methyl Phenyl acrylate,
(e) a hydroxyalkyl acrylate in which R ₁ is a hydroxyalkyl group having 1 to 8 carbon atoms: for example, p-tert-butylphenyl acrylate;
- hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate and the like; (f) R ₁ is - (CH _{2) m} NR ₂ aminoalkyl acrylate is R ₃ groups: for example, N, N-dimethylaminoethyl acrylate, N, N-diethylaminoethyl acrylate, N, N-dimethylaminopropyl acrylate, N, N-diethylaminopropyl acrylate, N, N-dimethylaminobutyl acrylate,
N, N-diethylaminobutyl acrylate, N, N-
Dimethylaminoneopentyl acrylate, N, N-diethylaminoneopentylethyl acrylate, and the like; (g) acrylates in which R ₁ is — (C ₂ H ₄ O) _n R ₄ group: for example, methoxyethyl acrylate;
Ethoxyethyl acrylate, lauryloxytrioxyacrylate, methoxypolyoxyethylene acrylate having n of 1 to 80, preferably 3 to 30; and the like. Among these, methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate,
And 2-hydroxypropyl acrylate are particularly preferred.

The compound having an aldehyde group is a compound having a hydroxyalkyl group as a residue, particularly a compound having a methylol group (R ₅ in the general formula (1) is a hydrogen atom) as a residue. Is preferred. Specifically, for example, formaldehyde, an oxymethylene compound represented by the general formula (3), trioxane, acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, cyclohexylaldehyde, benzaldehyde, tolualdehyde, anisaldehyde, furfural, and the like are used. No.

HO (CH ₂ O) _p Y (3) (where Y is a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms) And p is an integer of 1 to 100.) Specific examples of the oxymethylene compound include paraformaldehyde, a formaldehyde polymer (octamer to 100 mer), and 20 of formaldehyde. A 50% by weight aqueous solution (hydrated formaldehyde), a methanol aqueous solution having a formaldehyde concentration of 20% by weight to 50% by weight, and the like.

In order to suppress polymerization during the production of the compound represented by the above general formula (1), and to further improve the storage stability,
It is preferable to add a polymerization inhibitor or molecular oxygen. Examples of the polymerization inhibitor include hydroquinone, methylhydroquinone, tert-butylhydroquinone,
Quinones such as 4-di-tert-butylhydroquinone and 2,4-dimethylhydroquinone; amine compounds such as phenothiazine; 2,4-dimethyl-6-tert-butylphenol, 2,4-di-tert-butylphenol and p- Phenols such as methoxyphenol; p-
Substituted catechols such as tert-butyl catechol; substituted resorcinols, etc., are not particularly limited.

As the molecular oxygen, for example, air or a mixed gas of molecular oxygen and nitrogen can be used. The amino resin (B) will be described. The amino resin (B) is a methylol compound obtained by reacting an amino compound with formaldehyde or an alkyl ether compound obtained by dehydration condensation of a methylol compound with an alcohol.

Specifically, urea resin, melamine resin, isomeramine resin, benzoguanamine resin, acetoguanamine resin, cyclohexanecarboguanamine resin, cyclohexenecarboguanamine resin, norbornanecarboguanamine resin, norbornenecarboguanamine resin,
Guanyl melamine resin, spiro guanamine resin and the like can be mentioned.

Among the above-mentioned amino resins, amino resins having a triazine ring are preferred in view of the strength properties of the cured product, and specific examples thereof include melamine resins, isomeramine resins, benzoguanamine resins, acetoguanamine resins, cyclohexanecarboguanamine resins, and cyclohexenecarboguanamine resins. , Norbornane carboguanamine resin, norbornene carboguanamine resin, guanylmelamine resin, spirologamine resin and the like.

The above alcohols are usually aliphatic alcohols, and specifically include, for example, methanol, ethanol, n-propanol, iso-propanol, n-propanol.
Butanol, iso-butanol, sec-butanol, tert-butanol and the like. The method for producing the amino resin is not particularly limited, and various conventionally known methods can be used. When using an amino resin having a triazine ring as the amino resin, the methylolated product is preferably one in which 1 to 6 formaldehydes are bound per triazine ring,
Those obtained by condensing 1.2 to 3 pieces are more preferable.

The average degree of polymerization of the triazine ring of the amino resin having a triazine ring is preferably designed to be in the range of 1.0 to 4.0, and preferably in the range of 1.0 to 2.5. Is more preferred. The average degree of polymerization is 4.0.
When the viscosity exceeds the above, when a curable resin composition is prepared using the amino resin, the viscosity increases and the workability deteriorates. The compounding ratio of the compound (A) and the amino resin (B) (compound (A) / amino resin (B)) is 9/1 to 2 /
8 is preferred, and 8/3 to 3/7 is more preferred. If the weight ratio of the compound (A) to the amino resin (B) is smaller than 2/8, the condensation reaction between the amino resins takes precedence, and the cured product becomes brittle.

The curable resin composition of the present invention preferably contains a curing agent. The curing agent is not particularly limited, but examples of the heat curing system include diisopropyl peroxydicarbonate, benzoyl peroxide, methyl ethyl ketone peroxide, t-butyl peroxy-2-ethylhexanoate, , 1,
3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-amylperoxy-2-ethylhexanoate, t-butyl hydroperoxide, t-butylperoxy neodikenate, t-butylperoxide Organic peroxides such as benzoate, azobisisobutyronitrile,
Azo compounds such as azobisdiethylvaleronitrile and the like can be mentioned. If necessary, a curing accelerator such as an organic metal salt or an organic amine can be used in combination. Examples of the photocuring system include benzoin ethers such as benzoin ethyl ether, benzoin isopropyl ether and benzoin isobutyl ether, benzyl ketals such as dimethoxyphenyl acetophenone and hydroxycyclohexyl phenyl ketone, acetophenones such as diethoxyacetophenone, benzophenone, and benzyl. ,
Examples include ketones such as 2-chlorothioxanthone, anthraquinone, methylphenylglyoxylate, and the like.

The mixing ratio of the curing agent is as follows.
The range is preferably 0.5 to 5 parts by weight with respect to 00 parts by weight. The curable resin composition of the present invention includes a known catalyst, for example, a mineral acid such as phosphoric acid, an organic acid such as methanesulfonic acid, and paratoluenesulfonic acid, in order to promote a dehydration condensation reaction and a dealcoholization condensation reaction. A heteropolyacid such as phosphotungstic acid and silicotungstic acid, and a Lewis acid such as aluminum chloride and tin chloride may be added.

The curable resin composition of the present invention can contain a compound (A) and a radically polymerizable unsaturated bond-containing compound. As the unsaturated bond-containing compound, for example, styrene, vinyl toluene, vinyl acetate,
Diallyl phthalate, and methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, polyethylene glycol (meth) acrylate, ethylene glycol di (meth) acrylate , Diethylene glycol di (meth) acrylate, triethylene glycol di (meth)
Acrylate, polyethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa ( Polymerizable monomers such as acrylates such as (meth) acrylate and methacrylates are exemplified. Furthermore, unsaturated polyester resin, vinyl ester resin, urethane (meth)
Resins such as acrylate resins and polyester (meth) acrylate resins are exemplified.

The curable resin composition of the present invention may contain a compound having a functional group capable of undergoing a condensation reaction with a hydroxyalkyl group or an alkyl ether group. The compound having a functional group capable of a condensation reaction is a compound containing a carboxyl group, a hydroxyl group, an amino group, a methylol group, an alkyl ether group, and an isocyanate group. For example, alkyd resins, (meth) acrylic copolymers, polyester resins, polyols and the like can be mentioned.

The curable resin composition of the present invention may further contain a known ultraviolet absorber, antioxidant, plasticizer, leveling agent, defoaming agent, antistatic agent, flame retardant, lubricant, Additives such as organic or inorganic fillers, reinforcing agents, and coloring agents are appropriately blended. The curable resin composition of the present invention,
It is produced by mixing the compound (A), the amino resin and various additives that are added as required by a known method.

The curable resin composition of the present invention can be easily cured by heating or irradiation with an activation energy ray such as ultraviolet ray, electron beam, or radiation after impregnation or application. The curable resin composition of the present invention is a treating agent for improving the surface hardness, moisture resistance and water resistance of a cellulosic base material used for decorative laminated paper used for decorative boards and insulating laminates for electric parts. In addition, it can be used as a fiber processing agent, wood processing agent, paint, adhesive, adhesive, coating agent, sealant, molding material, and the like.

[0032]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. In the examples, "parts" means "parts by weight" unless otherwise specified.
Shall be expressed. Production Example 1 (Synthesis example of compound (A) (α-hydroxymethyl acrylate)) 1 equipped with a thermometer, a gas injection pipe, a cooling pipe, a stirrer, and a water bath
In a 000 ml four-necked flask, 400 g (4 mol) of ethyl acrylate as a vinyl compound, and a 35% by weight aqueous solution of formaldehyde 86 as an aldehyde compound
g (1 mol), 98 g (0.5 mol) of a 30% by weight aqueous solution of trimethylamine as a tertiary amine compound, and
0.4 g of p-methoxyphenol as a polymerization inhibitor was charged. The ratio of p-methoxyphenol to ethyl acrylate is 1000 ppm. Thereafter, while blowing air into the above reaction solution, the reaction solution is
The mixture was reacted by stirring at 3 ° C. for 3 hours.

After completion of the reaction, the reaction solution was separated into an organic phase and an aqueous phase. Next, fractional distillation of the above organic phase was performed,
Colorless transparent liquid 11 which is a fraction of ~ 76 ° C / 5 mmHg
1 g was obtained. The substance was identified by measuring ¹ H-NMR, ¹³ C-NMR and infrared absorption spectrum (IR) of the colorless transparent liquid obtained as described above. As a result, the above-mentioned transparent liquid, which is a reaction product, becomes α
-Ethyl hydroxymethyl acrylate (hereinafter, EHMA)
Abbreviated).

Further, EHMA was quantified by using gas chromatography (GC). As a result, the yield of EHMA based on formaldehyde was 85 mol%,
The selectivity was 91 mol%. Examples 1 to 3 Curable resin compositions (1) to (3) were prepared at the mixing ratios shown in Table 1.

120 g of the above-mentioned curable resin composition was placed on 80 g / m ² weighed titanium paper (paper filled with titanium dioxide).
/ M ² to make a surface decorative paper, and laminate the decorative paper and kraft paper impregnated with a phenol resin as a core material, at a temperature of 150 ° C. and a pressure of 25 kg / cm by a plane press.
^2. Decorative board (1) by thermocompression bonding for 30 minutes
(3) was obtained. Comparative Example 1 Comparative curable resin composition (1) was prepared in the proportions shown in Table 1.

The comparative curable resin composition (1) was mixed with 1 piece of titanium paper (filled paper containing titanium dioxide) weighing 80 g / m ^2.
20 g / m ² was impregnated to make a surface decorative paper, this decorative paper and kraft paper impregnated with a phenol resin were laminated as a core material, and the temperature was 150 ° C. and the pressure was 25 kg with a plane press.
Comparative decorative board (1) was obtained by thermocompression bonding under the conditions of / cm ² and 30 minutes. Comparative Example 2 A methylated melamine resin as shown in Table 1 was used as a comparative curable resin composition (2).

The comparative curable resin composition (2) was added to 1 piece of titanium paper (filled paper containing titanium dioxide) weighing 80 g / m ^2.
It was impregnated with 20 g / m ² and air-dried at room temperature. In addition, 1
Hot air drying was performed at 00 ° C. for 15 minutes to obtain a surface decorative paper. This decorative paper and kraft paper impregnated with a phenol resin are laminated as a core material, and the temperature is 150 ° C. and the pressure is 25
Thermocompression bonding was performed under the conditions of kg / cm ² and a time of 30 minutes to obtain a comparative decorative plate (2).

Decorative panels (1) to (3) and comparative decorative panels (1) and (2) in Examples 1 to 3 and Comparative Examples 1 and 2
Was evaluated by the following test method. Surface hardness test: A test was carried out based on the scratch hardness A test of the JAS special plywood standard. Water resistance test: A test was carried out based on the water resistance A test of the JAS special plywood standard.

Contamination test: A test was carried out based on the contamination A test of the JAS special plywood standard. Crack resistance test: A test was carried out based on the impact B test of the JAS special plywood standard. Table 1 shows the evaluation results.

As shown in Table 1, in the decorative plates (1) to (3) of Examples 1 to 3, the surface hardness test, the water resistance test,
Good results were obtained in both the contamination test and the crack resistance test. On the other hand, the comparative decorative board (1) of Comparative Example 1
Thus, the compound (A) is not blended, and only the alkyd resin is blended. Therefore, there is no problem in drying property and crack resistance. However, since the affinity with the base material is low, the water resistance is poor. And it is easy to pollute. In the comparative decorative board (2) of Comparative Example 2, since the methylated melamine resin is used alone, the rigidity thereof is poor in flexibility and poor in crack resistance.

[0041]

[Table 1]

[0042]

When the curable resin composition of the present invention is used as a treating agent for a cellulosic substrate, the surface hardness of the cellulosic substrate can be maintained without impairing the flexibility of the cellulosic substrate after the treatment. And moisture resistance and water resistance can be improved.

Claims (2)

[Claims] (A) a compound represented by the general formula (1), and (Wherein, R ₁ is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group,
Hydroxyalkyl group having 1 to 8 carbon atoms, - (CH _{2) m}
It represents an NR ₂ R ₃ group or a — (C ₂ H ₄ O) _n R ₄ group.
R ₂ and R _{3 each} represent a linear or branched alkyl group having 1 to 8 carbon atoms. R ₄ represents a linear or branched alkyl group having 1 to 18 carbon atoms. R ₅ represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group, a hydroxyalkyl group having 1 to 12 carbon atoms, an oxirane group having 2 to 8 carbon atoms. m is an integer of 2 to 5, and n is an integer of 1 to 80. A curable resin composition containing (B) an amino resin as an essential component. 2. The curable resin composition according to claim 1, wherein the compound (A) contains a compound in which R ₅ is a hydrogen atom in the general formula (1).