JPH08104705A - Photocurable resin composition for motor balance - Google Patents

Abstract

PURPOSE: To obtain a resin composition which is photocurable, rapidly and reduced in sagging by mixing an ethylenically unsaturated compound with an inorganic filler, a catalyst having an absorption in the visible region and a catalyst which can be activated by heating. CONSTITUTION: This composition comprises a compound having at least one radical-polymerizable ethylenic unsaturation in the molecule, an inorganic filler, a catalyst having an absorption in the visible region and a catalyst which can be activated by heating. The inorganic filler is desirably glass beads or α-alumina. The specific gravity of the composition can be adjusted by varying the particle diameter of the glass bead and the amount of the beads added. The glass beads are desirably used in an amount of 200-700 pts.wt. per 100 pts.wt. above resin. α-Alumina is useful to adjust the flow of the resin during curing and is used desirably in an amount of 5-30 pts.wt. per 100 pts.wt. above resin. As compared with a conventional composition of this kind, this composition has an improved curing rate and substantially the same adhesive strength and is reduced in sagging during curing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition used for so-called balancing to correct unbalance during rotation in a rotating body for a rotary electric machine (hereinafter referred to as a motor balance resin composition). Regarding

[0002]

2. Description of the Related Art A rotating body of a rotary electric machine generates a lot of vibration when it is rotated if it is not perfectly balanced, but conventionally, in order to balance the rotation, many methods of removing the outer diameter of the rotating body are used. If it was taken.

However, in this method, since noise is generated during rotation, a putty-shaped resin or lead may be attached to the rotating body itself or screws may be embedded in place of the cutting process to balance the resin. Has been done.

Among these, in particular, at present, balancing using a putty-like epoxy resin is the mainstream.
No. 42, JP-A-3-41089, and JP-A-3-107646 describe a resin for balancing using a one-component epoxy resin, but any resin has a long curing time and can be automated. Considering it, the productivity is limited, and further, a general epoxy type resin composition for motor balance has scattering of resin at the time of unbalance check due to insufficient adhesion.

[0005]

Since most of the unbalanced motor correction is automated, it is considered that improvement in productivity leads to faster curing time, and during unbalance check. The resin scattering not only does not satisfy the function, but also leads to deterioration of work efficiency such as work for removing the scattered resin.

Therefore, the present invention pays attention to the curing speed of the photocurable resin and combines high specific gravity and thixotropy.
In addition, as a result of intensive studies on a photocurable resin, which has a strong adhesive strength and replaces the conventional resin for motor balance, a resin composition for motor balance which is photocurable, has high specific gravity, fast cure, and has little sagging property is provided. It came to do.

[0007]

In the present invention, therefore, (a) a compound having at least one radically polymerizable ethylenically unsaturated group in the molecule, (b) an inorganic filler, (c) visible The invention proposes a photocurable resin composition for motor balance, which comprises a catalyst having absorption in the light region, and (d) a catalyst which is activated by heating.

Here, the compound having at least one radically polymerizable ethylenically unsaturated group in the molecule, which is the binder component of the resin, is a compound which undergoes a polymerization reaction upon irradiation with light to be cured. It is a combination of a polymerization catalyst that generates a free radical upon irradiation and a compound having an addition-polymerizable ethylenically unsaturated group, and the polymerizable ethylenically unsaturated compound corresponds to the following compounds.

1) A compound having at least one (meth) acryloyl group in the molecule, and (a) a polymer having at least one (meth) acryloyl group in the molecule (for example, urethane diacrylate, epoxy diacrylate). , Polyester diacrylate, etc. are easily available.)

(B) A monomer having at least one (meth) acryloyl group in the molecule (for example, 2-hydroxyethyl acrylate, diethylene glycol acrylate, phenoxyethyl acrylate, etc. are easily available) and the like, These are single or a mixture of two or more.

2) An unsaturated acid such as maleic anhydride or fumaric acid is always contained as one component, and a saturated polybasic acid such as phthalic anhydride or isophthalic acid is used in combination therewith to obtain propylene glycol, ethylene glycol, etc. The resin obtained by esterifying with the polyhydric alcohol of 1) is dissolved in a polymerizable monomer having a reactive ethylenically unsaturated bond in the molecule.

In the present invention, the inorganic fillers added to the photocurable resin are glass beads and α-alumina.
The specific gravity of the glass beads can be adjusted by the particle size and the addition amount thereof, and the particle size and the addition amount are proportional to the cohesive force of the beads, and the adhesiveness with the motor also largely changes.

Glass beads are 20 per 100 parts by weight of resin.
0 to 700 parts by weight, preferably 500 to 600 parts by weight,
If the amount is less than 200 parts by weight, the effect of improving the adhesion to the motor cannot be seen for the above reason, and if the amount is more than 700 parts by weight, the problem of sagging during curing occurs.

Α-Alumina is useful for controlling the fluidity of the resin during curing, and the addition of α-alumina can suppress sagging during curing.

In the present invention, α-alumina is resin 10
It is 5 to 30 parts by weight, preferably 10 to 20 parts by weight with respect to 0 parts by weight.If it is less than 5 parts by weight, the sagging suppression effect is not exhibited, and if it is more than 20 parts by weight, the adhesive force with the motor is increased. Is reduced.

The catalyst which is activated by irradiation with visible light is
For example, the following are known. Complex initiator system of dye and aliphatic amine (JP-B-44-20189), system of hexaarylbiimidazole and radical generator and dye (JP-B-45-37377), hexaarylbiimidazole and ρ
-Dialkylaminobenzylidene ketone system
-2528), a system of a cyclic cis-α-dicarbonyl compound and a dye (JP-A-48-84183), a system of a carbonyl compound and a tertiary amine (JP-A-52-134692), and a (keto) coumarin. The system used (JP-A-52-112681), the system of substituted-triazine and merocyanine dye (JP-A-54-151024), the system of biimidazole and indanone (JP-A-54-155292), hexaarylbibi System of imidazole and ρ-dialkylaminocinamylidene derivative (JP-A-58-19315), system of triazine derivative and cyanine dye (JP-A-58-29803),
System of triazine derivative and thiapyrylium salt (JP-A-58-4)
No. 0302), a system of a hexaarylbiimidazole and an n-dialkylstilbenzene derivative or a p-dialkylaminophenylbutadiene derivative and a thiol compound (JP-A-59-56403), a system of a ketone-substituted derivative and an organic peroxide (JP-A-59-56403). 60-32801) Coumarin dyes and diaryliodonium salt systems (JP-A-60-88005), α-diketones and mercaptocarboxylic acid systems (JP-A-61-258802)
, Xanthene-based dye and photopolymerization accelerator system (JP-A-60-22
1403), a system of α-diketone and polysulfide (JP-A-61-258803), a system of xanthene dye, a radical generator and a peroxide (JP-A-62-143043), and a dye borate complex. System (JP-A-62-143044), a system of coumarin dye and organic peroxide (JP-A-63-23901), a system using titanocene (JP-A-63-41484), a boron-based complex Organic cationic dyes (JP-A-2-103544), systems using metal arene complexes (JP-A-2-296802), titanium compounds and substituted coumarin compounds (JP-A-3-239703), 3-ketocoumarin compounds (JP Kaihei 4-145102), onium compounds and acridine derivatives (JP-A-4-170546), metal arene compounds and squarylium dyes, N, N-dialkylanilines (JP-A-5-311093), naphthalocyanine compounds and s-triazines. Examples thereof include compounds (JP-A-5-301910).

The photocatalyst having sensitivity to visible light has a content of 0.1 to 5. with respect to 100 parts by weight of the ethylenically unsaturated compound.
It can be used in an amount of 0 parts by weight, preferably 0.5 to 3.0 parts by weight, but if it is less than 0.1 parts by weight, the curing rate will decrease, and 5.
If it is more than 0 parts by weight, deterioration of the cured product is promoted.

Examples of the catalyst activated by heat include an azo compound and an organic peroxide. Here, the azo compound means a compound represented by the general formula R ₁ -N = N-R ₂ (provided that R ₁ , R 2 ₂ is the same or different substituted or unsubstituted alkyl group or alkenyl group.).

Specifically, 2,2'-azoisobutyronitrile, 4,4'-azobis (4-cyanovaleric acid),
2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 1,1'-azobis- (cyclohexane-1-carbonitrile) ), 2,2'-azobisisobutyric acid dimethyl, 2,2'-azobis (2-methylpropionic acid), 2,2'-azobis (2-cyclobutylpropionic acid), 2,2'-azobis (2-cyclo) Butylpropionic acid), 2,2'-azobis [2- (3-
Hydroxyphenyl) butyric acid], 2,2′-azobis (4
-Nitrovaleric acid), 2,2'-azobis (4-chlorovaleric acid) and the like.

Typical organic peroxides include diacyl peroxides, dialkyl peroxides, ketone peroxides, peroxyesters, etc. Among them, particularly useful ones are halved for 10 hours. It is an organic peroxide having a temperature of 70 to 110 ° C.

Specifically, t-butylperoxy (2-ethylhexanoate), m-toluoyl peroxide,
Benzoyl peroxide, t-butyl peroxyisobutyrate, cyclohexanoate peroxide, t-butyl peroxide isobutyl isopropyl carbonate, t-butyl peroxyacetate, t-butyl peroxybenzoate, dibutyl peroxyisophthalate, dicumyl Examples thereof include peroxide.

The catalyst for generating radicals by these heats is 0.1% with respect to 100 parts by weight of the ethylenically unsaturated compound.
It can be used in an amount of up to 1.0 part by weight, preferably 0.3 to 0.7 part by weight, but if it is less than 0.1 part by weight, the curability will be poor, and if it is more than 1.0 part by weight, the storage stability will be extremely poor.

Instead of (c) the catalyst having absorption in the visible light region and (d) the catalyst activated by heating, (e) the catalyst having absorption in the visible light region and the infrared region can be used.

As a catalyst which is activated by irradiation with visible light or infrared light, a system of a metal arene compound and a cyanine compound (JP-A-4-102855), a metal arene compound, a squarylium dye and an N, N-dialkylaniline are used. Systems (JP-A-5-311093), naphthalocyanine compounds, N-aryl-α-amino acids or organic peroxide systems (JP-A-5-3030).
1910) and the like.

The catalysts having sensitivity in the visible and infrared regions are 0.1% by weight with respect to 100 parts by weight of the above ethylenically unsaturated compound.
It may be used in an amount of 1 to 1.0 parts by weight, preferably 0.3 to 0.7 parts by weight. If the amount is less than 0.1 part by weight, the curability will be poor, and if it is more than 1.0 part by weight, the cured product will deteriorate rapidly.

In the present invention, in addition to the above-mentioned filler,
Various additives such as a polymerization inhibitor, an adhesion improver and an antioxidant can be added.

The resin composition for motor balance according to the present invention can be cured with light including at least a visible light region and a wavelength region longer than the visible light region.

Examples of the light source for irradiating light in a wavelength range longer than visible light include a xenon lamp and a metal halide lamp. Further, in a long wavelength range, near infrared, infrared, far infrared lamp or sun. Rays are also suitable,
Among these, halogen lamps and infrared lamps are particularly suitable as a light source that efficiently emits visible light and infrared rays.

[0029]

In the system of the present invention, a compound having at least one polymerizable ethylenically unsaturated group in the molecule, a catalyst which is activated when the filler is irradiated with visible light and a catalyst which is activated by heating are blended. When irradiated with visible light or infrared light, the compound having an ethylenically unsaturated group on the surface first reacts and cures.

Since the filler does not transmit visible light or infrared rays, the internal compound does not cure, but the heat of curing reaction on the surface and the filler absorbs light to generate heat, so that light is not transmitted. The inside is also heated, and the heating cure activates the heat-curing catalyst, and the curing reaction proceeds to the inside. Therefore, in the present invention, a one-component resin composition having a fast curing time can be obtained.

When ultraviolet rays are used instead of visible light or infrared rays, the light transmission efficiency is extremely low as compared with visible light rays and infrared rays, so that the curing reaction is lowered and therefore the reaction heat is reduced. Internal curing becomes difficult.

Further, when the catalyst is only a catalyst which is activated by heating, not only the curability differs depending on the thermal conductivity of the filler, but also the curing speed is considered slow because the light source is used only as the heat source. .

On the other hand, in a system in which a compound having at least one polymerizable ethylenically unsaturated group in the molecule and a filler are mixed with a catalyst which is activated in the visible light and infrared regions, the surface is When the reaction proceeds, the catalyst is activated by the heat of reaction and the internal curing reaction proceeds, so that a one-component resin composition having a fast curing time can be obtained.

[0034]

Example: Binder resin (epoxy acrylate 40
To 60 parts by weight of isoboronyl acrylate), the initiator and the filler shown in Tables 1 and 2 below were added, and the mixture was stirred and mixed with a planetary mixer. Curing was performed using a 1 KW halogen lamp and a 375 W infrared lamp at an irradiation distance of 20 cm. The evaluation items were confirmed according to the following criteria.

(1) Thick film curability Resin was put in a φ32 × 10 mm polycap and the light irradiation time was 3
The cured film thickness after the measurement was measured.

(2) Specific gravity ○: 2.6 or more ×: 2.6 or less

(3) Adhesiveness 1 g of resin was partially adhered on a motor coil winding having a diameter of 100 mm, and after curing, the state was confirmed by rotating at 1000 rpm. ○: Those that do not scatter when the motor coil is rotated ×: Those that scatter when the motor coil is rotated

(4) Dripping upon curing A test piece of SPCC-SD 0.5 × 25 × 150 was bent vertically and a resin was partially adhered to the vertical surface to confirm the curing. ◯: No fluidity when cured Δ: Fluidity of 1 mm or less when cured ×: Fluidity of 1 mm or more when cured

(5) Heat resistance 1 g of resin was cured on a motor coil winding having a diameter of 100 mm and left at 150 ° C. for 10 days, and the presence or absence of change in appearance such as cracks and floating was observed. ◯: No change in appearance X: There is change in appearance The results are shown in Tables 1 and 2 below.

[0040]

[Table 1]

[0041]

[Table 2]

[0042]

As described above, according to the present invention, as compared with the conventional one-part epoxy resin type motor balance resin composition, the curing speed is improved and the adhesive strength is almost unchanged. A resin composition for use is obtained.

Further, according to the present invention, since the sagging at the time of curing is small and the curing speed is high, it is possible to automate the motor balance correction and improve the productivity.

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Claims (5)

[Claims] 1. A) a compound having at least one radically polymerizable ethylenically unsaturated group in the molecule b) an inorganic filler c) a catalyst having absorption in the visible light region d) a catalyst activated by heating A photocurable resin composition for motor balance, comprising: 2. A compound containing a) at least one radically polymerizable ethylenically unsaturated group in the molecule, b) an inorganic filler, and e) a catalyst having absorption in the visible and infrared regions. A photocurable resin composition for motor balance. 3. The photocurable resin composition for motor balance according to claim 1, wherein b) the inorganic filler is f) glass beads and g) α-alumina. 4. A compound having at least one radically polymerizable ethylenically unsaturated group in the molecule a).
0 parts by weight f) glass beads 200 to 700 parts by weight g) α-alumina 5 to 30 parts by weight c) catalyst having absorption in the visible light region 0.1 to 5.0 parts by weight d) catalyst activated by heating 0.1 to 1.0 parts by weight The photocurable resin composition for motor balance according to claim 1. 5. A compound having at least one radically polymerizable ethylenically unsaturated group in the molecule.
0 parts by weight f) glass beads 200 to 300 parts by weight g) α-alumina 5 to 30 parts by weight e) catalyst having absorption in the visible and infrared regions 0.1 to 1.
0 parts by weight