JP2003201350A - Chopped strand, and unsaturated polyester resin-bmc molding using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chopped strand which gives BMC moldings comprising a matrix of a unsaturated polyester resin containing no air bubbles in the moldings even at a high temperature and as has excellent mechanical strengths, and to provide a BMC molding using it. <P>SOLUTION: The chopped strand contains a binder which contain a urethane resin, a vinyl acetate resin and a silane coupling agent, with a mass ratio of the above urethane resin: the above vinyl acetate resin being of 30:70 to 70:30. The unsaturated polyester resin-BMC molding contains 100 pts. by mass of a matrix resin mainly consisting of an unsaturated polyester resin and 30-150 pts. by mass of this chopped strand. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass chopped strand (hereinafter referred to as CS) used for a BMC molded product mainly composed of unsaturated polyester as a matrix resin, and an unsaturated polyester resin BMC using the same.
Regarding a molded body.

[0002]

BACKGROUND OF THE INVENTION Glass fibers are widely used as reinforcing fibers for producing FRP. Industrially, glass fibers are often used in the form of glass fiber bundles in which a large number of glass fibers drawn from a bushing are bundled,
A sizing agent containing a silane coupling agent and a film-forming agent is used in order to improve the workability by preventing fluffing and yarn breakage during handling in the manufacturing process (yarning process) and improving the workability. Attached. The glass fiber bundle (strand) thus produced is dried and used as a resin-reinforcing fiber. Then, a vulg molding compound (BMC) obtained by uniformly kneading a cut product of strands (chopped strand, abbreviated as CS) and a resin to disperse glass fibers in the resin is used as a molding material for producing FRP. Has been done. This BMC molded product is widely used in various applications because of its advantages such as strength, heat resistance and dimensional stability.

Among them, as a molded product used for a reflecting mirror of a headlamp mounted on an automobile or the like, a thermosetting resin is used because it is necessary to endure high heat generated from the lamp during use, and as a matrix resin. Unsaturated polyester resin BMC moldings mainly composed of unsaturated polyester have been conventionally used.

Such unsaturated polyester resin BMC
As a molded body, for example, in JP-A-5-293823, a sizing agent is applied to the surface as a BMC molded body having high strength while maintaining excellent characteristics of the molded body produced by the BMC molding method. A glass chopped strand obtained by bundling a group of glass filaments into a glass strand and then cutting the glass filament is used as a reinforcing material in a BMC molded body, wherein an undisentangled glass chopped strand is used for all the glass filaments. The BMC molding wherein the number of glass filaments constituting the above is 0.1% or more, preferably, the styrene solubility of the sizing agent is 40% or less, and the impregnation time of the unsaturated polyester resin is 10 minutes or less. The body is disclosed.

[0005]

However, when a BMC molded body is used as the reflecting mirror surface of a lamp as described above, a primer is applied to the surface of the molded BMC molded body, and then metal evaporation is performed as a reflective film. Is given. For this reason, it is necessary to apply a primer to the surface of the molded product, and then level and heat-cur it, and the molded product is exposed to a high temperature of 100 ° C. or higher. It is required to maintain sex.

However, when the BMC molded product is heated after the primer is applied, the bubbles existing in the molded product expand and move to the surface of the molded product due to the temperature rise due to heating, which sometimes causes a defect in the surface appearance. That is, when air bubbles are generated on the surface of the molded body, the air bubbles push up the primer coating film, and this causes a bubble-like defect, resulting in poor appearance and a problem that the yield of the vapor deposition process is reduced.

The air bubbles are derived from the air contained between the matrix resin and the CS, and depending on the degree of impregnation of the matrix resin into the CS and the nature of the sizing agent for focusing the CS, It is thought that it occurs by such a mechanism.

First, when the sizing agent component of the CS is rigid, the matrix resin does not penetrate into the CS, and the wetting property between the filament inside the CS and the matrix resin is not sufficiently ensured. Therefore, an air layer exists at the interface between the filament and the matrix resin, and appears as bubbles when heat-treated.

An example of such a rigid sizing agent is urethane resin. When the matrix resin is an unsaturated polyester resin, a styrene monomer is usually used as a typical crosslinking agent, but the urethane resin is relatively insoluble in the styrene monomer. Therefore, the sizing agent is likely to be rigid and bubbles are likely to be present therein.

Therefore, the above-mentioned Japanese Patent Laid-Open No. 5-29382.
In the BMC molded body of Japanese Unexamined Patent Publication No. 3 publication, the number of glass filaments constituting the undisentangled glass chopped strand is 0.1% or more, and the styrene solubility of the sizing agent is 40%.
Although the strength can be improved by the following, there is a problem that the wetting property of the filament inside the CS and the matrix resin is not sufficiently secured due to insufficient dissolution of the sizing agent, and the presence of air bubbles cannot be avoided.

On the other hand, if the sizing agent component of CS is softened in order to improve the wettability (impregnating property) between CS and the matrix resin, the CS is loosened during kneading with the matrix resin to form a monofilament. By this monofilament formation, the volume of the kneaded product expands, and air is trapped between the filaments. The air trapped in this material cannot be completely degassed during molding and remains in the molded product, causing bubble-like defects.

Further, in terms of strength, when the wetting characteristics of CS are improved, the bending strength is improved, but the impact strength is also decreased.

Examples of such a soft sizing agent include vinyl acetate resin. Vinyl acetate resin
Since the solubility of styrene monomer is high, the wettability between CS and the matrix resin is improved. However, the above phenomenon also tends to cause bubbles, and the impact strength is lowered.

From the above points, in the BMC molding material mainly composed of unsaturated polyester resin as the matrix resin, in order to prevent bubbles from being present while maintaining the mechanical strength, the CS sizing agent is CS Having a proper wettability between each filament and the matrix resin inside,
In addition, good bundling property is required without volume expansion due to monofilament formation during BMC kneading. However, it has been impossible to satisfy both of the conventional sizing agents at the same time.

Therefore, an object of the present invention is to mainly use unsaturated polyester in order that the unsaturated polyester resin BMC molded article does not generate bubbles on the surface of the molded article even at high temperature and has excellent impact strength. C which has appropriate wettability and good bundling property for the matrix resin
It is to provide S and an unsaturated polyester BMC molded product using the same.

[0016]

In order to solve the above problems, a chopped strand of the present invention is a chopped strand obtained by impregnating a glass fiber bundle used for an unsaturated polyester resin BMC molded body with a sizing agent. The agent contains a urethane resin, a vinyl acetate resin, and a silane coupling agent, and the mass ratio of the urethane resin and the vinyl acetate resin is 30:70 to 70:30.

According to this, since the urethane resin and the vinyl acetate resin are contained as a sizing agent in a predetermined ratio, the CS
The wettability between each filament and the matrix resin can be appropriately obtained, and at the same time, volume expansion due to monofilament formation during BMC kneading can be prevented. Therefore, BMC obtained by using an unsaturated polyester resin as a matrix
It is possible to prevent bubbles from being generated on the surface of the molded product when the molded product is at a high temperature. In addition, since the wettability between each filament in CS and the matrix resin becomes appropriate, B which is excellent in impact strength
An MC molded product can be obtained.

In a preferred embodiment of the chopped strand of the present invention, the urethane resin is mainly composed of an isocyanate component and a polyol component, and as the isocyanate component, dicyclohexylmethane-4,4-diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, tritrimethylene diisocyanate, It contains at least one kind of diisocyanate and, as a polyol component, at least one kind of a polyester polyol composed of polybutylene adipate or polyhexamethylene adipate, or a polyether polyol composed of polyoxypropylene polyol or polyoxybutylene polyol.

By using the urethane resin having the above-mentioned isocyanate component and polyol component, the rigidity of the urethane resin is relaxed and the styrene monomer swells to an appropriate degree, so that the wettability between each filament and the matrix resin is appropriately obtained. In addition, since CS is prevented from being excessively disentangled, it is possible to prevent the presence of air bubbles during kneading.

In another preferred embodiment of the chopped strand of the present invention, the vinyl acetate resin contains a silanol group. By containing the silanol group,
Vinyl acetate will swell moderately, its solubility in styrene monomers will be suppressed, CS will be prevented from unnecessarily falling apart and becoming monofilaments, and since the wettability of the matrix resin and monofilaments is improved, It is possible to prevent the formation of bubbles in the molded body.

In yet another preferred embodiment of the chopped strand of the present invention, the silane coupling agent is
It is amino-based and / or acrylic-based. This gives C
Since the adhesion between S and the matrix resin is improved, inclusion of bubbles can be effectively prevented.

In a further preferred embodiment of the chopped strand of the present invention, in the solubility test of the sizing agent, the ratio of the sizing agent to the mass of the sizing agent after immersion for 60 minutes in styrene monomer is 3 times. ~ 25%. When the solubility is in this range, the wettability of CS is appropriately maintained, so that the formation of bubbles in the molded body can be prevented.

In a further preferred embodiment of the chopped strand of the present invention, in the swelling test of the sizing agent, a coating of the sizing agent having a 4: 1 aspect ratio of the sizing agent is dipped in a styrene monomer for 60 minutes, and then the coating is obtained. The ratio to the length before immersion in the length direction is 1.5 to 2.5 times. When the degree of expansion is in this range, CS can be prevented from being unnecessarily loosened to form a monofilament, and the wettability between the matrix resin and the monofilament is improved, so that the formation of bubbles in the molded body can be prevented.

As another preferred embodiment of the chopped strand of the present invention, in the focusing test of the chopped strand containing the sizing agent, after the chopped strand is immersed in acetone and stirred for 250 seconds,
The volume increase ratio before immersion is 30% or less. When the focusing property is within this range, it is possible to prevent CS from being unnecessarily loosened and becoming a monofilament, so that it is possible to prevent generation of bubbles in the molded body.

As a further preferred embodiment of the chopped strand of the present invention, in the focusing test of the chopped strand containing the sizing agent, after the chopped strand is stirred with a steel ball for 5 minutes by a paint shaker, The mass of the fluff remaining on the sieve having an opening of 4 mm is 1% or less with respect to the amount of the chopped strands introduced. When the focusing property is within this range, fluff is not generated in the pipe during product transportation, good handling property is obtained, and strand defibration is small in the initial stage before kneading. Therefore, the progress of defibration of the strands when kneading with the matrix resin can be delayed, and as a result, generation of bubbles in the molded body can be prevented.

On the other hand, the unsaturated polyester resin B of the present invention
The MC molded body is a BMC molded body molded using the above chopped strands, and contains 30 to 150 parts by mass of the chopped strands with respect to 100 parts by mass of a matrix resin mainly composed of unsaturated polyester resin. Characterize.

As a result, the mechanical strength is excellent and
It is possible to obtain a BMC molded product that does not generate bubbles on the surface of the molded product even after being exposed to a high temperature after molding.

As a preferred embodiment of the unsaturated polyester resin BMC molded product of the present invention, in the swelling test of the unsaturated polyester resin BMC molded product, after coating the surface of the molded product with a primer, it is heated for 60 minutes in an atmosphere of 180 ° C. Sometimes, the number of swells on the surface of the molded body is zero. As a result, even if exposed to a high temperature after molding, bubbles will not be generated on the surface of the molded body.

In another preferred embodiment of the unsaturated polyester resin BMC molded product of the present invention, the unsaturated polyester resin BMC molded product is obtained by injection molding,
The molded body is used for a lamp reflector. Since this molded body does not generate bubbles on the surface of the molded body even after being exposed to a high temperature after molding, it is particularly suitable as a molded body that requires a smooth surface for vapor deposition such as a lamp reflector.

As still another preferred embodiment of the unsaturated polyester resin BMC molded product of the present invention, the strength of the unsaturated polyester resin BMC molded product molded by injection molding is the bending strength and Izod impact specified in JIS-K6911. In the strength test, the bending strength is 65 MPa or more, and the notched Izod impact strength is 60 J.
/ M or more. This makes it possible to obtain a molded article that is excellent not only in the prevention of air bubbles but also in mechanical strength such as bending strength and impact strength. Therefore, the present invention can be applied to a portion where vibration is severe, as represented by a lamp reflector of an automobile or the like. The molded product of can be preferably used.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. First, the CS containing the sizing agent of the present invention will be described.

The CS of the present invention contains a urethane resin, a vinyl acetate resin, and a silane coupling agent as a sizing agent, and the mass ratio of the urethane resin and the vinyl acetate resin is 30:70 to 70:30. It is a glass chopped strand.

As the glass fiber, conventionally known ones can be used, and as the glass composition, A glass, E glass and E glass can be used.
Although CR glass, S glass, AR glass and the like can be exemplified, it is particularly preferable to use glass fiber having an E glass composition which is inexpensive and widely used.

The urethane resin is not particularly limited, but is preferably one mainly containing an isocyanate component and a polyol component, and as the isocyanate component, at least dicyclohexylmethane-4,4-diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate and tolylene diisocyanate are used. It is particularly preferable to contain at least one of the polyester polyol containing polybutylene adipate or polyhexamethylene adipate or the polyether polyol containing polyoxypropylene polyol or polyoxybutylene polyol as the polyol component.

As the vinyl acetate resin, conventionally known ones are used, and although not particularly limited, cross-linking type resins are preferably used because of low solubility in styrene. Above all, a cross-linking type vinyl acetate resin containing a silanol group is particularly preferably adopted because it has low solubility in a styrene monomer and has swelling property.

The sizing agent of the present invention must contain the urethane resin and the vinyl acetate resin in a mass ratio of 30:70 to 70:30, and further 40:60 to 60 :.
It is preferably 40. As a result, the filaments in CS and the matrix resin have appropriate wettability,
At the same time, volume expansion due to monofilament formation during BMC kneading can be prevented at the same time.

When the amount of the urethane resin is less than 30% or the amount of the vinyl acetate resin is more than 70%, the sizing agent component of CS is softened, the CS is loosened during the kneading with the matrix resin, and the filament is formed into a monofilament. Is unfavorable because the volume of the resin expands and entraps air between the filaments, and when the amount of urethane resin is more than 70% or the amount of vinyl acetate resin is less than 30%, the sizing agent component is It becomes rigid, the matrix resin does not penetrate into the CS, the wetting characteristics of the filament inside the CS and the matrix resin are not sufficiently secured, and an air layer is likely to exist at the interface between the filament and the matrix resin, which is not preferable. The amount of the sizing agent, which is a combination of urethane resin and vinyl acetate, is preferably 0.2 to 2.0 parts by mass with respect to 100 parts by mass of glass fiber.

As described above, according to the present invention, a predetermined amount of a vinyl acetate resin which is soluble in styrene monomer which is a crosslinking agent for unsaturated polyester resin and a urethane resin which is insoluble in styrene monomer and swells. By mixing, each filament in CS and the matrix resin can be appropriately wetted, and volume expansion due to monofilament formation at the time of kneading BMC can be prevented at the same time, so that a BMC molded product obtained by using an unsaturated polyester resin as a matrix can be obtained. It is possible to prevent air bubbles from being generated on the surface of the molded product at high temperature.

Further, the sizing agent of the present invention contains a silane coupling agent. The silane coupling agent is not particularly limited, and at least one alkoxy group selected from the group consisting of a methoxy group and an ethoxy group, an amino group, a vinyl group, an acryl group, a methacryl group, an epoxy group, a mercapto group, and a halogen. An atom, a silane coupling agent having at least one reactive functional group selected from the group consisting of an isocyanate group can be exemplified, and above all, an amino coupling agent having an amino group or an acrylic coupling agent having an acrylic group Coupling agents are preferred, and it is more preferred to use both at the same time. Further, the amount of the coupling agent added is preferably 0.1 to 1.0 parts by mass with respect to 100 parts by mass of the sizing agent.

Next, the solubility and swelling degree of the sizing agent will be described. In the present invention, since the sizing agent has the following test physical properties, the wettability between each filament in CS and the matrix resin is appropriately obtained, and BM
Volume expansion due to monofilament formation during C kneading can also be prevented.

First, in the solubility test of the sizing agent of the present invention, the ratio of the sizing agent to the mass of the sizing agent before immersion is 3 to 25% after 60 minutes of immersion in the styrene monomer.
Is preferred.

Here, the solubility test in the present invention means
It means the solubility of an unsaturated polyester resin in a styrene monomer which is a cross-linking agent, and this affects the wettability of CS with a matrix resin. In particular,
50g CS and styrene monomer 1 in a polyethylene container
It means the numerical value obtained by the ratio of the adhesion amount after charging 00 g, leaving it for 60 minutes at room temperature and taking it out, compared with the initial adhesion amount.

When the above ratio is less than 3%, the resin is not sufficiently impregnated, the BMC molded article has a low bending strength, and
It is not preferable because the possibility that air will intervene in the unimpregnated portion becomes high, and if it exceeds 25%, the impregnation into the resin becomes excessive and impact strength becomes low, which is not preferable.

In the swelling test, the sizing agent of the present invention has a length of the sizing agent of 4: 1 aspect ratio after being dipped in styrene monomer for 60 minutes, before being dipped in the longitudinal direction of the coating. It is preferable that the ratio to the height is 1.5 to 2.5 times.

Here, the expansion test in the present invention means
It means the degree of swelling of the unsaturated polyester resin with respect to the styrene monomer, which is a cross-linking agent, and this affects the difficulty of dispersion when the CS is kneaded with the matrix resin. Specifically, the sizing agent is cast on a flat plate to prepare a strip-shaped film having a thickness of 0.1 mm, a width of 10 mm, and a length of 40 mm, and the film is allowed to stand in a dryer at 120 ° C. for 1 hour. After completely removing the water by immersing it in 50 g of styrene monomer at room temperature for 60 minutes, it means the numerical value obtained by the ratio of swelling in the length direction.

If the above ratio is less than 1.5, the bending strength of the molded product will be poor, and the possibility that air will intervene in the unimpregnated portion is not preferable, and if it exceeds 2.5, the impact of the molded product will be poor. It is inferior in strength and is not preferable.

The sizing agent of the present invention preferably has a diameter of 6 to 23 μ drawn from the bushing by a conventionally known method.
It is given when a large number of m glass fibers are bundled. CS can be obtained by cutting the glass strand thus obtained into an appropriate length. The length of CS is not particularly limited, but is preferably in the range of 1.5 to 25 mm.

Next, the CS focusing test will be described. In the present invention, the CS containing the sizing agent preferably has the following test physical properties, whereby it does not contain bubbles even after molding and excellent mechanical properties can be obtained.

First, in the focusing test of chopped strands containing the sizing agent of the present invention, the chopped strands were immersed in acetone and stirred for 250 seconds,
The volume increase ratio before immersion is preferably 30% or less.

Here, the focusing test by immersion in acetone in the present invention means that the bulkiness of CS in acetone is measured to measure the focusing property of CS. This is to quantify the ease of containing air. Specifically, acetone 2
It means the volume increase rate when 20 g of CS was added to 00 cc and the volume of CS before and after stirring was measured for 250 seconds with a shaker.

If the volume increase rate exceeds 30%, CS becomes monofilament and entraps air bubbles during kneading with the resin, which is not preferable.

In addition, in the test of the chopped strands containing the sizing agent of the present invention, the mass of the fluff remaining on the sieve having an opening of 4 mm after stirring the chopped strands with a steel ball for 5 minutes with a paint shaker Is preferably 1% or less with respect to the amount of the chopped strands added.

In the present invention, the sizing property of CS is also measured by a sizing test using a paint shaker, whereby the ease of containing air during the kneading of the CS into the matrix resin can be quantified. Here, the convergence test by the paint shaker in the present invention means CS
Put 500 g into a cylindrical container with a capacity of 980 cm ³ and add 4 more
It means the mass ratio of the fluff remaining on the sieve having a mesh of 4 mm after adding 5 g / piece of 5 steel balls and stirring at high speed for 5 minutes.

If the mass of the fluff exceeds 1%, fluff is generated during product transportation, clogging occurs in the pipe, and CS is easily defibrated, so that even when kneaded with the resin. It is not preferable because it facilitates defibration.

Next, an unsaturated polyester resin BMC molded product molded by BMC using the above CS will be described.

The unsaturated polyester BMC molded product of the present invention comprises an unsaturated polyester as a matrix resin, a polymerizable monomer having a double bond in one molecule as a crosslinking agent at the time of curing the unsaturated polyester, and , A thermoplastic resin for the purpose of suppressing shrinkage during curing of unsaturated polyester. The unsaturated polyester resin has a Tg (glass transition temperature) of 150 ° C. or higher, preferably 160 ° C. or higher, when the unsaturated polyester is cured.

As the polymerizable monomer, styrene monomer, vinyltoluene, divinylbenzene, methylmethacrylate, paramethylstyrene, diallylphthalate,
And diallyl isophthalate and the like,
These polymerizable monomers may be used either individually or in combination of two or more.

Examples of the thermoplastic resin include styrene type copolymers, polyethylene, polyvinyl chloride, polyvinyl acetate, polymethyl methacrylate, polymethyl methacrylate type copolymers, modified ABS resins, polycaprolactone and modified polyurethane. be able to. In particular, acrylic resins (including copolymers) such as polymethylmethacrylate and polymethylmethacrylate copolymers, vinyl acetate resins (including copolymers) such as polyvinyl acetate and styrene-vinyl acetate copolymers. Are preferable in terms of dispersibility, low shrinkage and rigidity.

The composition ratio of the above matrix resin is such that 30 parts of unsaturated polyester is contained in 100 parts by weight of matrix resin.
To 60 parts by mass, 25 to 60 parts by mass of polymerized monomer, and 8 to 35 parts by mass of thermoplastic resin are preferable, and 35 to 50 parts by mass of unsaturated polyester and 37 to 5 parts of polymerized monomer are more preferable.
0 parts by mass and 10 to 25 parts by mass of the thermoplastic resin.

The ratio of CS to matrix resin of the unsaturated polyester BMC molded product of the present invention is preferably 30 to 150 parts by mass of CS with respect to 100 parts by mass of matrix resin.

When the amount of CS is less than 30 parts by mass, the fiber reinforcement is insufficient and the mechanical strength is lowered, which is not preferable, and when it exceeds 150 parts by mass, CS which is not impregnated in the matrix resin exists and BMC is not present. It is not preferable because air is often entrained in the material, the surface property of the BMC molded product is deteriorated, the foaming at the time of primer treatment and the fluidity are deteriorated, and the BMC moldability is deteriorated.

The unsaturated polyester resin BM of the present invention
A curing catalyst that initiates the curing reaction of the unsaturated polyester resin can be appropriately used for the C molded body. As the curing catalyst, t-butylperoxybenzoate, t-butylperoxy-2 ethylhexanoate, t-butyl-peroxyisopropyl carbonate, t-butylperoxyisopropyl carbonate, 1,1-bis (t
-Butylperoxy) 3,3,5-trimethylcyclohexane and other organic peroxides are preferably used. The addition amount of the curing catalyst is preferably 0.5 to 5.0 parts by mass with respect to 100 parts by mass of the matrix resin, and more preferably,
It can be used in an amount of 1.0 to 4.0 parts by mass.

Various inorganic fillers known in the art can be added to the polyester resin BMC molded product of the present invention. Examples thereof include calcium carbonate, mica, talc, graphite, carbon black, asbestos, aluminum hydroxide and the like. Especially the average particle size is 0.2-2
It is preferable that 230 μm to 380 parts by mass of 0 μm calcium carbonate is mixed with 100 parts by mass of the matrix resin. As a result, it is possible to secure an appropriate fluidity necessary for performing injection molding to obtain the polyester resin BMC molded body.

Further, in the polyester resin BMC molded product of the present invention, an internal release agent can be used in order to easily remove the low shrinkable molded product from the mold. For example,
Fatty acid metal salts such as zinc stearate, magnesium stearate, calcium stearate and aluminum stearate are preferably used. The addition amount thereof is preferably 2 to 10 parts by mass, more preferably 3 to 8 parts by mass with respect to 100 parts by mass of the matrix resin. If it is 2 parts by mass or more, stable demolding can be performed at the time of molding without causing cracks in the molded product, and if it is 10 parts by mass or less, primer coating can be easily performed on the surface of the molded product. In addition, it is possible to sufficiently secure the leveling property and adhesion of the coating.

Furthermore, the polyester resin BMC molded product of the present invention may further contain a pigment and a thickener such as magnesium oxide or calcium oxide, if necessary.

The unsaturated polyester BMC molding of the present invention can be molded by injection molding, transfer molding,
Injection compression molding or the like can be used.

The unsaturated polyester resin BMC molded product obtained by the above injection molding has a bending strength of 65 MPa or more and a notched Izod impact strength in a bending strength and Izod impact strength test specified in JIS-K6911. Is preferably 60 J / m or more. As a result, not only the prevention of bubble generation, but also a molded product having excellent mechanical properties such as bending strength and impact strength can be obtained.
The molded product of the present invention can be suitably used even in a portion where vibration is severe, as represented by a lamp reflector of an automobile or the like.

In the swelling test, it is preferable that, in the swelling test, the number of swelling on the surface of the molded product is 0 when the molded product is coated with a primer and then heated in an atmosphere of 180 ° C. for 60 minutes.

Here, the swelling test in the present invention means that the surface of the molded article is spray-coated with an acrylic or polybutadiene-based paint as a primer by 10 to 20 μm.
It means the number of occurrence of bubble-like appearance defects per 900 cm ² of the surface of the molded product when it is cured at 180 ° C. for 60 minutes after being applied, and this is the number of swelling.

When the number of bulges is 0, it is possible to obtain a BMC molded body having a sufficient bubble generation preventing effect even when used in the above-mentioned lamp reflecting mirror.

The molded article of the present invention thus obtained can be used for various purposes, but as described above, bubbles are not generated even when exposed to high temperature after molding,
Since the smoothness of the surface can be maintained even when a primer is applied to the molded body, it is preferably used as a molded body for a lamp reflector such as an automobile.

[0072]

EXAMPLES The present invention will be described in more detail below with reference to examples.

Example 1 3.4 parts by mass of a vinyl acetate resin, the isocyanate component being dicyclohexylmethane diisocyanate (H ₁₂ MD
I), a sizing agent comprising 3.4 parts by mass of a urethane resin whose polyol component is polyhexamethylene adipate (PHA), 0.2 parts by mass of an amino silane coupling agent, and 0.2 parts by mass of an acrylic silane coupling agent. Was prepared.

Next, 1000 glass fibers were bundled into glass strands while applying the above-mentioned sizing agent to the glass fibers having a diameter of 13 μm drawn out from the bushing by a conventional method, and the glass strands were cut to obtain a length. 6 mm
The CS of Example 1 was obtained.

Further, using 90 parts by mass of this CS, 38 parts by mass of an unsaturated polyester, 16 parts by mass of a thermoplastic resin (polymethyl methacrylate resin), 46 parts of a styrene monomer.
Parts by mass, internal release agent (zinc stearate) 6 parts by mass, thickener (magnesium oxide) 0.4 parts by mass, catalyst (t-butyl peroxybenzoate) 3 parts, inorganic filler (average particle size 5 μm) 260 parts of calcium carbonate) was kneaded with a raw material according to a conventional method, and the unsaturated polyester resin BMC molding of the example was manufactured by an injection molding method.

Example 2 A CS of Example 2 was obtained under the same conditions as in Example 1 except that tolylene diisocyanate was used as the isocyanate component and polyoxypropylene glycol was used as the polyol component among the urethane resin components. In addition, this CS is used in the first embodiment.
BMC molding was carried out under the same conditions as above to obtain a BMC molded body of Example 2.

Example 3 The CS of Example 3 was obtained under the same conditions as in Example 1 except that the vinyl acetate resin was 4.4 parts by mass and the urethane resin was 2.4 parts by mass. Further, this CS was BMC molded under the same conditions as in Example 1 to obtain a BMC molded body of Example 3.

Example 4 A CS of Example 4 was obtained under the same conditions as in Example 1 except that 2.4 parts by mass of vinyl acetate resin and 4.4 parts by mass of urethane resin were used. Further, this CS was BMC molded under the same conditions as in Example 1 to obtain a BMC molded body of Example 4.

Example 5 A CS of Example 5 was obtained under the same conditions as in Example 1 except that xylene diisocyanate was used as the isocyanate component and polycarbonate polyol was used as the polyol component of the urethane resin. Further, this CS was BMC molded under the same conditions as in Example 1 to obtain a BMC molded body of Example 5.

Comparative Example 1 The CS of Comparative Example 1 was prepared under the same conditions as in Example 1 except that the vinyl acetate resin was not used in the sizing agent of Example 1 and the urethane resin was changed to 6.8 parts by mass. Got Also,
This CS was BMC molded under the same conditions as in Example 1 to obtain a BMC molded body of Comparative Example 1.

Comparative Example 2 The CS of Comparative Example 2 was prepared under the same conditions as in Example 1 except that the urethane resin was not used in the sizing agent of Example 1 and the vinyl acetate resin was changed to 6.8 parts by mass. Got Also, this CS was BMC molded under the same conditions as in Example 1,
A BMC molded body of Comparative Example 2 was obtained.

Comparative Example 3 Example 1 was repeated except that the sizing agent of Example 1 was changed to 1.4 parts by mass of vinyl acetate resin and 5.4 parts by mass of urethane resin (vinyl acetate: urethane resin = 2: 8). Under the same conditions, CS of Comparative Example 3 was obtained. Further, this CS was BMC molded under the same conditions as in Example 1 to obtain a BMC molded body of Comparative Example 3.

Comparative Example 4 Example 1 was repeated except that the sizing agent of Example 1 was changed to 5.4 parts by mass of vinyl acetate resin and 1.4 parts by mass of urethane resin (vinyl acetate: urethane resin = 8: 2). Under the same conditions, CS of Comparative Example 4 was obtained. Further, this CS was BMC molded under the same conditions as in Example 1 to obtain a BMC molded body of Comparative Example 4.

Comparative Example 5 Using 28 parts by mass of CS of Example 1, 38 parts by mass of unsaturated polyester, 16 parts by mass of thermoplastic resin (polymethylmethacrylate resin), 46 parts by mass of styrene monomer, internal release agent (stearin) Zinc acid) 6 parts by mass, thickener (magnesium oxide) 0.4 parts by mass, catalyst (t-butylperoxybenzoate) 3 parts, inorganic filler (average particle size 5 μm)
260 parts of calcium carbonate) was kneaded according to a conventional method, and an unsaturated polyester resin BMC molded product of Comparative Example 5 was obtained by an injection molding method.

Comparative Example 6 Using 155 parts by mass of CS of Example 1, 38 parts by mass of unsaturated polyester, 16 parts by mass of thermoplastic resin (polymethyl methacrylate resin), 46 parts by mass of styrene monomer, internal release agent (stearin) Zinc acid) 6 parts by mass, thickener (magnesium oxide) 0.4 parts by mass, catalyst (t-butylperoxybenzoate) 3 parts, inorganic filler (average particle size 5 μm).
m calcium carbonate) was mixed and kneaded according to a conventional method, and an unsaturated polyester resin BMC molded product of Comparative Example 6 was obtained by an injection molding method.

Test Example 1 With respect to the CS and the sizing agent obtained in Examples 1 to 5 and Comparative Examples 1 to 4, the items of acetone sizing property, paint shaker sizing property, solubility, and swelling property were measured by the above-described measuring methods. It measured and evaluated the converging property etc. of CS. The results are summarized in Table 1.

[0087]

[Table 1]

From the results shown in Table 1, all the evaluation items of Examples 1 to 5 were within the preferred range specified in the present invention. In contrast, Comparative Example 1 had a low solubility of 1%. Further, in Comparative Example 2,
All of the evaluation items were outside the preferred range specified in the present invention, and in Comparative Examples 3 and 4, the paint shaker focusing property and solubility were outside the preferred range specified in the present invention.

Test Example 2 Test pieces were prepared using the BMC molded bodies of Examples 1-5 and Comparative Examples 1-6, and the bending strength and notched impact strength were measured according to the test method of JIS-K6911. In addition, 10 flat plates of 900 cm ² were molded by injection molding, 15 μm of acrylic paint as a primer paint was applied and then cured at 180 ° C. for 60 minutes, and the number of appearance defects after aluminum vapor deposition was measured as a swelling number. Then, the surface smoothness was evaluated by a swelling test. The results are summarized in Table 2
Shown in.

[0090]

[Table 2]

From the results of Table 2, in Examples 1-5, no bubbles were generated and the surface smoothness was excellent, while in Comparative Examples 1-4.
Also, in Comparative Example 6, it can be seen that the surface smoothness is poor. Further, compared to Examples 1 to 5, Comparative Examples 1 and 3 are inferior in bending strength, Comparative Examples 2, 4 and 5 are inferior in impact strength, and molded articles having sufficient mechanical strength can be obtained. I see that I can't.

[0092]

As described above, by using the CS of the present invention, when a BMC molded product having an unsaturated polyester resin as a matrix is used, bubbles are not generated on the surface of the molded product even at high temperature, and It is possible to obtain a molded product having excellent mechanical strength. Therefore, it can be suitably used as, for example, a molded body for a lamp reflecting mirror that is exposed to a high temperature after molding.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) D06M 101: 00 D06M 101: 00 (72) Inventor Hideki Endo 3-6-3, Kanda Blacksmith, Chiyoda-ku, Tokyo Asahi Fiber Glass Co., Ltd. (72) Inventor Manabu Iizuka 3-6-3 Kanda Kajimachi, Chiyoda-ku, Tokyo 3 Asahi Fiber Glass Co., Ltd. (72) Inventor Hisayoshi Ocho 500 Kitawaki, Shimizu City, Japan Koito Manufacturing Co., Ltd. Shizuoka Factory (72) Inventor Hidetaka Tanaka 500 Kitawaki Shimizu City, Shizuoka Prefecture Koito Manufacturing Co., Ltd.Shizuoka Factory (72) Inventor Yuji Yoshimoto 500 Kitawaki Shimizu City, Shizuoka Prefecture Koito Manufacturing Shizuoka Factory F-term (reference) 4F072 AA02 AA08 AB09 AB22 AC02 AC06 AC08 AC14 AD08 AD38 AD43 AE01 AF21 AG13 AK02 AK15 AL02 AL11 4L033 AA09 AB03 A C15 CA28 CA45 CA50 CA59

Claims (12)

[Claims] 1. A chopped strand obtained by impregnating a sizing agent into a glass fiber bundle used for an unsaturated polyester resin BMC molded article, wherein the sizing agent contains a urethane resin, a vinyl acetate resin, and a silane coupling agent, The mass ratio of the urethane resin and the vinyl acetate resin is 30: 7.
A chopped strand characterized in that it is 0 to 70:30. 2. The urethane resin is mainly composed of an isocyanate component and a polyol component, and contains at least one of dicyclohexylmethane-4,4-diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, and tolylene diisocyanate as the isocyanate component, and the polyol component. As the polyester polyol comprising polybutylene adipate or polyhexamethylene adipate, or at least one polyether polyol comprising polyoxypropylene polyol or polyoxybutylene polyol,
The chopped strand according to claim 1. 3. The chopped strand according to claim 1, wherein the vinyl acetate resin contains a silanol group. 4. The chopped strand according to claim 1, wherein the silane coupling agent is an amino type and / or an acrylic type. 5. In the solubility test of the sizing agent, the ratio of the sizing agent to the mass of the sizing agent before immersion after immersion for 60 minutes in styrene monomer is 3 to 25%. The chopped strand according to any one. 6. In the swelling test of the sizing agent, the ratio of the sizing agent having a 4: 1 aspect ratio of the sizing agent to the length before dipping in the lengthwise direction of the coating after 60 minutes of immersion in styrene monomer. Is 1.5 to 2.5 times, The chopped strand according to any one of claims 1 to 5. 7. In the focusing test of chopped strands containing the sizing agent, the volume increase ratio after immersion in acetone of the chopped strands and stirring for 250 seconds is 30% or less relative to that before immersion. ~ 6
The chopped strand according to any one of 1. 8. In the focusing test of chopped strands containing the sizing agent, after the chopped strands are stirred with a steel ball for 5 minutes with a paint shaker, the mass of fluff remaining on a sieve having an opening of 4 mm is 1 for the amount of chopped strands added
% Or less, The chopped strand according to any one of claims 1 to 7. 9. A BMC molded body formed by using the chopped strand according to claim 1, wherein the chopped is based on 100 parts by mass of a matrix resin mainly composed of an unsaturated polyester resin. Strand 3
An unsaturated polyester resin BMC molded product containing 0 to 150 parts by mass. 10. In the swelling test of the unsaturated polyester resin BMC molded product, the number of swelling on the surface of the molded product is 0 when heated for 60 minutes in an atmosphere of 180 ° C. after coating the surface of the molded product with a primer. The unsaturated polyester resin BMC molded product according to claim 9. 11. The unsaturated polyester resin BMC molded product according to claim 9, which is a molded product obtained by injection molding and is used for a lamp reflecting mirror. 12. The flexural strength and the Izod impact strength test specified in JIS-K6911 have a flexural strength of 6 or less.
The unsaturated polyester resin BMC molded product according to any one of claims 9 to 11, which has a notched Izod impact strength of 60 J / m or more at 5 MPa or more.