JPH03281514A - Vinyl ester resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition useful in FRP field, curable with organic peroxide, heat and light energy and having excellent mechanical strength and heat resistance, etc., containing a vinyl ester resin, thermoplastic (co)polymer having specific molecular weight and graphite in a specific ratio. CONSTITUTION:The objective composition comprises (A) a vinyl ester resin (e.g. epoxy acrylate resin), (B) thermoplastic (co)polymer having 50000-500000, preferably 100000-300000 weight-average molecular weight and <=1mm granular size and (C) natural or artificial graphite. In the composition, a weight ratio of the component A to the component B is 70/30-95/5 and a weight ratio of total amount of the components A and B to the component C is 35/65 to 55/45.

Description

[Detailed Description of the Invention] [Industrial Field of Application J] This invention can be cured by the action of organic peroxide, heat, light energy, etc., and its mechanical strength, heat resistance, chemical resistance, etc. The present invention relates to a vinyl ester resin composition that can be widely used in the field of FRP by taking advantage of its characteristics.

L Prior Art j Conventionally, molded products obtained by heating SMC (sheet molding compound) or BMC (bulk molding compound) under pressure have been used in many industrial fields. However, these SMCs and BMCs
Because the resin component is unsaturated polyester resin or the filler is calcium carbonate or aluminum hydroxide, it lacks sufficient acid and alkali resistance and is difficult to use in applications that require chemical resistance. .

On the other hand, vinyl ester resin is widely used in combination with glass fiber for various types of corrosion-resistant FRP and high-strength FRP, as well as in heavy-duty anti-corrosion coating materials in combination with glass flakes, due to its excellent chemical resistance and adhesive properties. There is.

However, SMC and BMC containing a large amount of filler
When using polyester resin, there are problems in terms of chemical resistance, and unlike unsaturated polyester resin, it is not easy to adjust the thickening.
There was a problem with moldability in hot pressure molding.

L Problems to be Solved by the Invention J The main purpose of the present invention is to improve the chemical resistance of conventional SMC and BMC, and also to provide a molding material that has excellent moldability and can be heat-formed under pressure. shall be.

1. Means for Solving the Problem] In order to achieve the above object, the present inventors used a vinyl ester resin with excellent chemical resistance in place of the unsaturated polyester resin to adjust the viscosity of the vinyl ester resin. The present inventors have discovered that a composition containing a thermoplastic polymer or copolymer and natural or artificial graphite as a filler provides a molded article with excellent heat resistance and chemical resistance, and has completed the present invention.

In other words, one aspect of the present invention is.

fA) Vinyl ester resin FB + weight average molecular weight of 50.000 to 500.000
A composition comprising a thermoplastic polymer or copolymer (C) natural or artificial graphite, wherein the weight ratio of the component (A) to the component (Bl) is 70-95:30-5, and (A)
(B) The total amount of component and the weight ratio of fcl component is 3
5 to 55: Provides a vinyl ester resin composition characterized in that it has a molecular weight of 65 to 45, and further provides a glass fiber reinforced composition comprising 100 parts by weight of the vinyl ester resin composition and 5 to 30 parts by weight of glass fiber. A vinyl ester resin composition is provided.

The present invention will be explained in more detail below.

In the present invention, vinyl ester resins refer to epoxy compounds having one or more epoxy groups in the molecule and unsaturated monocarboxylic acids such as acrylic acid and methacrylic acid.
Alternatively, if necessary, part or most of the unsaturated monocarboxylic acid may be replaced with a saturated monocarboxylic acid, a saturated or unsaturated polycarboxylic acid, a saturated or unsaturated polycarboxylic anhydride, a saturated or It can be substituted with 1M or more selected from unsaturated alkyds. ) in the presence of an esterification catalyst such as amines, amine salts, or phosphines, and then react the resulting unsaturated ester compound with polymerizable monomers such as styrene monomer, acrylic acid ester, diallyl phthalate, etc. It is a liquid resin dissolved in the body, and is also called epoxy acrylate resin.

The epoxy compound, unsaturated carboxylic acid, esterification catalyst, polymerization inhibitor, and polymerizable monomer used in the production of the vinyl ester resin of the present invention are not particularly limited (all known ones may be used). be able to.

Examples of epoxy compounds that can be used in the present invention include:
The most common one is an epoxy resin obtained by reacting bisphenol A with epichlorohydrin. In this case, it is often preferable for the base epoxy resin to have a high degree of condensation, but since the viscosity increases, it is necessary to adjust the viscosity using a polymerizable monomer. In addition to this, there is a type in which ethylene oxide or propylene oxide is added to bisphenol A, but this type has a low viscosity and can be used as a reaction diluent.

In addition, other types such as novolak phenol type epoxy resin, cycloaliphatic type, and epoxidized butadiene type can also be used.

Further, as unsaturated carboxylic acids, unsaturated monocarboxylic acids such as acrylic acid and methacrylic acid are most commonly used, but crotonic acid and the like can also be used. A part or most of this unsaturated monocarboxylic acid is converted into fumaric acid, itaconic acid,
Unsaturated polycarboxylic acids such as citraconic acid, saturated polycarboxylic acids such as acetic acid, propionic acid, lauric acid, and palmitic acid.
Saturated polyhydric carboxylic acids such as polycarboxylic acids, phthalic acid, or their anhydrides, and in some cases, saturated or unsaturated alkyds having a carboxyl group at the end can also be used.

Examples of the esterification catalyst include quaternary ammonium salts such as trimethylbenzylammonium chloride, tertiary amines such as dimethylbenzylamine, and phosphines such as triphenylphosphine.

Further, as the polymerization inhibitor added as necessary, known polymerization inhibitors such as methylhydroquinone, hydroquinone, parabenzoquinone, paratoluquinone, etc. can be used.

The most commonly used polymerization monomer is styrene monomer, but other monomers include divinylbenzene, chlorostyrene, (meth)acrylic acid ester, diallylphthalate, vinyl acetate, Trimethylol prohant triacrylate and the like can be used. This polymerizable monomer may be used as a solvent in reactions and can also be used as a solvent for high viscosity vinyl ester resins to adjust the viscosity.

Furthermore, the thermoplastic polymer or copolymer used as component (B) in the present invention has a weight average molecular weight of so, ooo to soo, ooo, preferably ioo, ooo to 300.0 when dissolved in polymerized bamboo shoots. It is preferable that the particle size is 0 and the particle size is 1 mm or less.

The polymer mentioned above is a homopolymer of methyl methacrylate, styrene, vinyl acetate, etc., and the copolymer is a copolymer of a vinyl monomer copolymerizable with the above monomers.

The weight average molecular weight of the thermoplastic polymer or copolymer is so,
If the amount is less than 00, the flow resistance within the mold during molding of a composition containing the same is insufficient, and defects such as pinholes and cavities are likely to occur in the molded product. On the other hand, the weight average molecular weight of the thermoplastic polymer or copolymer is 500.0
If it exceeds 00, the effect will be similar to that of adding a filler, and the fluidity in the mold during molding will decrease, resulting in unfilling, and the resulting molded product will be brittle and not have sufficient strength.

The blending amount of the thermoplastic polymer or copolymer is a weight ratio of vinyl ester resin and thermoplastic polymer or copolymer of 70 to 9.
5 to 30 to 5.

If the weight ratio of the thermoplastic polymer or copolymer is less than 5, the flow resistance in the mold during molding of the composition containing the thermoplastic polymer or copolymer will not be sufficient, resulting in defects such as pinholes and cavities in the molded product. Not only this, but also the thermal shock resistance of the molded product is insufficient, and cracks may occur due to local heating of the molded product or repeated heating and cooling. On the other hand, if the proportion of the thermoplastic polymer or copolymer exceeds 30% by weight,
The heat resistance of the resulting molded product decreases, and the molded product surface becomes uneven due to high-temperature heating, and its strength at high temperatures decreases.

Component (C) used in the present invention is natural or artificial graphite, and its particle size is preferably 1 to 350 μm. If it is coarser than this, the surface of the molded product will have a rough appearance (glossy,
Smoothness) is not good.

The amount of graphite blended is a weight ratio of the total amount of vinyl ester resin and thermoplastic polymer or copolymer to graphite of 35:65 to 5.
It is within the range of 5:45.

If the blending ratio of graphite exceeds 65 in terms of weight ratio, the filler becomes excessive, resulting in a decrease in crosstalk during composition preparation, making it difficult to mix uniformly, and the fluidity of the resulting composition is also significantly reduced. , it becomes impossible to form satisfactorily. On the other hand, if the blending ratio of graphite is less than 45% by weight, the mechanical strength of the molded article tends to decrease, and furthermore, the shrinkage rate during curing increases, causing the disadvantage that the molded article warps.

Note that the glass fiber used in the vinyl ester resin composition of the present invention preferably has a single fiber thickness of about 9 to 14 μm,
The length is 3 to 13 mm, and the blending ratio is about 10 to 20%.

In addition, as a catalyst, peroxide-based catalysts can be used, but are not limited thereto, such as tert-butyl peroxybenzoate, di-t-butyl peroxide, dicumyl peroxide, tert-butyl perbenzoate, and t-butyl bar. Oxyisobrobyl carbonate and the like can be mentioned.

The amount added is usually 0.3 to 1.0%.

Curing conditions vary depending on the catalyst system, but for boat fishing 13
Approximately 0 to 160℃, pressure varies depending on compression molding, transfer molding, injection molding, etc., and cannot be specified.Curing time varies depending on the thickness of the molded product, curing temperature, etc., but is usually about 1 to 5 minutes. .

The vinyl ester resin composition of the present invention may contain a female molding agent, a polymerization initiator, a polymerization inhibitor (stabilizer), a coloring agent, an ethylenically unsaturated monomer, an inorganic fiber reinforcing agent, and an organic fiber reinforcing agent as necessary. etc. are mixed.

In addition, the vinyl ester resin composition of the present invention can be mixed with a general-purpose kneader, kneader/rouge extruder, etc.
, using a speed mill etc.

Easily manufactured by mixing or cross-fertilizing. The temperature of mixing or cross-conducting is set at 7 to suppress the cross-linking reaction (gelation).
The resulting block, sheet, or rod-like composition, which is preferably heated to 0° C. or lower, can be easily molded into any desired shape by a general-purpose molding method such as compression molding, transfer molding, or injection molding.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited in any way by these Examples.

(Examples 1 to 4 and Comparative Examples 1 to 6) A vinyl ester resin obtained by reacting a novolac type epoxy resin with methacrylic acid, polystyrene (weight average molecular weight 150.000), artificial graphite (average particle size 6
0LLm), glass fiber, dicumyl peroxide and zinc stearate were weighed in the proportions shown in Table 1.

All raw materials except the glass fiber weighed above were added to a volume of 1O.
After kneading for about 30 minutes at 30 to 50°C using a I2 kneader, glass fibers were added and kneaded for about 10 minutes.

The mixed wire was taken out from the kneader, placed in a vinylon bag, sealed, and used as a sample for physical property evaluation. Each sample had a diameter of 200 mm, a depth of 50 mm, and a thickness of 3 mm.
A container was molded and the moldability was evaluated. In addition, various test pieces were cut out from this material and used as samples for physical property evaluation.

The molding conditions were as follows.

Mold temperature: 160 ℃ Molding pressure: 50 Kgf/cm" Curing time
- The results of the 3-minute test are shown in Table 1.

(Left below) (Example 5 and Comparative Examples 7-8) Vinyl ester resin obtained by reacting bisphenol-type epoxy resin and methacrylic acid, polymethyl methacrylate, natural graphite (average particle size 40 am>, glass fiber ,
Tert-butyl perbenzoate and calcium stearate were weighed in the proportions shown in Table 2.

”-2Weighed all raw materials except glass fiber to a capacity of 10I2
After kneading for about 20 minutes at 30 to 50 DEG C. using a pressure kneader, glass fibers were added and kneaded for about 4 minutes.

The mixed wire was taken out from the kneader, placed in a vinylon bag and sealed, and used as a sample for physical property evaluation. Evaluation was performed in the same manner as in Example 1.

The molding conditions were as follows.

Mold temperature: 140 ℃ Molding pressure: 50 Kgf/cm" Curing time
: The results of the 3-minute test are shown in Table 2.

(Left below) Note) Polymethyl methacrylate A: Weight average molecular member approximately 80
0.000// B; 7r
Approximately 200.0on〃C〃
Approximately 30,000 [Effect of the Invention] As is clear from Tables 1 and 2, the compositions of Examples 1 to 5 were superior to Comparative Examples 1 to 8 in moldability, heat resistance, strength, chemical resistance, and balance. It can be seen that it is superior to the composition.

Claims (2)

[Claims] (1) (A) Vinyl ester resin (B) Weight average molecular weight is 50,000 to 500,000
A composition comprising a thermoplastic polymer or copolymer (C) natural or artificial graphite,
The weight ratio of component (A) and component (B) is 70 to 95:30
5, and the total amount of component (A) and component (B) and (C
) A vinyl ester resin composition characterized in that the weight ratio of the components is 35-55:65-45. (2) A glass fiber reinforced vinyl ester resin composition comprising 100 parts by weight of the vinyl ester resin composition of claim 1 and 5 to 30 parts by weight of glass fibers.