JPS60258231A - Molding material capable of giving cured article having improved transparency and flame retardancy - Google Patents

Abstract

PURPOSE:A molding material, obtained by impregnating a specific fibrous reinforcing material with a resin composition containing a specific polyfunctional (meth)acrylic resin and aluminum hydroxide as essential components, and capable of giving a cured article having high transparency and improved flame retardancy and water and corrosion resistance. CONSTITUTION:A molding material obtained by incorporating 100pts.wt. polyfunctional (meth)acrylic resin having 1.57+ or -0.02 refractive index at 15 deg.C when cured into a cured article with >=30pts.wt. aluminum hydroxide having 3-50mu average particle diameter and >=90 whiteness and a hardener, etc., and impregnating >=5pts.wt. fibrous reinforcing material, preferably E-glass having 1.57+ or - 0.02 refractive index at 15 deg.C with the resultant composition. Examples of the polyfunctional (meth)acrylic resin to be used include epoxy (meth) acrylate obtained by reacting an epoxy resin with (meth)acrylic acid and a resin obtained by esterifying the residual hydroxyl groups further with (meth)acrylic acid, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a molding material that provides a cured product that is highly transparent, flame retardant, and has excellent water resistance and corrosion resistance.
It is related to the molding material consisting of a specific multiple function (meta) acrylic IT1 + fat) -Kei φ, two dodly lutors, two spoons.

It has been known to mix aluminum hydroxide with various thermosetting resins as a flame-retardant molding material, but this method often significantly impairs the transparency of the cured product. Conventional resin compositions containing aluminum hydroxide have drawbacks such as high viscosity, poor impregnation into glass fibers, and markedly poor molding workability.

The inventors of the present invention conducted extensive studies in light of these circumstances, and as a result, discovered a molding material that provides a cured product that is highly transparent, flame retardant, and has excellent water and corrosion resistance, thereby completing the present invention. This is what led to this.

That is, the present invention has a refractive index of 15°C when cured.
A polyfunctional (meth)acrylic resin in the range of 1.57 to 0.02 and aluminum hydroxide with an average particle size of 3 to 50 microns and a whiteness of 90 or more are essential, and 1 to 100 parts by weight of the former is required. ．． The refractive index at 15°C is 1.57 when the + Tadazuki kirin fat composition of 30 times Ikushi l- is transferred.
The present invention provides a molding material that is impregnated with a fibrous reinforcing material in the range of ±0.02 and that provides a cured product that is highly transparent, flame retardant, and has excellent water and corrosion resistance. .

Polyfunctional (meth)acrylic resins that can be used in the present invention include epoxy (meth)acrylates obtained by reacting (meth)acrylic acid with various epoxy resins such as bisphenol type and phenol/cresol novolac type, and these epoxy (meth)acrylates. Resins in which the residual hydroxyl groups of meth)acrylate are further esterified with (meth)acrylic acid, di(meth)acrylates of diols made by adding ethylene oxide or propylene oxide to bisphenols,
Styrene, vinyltoluene, divinylbenzene, 0-1m-1p-phthalic acid and di(meth)acrylate of polyester glycol reacted with glycol, etc.
The viscosity is adjusted to an appropriate level by adding 1m-1p-diallyl phthalate, benzyl (meth)acrylate, (meth)acrylate of phenol with ethylene oxide and propylene oxide, and in the present invention, polyfunctional It is necessary that the refractive index of the cured (meth)acrylic resin be in the range of 1.57±0.02 at 15°C.

Aluminum hydroxide generally has the chemical formula All
It is a compound represented by (OH)s or k120s ・3 H2O, but in the present invention, it is a compound with an average particle diameter of 3
It is necessary that the diameter is 50 microns and the whiteness measured by a photoelectric whiteness meter is 90 or more. If the average particle size is less than 3 microns, the viscosity will increase too much, and if it is more than 50 microns, the resin composition will tend to become non-uniform due to sedimentation. The whiteness also needs to be 90 or more in order to reduce coloring and improve transparency. Aluminum hydroxide is used in an amount of 30 parts by weight or more per 100 parts by weight of the polyfunctional (meth)acrylic resin, but this is the necessary amount to obtain flame retardancy. It is preferable to use a large amount in the

Curing agents include organic peroxides and diazo compounds that are used before polymerization starts, as well as accelerators that are used in combination with organic peroxides. Examples of the polymerization initiator include penzoyl peroxide, lauroyl peroxide, cyclohexanone peroxide, dicumyl peroxide, methyl ethyl ketone peroxide, and azobisisobutyronitrile.

If necessary, tertiary amines are used as accelerators in combination with organic peroxides, 12! There are metal soaps that are soluble in organic solvents, such as i1M ammonium salts Jacobalt, Manganese, Copper, and Calcium Nato, which can be used alone or in combination. The amount of curing agent used is usually 0.2 to 5 parts by weight per 100 parts by weight of the polyfunctional (meth)acrylic resin.

As a fibrous reinforcement material, the refractive index at 15°C is 1.57.
Any material, organic or inorganic, can be used as long as it is within the range of ±0.02, but particularly preferred is E-glass, which has a refractive index of 1.5°C at 15°C. It is in the range of 0.02 to 57 and provides excellent translucency. The reinforcing material is used in roving,
chopped strand, chopped strand mat,
Crosses are common. The amount of reinforcing material used is preferably 5 parts by weight or more based on 100 parts by weight of the polyfunctional (meth)acrylic resin in order to obtain a molding material with good mechanical strength of the cured product.

Representative embodiments of the invention are as follows.

Kneading 30 parts by weight or more of the aluminum hydroxide with 10'O parts by weight of the polyfunctional (meth)acrylic resin,
Next, the above-mentioned curing agent and, if necessary, the above-mentioned accelerator are added to prepare a resin composition. The object of the present invention can be achieved by defoaming this resin composition if necessary and impregnating it into the above-mentioned fibrous reinforcing material.

The molding material of the present invention can be made into a cured product with excellent transparency and flame retardancy by molding and curing according to a normal FRP molding method.

The present invention will be explained in more detail with reference to Examples below.
These do not include all aspects of the present invention.

Example: When dimethacrylate, a diol made by adding 3 moles of ethylene oxide to bisphenol A, is dissolved in styrene monomer and cured, the refractive index is approximately 1 at 15°C.
．． A polyfunctional methacrylic resin No. 56 was obtained.

In 100 parts by weight of the obtained polyfunctional methacrylic resin, 0.5 tft part of lauryltrimethylammonium chloride (concentration 60% impropatol solution) and 1.0 part by weight of dicumyl peroxide (concentration 80% probanol solution) were dissolved. Next, the average particle size is 16 microns and the whiteness is 9.
A resin composition was obtained by kneading 1.00 parts by weight of 7.5 aluminum hydroxide.

After degassing the resulting resin composition, the refractive index at 15°C is approximately 1.
．． The molding material of the present invention was obtained by impregnating a glass chopped strand mat of 3sof/,/56.

The resulting molding material was laminated in two layers, sandwiched between Tetron films to remove air bubbles, and then cured at 60°C for 30 minutes under contact pressure, and then held at 100°C for 2 hours to complete curing. An F'RP board having a thickness of about 31 layers was obtained. This FRP board has self-extinguishing properties with an oxygen index of approximately 33,
It exhibited transparency to the extent that letters could be easily read when stacked on newspaper, and this transparency did not disappear even after boiling in water for 500 hours.

Example 2 A polyester methacrylate obtained by addition-reacting propylene oxide and phthalic anhydride using hydroxypropyl methacrylate as an initiator was reacted with toluylene diisocyanate to obtain a methacrylate at both ends. Polyester urethane methacrylate was dissolved in styrene monomer. , the refractive index of the cured product is approximately 15°C.
A polyfunctional methacrylic resin was obtained.

1 part by weight of lauroyl peroxide and 0.5 part by weight of benzoyl peroxide were dissolved in 100 parts by weight of the obtained polyfunctional methacrylic resin, and then the average particle size was 3.44.
Aluminum hydroxide 70 with a whiteness of 97.0 in microns
Parts by weight were kneaded to obtain a resin composition.

After degassing the resulting resin composition, it is first applied thinly onto a Tetron film, and then a film with a refractive index of about 1.5 at 15°C is coated on top of the Tetron film.
Chops of glass roving (No. 6) were uniformly scattered, and the resin composition was further spread evenly thereon, and the resin composition was defoamed and impregnated while being covered with a Tetron film from above to obtain the molding material of the present invention.

The resulting molding material was heated at 60° C. for 10 minutes to obtain a subsequent FRP board. This FRP board exhibited flame retardancy with an oxygen index of about 30, a total light transmittance of 78, and did not lose its transparency even after being immersed in boiling water for 200 hours.

Example 3 Ethylene oxide 3 to tetrabromobisphenol A
The refractive index of the cured product obtained by dissolving the diol dimethacrylate to which moles have been added in styrene monomer is 1.
A polyfunctional methacrylic resin having a molecular weight of about 1.58 at 5°C was obtained.

1 part by weight of lauroyl peroxide and 0.5 parts by weight of benzoyl peroxide were dissolved in 100 parts by weight of the obtained polyfunctional methacrylic resin, and then 150 parts by weight of aluminum hydroxide having an average particle size of 18 microns and a whiteness of 97 was dissolved. were kneaded to obtain a resin composition.

After defoaming the obtained resin composition, the refractive index at room temperature is about 1.
The molding material of the present invention was obtained by impregnating two layers of glass chopped strand mat with a thickness of 57 mm and a thickness of 4 soy/77 mm.

This molding material was placed between Tetoron films to remove air bubbles, and then cured at 60'C for 30 minutes under contact pressure.
Then, it was held at 100'C for 2 hours to complete curing, and an FRP board with a thickness of about 4 mm was obtained. This FRP board exhibited flame retardancy with an oxygen index of 63, and was transparent enough to allow characters to be distinguished when stacked on newspaper.

Comparative Example 1 Epoxy methacrylate obtained by addition reaction of methacrylic acid to bisphenol A-based epoxy resin was dissolved in a mixed monomer of styrene and methyl methacrylate,
A vinyl ester resin having a refractive index of about 1.54 at 15° C. when cured was obtained.

To 100 parts by weight of the obtained vinyl ester resin, 0.5744 parts of lauryltrimethylammonium chloride (concentration: approx. 60% propanol solution) and 1.0 parts by weight of dicumyl peroxide (isopropanol solution, concentration: about 80%) were added. was then kneaded with aluminum hydroxide having an average particle diameter of 16 microns and a whiteness of 97.5 to obtain a resin composition.

After degassing the resulting resin composition, the refractive index at 15°C is approximately 1.
．． A molding material for comparison was obtained by impregnating a glass strand mat of 3 B 0 f/rrt, which is 56, to obtain a molding material for comparison.

The resulting molding material was laminated in two layers, sandwiched between Tetron films to sufficiently remove air bubbles, and then cured at 60°C for 30 minutes under contact pressure, and then held at 100°C for 2 hours to complete curing. An FRP board with a thickness of about 3 mm was obtained. This FRP board was self-extinguishing with an oxygen index of approximately 30, and although it was transparent, the letters visible through the newspaper could only be seen, but could not be distinguished.

Comparative Example 2 Epoxy methacrylate obtained by addition reaction of methacrylic acid to tetrabromobisphenol A-based epoxy resin is dissolved in a mixed monomer of styrene and O-chlorostyrene to form a cured product with a refractive index of 15 Approximately 1.6 in °C
0 vinyl ester resin was obtained.

A comparative molding material was obtained in the same manner as in Example 3, except that 100 parts by weight of the obtained beer ester resin was used in place of the polyfunctional methacrylic resin in Example 3, and further in the same manner as in Example 3. After that, an FRP board with a thickness of 1 mm was obtained. This FRP board showed flame retardancy with an oxygen index of 67, but its transparency was only so high that the presence of letters could be seen as black dots when viewed through the newspaper.

Comparative Example 3 In place of the 38oy/i glass chopped strand mat having a refractive index of about 1.56 at 15°C in Example 1, 3soy/i having a refractive index of about 1.53 at 15°C was used.
A comparative molding material was obtained in the same manner as in Example 1, except that the glass chopped strand mat of No. 1 was used, and an FRP board with a thickness of about 3 mm was obtained in the same manner as in Example 1. . However, when layered on newspaper, the letters were only transparent enough to be seen through as black dots.

Comparative Example 4 Except for using aluminum hydroxide with an average particle diameter of 9 microns and a whiteness of 85 instead of aluminum hydroxide with an average particle diameter of 16 microns and a whiteness of 97.5 in Example 1. A comparative molding material was obtained in the same manner as in Example 1, but when stacked on newspaper, the letters only showed transparency to the extent that they could be seen through as black dots.

Claims (1)

[Claims] 1.Refractive index of cured product is 1.57±0 at 15℃
．． A polyfunctional (meth)acrylic resin in the range of 0.02 and an average particle size of 3 to 50 microns and a whiteness of 90.
A fibrous reinforcing material having a refractive index of 1.57±0.02 at 15° C. is made of a resin composition in which the above aluminum hydroxide is essential and the ratio of the latter is 30 parts by weight or more to 100 parts by weight of the former. A molding material that provides a cured product with excellent transparency and flame retardancy.