JPS5824443B2 - General information - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing molding materials, prepregs, etc. using a curable unsaturated ester polymer.

Currently, the resins used for molding materials and lamination are:
There are a wide variety of types, including phenolic, amino, epoxy, and unsaturated polyester, and each type has found its uses by exhibiting its characteristics.

However, as demands become more diverse, it is becoming increasingly difficult for these existing resins to meet these demands.

For example, phenolic resins are difficult to use for applications that require tracking resistance, mineral-based amino resins have problems with moldability, and types using epoxy resins have poor material shelf life. The high price is a fatal drawback and it has not been able to grow.

Although the plastic IJ mix using unsaturated polyester has improved physical properties and is promising, its one drawback is that it is putty-like and has a limited molding surface.

The putty-like appearance is due to the fact that the unsaturated polyester is liquid.

Generally, unsaturated polyester is in a liquid state before curing because a brittle solid unsaturated alkyd is dissolved in a liquid monomer.

Although being in liquid form is generally considered to be advantageous in terms of handling, depending on the application, liquid form may be disadvantageous.

For example, if the putty-like premix compound described above is disadvantageous in use, a powder or granular premix is desired, but this cannot be produced using conventional unsaturated polyester (resin in which an unsaturated alkyd is dissolved in a monomer). I can't.

Prepreg is also manufactured by coating glass fiber with resin, but after coating, it must be kept dry without stickiness before it can be handled.

In order to satisfy these points, it is necessary to convert the unsaturated polyester from a liquid state to a non-tacky state by some method before molding it, or to use a solid crosslinking agent from the beginning. There are two possible methods.

One method currently available is to use a solid alkyd and a monomer that is solid at room temperature, without using a liquid monomer.
This is dissolved in a solvent to produce an unsaturated polyester, and when used, the solvent is evaporated to produce an unsaturated polyester composition that does not leave any sticky residue when a prepreg or molding material is produced.

Various solid crosslinking agents used for this purpose are considered in the literature, but in reality, diallyl phthalate prepolymers are the only one that is actually used.

However, using only the diallyl phthalate prepolymer and an unsaturated alkyd containing no monomers is not sufficient in terms of moldability, which is a combination of fluidity and curability.

Although the use of an appropriate amount of diallyl phthalate monomer is practically sufficient to improve the curability, the combined use of a considerable amount of diallyl phthalate monomer is extremely undesirable from the viewpoint of causing stickiness.

Further, if the diallylphthalate monomer is used in a small amount that does not affect the flatness, it is of no practical use.

That is, in order to produce molding materials, prepregs, etc. without lowering the softening point even if a considerable amount of monomer is used, an unprecedented technique is required.

In order to improve the above-mentioned drawbacks, the method discovered by the present inventors uses an α-β unsaturated polybasic acid anhydride and a polymerizable monomer containing at least an aromatic vinyl compound copolymerizable with the α-β unsaturated polybasic acid anhydride. An unsaturated ester polymer (A) having a free carboxyl group obtained by partially esterifying a copolymer having an acid anhydride group in the side chain synthesized from a copolymer with an unsaturated epoxy compound and an unsaturated alcohol or an unsaturated alcohol.
On the other hand, it is characterized by containing a metal oxide or hydroxide capable of reacting with the carboxyl group in (A) alone or at the same time, and which can be used for laminate products, molding materials, etc. A method of producing a possible polymer composition is presented.

In this way, (1) taking maleic anhydride as an example, a copolymer obtained by arbitrarily selecting such an unsaturated polybasic acid anhydride and a monomer copolymerizable therewith is esterified with an unsaturated alcohol. An unsaturated ester polymer that shares an unsaturated bond and a carboxyl group in the side chain obtained by
A) and (2) the unsaturated ester PO+J-7-(A)
It is made by blending alone or simultaneously with a metal oxide or hydroxide that can react with the residual carboxyl groups in the polyester, and it is also possible to modify it by using an unsaturated polyester in combination, if necessary.

Chemical formulas are shown to aid understanding.

That is, the residual carboxyl groups in the unsaturated ester polymer form side chains, and these are combined with metal oxides such as magnesia or hydroxides, or a combination thereof to form a network structure due to metal crosslinks. However, even in the presence of liquid monomers such as diallyl phthalate, it is possible to create a non-sticky, moldable pre-gel state after using reinforcing materials, fillers, etc., as they solidify over time. ,
During hot molding, the metal crosslinks become loose (thus, combined with the presence of the monomer, the fluidity is regained, making molding possible.

At this time, insolubility and infusibility are finally completed by crosslinking polymerization between unsaturated bonds.

It is known that the free carboxyl groups at the ends of unsaturated polyester molecules can be used to produce prepregs by using metal oxides such as magnesium oxide, but this is not sufficient for powder or granulation. .

In other words, in order to maintain granularity while using a large amount of monomer, it is necessary to use a large amount of metal oxide to greatly raise the softening point, but this results in poor formability and lacks practical value. .

However, if the amount of metal oxide and monomer is small, even if the fluidity is improved, the curability will not be balanced, resulting in a small material during molding.

In the present invention, an α/β-unsaturated polybasic acid anhydride,
By using a copolymer between these and an aromatic vinyl monomer copolymerizable with an unsaturated alcohol, or an unsaturated epoxy ester and an unsaturated alcohol as resin constituents, the side chains of a polymeric unsaturated ester can be produced. Because we succeeded in having a large number of carboxyl groups in Mg oxide, the reaction between it and metal oxides such as magnesium oxide is not limited to simply increasing the molecular weight due to one-dimensional linkage between chain molecules, but also increases the molecular weight by metal cross-linking. The present invention is essentially different from known methods in that a three-dimensional network structure can be obtained.

That is, depending on the conventional method, the effect of metal bonding could not be sufficiently exhibited, and when a monomer was present, the drawback that adhesiveness remained for a long time could not be avoided, but according to the present invention, adhesiveness could not be fully exhibited. It is possible to obtain a product with extremely low susceptibility, and has the advantage of being extremely convenient in handling.

The constituent components of the unsaturated ester polymer for use in the present invention include the following types.

That is, as the unsaturated carboxylic acid or anhydride, maleic anhydride is most suitable and is advantageous in terms of operation and cost, but if necessary, maleic acid, itaconic acid, fumaric acid, maleic acid or fumaric acid can be used. monoesters, acrylic acid, methacrylic acid, etc., and unsaturated epoxy compounds may be used for introducing unsaturated groups.

Further, as the monomers to be copolymerized with these unsaturated acids, any monomer that can be copolymerized with the above-mentioned unsaturated acids can be used, and among them, styrene, vinyltoluene, etc. are representative.

In addition, if necessary, for example, acrylic esters, vinyl acetate, methacrylic esters, vinyl chloride,
General monomers such as inbutylene, vinyl ethers, glycidyl methacrylate, allyl glycidyl ether, and acrylonitrile can be used in combination, and two or more of these may be used in combination.

The copolymerization ratio of unsaturated acid and monomer can be arbitrarily changed depending on the final demand, but it is undesirable to reduce the carboxyl concentration too much (less than 1 mole of unsaturated acid per 20 moles of unsaturated acid). It becomes difficult to obtain a final cured product with good properties.

In order to introduce an unsaturated bond into a polymer having a carboxyl group in the side chain, unsaturated alcohols such as allyl alcohol and 2-hydroxyethyl methacrylate are most commonly used as long as the acid anhydride group is in the side chain. Although sufficient for the purposes of the invention, if carboxyl groups are also present in the side chain, unsaturated epoxy compounds such as glycidyl methacrylate, allyl glycidyl ether, vinyl cyclohexene monoepoxide, etc. must be used.

Of course, there is no problem in using an unsaturated alcohol and an unsaturated epoxy compound together for the acid anhydride group.

Another feature of the present invention is that an unsaturated alkyd obtained by esterifying an α-β unsaturated polybasic acid with a saturated polybasic acid and a polyhydric alcohol can be used in combination.

There is no particular restriction on the type of unsaturated alkyd used, and the mixing ratio can also be changed arbitrarily.

Examples of metal acid compounds or hydroxides used, which are one of the requirements of the present invention, include alkaline earth metals such as beryllium oxide, magnesium oxide, zinc oxide, calcium oxide, magnesium hydroxide, and calcium hydroxide. Examples include oxides or hydroxides of

Of course, hydroxides of trivalent metals such as aluminum hydroxide can also be used as property modifiers.

Furthermore, a method characterizing the present invention includes reacting a thermoplastic polymer having an acid anhydride group or, optionally, a carboxyl group in the side chain with an unsaturated alcohol or an unsaturated epoxy compound in a monomer. .

By employing such a method, a monomer solution of an unsaturated ester polymer can be directly obtained, which is extremely convenient in practical use.

Next, examples will be shown below to help understand the present invention.

Example 1 Preparation of Unsaturated Ester Polymer (A) In a 21-meter four-eye flask equipped with a stirrer, reflux condenser, dropping funnel, and temperature acupuncture gas inlet tube, 50% of dioxane was added.
002, charge 3 grams of benzoyl peroxide.

Raise the temperature to 80°C and introduce 520 g of styrene and 98 g of maleic anhydride from the dropping funnel while introducing nitrogen gas.
! , lauryl mercaptan 6g, dioxane 100g,
When the solution of is added dropwise, a styrene-maleic anhydride copolymerization reaction begins with heat generation.

After completing the addition in about 30 minutes, the temperature is raised to the boiling point of dioxane and the reaction is continued for 12 hours under reflux of dioxane.

After the reaction is completed, 0.22 g of hydroquinone is added to stop the polymerization, and 60 g of allyl alcohol is added, and the reaction is again carried out at the boiling point of dioxane for 6 hours.

The acid anhydride group of the styrene-maleic anhydride copolymer is esterified with allyl alcohol, and the styrene-maleic acid monoallyl ester copolymer has an allylic unsaturated bond in the side chain with an acid value of about 35 to 39. A polymer is obtained.

When all the above reactions were completed, diallyl phthalate monomer 6502 was further added, and then 10 to 15 mm
Dioxane, mercaptan, and unreacted residues are distilled off under reduced pressure while heating with Hg.

Finally, a diallyl phthalate solution of a styrene-maleic acid monoallyl ester copolymer is obtained.

It is pale yellowish brown and extremely viscous and sill-like. This is referred to as unsaturated ester polymer (A).

Manufacture and properties of molding material (I) A molding material (I) was manufactured by kneading the following formulation with a roll at 100 to 105° C. for 10 minutes.

Unsaturated ester polymer (A) 100 parts Calcium carbonate 400 Zinc stearate 2 Magnesia
2〃Dicumyl peroxide
2. After kneading, the obtained sheet is coarsely crushed using a speed mill, and coarse particles are removed using a 10-mesh sieve.

When the elongation of the obtained granular material was measured using the JIS disc nozzle measurement method, it was 85 mm and could be molded.

160°C, 5 minutes, under a pressure of 150kg/cr;t,
A test piece was formed and its electrical insulation properties were measured, and the following results were obtained.

Arc resistance (JIS method) 186 seconds normal insulation resistance (JIS method) 2X1014Ω Insulation resistance after 2 hours of boiling (JIS 1.4X1011Ω method) Rockwell hardness (M scale) 116 The molded product is extremely glossy, hard (and electrical performance Together with this, it was determined that the material was fully usable as a molding material.

Example 2 Synthesis of unsaturated ester polymer (B) Using the same reaction apparatus as in Example 1, dioxane 5001
, charged with 3 g of benzoyl peroxide and heated under inert gas flow for 8 hours.
At 0°C, 355 g of vinyltoluene, 9 g of maleic anhydride
A mixture of 8y' and 3 grams of lauryl mercaptan is added dropwise.

After the completion of the dropwise addition, the mixture was refluxed at the boiling point of dioxane for 12 hours to complete the polymerization.

After cooling to room temperature, the contents of the flask are added to a large amount of petroleum ligroin with vigorous stirring, the polymer is precipitated, and the solvent is removed in a centrifuge.

Further, residual solvent is removed in a vacuum dryer at 50-60°C and 0.1-1 mmHg.

230 parts of the thus obtained powdered vinyltoluene-maleic anhydride copolymer, 60 parts of 2-hydroxyethyl methacrylate, 31 parts of glycidyl methacrylate, and 150 parts of ethylene glycol dimethacrylate.
part, 0.1 part of hydroquinone, 2 ppm of naphthene EM,
) ') Methylbenzylammonium chloride 0.2
When the above composition is stirred and reacted at 80 to 100°C for 5 hours, an unsaturated ester polymer (B) having an acid value of 10 to 11 is obtained as a pale yellowish brown viscous starch syrup.

At this time, ethylene glycol dimethacrylate is not directly involved in the reaction, but is necessary to prevent gelation during the reaction and to lower the viscosity to make handling possible and easy.

The following formulation was kneaded on a kneader at 90 to 100°C for 10 minutes, extruded into a sheet, cooled and coarsely crushed to produce a hard granular molding material.

When its properties were measured, the following results were obtained.

Blend: Unsaturated ester polymer (B) 100 parts Clay #33 350 Dicumyl peroxide 2 Glass fiber 1/8
5 Q // Zinc stearate
3〃Magnesium hydroxide
2 tt calcium oxide
l tt properties: Bending strength 134-17.9 to 9. Ru-
Charpy impact value 5.1-7.9 kgCm/
crA Arc resistance 184 seconds Normal insulation resistance (JIS) 1.4X1015Ω Insulation resistance after 2 hours boiling 5.9X1012Ω Heat distortion temperature
236°C Example 3 Synthesis of unsaturated alkyd (D) 680 L of ethylene glycol was placed in a 3J four-bottle flask equipped with a stirrer, gas inlet tube, thermometer, and fractionating condenser. , isophthalic acid 3322 is charged, and after esterification at 190 to 200°C to give an acid value of 30 or less, fumaric acid 928
esterification in a stream of inert gas.

The reaction is stopped when the acid value reaches 40 or less, and the ester is poured out into a vat and cooled.

The unsaturated alkyd (D) is obtained as a pale yellow-brown, brittle, transparent solid.

The following formulation is kneaded on a roll at 95-100°C for 10 minutes.

Unsaturated ester polymer (A) of Example 1 100 parts Unsaturated alkyd (D) 50 Calcium carbonate 450 Zinc stearate 4 Dicumyl peroxide
4〃Magnesia
2//Magnesium hydroxide
2. Pulverize the kneaded material taken out in the form of a sheet using a speed mill to obtain a coarse-grained molding material (2).

Molding material ■ at 160℃ for 3 to 10 minutes at 100kg/c
The properties of the molded product molded using rA were as follows.

Insulation resistance (JIS method) 5.9X1014Ω
Insulation resistance after boiling for 2 hours (JIS method) 4X 1011
Ω arc resistance 187 seconds heat distortion temperature
No surface deterioration of the test piece was observed after boiling at 237°C, and it appears to be extremely stable.

Claims (1)

[Claims] 1 A copolymer having an acid anhydride group in the side chain synthesized from an α-β unsaturated polybasic acid anhydride and a polymerizable monomer containing at least an aromatic vinyl compound that can be copolymerized therewith. , an unsaturated epoxy compound and an unsaturated alcohol, or an unsaturated ester polymer (A) having free carboxyl groups obtained by partial esterification with an unsaturated alcohol.
), a metal oxide or hydroxide capable of reacting with the carboxyl group in (A) is added alone or simultaneously, and can be used for laminated products, molding materials, etc. A method of making a curable polymer composition.