KR820000607B1 - Unsaturated polyester resin composition for use in pressure molding - Google Patents

Abstract

Press-moldable unsatd. polyesters including epoxy resin vinyl ester contained a filler composed of (a) 0.5-80 CaCO3 (b) 40-100 silica sand, and (c) 0.2-8mm long fiber where a/b = 0.7-10, (a+b)/polyester = 1.5-7, and C (based on polyester +a+b) = 1-1.5 %. Thus, a compn. from bisphenol A-epichlorohydrin copolymer methacrylate 100, 1.3-diallylhydantoin 20, dicumyl peroxide 1, Zn stearate 2, KBM 503 1, glass fiber and silica sand + CaCO3 [CaCO3/(sand + CaCO3)=50-90%, sand size 800-55 400parts was tranfer-molded using a 30mm - thick metal insert with 1mm-diam. holes to give a crack-free molding with complete filling of the holes.

Description

Unsaturated polyester resin composition for pressure molding

The present invention relates to an unsaturated polyester resin composition for pressure molding.

The composition of the present invention is a calcium carbonate powder (a) passing through an unsaturated polyester resin and a 325 mesh body, the inorganic mineral particles (b) that pass through the 12 mesh body and remain on the 200 mesh body and a glass fiber having a length of 0.2 mm or more (c). (A) to (b) is 0.3 to 10, and the ratio of (a) to (b) to unsaturated polyester resin is 1.5 to 7 (c) to resin, The ratio of the amount of calcium carbonate, silica sand and glass fiber was comprised in the range of 0.01 to 0.25.

The composition of the present invention can fill small voids or cracks in the molding die, thereby producing an accurate molded article. In recent years, unsaturated polyester resin compositions including reinforcing materials such as fiberglass are widely used in the fields of electrical insulation and structural materials, and these compositions can provide cured products having excellent mechanical strength, dimensions, stability, and electrical properties. have. When the compositions are used for the conversion or injection molding of inserts, these compositions suffer from the disadvantage that the stirring of the composition and the orientation of the glass fibers during molding cause separation between the resin and the glass fibers. Various resin compositions are known including fillers in powders such as silica powder, mud, silica sand and calcium carbonate powder for use in structural materials.

U.S. Pat. A composition composed of an unsaturated polyester resin comprising was described in Example 3.

The advantage of the composition is that by absorbing the liquid component of the resin by the absorbent, the composition has reduced fluidity under normal conditions and improved flowability of the composition as the absorbed components flow out when the molding pressure is applied to the composition.

The compositions described above are useful for injection or extrusion molding. U.S. Patent 3,758,799 describes a resin-filler composition comprising a filler that passes through a 40 mesh sieve and remains on a 100 mesh sieve, which composition is comprised of 65 to 80 weight percent filler and 35 to 20 weight percent resin.

This composition comprises glass fibers.

U. S. Patent No. 3,658, 750 describes a thermosetting resin composition consisting of a thermosetting resin, a coarse powder having a particle size of 100 to 850 mu m and a fine powder having a particle size of less than 60 mu m, which has improved flowability under pressure. U.S. Patent 3,763,080 describes a moldable composition consisting of an unsaturated polyester resin, a filler of 30-100 mesh and a separation inhibitor.

The composition may also comprise glass fibers.

This composition has improved flowability and can therefore flow into small cavities or crevices.

US Patent 2,890,914 describes an electric machine such as a motor, the stator of which can be molded into a composition comprising an unsaturated polyester resin and a filler such as powder consisting of mica, silica or alumina and glass fibers.

It is known to include powders of thermoplastic resins to reduce shrinkage of the composition during curing of the compositions described in US Pat. No. 3,562,201.

Investigations of known compositions show that they have unsatisfactory molding properties when used in the transition or injection molding of small devices. As described in US Pat. No. 3,562,201, when the composition contains only very fine fillers, the viscosity of the composition is very high and requires high molding pressure, which is undesirable when small devices contain brittle parts.

On the other hand, if the resin composition contains only coarse fillers as described in US Pat. No. 3,758,799, the fine voids of the device cannot be sufficiently filled with the composition.

U.S. Patent No. 3,658,750 describes the formulation of coarse and fine fillers, but no mention is made of fiber reinforcement, and it is mentioned as a fine filler for hard materials. It has been found to lose its function as.

The compositions described in US Pat. No. 3,763,080 contain only coarse fillers which have the drawbacks described above.

Accordingly, an object of the present invention is to provide an unsaturated polyester resin composition capable of producing a cured article having improved molding properties and excellent mechanical properties.

According to the present invention, an unsaturated polyester resin composition for pressure molding comprising a liquid-unsaturated polyester resin and a [II] filler comprising a curing catalyst for reacting with an [I] ethically unsaturated compound monomer is provided. Fine calcium carbonate powder, (b) inorganic minerals having a larger particle size than the particles of calcium carbonate powder, and (c) glass fibers, each of which is a cavity of an article or device to be molded from the composition ( The ratio of calcium carbonate powder to mineral particles in the composition is 0.3 to 10, the ratio of calcium carbonate powder to mineral particles to polyester resin is 1.5 to 7 and glass fiber to calcium carbonate powder, mineral particles, and poly The ratio of ester resin and glass fiber is 0.01 to 0.25.

Other objects of the present invention will become apparent from the following description of suitable examples of the present invention.

In the present invention, filler blending of inorganic mineral particles such as calcium carbonate powder and silica sand powder is important.

Calcium carbonate powder not only acts as a fine filler but also as a protective powder for glass fibers used as a reinforcing material.

Calcium carbonate is not as hard as quartz glass powder, mud and powder, thus preventing glass fibers from crumble during stirring of the composition. Silica sand is inexpensive and has a relatively small coefficient of linear thermal expansion, thus providing a cured material having a small coefficient of linear thermal expansion.

In the present invention, limestone is used as the mineral particle powder. When the weight ratio of calcium carbonate powder to mineral particles exceeds 10, the mechanical strength of the cured material is unsatisfactory because small cavities in the molding apparatus tend to remain unfilled.

Also, if the ratio is greater than 10, cracks often occur in the hardened object.

In addition, when the ratio is 0.3 or less, the composition has a high viscosity, so that small cavities in the apparatus tend to remain unfilled.

When the weight ratio of the total weight of the calcium carbonate powder to the mineral particles to the unsaturated polyester resin is less than 1.5, the coefficient of linear thermal expansion is so large that the crack resistance of the cured material is degraded and the resin separation during molding is excessive.

If the ratio is greater than 7, the fluidity of the composition is significantly lowered, making molding under low pressure difficult, and insufficient binding of the filler particles by the resin.

When the ratio of the total weight of glass fiber to unsaturated polyester resin, calcium carbonate powder, mineral particles and glass fiber is 0.01 or less, the effect of the glass fiber is not expected and the reinforcement of the cured article by the glass fiber is insufficient.

On the other hand, when the ratio exceeds 0.25, the composition is expensive and the stirring and molding of the composition are difficult.

Therefore, the ratio of calcium carbonate to mineral particles should be in the range of 0.3 to 4, and the ratio of calcium carbonate powder to mineral particles and the ratio of polyester resin is in the range of 2.5 to 7 and glass fiber to polyester resin calcium carbonate powder The ratio of the total weight of the mineral particles and the glass fibers is suitably in the range of 0.1 to 0.2.

Silica and limestone powders are suitable mineral particles, and the term "silica" includes a group of minerals containing at least 70% silica by weight. Examples of such materials are mountain sand, river sand and beach sand.

The shape of the silica sand particles is not limited and spherical particles are suitable to maintain the good flowability of the composition. The following mesh numbers are US mesh numbers.

Industrial sands that can be used industrially in Japan are classified into A-4, A-5, A-6 and A-7 grades, while sand is classified into N-40, N-50, N-60 and N-80 grades. Are classified.

These sands have a particle size distribution shown in Table 1, which is merely given as an example and the distribution may be indicated in any other way.

For example, the distribution may be represented by a more detailed mesh range.

TABLE 1

The term "-12 mesh + 32 mesh" means that the particles pass through the 12 mesh body and remain on the 32 mesh body.

A-4, A-5, A-6 and A-7 grades of sand are all useful in the present invention because they have a particle size of 1410 ~ 74㎛, among them A-4, A-5 and A-6 grade Especially suitable.

Class A-7 is not suitable because it contains smaller particles than other grades.

Acid sands of class N-40, N-50 and N-60 are suitable for the present invention because at least 91% of them have a particle size larger than 105 mu m.

Class N-80 contains a relatively large amount of fine particles and thus is not suitable for the present invention and the most suitable class is N-40 and N-50. Limestone ore powder is useful as an inorganic particle, which is prepared by grinding and grinding limestone ore whose main component is calcium carbonate. This limestone powder has a particle size of about 1500-100 μm. The silica sand has a particle size in the range of 74 to 1500 µm larger than the calcium carbonate powder. At least 95% by weight of silica sand passes through 12 mesh sieves and does not pass through 200 mesh sieves, in particular, 12 mesh sieves pass through and remain on 150 mesh sieves, so silica sand has a particle size range of 1410 to 105 µm. Calcium carbonate powder should be fine powder and especially have a particle size of less than 80㎛.

In particular, since it passes through a 325 mesh sieve and has a particle size of 44 μm or less, precipitated calcium carbonate powder or fine limestone powder is used. The chopped glass fiber has a length of 0.2 mm or more in the composition after stirring, preferably a length of 0.2 to 8 mm, and particularly preferably a glass fiber having a length of 1 to 6 mm.

A satisfactory reinforcing effect cannot be expected when the length of the glass fibers is 0.2 mm or less, while the composition cannot flow sufficiently into the small cavity of the device to be molded when the length is larger than 8 mm. Even if the glass fibers are long, for example more than 10 mm, they are shortened during stirring of the composition before blending them into the composition.

Therefore, long glass fibers may be used provided that the length of the glass fibers in the stirred composition is within the range in which the composition can be molded by injection or delivery molding machines.

If the glass fibers have a large diameter they are broken and easily break during stirring of the composition, so they have a diameter of 150 μm or less, in particular 50 μm or less.

Glass fiber for molding compositions which can be used industrially in Japan has a diameter of 6-15 micrometers.

Unsaturated polyester resins used in the present invention include polycondensates or condensates synthesized from unsaturated or saturated polyhydric acids and hydroxyl compounds in the presence or absence of a catalyst. The term "unsaturated polyester resin" as used to describe the components of the composition means a mixture consisting of a condensate, a compound such as ethyleneically unsaturated styrene and a curing catalyst such as benzoyl peroxide. Liquid unsaturated polyester resins have a viscosity of 50,000-50 psi at 25 ° C.

Conventional suitable unsaturated polyester resins are vinyl ester resins synthesized from bisphenol A type epoxy compounds or novolak type epoxy compounds and meta acrylate or acrylate. Representative unsaturated and saturated polyacids include maleic acid, maleic anhydride, fumaric acid, chromomaleic acid, dichromamic acid, metacoic acid, itaconic acid, adipic acid, sebacic acid, phthalic acid, phthalic anhydride, Isophthalic acid, pyromethic acid and het acid.

Suitable hydroxyl compounds include ethylene glycol, diethylene glycol, triethylene glycol, polystyrene glycol, propylene glycol, diphthopyrene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, 2.2-di Ethyl propane, dio-1,3 neopentyl glycol, bromoneopentyl glycol, bisphenol dioxyethyl ether, hydrogenated bisphenol A, 2.2-di94-hydroxy propoxy phenyl) propane, ethylene oxide, propylene oxide Diols such as propylene oxide, phenylglycidyl ether, arylglycidyl ether, and the like.

Polyhydric acids having three or more carboxyl groups may be used in combination with diacids, and polyhydroxy compounds having three or more hydroxyl groups may be used in combination with glycols. Ethylene unsaturated compounds which can be mixed with unsaturated polyester resins as crosslinking agents include styrene, vinyl toluene, α-methyl toluene, divinyl toluene, diarylphthalate, chromostyrene, dichrostyrene, bromostyrene, di Bromostyrene, polyaryl benzene phosphate, diaryl atryl phosphyl ester, acrylate ester, methacrylate ester, triaryl cyanurate and tribromophenol aryl ether.

Ethyrenically unsaturated compounds comprise from 20 to 50% by weight, in particular from 30 to 45%, based on the total amount of the mixture.

Curing catalysts for the polymerization of a mixture of unsaturated polyester resins and ethyleneically unsaturated compounds include 1.1-bis (butylperoxy) 3.3.5-trimethylcyclohexane, benzoyl peroxide, parachloro benzoyl, 2.4-dicro Robenzoyl peroxide, capryl peroxide, lauroyl peroxide, acetyl peroxide, cyclohexanone peroxide, bis (1-hydroxycyclohexyl) peroxide, hydroxyheptyl peroxide, t-butylhydro Peroxide, P-mentane hydroperoxide, cumenehydro peroxide, 2.5-dimethylhexyl-2,5-dihydro peroxide, di-t-butyl peroxide, dicumyl peroxide, 2.5-dimethyl-2.5-di ( t-butyl peroxy) hexane, 2.5-dimethylhexyl-2.5-di (peroxybenzoate), t-butyl perbenzoate, t-butylperacetate, t-butylperoctoate, t-butylperoxy butylate And di-t-butyl-puff Thallate and the like.

If desired, conventional accelerators for the catalyst can be used, which include lauryl mercaptan, N-butylsulphite, diphenyl sulfite, p-toluenesulfonate, tetravalent ammonium salts, β-dike Tones, peracerates of epoxy compounds, sulfonium salts, copper naphates, vanadil octoates, manganese naphates, calcium naphates, amines, phospho compounds and sulfur compounds.

The composition includes a polymerization inhibitor in order to extend the service life. Suitable compounds include p-benzoquinone, naphthoquinone, phenanthraquinone, paraxiroquinone, 2.5-diphenyl-p-benzoquinone, 2.5-diacene. Oxy-p-benzoquinone, hydroquinone, pt-butylcatechol, 2.5-di-t-butylhydroquinone, mono-t-butyl hydroquinone, di-t-butyl-paracresol, hydroquinone monomethyl ether and alpha Contains naphthol.

Studies of the composition have found that an appropriate amount of diaryl phthalate prepolymer is useful for controlling the viscosity of the composition. When the viscosity of the unsaturated polyester resin used in the composition is too low, the separation of the resin and filler is exceeded, and the mechanical and electrical properties of the cured article are not satisfied.

Suitable amounts of diaryl phthalate prepolymers range from 1 to 10 weight percent based on total amount of resin and prepolymer. If the amount is more than 10%, the crack resistance of the cured article is lowered. If the amount is less than 1%, a moderate effect cannot be expected. Prepolymers include prepolymers of oligomers and diaryl phthalates.

Mimetics such as polybutadiene, polystyrene, polystyrene, phenol resins, melamine resins or urine resins; Glass agents such as stearic acid, zinc stearate, calcium stearate or polycrystalline waxes; Coupling agents such as vinylsilane epoxy silane or amino silane: Various types of additives can be used, such as titanic acid, titania, chromium oxide, minimium, pigments such as iron oxide or carbon black and thixotropic agents such as silicate anhydride.

The invention has been described in detail with reference to the following examples. The following examples are intended to illustrate the invention and are not intended to limit the scope thereof.

Imitations and improvements can be made within the scope of the appended claims.

Example 1

The composition is 100 parts by weight of a vinyl ester resin (containing 6 poses, 40% styrene), 1 part of dicumyl peroxide (hereinafter simply referred to as DCPO) by weight synthesized from bisphenol A epoxy resin and methacrylate. 2 parts zinc stearate (hereinafter referred to as zn-st for simplicity) as glass, 1 part methacrylicoxy propyl trimellitic acid as capping agent, 400 parts steel grit powder and calcium carbonate powder (325 mesh sieve Having an average particle size of 탆). The steel sand powder has a particle size as shown in Table 1 and 25 parts chopped glass fibers having a length of 3 mm and a diameter of 6 μm are added to the composition.

It stirs at room temperature by the apparatus of the roll stirrer of a composition, and obtains a desired unsaturated polyester resin composition.

The composition is molded with an internal liner-type low pressure injection transfer molding machine having a thickness of 30 mm, an inner diameter of 30 mm and an outer diameter of 50 mm, operated for 3 minutes at a pressure of 30 kg / cm ² and 150 ° C.

The injection has 24 holes 1 mm in diameter extending along the axis of the injection.

Table 2 shows the range of pores filled with the cured resin and the appearance after molding.

TABLE 2

Note: The term “-12 mesh + 32 mesh” means that the silica sand passes through the 12 mesh body and remains on the 32 mesh body.

× indicates that the filling of the holes is unsatisfactory and a crack is observed.

Δ means that a crack is observed while the filling range of the hole is satisfactory.

○ means that the filling range is satisfactory and no cracks are found.

◎ means that the filling range is satisfactory, there is no crack and the appearance is excellent.

It is evident from Table 2 that the filling range and appearance of the cured article are not always good when the silica sand contains a large amount of small particles, as in Test Sequences 4, 5 and 6.

However, the silica sand used in Test Sequences 4 and 5 is useful when properly selecting the ratio of calcium carbonate powder large sand.

Example 2

100 parts of unsaturated polyester resin (6 psi), 1 part of DCPO, 2 parts of zn-st, 1 part of capping agent, 25 parts of chopped glass fibers having a diameter of 6 mm and a diameter of 6 μm From calcium carbonate powder and silica sand.

Unsaturated polyester resins are synthesized from isophthalic acid, maleic anhydride and propyl glycol and comprise 40% styrene by weight. The total weight of calcium carbonate and silica sand can be varied as shown in Table 2 while maintaining the ratio of calcium carbonate to silica sand at 75/25. The particle size of calcium carbonate is the same as in Example 1 and the silica sand used passes through 12 mesh sieves and remains on 100 mesh sieves.

The main composition is stirred at room temperature with a roll stirrer to obtain the desired unsaturated polyester resin composition.

The data on the filling range and the appearance of the compound are shown in Table 3 in the same manner as in Example 1.

TABLE 3

According to Table 3, moldings having a good filling range and appearance when the ratio of calcium carbonate and silica sand to resin are 7 or less and having a small limit of the ratio, such as 1.5 to ² kgcm / cm ² , are obtained.

Example 3

10 parts of diarylphthalate prepolymers (6 poses, including 40% styrene by weight), 1 part DCPO, 2 parts zn-st, 1 part etaacryloxy propyltrimethoxy silane (capling agent), Prepared from 5 parts thixotropic agent (erozyl) and the amount of filler indicated in Table 3 below.

Unsaturated polyester resins are synthesized from isophthalic acid, maleic anhydride and propylene glycol.

The compositions are stirred at room temperature by a roll stirrer and the cylindrical metal inserter is transfer molded as a composition in the same manner as in Example 1 to show the filling range and appearance of the composition in Table 4 below.

TABLE 4

When the ratio of the total weight of glass fiber to resin, calcium carbonate, silica sand and glass fiber is 0.01 or less, cracking occurs in the molded article, and an excellent molding is obtained when the ratio is 0.01 to 0.2.

Example 4

The following compositions have well balanced molding properties and can produce moldings with good mechanical properties.

(I) 95 parts by weight of unsaturated polyester resin

(Vinyl ester of bisphenol A type epoxy resin and methacrylate, containing 30% styrene by weight, 600 μtifois at 25 ° C) DCD0 1

(II) (a) Calcium Carbonate Powder (-325 Mesh) 190

(b) River sand (-12 mesh + 100 mesh) 185

(c) Glass fiber (length 6mm, diameter 9㎛) 50

(III) Diarylphthalate Prepolymer The weight ratio of each component in the composition is as follows. 5

(a) / (b) = 1, (a) + (b) / I = 4, (c) / [I] + [II] = 0.1 and [III] / [I] + [III] = 0.05

The glass fibers are shortened during stirring of the composition and the length of the glass fibers in the stirred composition is about 1-5 mm.

Example 5

The following composition was prepared in the same manner as in Example 1 and contained 100 parts of unsaturated polyester resin by weight used in Example 4.

Part 1 DCPO

2 parts zn-st (glass)

1 part methacryloxy propyltrimethoxy silane (capping agent)

150 parts calcium carbonate powder (-325 mesh)

202.5 parts limestone powder (-32 mesh + 100 mesh)

45 parts glass fiber (length 6mm, diameter 9㎛)

The composition exhibits good molding properties and results in moldings of good crack resistance.

Both calcium carbonate powder and limestone powder are not hard and therefore protect the glass fibers from breaking and the reinforcing function of the glass fibers is highly preserved even after the composition has been sufficiently stirred.

Claims (1)

20-50% by weight of an ethically unsaturated compound monomer and polyester resin, based on unsaturated polyester resins and mixtures of unsaturated or saturated polybasic acids or their anhydrides and condensates synthesized from hydroxyl compounds or their precursors; Liquid mixture [I] and [II] calcium carbonate powder having a viscosity of 50 to 50,000 psi at 25 ° C. composed of a curing catalyst in an amount capable of effective polymerization between the monomers of the monomers. In the filler of smaller silica sand (b) and flat glass fibers (c), the weight ratio of (a) to (b) is in the range of 0.2 to 10 and the ratio of (a) to (b) to [I] is in the range of 2.5 to 6. (c) Unsaturated polyester resin composition for pressure molding comprising a filler having a weight ratio of [I] to [II] in the range of 0.01 to 0.25.