JP2003212979A - Unsaturated polyester resin, unsaturated polyester resin composition, and thermosetting molding material using the composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an unsaturated polyester resin composition for an SMC or BMC purpose which gives such a viscosity a to bring a good impregnatability into a fibrous reinforcing material and a good workability at the time of molding an SMC or BMC after a definite time passage from the addition of a thickener, and to provide a thermosetting molding material using it. <P>SOLUTION: The unsaturated polyester resin composition which contains an unsaturated polyester resin, a liquid vinyl-based monomer, a low shrink controlling agent, a filler and a polymerization initiator and is used as an SMC or BMC purpose, is characterized in that the above polyester resin has an Mn of 1,000-4,000, an Mw/Mn of 3.6 or less and an acid value of 15-20; the above polyester resin composition contains additionally a thickener; and the thermosetting molding material for an SMC or BMC purpose contains a fibrous reinforcing material of 10-70 wt.% on the basis of the whole weight of the molding material. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an unsaturated polyester resin composition and a thermosetting molding material using the same, and more specifically, impregnation into a fibrous reinforcing material and SM.
The present invention relates to an unsaturated polyester resin composition for SMC or BMC, which gives a viscosity that provides good workability during C or BMC molding, and a thermosetting molding material using the same.

[0002]

2. Description of the Related Art Fiber Reinforced Plastics
Reinforced Plastics, FRP)
Is widely used as a composite material in various fields such as the construction field, the transportation field, the electric field, and the aerospace field. Various methods have been developed as a method for manufacturing this FRP, and for example, SMC (Sheet Mol) is used.
ing Compound) method or BMC (Bul)
The abbreviation for “KMolding Compound” method and the like are known.

The SMC or BMC is formed into a sheet or putty by impregnating a fibrous reinforcing material such as glass fiber with a resin composition obtained by adding a low shrinkage agent, a filler, various additives and the like into a resin matrix. It is a thermosetting molding material processed into a shape, and is generally cured by heating and pressing in a mold, and an FRP molded body can be easily obtained. In the SMC or BMC, as the resin matrix, unsaturated polyester resin, vinyl ester resin, epoxy resin,
Phenol resin or the like is used, and examples of the low-shrinking agent include polystyrene, polyvinyl acetate, polymethyl methacrylate, polyurethane, styrene-butadiene block polymer and the like. On the other hand, as the filler, calcium carbonate, talc, aluminum hydroxide,
Clay is used.

Among them, SMC or BMC using an unsaturated polyester resin and glass fiber is excellent in handling property, fluidity and curability, and also has surface properties of a molded product, mechanical strength, heat resistance, water resistance and resistance to water. Since it has excellent chemical properties, it is used in various industrial fields and forms a large market. In particular, panel tanks, septic tanks,
It is used in many applications as a building material such as cooling towers, unit baths and balconies.

In the production of such a molded product by SMC or BMC, in the step of impregnating the fibrous reinforcing material, the viscosity is as low as about 10 to 300 Pa.s, and the impregnating property into the reinforcing material is good, and the SMC is good. In the BMC molding process, viscosity 1
It is desirable that the workability is good because it is as high as about 20,000 to 200,000 Pa · s. In thermosetting molding materials for SMC and BMC, generally, a liquid resin composition containing an unsaturated polyester resin, a liquid vinyl monomer, a low-shrinking agent, a filler, a polymerization initiator and the like is added to a liquid resin composition containing magnesium oxide and the like. Viscosity is added and viscosity is 10-300
After the fibrous reinforcing material is impregnated at about Pa · s, SMC or BMC is formed, and if the viscosity further increases to about 10,000 to 200,000 Pa · s,
A molded product having a desired shape is produced by compression molding, transfer molding, or the like.

In the method for producing such a molded body,
From an industrial perspective, the viscosity of the composition becomes about 10 to 300 Pa · s after about 30 minutes (when the fibrous reinforcing material is impregnated) after adding the thickener, and the thickener is added. After at least one day has passed since the addition, the molding material (SM
C or BMC) has a viscosity of 10,000 to 200,000
It is preferably about Pa · s. However, it has been difficult to stably prepare a composition having the above viscosity at the above time after adding the thickener.

[0007]

Under the above circumstances, the present invention provides a fibrous reinforcing material in the production of a molded article using SMC or BMC, after a certain time has passed after the addition of the thickener. SMC or BM, which gives a good impregnation property and viscosity giving good workability during SMC or BMC molding
It is an object of the present invention to provide an unsaturated polyester resin composition for C and a thermosetting molding material using the same.

[0008]

DISCLOSURE OF THE INVENTION As a result of intensive studies for achieving the above-mentioned object, the inventors have found that the unsaturated polyester resin has a number average molecular weight, a molecular weight distribution and an acid value within a specific range. It was found that the purpose can be achieved by using the thing. The present invention has been completed based on such findings.

That is, according to the present invention, (1) the number average molecular weight (Mn) is 1000 to 4000, and the weight average molecular weight (M).
w) to number average molecular weight (Mn) ratio Mw / Mn (molecular weight distribution) of 3.6 or less and acid value of 15 to 25 KOHmg /
unsaturated polyester resin characterized by being g,
(2) Contains unsaturated polyester resin, liquid vinyl monomer, low-shrinking agent, filler and polymerization initiator, and SM
In the resin composition used for C or BMC,
The unsaturated polyester resin composition of (1) above is used as the unsaturated polyester resin, and (3) the unsaturated polyester resin is an α, β-olefin unsaturated dicarboxylic acid. The unsaturated polyester resin composition of (2) above, which is obtained by the esterification reaction of a dicarboxylic acid component containing and a glycol component, and (4) above, wherein the low-shrinking agent is a thermoplastic resin. The unsaturated polyester resin composition of (3),
(5) Temperature 2 including a thickener and 30 minutes after addition of the thickener
The unsaturated polyester resin composition of (2), (3) or (4), which has a viscosity of 10 to 300 Pa · s at 5 ° C., (6) the unsaturated polyester resin composition of (5), and a molding material. Fibrous reinforcement 10-7 based on total weight
0% by weight of thermosetting molding material for SMC or BMC, (7) Thermosetting molding material of (6) above, wherein the fibrous reinforcing material is glass fiber, and (8) thickener The viscosity at 25 ° C 24 hours after the addition was 10,000.
~ 200,000 Pa · s above (6) or (7)
To provide a thermosetting molding material.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The unsaturated polyester resin composition of the present invention comprises an unsaturated polyester resin, a liquid vinyl monomer, a low-shrinking agent, a filler and a polymerization initiator, and S
Used for MC or BMC. There is no particular limitation on the composition of the unsaturated polyester resin.
A well-known composition used for the unsaturated polyester resin composition for C or BMC can be used. Examples thereof include those obtained by subjecting a dicarboxylic acid component containing an α, β-olefin unsaturated dicarboxylic acid and a glycol component to an esterification reaction. Here, as the dicarboxylic acid component containing an α, β-olefinic unsaturated dicarboxylic acid, an α, β-olefinic unsaturated dicarboxylic acid, or this α, β-olefinic unsaturated dicarboxylic acid and a saturated dicarboxylic acid or aroma is used. Mention may be made of mixtures with group dicarboxylic acids.

Examples of the α, β-olefinic unsaturated dicarboxylic acid include maleic acid, fumaric acid, itaconic acid, citraconic acid and acid anhydrides thereof, and these may be used alone. Alternatively, two or more kinds may be used in combination. Examples of the saturated dicarboxylic acid and aromatic dicarboxylic acid used in combination with the α, β-olefin unsaturated dicarboxylic acid include adipic acid, suberic acid,
Azelaic acid, sebacic acid, succinic acid, glutaric acid, pimelic acid, dimethylsuccinic acid, succinic anhydride, phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, tetrahydrophthalic anhydride, halogenated phthalic anhydride And the like. These may be used alone or in combination of two or more.

On the other hand, examples of the glycol component include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 1,4-butylene glycol and neo. Examples include pentyl glycol, hexylene glycol, bisphenol A-alkylene oxide adducts, hydrogenated bisphenol A and the like. These glycol components are
One kind may be used alone, or two or more kinds may be used in combination, and if necessary, a polyhydric alcohol such as trimethylolpropane or glycerin may be used in combination.

The production of the unsaturated polyester resin is generally carried out by heating the reaction while removing the by-produced water out of the system. In the present invention, the unsaturated polyester resin thus obtained needs to have the following properties. First, the number average molecular weight is selected in the range of 1000 to 4000. If the number average molecular weight is less than 1000, the viscosity will not be sufficiently increased when a thickener is added to increase the viscosity, and the cured product will have poor physical properties. On the other hand, when the number average molecular weight exceeds 4000, the flow during press molding becomes poor and the reactivity during press molding deteriorates.

The ratio Mw / Mn (molecular weight distribution) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 3.6.
It is the following. If this Mw / Mn exceeds 3.6, the content of the high molecular weight component will increase, and when the thickener is added, the viscosity after 30 minutes becomes too high, and the fibrous reinforcing material is impregnated. The sex becomes worse. The preferable Mw / Mn is 3.3 or less, and particularly preferably 3.0 or less.

The number average molecular weight (Mn) and the weight average molecular weight (Mw) are polystyrene equivalent values measured by the gel permeation chromatography (GPC) method. Furthermore, the acid value is 15 to 25 KOHmg
/ G is selected. When the acid value is within the above range, the reaction proceeds properly.

The liquid vinyl-based monomer in the unsaturated polyester resin composition of the present invention is not particularly limited as long as it functions as a solvent for the unsaturated polyester resin and also as a crosslinking agent.
In the unsaturated polyester resin composition for BMC or BMC, an arbitrary one can be appropriately selected and used from those conventionally used as a liquid vinyl-based monomer. Examples of such liquid vinyl monomers include styrene and α
-Aromatic compounds having an ethylenic double bond such as methylstyrene, p-methylstyrene, vinylstyrene and divinylstyrene, (meth) acrylic acid, (meth) acrylic acid ester, acrylonitrile, ethylene glycol di (meth) acrylate, An aliphatic compound having an ethylenic double bond such as trimethylolpropane tri (meth) acrylate may be mentioned. These may be used alone or in combination of two or more,
Of these, styrene is particularly preferable.

The amount of the liquid vinyl monomer compounded is usually 10 to 150 parts by weight, preferably 100 parts by weight based on 100 parts by weight of the total amount of the resin components, that is, the unsaturated polyester resin and the low-shrinking agent described below. It is selected in the range of 15 to 80 parts by weight. There is no particular limitation on the low-shrinking agent in the unsaturated polyester resin composition of the present invention.
In the unsaturated polyester resin composition for C and BMC,
Any one can be appropriately selected and used from those commonly used as the low-shrinking agent. Examples of the low-shrinking agent include thermoplastic resins such as polystyrene, polyethylene, polyvinyl acetate, polymethyl methacrylate, saturated polyester, styrene-butadiene copolymer, styrene-methacrylic acid copolymer, polycaprolactone, and polybutadiene. Can be mentioned. These may be used alone or in combination of two or more. Also,
The blending amount is selected in consideration of the shrinkage rate, surface smoothness, surface gloss and the like of the molded product, but the weight ratio of the unsaturated polyester resin to the low-shrinking agent is usually 90:10 to 50: It is selected in the range of 50, preferably 80:20 to 60:40.

The filler in the unsaturated polyester resin composition of the present invention is not particularly limited, and conventional SMC and B are used.
In the unsaturated polyester resin composition for MC, any one can be appropriately selected and used from among those commonly used as a filler. An example of this filler is
Calcium carbonate, silica, talc, aluminum hydroxide, clay, mica, hollow balloon (glass, shirasu,
Cement), ferrite, zinc white, etc.
Of these, calcium carbonate is preferred. The filler may be surface-treated in order to improve dispersibility. These fillers may be used alone or in combination of two or more. Also, the blending amount is
Total amount of unsaturated polyester resin and low-shrinking agent 1
It is usually selected in the range of 50 to 300 parts by weight with respect to 00 parts by weight.

An organic peroxide is usually used as a polymerization initiator in the unsaturated polyester resin composition of the present invention. As the organic peroxide, any one can be appropriately selected and used from those conventionally used as a polymerization initiator in the unsaturated polyester resin composition. Examples of this organic peroxide include methyl ethyl ketone peroxide, acetylacetone peroxide, t-butyl peroxybenzoate, benzoyl peroxide, dicumyl peroxide, cumene hydroperoxide, etc. Alternatively, two or more kinds may be used in combination. The amount of the polymerization initiator compounded is usually 0.3 to 100 parts by weight of the total amount of the unsaturated polyester resin and the low-shrinking agent.
5 parts by weight, preferably 0.7 to 3 parts by weight is selected.

A thickener is usually added to the unsaturated polyester resin composition of the present invention. As this thickening agent, any one can be appropriately selected and used from those conventionally used as a thickening agent in unsaturated polyester resin compositions for SMC and BMC. Examples of the thickener include magnesium oxide, magnesium hydroxide, potassium oxide, potassium hydroxide and the like, but magnesium oxide is generally used. The amount of the thickener to be added is usually 0.5 to 5 parts by weight, preferably 0.7 to 2 parts by weight, based on 100 parts by weight of the total amount of the unsaturated polyester resin and the low-shrinking agent. To be done.

In the resin composition of the present invention, the viscosity at a temperature of 25 ° C. 30 minutes after the addition of the thickener is 10 to
It is preferably in the range of 300 Pa · s. If the viscosity exceeds 300 Pa · s, the impregnating property into the fibrous reinforcing material will be insufficient, which is not preferable. In the unsaturated polyester resin composition of the present invention, other additives conventionally used in unsaturated polyester resin compositions, for example, curing accelerators, polymerization inhibitors, release agents, antioxidants, ultraviolet absorbers, coloring Agents, defoaming agents, thixotropic agents, and the like can be added as desired.

Examples of the curing accelerator include cobalt naphthenate; cobalt octoate; N, N-dimethylaniline; N, N-diethylaniline; N, N-dimethyl-
p-toluidine; acetylacetone; ethyl acetoacetate and the like. Examples of the polymerization inhibitor include hydroquinone; p-benzoquinone; methylhydroquinone; trimethylhydroquinone; t-butylhydroquinone; catechol; t-butylcatechol; 2,6-di-t-butyl-4-methylphenol. Can be mentioned.

Next, the thermosetting molding material of the present invention contains the unsaturated polyester resin composition containing the above-mentioned thickener and the fibrous reinforcing material, and is used for SMC or BMC. Examples of the fibrous reinforcing material include glass fibers, carbon fibers, and organic fibers such as polyester fibers, nylon fibers, and aramid fibers. Among these, glass fibers are preferred. As the glass fibers, long fibers and short fibers obtained by cutting rovings are used. Long fibers usually have a length of 15 to 100 m.
m, preferably 20 to 50 mm, and the short fibers have a length of usually 3 mm or more and less than 15 mm, preferably 6 to 13 mm.

The roving usually has a fiber diameter of 5 to 25.
It is obtained by bundling about 50 to 4000 single fibers of μm with a sizing agent such as polyvinyl acetate, polyester, epoxy resin or polyurethane. In the thermosetting molding material of the present invention, the fibrous reinforcing material is 10 to 70% by weight based on the total weight of the molding material,
It is preferably contained in the range of 20 to 50% by weight. Further, the viscosity of the resin composition at a temperature of 25 ° C. 30 minutes after the addition of the thickener can be adjusted to 10 to 300 Pa · s. It is preferable to impregnate the material from the viewpoint of impregnation property.
Furthermore, after impregnating the fibrous reinforcement, SMC or B
After 24 hours after adding MC and adding the thickener, the viscosity of the molding material at a temperature of 25 ° C. was 10,000 to 200,000.
Since it can be adjusted to a range of Pa · s, while the viscosity is within the above range, SMC or BMC is molded by a method such as compression molding or transfer molding to obtain a desired molded article with good workability. can do.

Next, an embodiment of producing a molded article using the thermosetting molding material of the present invention will be described by taking the case of SMC as an example. First, the unsaturated polyester resin,
A liquid vinyl monomer, a low-shrinking agent, a filler, a polymerization initiator and, if necessary, a curing accelerator and other additives are kneaded to prepare a compound paste. Then, the unsaturated polyester resin composition obtained by mixing this with magnesium oxide as a thickener is immediately supplied to the SMC impregnating machine.

Next, a predetermined amount of the above composition is applied to each of the two carrier films, and then glass rovings are dropped on the application layer of the lower film while chopping with a cutter. At this time, the composition has a viscosity (25 ° C.) of 10 to 10.
The range of 300 Pa · s is preferable. Then, an upper film having a coating layer thereon is laminated so that the coating layer is on the inside, and rolls are pressed above and below the laminated film to impregnate the sandwiched glass fibers with the composition. Thus, the sheet-like thermosetting molding material (SMC) of the present invention is obtained.

The thickness of the sheet-like thermosetting molding material of the present invention thus obtained is usually 1 to 10 mm, preferably 1 to 10 from the viewpoint of the permeability of the composition into the glass fiber.
It is selected in the range of 5 mm. Further, the content of the glass fiber in the sheet-shaped thermosetting molding material is selected in the range of usually 10 to 70% by weight, preferably 20 to 50% by weight, as described above. Next, a plurality of the sheet-like thermosetting molding materials obtained as described above are usually used and set in a mold by stacking them, usually 1 to 10 MPa, 130 to
A glass fiber reinforced molded body is obtained by heating and pressurizing for about 1 to 10 minutes under the condition of 150 ° C. to cure.

EXAMPLES Next, the present invention will be described with reference to Examples.
As will be described in more detail, the present invention is in no way limited by these examples.

Examples 1 and 2 and Comparative Example 1 Unsaturated polyester resin A having the properties shown in Table 1.
(Example 1), B (Example 2) and C (Comparative Example 1) 75 parts by weight each, polystyrene resin 25 parts by weight, styrene monomer 20 parts by weight, ground calcium carbonate 180 parts by weight, tert-butyl peroxybenzoate. An unsaturated polyester resin composition containing 1 part by weight and 1.2 parts by weight of magnesium oxide was prepared.

The unsaturated polyester resin used in each example was prepared by using a combination of terephthalic acid and maleic acid as the dicarboxylic acid component and a combination of propylene glycol and neopentyl glycol as the glycol component. It was obtained by a chemical reaction. The initial viscosity of each composition at a temperature of 25 ° C. and the viscosity (25 ° C.) 30 minutes after the addition of magnesium oxide were measured. The results are shown in Table 1.

Approximately 30 minutes after the addition of magnesium oxide, a glass roving is chopped with a cutter to a length of 25 m.
m of glass fiber was added at a rate of 25% by weight, based on the total weight of the molding material, to prepare each thermosetting molding material. The viscosity (25 ° C.) 24 hours after the addition of magnesium oxide in each molding material was measured. The results are shown in Table 1.

[0032]

[Table 1]

(Note) (1) Initial viscosity: viscosity of composition immediately after addition of magnesium oxide (25 ° C.) (2) Viscosity after 30 minutes: viscosity of composition 30 minutes after addition of magnesium oxide (25 ° C.) (3) ) Viscosity after 24 hours: Viscosity of molding material 24 hours after addition of magnesium oxide (25 ° C)

As can be seen from Table 1, the unsaturated polyester resin of Comparative Example 1 has a molecular weight distribution (Mw / Mn) and acid value outside the ranges specified in the present invention, and therefore after 30 minutes of the composition. Is much higher than that of the example, and the viscosity of the molding material after 24 hours is lower than that of the example.

[0035]

EFFECTS OF THE INVENTION According to the present invention, an unsaturated polyester resin composition for SMC or BMC, which gives a viscosity in which both the impregnation property into the fibrous reinforcing material and the workability during SMC or BMC molding are improved, and the same It is possible to provide a thermosetting molding material using.

Continued front page    F-term (reference) 4F072 AA04 AA07 AA09 AB09 AB27                       AD39 AD54 AE00 AE02 AE12                       AE13 AF04 AF11 AG03 AG04                       AH02 AH21 AJ21 AK05 AK14                       AL06 AL07                 4F204 AA13 AA41 AB03 AB11 AB16                       AD16                 4J027 AB02 AB06 AB07 AB08 AB15                       AB16 AB17 AB18 AB19 AB23                       AB24 AB25 AJ01 AJ05 AJ06                       BA05 BA06 BA07 BA13 BA18                       BA20 BA26 CA02 CA03 CA04                       CA05 CA06 CA14 CA18 CA19                       CA32 CA36 CB03 CC02 CD02                 4J029 AA07 AB01 AB07 AC02 AD01                       AD02 AD10 AE01 BA02 BA03                       BA05 BA07 BA08 BA09 BA10                       BD10 BF09 BF10 BF18 BF26                       CA02 CA04 CA05 CA06 CB04                       CB05 CB06 CD03 CG06 GA13                       GA14 GA15 GA17 HA01 HB01                       JE18

Claims (8)

[Claims] 1. A number average molecular weight (Mn) of 1000 to 40.
00, weight average molecular weight (Mw) and number average molecular weight (Mn)
An unsaturated polyester resin having a ratio Mw / Mn (molecular weight distribution) of 3.6 or less and an acid value of 15 to 25 KOHmg / g. 2. A sheet molding compound (hereinafter abbreviated as SMC) or a bulk molding compound (hereinafter B) containing an unsaturated polyester resin, a liquid vinyl monomer, a low-shrinking agent, a filler and a polymerization initiator.
In the resin composition used for MC)
An unsaturated polyester resin composition, wherein the unsaturated polyester resin according to claim 1 is used as the unsaturated polyester resin. 3. The unsaturated polyester resin according to claim 2, wherein the unsaturated polyester resin is obtained by esterifying a dicarboxylic acid component containing an α, β-olefinic unsaturated dicarboxylic acid and a glycol component. Resin composition. 4. The low-shrinking agent is a thermoplastic resin.
Or the unsaturated polyester resin composition according to item 3. 5. The unsaturated polyester resin composition according to claim 2, 3 or 4, which contains a thickener and has a viscosity of 10 to 300 Pa · s at a temperature of 25 ° C. 30 minutes after the thickener is added. 6. The fibrous reinforcing material 10 based on the unsaturated polyester resin composition according to claim 5 and the total weight of the molding material.
~ 70 wt% SMC or BMC
Thermosetting molding material 7. The thermosetting molding material according to claim 6, wherein the fibrous reinforcing material is glass fiber. 8. The thermosetting molding material according to claim 6, which has a viscosity of 10,000 to 200,000 Pa · s at a temperature of 25 ° C. after 24 hours from the addition of the thickener.