JPH10324739A - Unsaturated polyester resin composition and fiber-reinforced molding material using the same and sheet-like molding material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject resin composition good in colorability, etc., by reacting a polybasic acid component containing an unsaturated α,β-unsaturated polybasic acid or its anhydride as an essential component with a polyhydric alcohol and a compound selected from phosphorous triesters and phosphoric triesters as raw materials and further adding a copolymerizable monomer. SOLUTION: This unsaturated polyester resin composition comprises an unsaturated polyester resin obtained by reacting (A) a polybasic acid component containing an α,β-unsaturated polybasic acid or its anhydride (e.g. maleic acid) as an essential component with (B) a polyhydric alcohol (e.g. ethylene glycol) and (C) a compound (e.g. trimethyl phosphite) selected from phosphorous triesters and phosphoric triesters, and a copolymerizable monomer (e.g. styrene). The resin composition is good in colorability and also good in mold releasability from molds after cured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an unsaturated polyester resin composition, a fiber-reinforced molding material and a sheet-like molding material using the same, and more particularly, to a fiber having good releasability from a mold after molding. The present invention relates to an unsaturated polyester resin composition which can obtain a reinforced molding material and is lightened, and a fiber reinforced molding material and a sheet-like molding material using the same.

[0002]

2. Description of the Related Art A sheet molding compound (SMC) method widely used as one of FRP molding methods is a molding method using a sheet-like molding material, that is, SMC. SMC applies the blended resin on the release film on the lower side, sprinkles glass fiber on it, stacks the release film coated with the blended resin on it, then impregnates and defoams between rollers. It is obtained by winding and subsequently aging. After aging, the film is peeled off, loaded into a mold, and heated and pressed to obtain a molded product. Further, as a molding material, a bulk molding compound (BMC) obtained by mixing a blended resin with glass fibers cut short, thickening and aging is used. As the blended resin, generally, an unsaturated polyester resin, a copolymerizable monomer, a filler such as calcium carbonate, a curing agent such as an organic peroxide, a low shrinkage agent such as polystyrene, a release agent, a pigment, An unsaturated polyester resin composition in which a viscosity agent and the like are appropriately mixed is used.

[0003]

When the molded product is taken out of the mold, the molded product is removed from the mold by using air or the like, and the mold is automatically or manually removed. At this time, if the molded product adheres strongly to the mold and the releasability is poor, it becomes difficult to remove the mold,
The time required for demolding results in a longer molding cycle, resulting in reduced productivity. To solve this,
In the synthesis of unsaturated polyester resins, measures such as lowering the acid value of the reaction end point or increasing the curing shrinkage by increasing the blending amount of the copolymerizable monomer have been taken. However, for a sheet-like molding material used for molding a waterproof pan, a bathtub, or the like, a shortening of a thickening period is required for improving productivity. This thickening is determined by the acid value and molecular weight of the reaction end point in the synthesis of the unsaturated polyester resin. When the reaction end point acid value is lowered, there is a problem that the progress of thickening is slowed down or the thickening does not occur even when a thickener is added. Also, if the blending amount of the copolymerizable monomer is increased, the prepared resin has a low viscosity, and when it is made into a sheet-shaped molding material, sagging and exudation occur,
There is a problem that the production of BMC is also difficult, and there is a great difficulty in putting it to practical use. In addition, the unsaturated polyester resin has some coloring, which sometimes hinders coloring.

[0004] In view of the problems of the prior art, the present invention has
Reaction end point acid value in the synthesis of unsaturated polyester resin,
Without changing the molecular weight, or without increasing the amount of the copolymerizable monomer, a fiber-reinforced molding material having good release properties after molding can be obtained, and a light-colored unsaturated polyester resin. It is an object to provide a composition and a fiber-reinforced molding material using the unsaturated polyester resin composition.

[0005]

The invention according to claim 1 of the present invention comprises a polybasic acid component, a polyhydric alcohol, and an α, β-unsaturated polybasic acid or an anhydride thereof as essential components. , Unsaturated polyester resin obtained by reacting a compound selected from a triester of phosphorous acid and a triester of phosphoric acid as a synthesis raw material, and an unsaturated polyester resin composition comprising a copolymerizable monomer as an essential component It is.

[0006] The invention described in claim 2 is the invention according to claim 1.
A fiber-reinforced molding material further comprising a fiber-reinforced material in the unsaturated polyester resin composition described above.

[0007] The invention according to claim 3 is a sheet-like molding material obtained by forming the fiber-reinforced molding material into a sheet.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the α, β-unsaturated polybasic acid or its anhydride as a raw material for the synthesis of unsaturated polyester resin includes, for example, α, β-unsaturated dibasic acid or its anhydride. Products such as maleic acid, fumaric acid, itaconic acid, citraconic acid, maleic anhydride and anhydrides thereof. These may be used in combination of two or more. As the polybasic acid component, to adjust the concentration of the unsaturated group, flexibility, to impart properties such as heat resistance,
It is preferable to use a saturated polybasic acid or its anhydride in addition to the α, β-unsaturated polybasic acid or its anhydride. At this time, as the α, β-unsaturated polybasic acid or its anhydride,
Preferably, the content is 40 mol% or more of the polybasic acid component. When the amount of α, β-unsaturated polybasic acid or its anhydride is less than 40 mol%, the strength of the obtained molded article tends to gradually decrease. For this reason, the content of the α, β-unsaturated polybasic acid or its anhydride is more preferably from 45 to 80 mol%, particularly preferably from 50 to 70 mol%.

The saturated polybasic acids or anhydrides to be used in combination include phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, tetrahydrophthalic anhydride, 3,6-endomethylenetetrahydrophthalic anhydride, Hexahydrophthalic acid, hexahydrophthalic anhydride, glutaric acid, adipic acid, sebacic acid, trimellitic acid, trimellitic anhydride, pyromellitic acid, dimer acid, succinic acid, azelaic acid, rosin-maleic acid adducts, etc. Can be These may be used in combination of two or more.

Polyhydric alcohols which are another raw material for the synthesis of unsaturated polyester resins include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol,
6-hexanediol, neopentyl glycol, 1,
Examples thereof include dihydric alcohols such as 4-cyclohexanediol and hydrogenated bisphenol A, trihydric alcohols such as glycerin and trimethylolpropane, and tetrahydric alcohols such as pentaerythritol. These may be used in combination of two or more.

The polybasic acid component and the polyhydric alcohol are preferably used in an equivalence ratio of 1 to 1.3 when the polybasic acid component is set to 1;
More preferably, it is used in the range of 1.05 to 1.05. When the polyhydric alcohol decreases, the molecular weight of the resulting unsaturated polyester resin tends to decrease, and when the polyhydric alcohol increases, the acid value decreases and the progress of thickening by the thickener tends to be slow.

Compounds selected from phosphoric acid triesters and phosphoric acid triesters, which are other raw materials for the synthesis of unsaturated polyester resins, include trimethyl phosphite, triethyl phosphite, triphenyl phosphite, Triphenyl phosphate and the like. To improve mold release,
Triesters of phosphorous acid are particularly effective. Triesters of phosphorous acid and phosphoric acid have a polybasic acid component and, when the total of polyhydric alcohols is 100 parts by weight, 0.01 to
It is preferred to use 1.0 part by weight. When the amount of the triester of phosphorous acid or phosphoric acid is less than 0.01 part by weight, the effect of improving the releasability is small. The unsaturated polyester resin obtained tends to be colored. From this, it is more preferable to be 0.05 to 0.5 parts by weight,
It is more preferred to use 0.1 to 0.3 parts by weight.

The method for producing the unsaturated polyester resin can be a conventionally known method. For example,
Polycondensation reaction with polybasic acid component and polyhydric alcohol component,
The reaction proceeds while removing condensed water generated when both components react. The removal of the condensed water out of the system is preferably carried out by natural distillation or vacuum distillation by passing an inert gas. In order to promote the distillation of condensed water, a solvent such as toluene or xylene can be added to the system as an azeotropic component. The progress of the reaction can be generally known by measuring the amount of distillate generated by the reaction, quantifying the functional group at the end, measuring the viscosity of the reaction system, and the like. The reaction temperature is preferably 150 ° C. or higher, and the reaction is preferably performed while passing an inert gas such as nitrogen or carbon dioxide in order to prevent a side reaction due to oxidation.

For this reason, as the reaction apparatus, those made of glass, stainless steel or the like are selected, and a stirrer, a fractionating apparatus for preventing distillation of the alcohol component due to azeotropic distillation of water and the alcohol component, and a reaction system are used. It is preferable to use a heating device for raising the temperature, a temperature control device for the heating device, a reaction device provided with a blowing device for an inert gas such as nitrogen, and the like.

The copolymerizable monomer used in the present invention includes, for example, styrene derivatives such as styrene, chlorostyrene, divinylbenzene, tertiary butyl styrene, and styrene bromide, methyl methacrylate, ethyl methacrylate, and acrylic acid. Ethyl, alkyl esters of methacrylic acid or acrylic acid such as butyl acrylate, β-hydroxyethyl methacrylate, hydroxyalkyl esters of methacrylic acid or acrylic acid such as ethyl β-hydroxyacrylate, diallyl phthalate, acrylamide, phenylmaleimide and the like. can give. In addition, polyfunctional methacrylic acid or acrylic acid esters such as ethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, and trimethylpropane trimethacrylate can also be used.

The unsaturated polyester resin is mixed with a copolymerizable monomer, and if necessary, a polymerization inhibitor and the like are added to obtain an unsaturated polyester resin composition. The mixing ratio of the unsaturated polyester resin and the copolymerizable monomer at this time, when the total amount of both is 100 parts by weight, the unsaturated polyester resin is 25 to 80 parts by weight, the copolymerizable monomer is 75-2
It is preferably 0 parts by weight. When the amount is less than 25 parts by weight, the viscosity of the unsaturated polyester resin composition is too low to be easily applied to a sheet, and it is difficult to uniformly mix with other components due to sedimentation and the like. Even when the material is molded, the curing shrinkage is large, and the molded product may be cracked or cracked. If the unsaturated polyester resin exceeds 80 parts by weight, the viscosity is too high,
It may be difficult to mix with other components. For this reason, it is more preferable that the unsaturated polyester resin be 40 to 65 parts by weight and the copolymerizable monomer be 60 to 35 parts by weight. Examples of the polymerization inhibitor include p-benzoquinone, naphthoquinone, tolquinone, hydroquinone, mono-t-butylhydroquinone, and the like. The polymerization inhibitor is preferably used in an amount of 0.5% by weight or less based on the total amount of the unsaturated polyester resin and the polymerizable monomer. When a curing agent is added, 0.05% by weight for storage stability
It is preferable to contain the above.

The unsaturated polyester resin composition of the present invention is further blended with a low shrinkage agent, a filler, a thickener, a curing agent, a release agent, a stabilizer and the like.

As the low-shrinkage agent, polymethyl methacrylate, polystyrene, polycaprolactone, polyvinyl acetate, polyethylene, butadiene rubber and the like are used.
The amount used is determined in consideration of the shrinkage, surface smoothness, and surface gloss of the molded product, and is not particularly limited. The low-shrinkage agent is preferably used in an amount of 20 to 50% by weight based on the total amount of the unsaturated polyester resin and the polymerizable monomer.

As the filler, silica sand, calcium carbonate,
Examples include inorganic fillers such as talc and clay, and organic fillers such as wood powder, polyethylene powder, and pulverized products of various FRP molded products. Of these, calcium carbonate, particularly heavy calcium carbonate, is preferred. The amount used is the physical properties such as the strength of the molded article, the viscosity of the unsaturated polyester resin composition,
It is determined in consideration of fluidity, but is 100 to 18 with respect to the total amount of the unsaturated polyester resin and the polymerizable monomer.
0% by weight, and particularly preferably 105 to 125%.
It is preferable to set the weight%. If the amount of the filler is too small, sedimentation may occur. If the amount of the filler is too large, the viscosity tends to be high and stirring tends to be difficult.

Examples of the curing agent include ketone peroxides, peroxydicarbonates, hydroperoxides, diacyl peroxides, peroxyketals, dialkyl peroxides, and peroxyesters. Since the amount of the curing agent affects not only the molding cycle but also the preservability of the material, color unevenness, and the like, it is determined according to each. From the viewpoint of the storage stability of the material and the molding cycle, it is preferably 0.5 to 5% by weight based on the total amount of the unsaturated polyester resin and the polymerizable monomer,
More preferably, it is 1 to 2% by weight.

As the thickener, magnesium oxide, magnesium hydroxide, potassium oxide, potassium hydroxide and the like are used, but magnesium oxide is generally used. The amount of the thickener is determined depending on the workability of the molding material, but is preferably 0.5 to 5% by weight, more preferably 0.5% by weight, based on the total amount of the unsaturated polyester resin and the polymerizable monomer. 0.7 to 2% by weight. If the amount of the thickener is too small, the viscosity of the resin composition may not increase. On the other hand, if the amount of the thickener is too large, the viscosity may be too high to control.

As the release agent, zinc stearate, calcium stearate and the like are used. The amount of the release agent is preferably 1 to 10% by weight, more preferably 2 to 10% by weight based on the total amount of the unsaturated polyester resin and the polymerizable monomer.
4% by weight. If the amount of the release agent is too small, if the amount is less than 1 part by weight, the molded article may stick to the mold, making it difficult to remove the mold, and cracking the molded article. If the amount of the release agent is too large, the strength of the molded article tends to decrease.

The unsaturated polyester resin composition of the present invention can further contain a reinforcing fiber to obtain a fiber-reinforced molding material. At this time, the unsaturated polyester resin contains a thickener and a curing agent as essential components. Further, it preferably contains a filler, a low shrinkage agent, a release agent, and a polymerization inhibitor. As fiber reinforced molding materials, SMC,
BMC and the like. As the reinforcing material, glass fiber, carbonate fiber, aramid fiber, polyvinyl alcohol-based fiber, or the like can be used, and glass fiber is generally used. These reinforcing materials are used in the form of continuous fibers, woven fabrics, non-woven fabrics, etc., and it is preferable to use a roving-shaped material cut to an appropriate length (in the case of SMC, cut to 20 to 30 mm, In the case of (1), a material cut to preferably 6 to 15 mm) is used. In producing the fiber-reinforced molding material, the amount of the reinforcing fiber used depends on the required strength, but is 15 to 35% by weight based on the total amount of the unsaturated polyester resin and the polymerizable monomer.
Is preferably within the range.

The fiber-reinforced molding material of the present invention, for example, SM
C and BMC can be manufactured using an ordinary SMC manufacturing apparatus or BMC manufacturing apparatus, respectively. SMC
In the case of, apply the compounding resin on the release film so as to have a uniform thickness, and uniformly spread a reinforcing material such as glass fiber cut to a predetermined length on this, and further compound on this Another resin-coated film is superimposed such that the sprinkled reinforcing material is sandwiched by the compounded resin, wound up into rolls, and, if necessary, aged to form a sheet-like molding material. it can. When a thickener is added, it is preferable to heat the mixture to a temperature of room temperature to 60 ° C. for aging.
As the release film, a polyethylene film, a polypropylene film, or the like can be used. In the case of BMC, reinforcing fibers are mixed with the unsaturated polyester resin composition described above, but there is no particular limitation on the mixing order of the components used in these.

The viscosity of the fiber-reinforced molding material is preferably adjusted so as to be 1,000 to 18,000 pa · s at 40 ° C. If the viscosity is too low, scumming is likely to occur on the surface of the molded article, and if the viscosity is too high, the mold clamping time will be long and the molding cycle will tend to be long. The viscosity of the fiber-reinforced molding material is 1,5 at 40 ° C.
It is more preferably adjusted to be from 00 pa · s to 15,000 pa · s, and from 3.500 to 12,000 P
It is particularly preferred that the adjustment be made to be a · s. However, the optimum viscosity of the fiber-reinforced molding material is determined by the molded product. The viscosity of the fiber-reinforced molding material can be adjusted by the amount of the thickener and the aging conditions. The sheet-shaped molding material in the present invention is molded by compression molding, transfer molding, or the like, so that a wide range of FRP molded products can be obtained.

[0026]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.
Hereinafter, parts means parts by weight.

Example 1 Synthesis of unsaturated polyester resin (a) 996 parts of terephthalic acid, propylene glycol 506
Parts, 312 parts of neopentyl glycol and 372 parts of ethylene glycol, and 30 parts of triphenyl phosphate,
The mixture was charged into a 3 liter flask equipped with a thermometer, a nitrogen blowing tube, a rectification tower, and a stirrer, and was heated using a mantle heater and heated to 230 ° C. in 5 hours. Then 2
After cooling to 20 ° C. and keeping the temperature until the acid value became 12, 882 parts of maleic anhydride was added, and the temperature was raised again to 215 ° C. in 5 hours. Thereafter, the reaction was cooled to 210 ° C., and when the acid value reached 18, the reaction was terminated.

Preparation of unsaturated polyester resin composition (a) 620 parts of unsaturated polyester resin (a) is dissolved in 380 parts of styrene as a copolymerizable monomer, and 0.02 parts of hydroquinone is used as a polymerization inhibitor. Was dissolved. The viscosity of this unsaturated polyester resin composition (a) at 25 ° C. was 1.54 Pa · s, and the hue was 1 in Gardner number.
It was below.

Preparation of Formulated Resin (a) 800 parts of the unsaturated polyester resin composition (a) and 60 parts of polystyrene having a number average molecular weight of 80,000 were mixed with styrene 1
200 parts of a solution dissolved in 40 parts of t-butyl perbenzoate (Perbutyl Z (trade name) manufactured by NOF Corporation)
10 parts), calcium carbonate (using NS # 200 (trade name) manufactured by Nitto Powder Chemical Co., Ltd.) 125
0 parts and 40 parts of zinc stearate were added and mixed well with a Cowles-type blade. The viscosity of this mixture is 36 at 25 ° C.
Pa · s. 8.5 parts of magnesium oxide was added to this mixture, stirred well, and aged at 40 ° C. for 24 hours to prepare a prepared resin (a). The viscosity of the prepared resin (a) was 3450 Pa · S at 40 ° C.

Preparation of sheet-shaped molding material (a) Using the compounded resin (a), a dual-wire mesh type SMC manufacturing apparatus was used to set a glass content to 30% by weight and to use a 50 μm thick polypropylene film as a release film. The sheet-shaped molding material (a) was prepared by aging in a ripening furnace at 40 ° C. for 3 days. The viscosity of the prepared sheet-shaped molding material (a) is 1 at 40 ° C.
It was 1,500 Pa · s.

Measurement of Aluminum Peel Strength In order to examine the releasability of the sheet-shaped molding material (a), the aluminum peel strength was measured as follows. The release film was peeled off from the sheet-shaped molding material (a), and the aluminum foil was sandwiched between 300 × 250 mm aluminum foil so that the glossy surface of the aluminum foil was in contact with the sheet-shaped molding material (a).
Using a 0-ton press, the surface pressure is 5.0 MPa, and the mold temperature is
The upper is 140 ° C, the lower is 130 ° C, and the molding time is 5 minutes,
Heat and pressure were applied to produce a flat plate. The dimensions of the flat plate were 300 × 280 mm on a flat surface and 6 mm in thickness. Next, a width of 50 mm
An aluminum peel strength of 18 N / m was obtained by cutting a strip having a length of 150 mm and a length of 150 mm, grasping one end in the length direction, and peeling off the strip at 50 mm / min.

Example 2 30 parts of triphenyl phosphate was replaced with 9 parts of triphenyl phosphite.
2 parts, the reaction was terminated at an acid value of 17.9, and the same procedure as in Example 1 was repeated to obtain an unsaturated polyester resin (b).
Was synthesized. Hereinafter, in the same manner as in Example 1, preparation of the unsaturated polyester resin composition (b), preparation of the compounded resin (b), preparation of the sheet-shaped molding material (b), and measurement of the aluminum peel strength were performed. As a result, the viscosity at 25 ° C. of the unsaturated polyester resin composition (b) was 1.56 Pa · s
And the hue was 1 or less in Gardner number. The viscosity of the mixture in the preparation process of the compounded resin (b) is 25
At 38 ° C., and the viscosity of the prepared resin (b) is 4
At 0 ° C., 3550 Pa · s, and the viscosity of the sheet-shaped molding material (b) at 40 ° C. was 12,200 Pa · s. Further, the aluminum peel strength was 13 N / m.

Comparative Example 1 In the synthesis of an unsaturated polyester resin, the amount of propylene glycol was changed to 470 parts, triphenyl phosphate was not added, and the reaction was terminated at an acid value of 28. In the same manner as in Example 1, an unsaturated polyester resin (c) was synthesized. Also, the preparation of the unsaturated polyester resin composition (c) and the preparation of the preparation resin (c) were performed in the same manner as in Example 1 except that the amount of calcium carbonate in preparing the preparation resin (c) was changed to 1050 parts. Then, production of a sheet-shaped molding material (c) and measurement of aluminum peel strength were performed. As a result, the viscosity at 25 ° C. of the unsaturated polyester resin composition (c) was 1.51 Pa · s, and the hue was 4 in Gardner number. The viscosity of the mixture in the preparation process of the prepared resin (c) was 2 at 25 ° C.
9 Pa · s, and the viscosity of the prepared resin (c) is 40 ° C.
And the viscosity of the sheet-shaped molding material (c) was 13200 Pa · s at 40 ° C. further,
The aluminum peel strength was 41.9 N / m.

Comparative Example 2 In the synthesis of an unsaturated polyester resin, the amount of propylene glycol was changed to 506 parts, and the reaction was carried out at an acid value of 1
In the same manner as in Comparative Example 1 except that the reaction was terminated at 8, the unsaturated polyester resin (d) was synthesized. Hereinafter, in the same manner as in Comparative Example 1, the unsaturated polyester resin composition (d)
, Preparation of a compounded resin (d), preparation of a sheet-shaped molding material (d), and measurement of aluminum peel strength. As a result, the unsaturated polyester resin composition (d)
Was 1.54 Pa · s, and the hue was 3 in Gardner number. The viscosity of the mixture in the preparation process of the prepared resin (d) is 34 Pa · s at 25 ° C.,
The viscosity of the prepared resin (d) at 40 ° C. is 3650 Pa ·
s, the viscosity of the sheet-shaped molding material (d) is 11
It was 900 Pa · s. Further, the aluminum peel strength was 29.8 N / m.

[0035]

The unsaturated polyester resin composition according to the first aspect of the present invention is light in color and therefore has good coloring properties, and the fiber-reinforced molding material using the same can be used for molding from a cured mold. Good releasability. Further, since the fiber-reinforced molding material according to the second aspect and the sheet-shaped molding material according to the third aspect have good releasability, the molding cycle can be shortened by using them. .

Claims (3)

[Claims] 1. A compound selected from a polybasic acid component, a polyhydric alcohol, and a triester of phosphorous acid and a triester of phosphoric acid, wherein an α, β-unsaturated polybasic acid or an anhydride thereof is an essential component. And an unsaturated polyester resin obtained by reacting as a synthetic raw material, and an unsaturated polyester resin composition comprising a copolymerizable monomer as an essential component. 2. A fiber-reinforced molding material comprising the unsaturated polyester resin composition according to claim 1 and a fiber reinforcing material. 3. A sheet-shaped molding material obtained by forming the fiber-reinforced molding material according to claim 2 into a sheet.