JP3072052B2 - (Meth) acrylic molding material and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a molding material (hereinafter referred to as a molding material) comprising a so-called acrylic syrup composed of a (meth) acrylic polymer (which is a general term for both a methacrylic polymer and an acrylic polymer) and a vinyl monomer as main components. In detail, it is possible to easily control the viscosity during the molding operation, and to mold the molding material for sheet molding compound (SMC) or bulk molding compound (BMC) or the molding material for casting. Applicable to various molding methods (meta)
The present invention relates to an acrylic molding material and a method for producing the same.

[0002]

2. Description of the Related Art Molding materials containing an unsaturated polyester resin as a main component are well known as raw materials for fiber reinforced composite materials (FRP). When manufacturing FRP, in the step of impregnating the reinforcing fiber, which is a reinforcing material, with the matrix resin, the viscosity of the matrix resin should be lower in order to enhance the impregnation property, and after impregnation, it can be handled as SMC or BMC. It is required that the viscosity does not substantially change with time after the viscosity is increased and the SMC or BMC is formed. Therefore, the viscosity control of the molding material is indispensable.

For example, Japanese Patent Application Laid-Open No. 52-38661 discloses that
It is described that magnesium oxide and a succinic acid derivative are added to an unsaturated polyester resin having an average molecular weight of 1500 to 5000, a specific acid value, and an ethylenically unsaturated monomer. According to the present invention, when a thickener such as magnesium oxide is used, the viscosity of the molding material rises too fast and the time for impregnating the reinforcing fibers is too short, or conversely, when the thickener is reduced, the viscosity increases. The difficulty in controlling the viscosity, that is, the time required to reach the ideal viscosity as SMC or BMC without causing the problem, is due to the combination of unsaturated polyester resin, thickener, and succinic acid derivative (however, the viscosity control effect I don't know why
It discloses that it was possible to solve the problem.

[0004] Molding materials containing polymethyl methacrylate as a main component have been applied in various fields to provide molded articles having excellent transparency, weather resistance, appearance, surface gloss and the like. Such a (meth) acrylic molding material often uses a liquid material called acrylic syrup in which a polymer and a monomer are mixed. JP-A-49-
No. 104937 discloses an acrylic syrup in which a polymer obtained by copolymerizing methyl methacrylate, ethyl acrylate and acrylic acid, and a monomer such as methyl methacrylate are mixed. In this example, a carboxyl group is introduced into a polymer by using acrylic acid, and a viscosity suitable for a molding operation is adjusted by adding a thickener such as magnesium oxide or magnesium hydroxide. Japanese Patent Publication No. 64-11652 also discloses a crosslinked acrylic syrup containing a carboxyl group-containing polymer and a polyfunctional monomer, and describes that the viscosity is adjusted with magnesium oxide or the like. That is, (meta)
As in the case of the unsaturated polyester resin, a method of increasing the viscosity of the acrylic molding material by the action of magnesium oxide and a carboxyl group has been used.

[0005]

However, when aluminum hydroxide, which is often blended as an inorganic filler, is used for a molding material using an acrylic syrup containing a polymer having a carboxyl group, a shear force is applied to the molding material. Immediately after mixing with the syrup, a low viscosity was exhibited, but thereafter a phenomenon was observed in which the viscosity continued to increase over time. This phenomenon occurs even though magnesium oxide as a thickener is added in a predetermined amount so as to have an appropriate viscosity in advance, and it is very difficult to control the thickening state. In such an irregularly thickened state, it takes a long time to reach the desired viscosity, or the viscosity becomes too high, which causes problems in actual operation, such as making the molding operation extremely difficult, and is obtained. Variations also occurred in the performance of molded products, and improvements have been strongly demanded.

Accordingly, the present invention provides a (meth) acrylic molding material which can be applied to various molding methods by controlling the thickening behavior of the carboxyl group-containing (meth) acrylic molding material to prevent the viscosity from changing over time. It is an object of the present invention to provide a manufacturing method thereof.

[0007]

The (meth) acrylic molding material of the present invention, which has achieved the above-mentioned object, comprises a monomer component (A) which essentially contains a carboxyl group-containing vinyl monomer and a (meth) acrylic acid alkyl ester monomer. And (B) a (meth) acrylic molding material containing (B) an acrylic syrup comprising at least one monomer having a vinyl group. A total of 8 to 8 carbon atoms having 30 to 600 parts by weight of aluminum hydroxide, a succinic acid skeleton or a succinic anhydride skeleton, and having an alkenyl group as a substituent in the ethylene group, based on 100 parts by weight of the total monomers. The gist lies in that 0.01 to 10 parts by weight of the succinic acid derivative is contained. The term “acryl syrup” refers to a mixture of a methacrylic polymer and / or an acrylic polymer (both of which are referred to as a (meth) acrylic polymer) and the monomer (B).

[0008] The (meth) acrylic polymer of (A)
It is obtained by polymerizing a monomer component essentially containing (meth) acrylic acid and methyl methacrylate,
It is preferable in that the weather resistance and other properties of the molded product are improved.

It is recommended that the carboxyl group required for thickening be 0.05 to 1.5 mol as the carboxyl group in 1000 g of the (meth) acrylic polymer. The preferable mixing ratio of the polymer and the monomer in the acrylic syrup is 7 to 80 parts by weight for the (meth) acrylic polymer (A) and 93 to 20 parts by weight for the monomer (B). Alkaline earth metal oxides and / or hydroxides that behave as thickeners may be used in combination if they are 5 parts by weight or less.

In order to produce the (meth) acrylic molding material of the present invention, a monomer component essentially containing a carboxyl group-containing vinyl monomer and a (meth) acrylate monomer is polymerized by a bulk polymerization method. Acrylic syrup was produced by terminating the polymerization before reaching 100%, and then 30 to 600 parts by weight of aluminum hydroxide and 0.01 to 10 parts by weight of succinic acid derivative based on 100 parts by weight of the acrylic syrup. The method of adding parts by weight is optimal. At this time, the acrylic syrup is a mixture of the residual monomer and the already synthesized carboxyl group-containing (meth) acrylic polymer. Further, after the polymerization is completely stopped, one or more monomers having a vinyl group (B) may be added to form an acrylic syrup. Furthermore, if the method of terminating the polymerization by adding one or more vinyl group-containing monomers of (B) is adopted, the residual monomer and the already synthesized carboxyl group-containing (meth) acrylic polymer may be terminated. Acrylic syrup, which is a mixture of monomers added for the above, can be easily produced.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have conducted various studies on the causes of variations in the thickening behavior of molding materials. As a result, the viscosity of the system containing aluminum hydroxide as an inorganic filler is remarkably increased. Was found. That is, when mixing aluminum hydroxide and acrylic syrup blended as an inorganic filler, the viscosity of the molding material is low immediately after mixing them by applying a shearing force, but thereafter the viscosity increases with time. The phenomenon of continuing was recognized. Further studies have shown that aluminum hydroxide or the unavoidable impurities contained in this aluminum hydroxide product can thicken (meth) acrylic molding materials, and this thickening behavior requires the use of succinic acid derivatives. Have been found to be controllable by the present invention. Hereinafter, the present invention will be described in detail.

First, the (meth) acrylic molding material of the present invention is obtained by polymerizing (A) a monomer component essentially containing a carboxyl group-containing vinyl monomer and an alkyl (meth) acrylate monomer. Acrylic polymer (In the present invention, “copolymer” or “multi-component copolymer” is simply abbreviated as “polymer” for convenience).
And (B) an acrylic syrup comprising at least one monomer having a vinyl group is used as a main component. "Acrylic syrup" refers to a methacrylic polymer and / or
Or, it refers to a mixture of an acrylic polymer and the monomer (B).

The carboxyl group-containing vinyl monomer which is an essential component for constituting the polymer (A) in the acrylic syrup includes unsaturated carboxylic acids such as acrylic acid, methacrylic acid and crotonic acid, maleic acid, fumaric acid, itacone One or more kinds of unsaturated dicarboxylic acids such as acids and citraconic acids and monoesters thereof can be used. The carboxyl group-containing vinyl monomer has a carboxyl group in the obtained polymer of 1,000 g of 0.05 to
It is preferable to use 1.5 mol. If the amount of carboxyl group is less than 0.05 mol, SMC or B
As a material of MC, the viscosity is too small and the stickiness is large, and the handleability during molding is poor. Further, pinholes and cracks are easily generated in the obtained molded product. 1.5
If the amount exceeds mol, the initial thickening is large, so that SMC, BM
During the production of C, impregnation into reinforcing fibers (mat, cloth, etc.), which is a reinforcing material, is poor, resulting in inconveniences such as separation of the compound from the reinforcing material and cracks after molding. A large amount of the succinic acid derivative is required in order to avoid such a rapid increase in viscosity, but this is not preferable because the physical properties such as water resistance and weather resistance of the obtained molded article are deteriorated. Also when applied to a casting material, the viscosity of the material increases during kneading, so that defoaming cannot be performed well, and pinholes are likely to occur in the obtained molded product.

(A) The alkyl (meth) acrylate monomer, which is another essential component for constituting the polymer, includes methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, propyl ( Examples thereof include (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylate, (meth) acrylamide, and glycidyl (meth) acrylate. One or more of these can be used as a mixture, and it is particularly preferable to mainly use methyl methacrylate which gives a high-performance molded article.

As the monomer constituting the polymer (A), another vinyl monomer can be used in combination, if necessary. However, the amount of the other vinyl monomer is preferably not more than the total amount of the carboxyl group-containing vinyl monomer and the alkyl (meth) acrylate monomer, which are the essential components.

Other vinyl monomers used as required include, for example, styrene, α-methylstyrene, vinyltoluene, chlorostyrene, vinyl acetate, allyl alcohol, ethylene glycol monoallyl ether, propylene glycol monoallyl ether and the like. Can be

Unsaturated polyester resins and vinyl ester resins which can be copolymerized with carboxyl group-containing vinyl monomers and alkyl (meth) acrylate monomers, reaction products of hydroxyl group-containing (meth) acrylates and polyisocyanate compounds, etc. May be used as a part of the monomer.

The (meth) acrylic polymer of (A)
The above-mentioned monomer components are prepared by known solution polymerization, bulk polymerization,
It can be synthesized by polymerizing by a method such as emulsion polymerization or suspension polymerization. Above all, when synthesized by bulk polymerization, the viscosity of the resulting molding material is improved. In addition, there is an advantage that an acrylic syrup can be manufactured without a complicated process by adopting a manufacturing method utilizing bulk polymerization (described later). The weight average molecular weight of the produced polymer should be 30,000 to 1,000,000, and the number average molecular weight should be 10,000 to 200,000, because viscosity control is easy, molding workability is good, and physical properties of molded products are good. Recommended.

As the vinyl group-containing monomer (B) used to form a liquid acrylic syrup by mixing with the produced polymer, any of the monomers exemplified as the monomer for constituting the polymer (A) can be used. Can also be used. Most preferably, methyl methacrylate can be used.

If necessary, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate (Meth) acrylates such as trimethylolpropane tri (meth) acrylate and pentaerythritol tetra (meth) acrylate; and polyfunctional (meth) acrylates such as divinylbenzene, diallyl phthalate, diallyl isophthalate, triallyl cyanurate and triallyl isocyanurate. Functionally crosslinkable monomers may be used.

The mixing ratio of the polymer (A) and the monomer (B) in the acrylic syrup is as follows: (A) polymer: 7 to 80
Parts by weight, (B) monomer: 93 to 20 parts by weight. The acrylic syrup before thickening preferably has a viscosity range at 25 ° C. of 0.5 to 400 poise, more preferably 1 to 200 poise. Since the viscosity of the acrylic syrup varies depending on the molecular weight of the polymer (A) and the amount of carboxyl groups, it is desired to adjust the viscosity range by appropriately increasing or decreasing the amount of the monomer (B).

The (meth) acrylic molding material of the present invention contains aluminum hydroxide as an essential component together with the acrylic syrup. The present inventors have found that aluminum hydroxide can act not only as a filler and a bulking agent, but also as a thickener, so that the molding material of the present invention contains aluminum hydroxide and The viscosity of the acid derivative is controlled by using both of them in an optimum blending amount.

Aluminum hydroxide is mixed in an amount of 30 to 600 parts by weight with respect to 100 parts by weight of the acrylic syrup.
More preferred amounts are 30 to 300 parts by weight when used as SMC, 150 to 600 parts by weight as BMC, and 30 to 250 parts by weight as casting material.

The aluminum hydroxide is preferably in the form of particles, and the average particle size is not particularly limited, but is 1 to 100 μm,
Preferably it is 1 to 25 μm. When aluminum hydroxide surface-treated with a known coupling agent is used, the strength of the obtained molded article is improved. As the coupling agent, various coupling agents of silane type, titanate type, aluminate type, zircoaluminate type can be used,
The surface treatment may be performed by a known method.

Commercially available and industrially available aluminum hydroxides include the "Heidilite" series manufactured by Showa Denko KK; H-320, H-320ST (silane-coupled), H-341; H-100, HS
-320, CW-308 manufactured by Sumitomo Chemical Co., Ltd.,
CW-316, C-303 and the like.

Another essential component in the (meth) acrylic molding material of the present invention is a succinic acid derivative. This succinic acid derivative has a function of suppressing excessive thickening of acrylic syrup caused by aluminum hydroxide. In a system that does not contain a succinic acid derivative, the viscosity of the molding material suddenly increases during the preparation of the material, making subsequent molding work difficult or even if the molding work can be performed, strengthening the glass fiber etc. Problems such as insufficient impregnation with fibers, insufficient defoaming, and poor appearance due to insufficient fluidity occur. Therefore, in the (meth) acrylic molding material of the present invention, a succinic acid derivative is an essential component.

The succinic acid derivative of the present invention is a compound having a succinic acid skeleton or a succinic anhydride skeleton and having an alkenyl group as a substituent in the ethylene group. In the present invention, a mixture of several isomers may be used as the succinic acid derivative, and the mixture is not limited to a single compound. In addition, the present invention can be used for the total carbon number of 8 to 30.
Is a succinic acid derivative of If the total number of carbon atoms is less than 8, the solubility in acrylic syrup tends to be inferior. If the total number of carbon atoms exceeds 30, the effect of suppressing thickening is reduced.

Specific examples of the succinic acid derivative having an alkenyl group include hexenyl succinic acid, heptenyl succinic acid, octenyl succinic acid, nonenyl succinic acid, decenyl succinic acid, dodecenyl succinic acid, tetradecenyl succinic acid, cyclododecyl succinic acid, cyclododede. Cenylsuccinic acid, hexadecenylsuccinic acid, heptadecenylsuccinic acid, octadecenylsuccinic acid, pentadecenylsuccinic acid, pentadodecenylsuccinic acid, eicosenylsuccinic acid and diphenylbutyric acid Tenyl succinic acid and the like and anhydrides thereof can be mentioned, and one or more kinds can be used.

The succinic acid derivative is acrylic syrup 10
0.01 to 10 parts by weight with respect to 0 parts by weight.
If the amount of the succinic acid derivative is less than 0.01 part by weight, the effect of controlling the thickening is not exerted, and a problem occurs due to the rapid thickening of the molding material. On the other hand, if the amount of the succinic acid derivative exceeds 10 parts by weight, the water resistance of the obtained molded article may deteriorate, which is not preferable. Although the preferred specified range of the amount of the succinic acid derivative used is as described above, the thickening behavior of the molding material is determined by the amount of the carboxyl group, the amount of the aluminum hydroxide, and the amount of the succinic acid derivative in the polymer of the acrylic syrup. Therefore, it is recommended that the amount of the carboxyl group and the amount of aluminum hydroxide be determined according to the molding method and application, and the amount of the succinic acid derivative be set and changed according to these amounts.

As a result of further studies by the present inventors, the thickening effect of aluminum hydroxide can be caused by aluminum hydroxide itself or a water-soluble sodium compound which is an inevitable impurity contained in aluminum hydroxide industrial products. Has been found to be high. Sodium-based compounds are inevitably contained in the aluminum raw material used in the production of aluminum hydroxide, and aluminum hydroxide containing no aluminum hydroxide cannot be produced or obtained at this time. It is not possible to determine which of them has a stronger thickening effect, but it has been found that when aluminum hydroxide having a small amount of sodium compound, that is, relatively high purity, is used, the thickening behavior tends to be slow. All of the currently available aluminum hydroxides can of course be used as a thickener for the molding material of the present invention, but since the thickening behavior may vary depending on the type of product, the control with the succinic acid derivative can be further improved. Will be emphasized.

The (meth) acrylic molding material of the present invention comprises:
As described above, acrylic syrup, aluminum hydroxide and a succinic acid derivative are essential components, but various known additives can be added as necessary. Hereinafter, each additive will be described. The following additives are not limited to those illustrated, and may be used for purposes other than those illustrated.

[Polymerization initiator] In order to polymerize the monomer in the acrylic syrup to obtain a cured molded product, it is preferable to add a polymerization initiator. Examples of the initiator include benzoyl peroxide, lauryl peroxide, methyl ethyl ketone peroxide, t-butyl peroxy-2.
Organic peroxides such as -ethylhexanoate, t-butylperoxyoctoate, t-butylperoxybenzoate, cumenehydroperoxide, cyclohexanone peroxide, and dicumyl peroxide;
Azo compounds such as 2'-azobisisobutyronitrile and 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile can be used. These initiators may be used in the range of 0.1 to 5 parts by weight based on 100 parts by weight of the acrylic syrup. Further, a polymerization inhibitor generally used for SMC and BMC may be used in combination.

[Thickener] The molding material of the present invention can suppress a sharp increase in viscosity by the action of the succinic acid derivative. Control is possible. Thus, the use of alkaline earth metal oxides or hydroxides is not limited. However, when these thickeners are used, the weather resistance and water resistance of the obtained molded article tend to deteriorate,
It is used in a range of 5 parts by weight or less based on 100 parts by weight of the acrylic syrup. Specific examples of the thickener include magnesium oxide, magnesium hydroxide, calcium oxide, calcium hydroxide and the like.

[Filler] In the present invention, aluminum hydroxide, which acts not only as a thickener but also as a filler, is an essential component.
Addition of inorganic or organic fillers such as barium sulfate, alumina, clay, talc, milled fiber, silica sand, river sand, diatomaceous earth, mica powder, gypsum, dolomite, asbestos powder, glass powder, glass spheres, polymer beads, etc. Good.

[Reinforcing Material] In order to enhance the strength by being compounded with a molded article, it is preferable to incorporate a reinforcing material such as a fiber shape. Specifically, glass fibers, carbon fibers, metal fibers, inorganic fibers such as ceramic fibers, and aramid, various organic fibers and natural fibers including polyester can be used, and as a form, for example, roving, cloth, The type and amount of the mat, woven fabric, chopped roving, chopped strand, etc. may be determined according to the intended use. Since the molding material of the present invention has a low viscosity and does not have an excessive increase in viscosity, it is excellent in workability of impregnating these reinforcing fibers.

[Release Agent] In order to improve mold release, stearic acid, zinc stearate, aluminum stearate, calcium stearate, barium stearate,
Known release agents such as stearic acid amide, alkyl phosphate and silicone oil can be used. [Colorant] Depending on the use of the molded article, a known colorant such as an inorganic pigment or an organic pigment may be added.

[Low-shrinking agent] When high-precision dimensional stability is required, it is preferable to add a low-shrinking agent. Examples of the low-shrinkage agent include thermoplastic polymers such as polyethylene, polypropylene, polystyrene, polyethylene glycol, polypropylene glycol, cellulose butyrate, acetate, polyvinyl chloride, polyvinyl acetate, polycaprolactone, saturated polyester, and copolymers thereof. And the like.

The method for producing the molding material of the present invention is not particularly limited, but a method of synthesizing the (meth) acrylic polymer (A) by bulk polymerization is preferred. A (meth) acrylic polymer is synthesized by polymerizing a monomer component essentially containing a carboxyl group-containing vinyl monomer and a (meth) acrylate monomer by a bulk polymerization method without using any solvent. If the polymerization is stopped before the polymerization is completely completed, that is, before the polymerization rate reaches 100%, the already synthesized (meth) acrylic polymer and the raw material monomer are mixed in the polymerization vessel, Since the monomer is always a monomer containing a vinyl group of (B), it can be used as it is as an acrylic syrup. The termination of the polymerization may be carried out by rapidly lowering the system temperature by adding a monomer having a vinyl group at the same temperature level as room temperature into the vessel in which the polymerization is being performed. Other methods for stopping the polymerization include a method of rapidly cooling the temperature around the polymerization vessel, a method of adding a polymerization inhibitor, and a method of blowing oxygen into the system.

After the polymerization is completely stopped, (B)
The composition of the acrylic syrup may be prepared by adding one or more kinds of monomers having a vinyl group (the same or different monomers as the raw material monomers).

After the above-mentioned acrylic syrup is prepared, aluminum hydroxide and a succinic acid derivative are added, and if necessary, the above-mentioned additives are added and mixed to obtain a (meth) acrylic molding material. Thereafter, a known method for producing SMC, BMC or the like may be used to prepare a molding material suitable for various uses. The molding material of the present invention can be applied as a molding material for casting in addition to SMC and BMC. The molding may be performed according to a conventionally known molding method.
Heating in the range of 0 to 180 ° C and pressurization of 20 MPa or less are basic, but not particularly limited.

The molding material of the present invention can be used after the preparation of the molding material,
Since the viscosity of the obtained SMC or BMC does not substantially change, the workability is excellent, and the defoaming and casting operations are also easy in cast molding. In addition, since the optimum fluidity can be maintained for a long time, the appearance of the resulting molded article, such as surface smoothness and gloss, becomes beautiful regardless of which molding means is used. Furthermore, since the reinforcing fibers have excellent impregnating properties and the dispersibility of the fibers during molding is good, a high-performance (meth) acrylic FRP can also be produced.

[0042]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which do not limit the present invention.
Modifications and alterations that do not depart from the spirit described below are all included in the technical scope of the present invention. In addition, "part", "%"
“Parts” means “parts by weight” and “% by weight” unless otherwise specified.

Example 1 [Production of Acrylic Syrup 1] 190 parts of methyl methacrylate and 10 parts of methacrylic acid were charged into a reaction vessel equipped with a stirrer, a thermometer, a nitrogen inlet tube, and a cooler. Under a nitrogen atmosphere at 80 ° C., 0.05 parts of azobisisobutyronitrile as a polymerization initiator and 0.8 parts of n-dodecylmercaptan as a chain transfer agent were added to perform bulk polymerization. When the viscosity of the polymer reached 30 to 35 poise at 25 ° C., 50 parts of methyl methacrylate was added and quenched to obtain acrylic syrup 1. This syrup had a viscosity of 7 poise at 25 ° C. and a solid content of 20.8%. Further, in order to examine the carboxyl group concentration of the syrup, a polymer was obtained by reprecipitation in a large amount of methanol, and the polymer was titrated with KOH. As a result, it was 0.57 mol in 1000 g of the polymer.

[Thickening Experiment 1] Using the above acrylic syrup 1, the difference in thickening behavior depending on the type of aluminum hydroxide was examined. To make the viscosity change easier to understand,
15 parts of methyl methacrylate were further added to 85 parts of acrylic syrup 1, and 100 parts of each of the three kinds of aluminum hydroxides shown in Table 1 were added to the diluted syrup.
Three aluminum hydroxide used are all in "HIGILITE" series manufactured by Showa Denko KK can be extracted by w-Na ₂ O (water According to the catalog Na ₂ O
It is considered to mean. The total Na ₂ O content of the three aluminum hydroxides used was the same at 0.13% by weight. ) Are different as shown in Table 1. Viscosity was measured immediately after the addition of each sample (initial stage), 24 hours and 48 hours later. The initial viscosity was measured at 25 ° C., and the other values were measured at 40 ° C. The results are shown in Table 1.

[0045]

[Table 1]

As is clear from Table 1, the system using Hygilite H-320I, which has the smallest w-Na ₂ O content of 0.003%, shows almost no change in viscosity.
Heidilite H- which has the highest w-Na ₂ O content of 0.02%
In the system using 320ST, the thickening is remarkable. From this experiment, it can be inferred that water-soluble Na ₂ O, which is an unavoidable impurity in aluminum hydroxide, has a thickening effect.

[Thickening Experiment 2] Next, an experiment was conducted to confirm the viscosity control effect of the succinic acid derivative. This time, use acrylic syrup 1 as it is, and for 100 parts of syrup,
The amount of pentadodecenyl succinic acid used was changed as shown in Table 2 with 100 parts of Hygilite H-320ST, and the change over time in viscosity was examined. The results are shown in Table 2.

[0048]

[Table 2]

As is clear from Table 2, the viscosity of the system not using pentadodecenyl succinic acid shows a remarkable change with time, while the viscosity of the system using pentadodecenyl succinic acid increases. It is clear that the viscosity is controlled.

[Manufacture and molding of BMC] Next, the characteristics as an actual molding material were examined. 100 parts of acrylic syrup 1, 2 parts of pentadodecenylsuccinic acid, 1 part of polymerization initiator t-butylperoxy-2-ethylhexanoate, 4 parts of mold release agent zinc stearate, and polymerization inhibitor p-
350 parts of aluminum hydroxide (manufactured by Showa Denko KK; Heidilite H-320) containing 0.01 part of benzoquinone.
And 5% of the total weight of glass fiber (1/4 inch chopped strand) was added and kneaded with a double arm kneader.
MC was obtained. The obtained BMC was wrapped in a polyvinyl alcohol-based film and aged at 40 ° C. for 1 day.

Using the aged BMC, heat and pressure molding was performed in a mold to obtain a molded product having a thickness of 3 mm. The aged BMC had no stickiness and the workability was good. The molding conditions are as follows. Mold temperature: upper mold 110 ° C, lower mold 100 ° C Molding pressure: 6 MPa Pressing time: 10 minutes

The obtained molded article was glossy and had excellent surface smoothness. When the strength was measured according to JIS K-6911, the bending strength was 115 MPa and the tensile strength was 31 MPa. No substantial discoloration or chalking was observed in the accelerated weathering test for 1000 hours using a sunshine weather meter according to JIS A-1415. Further, no inconvenience due to excessive thickening was observed in each of the kneading, aging and molding steps. As a water resistance evaluation, a boiling test was performed at 90 ° C. for 100 hours. As a result, the gloss remained good, and no substantial discoloration was observed.

Comparative Example 1 Using the acrylic syrup 1 obtained in Example 1, kneading was carried out in the same manner as in Example 1 except that pentadodecenylsuccinic acid was not added. During the kneading, a sharp increase in viscosity occurred, making it impossible to continue the kneading.

Comparative Example 2 Using the acrylic syrup 1 obtained in Example 1, kneading with a kneader was performed in the same manner as in Example 1 except that the amount of pentadodecenylsuccinic acid was increased from 2 parts to 11 parts. went. 4
After aging for 1 day at 0 ° C., the viscosity did not increase and stickiness remained. Heat and pressure molding was performed in the same manner as in Example 1. However, bubble removal was poor, and pinholes and cracks were observed on the surface of the obtained molded product.

Comparative Example 3 An acrylic syrup 2 was obtained in the same manner as in Example 1 except that 10 parts of methacrylic acid was changed to 10 parts of methyl methacrylate in the production of the acrylic syrup of Example 1. The viscosity of this syrup 2 was 10 poise at 25 ° C., and the solid content concentration was 22.9%. Using this syrup 2, BMC was manufactured in the same manner as in Example 1. BMC obtained
Was aged at 40 ° C. for 1 day, but did not increase in viscosity and remained sticky. Heat and pressure molding was performed in the same manner as in Example 1 using the aged BMC. However, bubble removal was poor, and pinholes and cracks were observed on the surface of the obtained molded product.

Example 2 The aluminum hydroxide (Higilite H-320) used in the production of the BMC of Example 1 was treated with a silane coupling agent and treated with aluminum hydroxide (manufactured by Showa Denko KK; Hygilite). H-320ST), and the production and molding of BMC were carried out in the same manner as in Example 1 except that the amount of pentadodecenylsuccinic acid used was increased to 4 parts.

No inconvenience due to rapid thickening was observed in each step, and the BMC after aging had no stickiness and good workability. The obtained molded article was glossy and had excellent surface smoothness. When the strength was evaluated in the same manner as in Example 1, the bending strength was 126 MPa and the tensile strength was 39 M
Pa. When weather resistance and water resistance were also evaluated, very good results were obtained as in Example 1.

Comparative Example 4 Kneading was carried out in the same manner as in Example 2 except that pentadodecenylsuccinic acid was not added. During the kneading, a sharp increase in viscosity occurred, making it impossible to continue the kneading.

Example 3 BMC was produced and molded in the same manner as in Example 1 except that 1 part of magnesium oxide was added and 3 parts of pentadodecenylsuccinic acid were used in the production of BMC of Example 1. went.

No inconvenience due to rapid thickening was observed in each step. BMC after aging has no stickiness,
Workability was good. The obtained molded article was glossy and had excellent surface smoothness. When the weather resistance and the water resistance were evaluated, the gloss was slightly inferior to that of Example 1, and slight discoloration was observed. In the water resistance test, slight discoloration was observed. This is probably because magnesium oxide was used in combination.

Comparative Example 5 Example 3 except that pentadodecenyl succinic acid was not added.
Kneading was carried out in the same manner as in Example 1. However, a sharp increase in viscosity occurred during kneading, making it impossible to continue kneading.

Example 4 An acrylic syrup 3 was prepared in the same manner as in Example 1 except that the acrylic syrup of Example 1 was changed to 50 parts of trimethylolpropane trimethacrylate instead of adding 50 parts of methyl methacrylate and rapidly cooling. I got The viscosity of this syrup 3 was 8 poise at 25 ° C., and the solid content concentration was 21.5%. This syrup 3
In the same manner as in Example 1, BMC was manufactured and molded.

No inconvenience due to rapid thickening was observed in each step. BMC after aging has no stickiness,
Workability was good. The obtained molded article was glossy and had excellent surface smoothness. Further, when the strength was evaluated in the same manner as in Example 1, the bending strength was 118 MPa and the tensile strength was 33 MPa. When weather resistance and water resistance were also evaluated, very good results were obtained as in Example 1.

Comparative Example 6 Example 4 except that pentadodecenyl succinic acid was not added.
Kneading was carried out in the same manner as in Example 1. However, a sharp increase in viscosity occurred during kneading, making it impossible to continue kneading.

Example 5 The procedure of Example 4 was repeated except that 1 part of magnesium oxide was added and 3 parts of pentadodecenyl succinic acid were used in the production of BMC using the acrylic syrup 3 of Example 4.
BMC was manufactured and molded.

No inconvenience due to rapid thickening was observed in each step. BMC after aging has no stickiness,
Workability was good. The obtained molded article was glossy and had excellent surface smoothness. When the weather resistance and the water resistance were evaluated, the gloss was slightly inferior to that of Example 4, and slight discoloration was observed. In the water resistance test, slight discoloration was observed. This is probably because magnesium oxide was used in combination.

Comparative Example 7 Example 5 except that pentadodecenyl succinic acid was not added.
Kneading was carried out in the same manner as in Example 1. However, a sharp increase in viscosity occurred during kneading, making it impossible to continue kneading.

Example 6 350 parts of aluminum hydroxide (Heidilite H-320) used in the production of BMC in Example 1 was reduced to 250 parts, and 100 parts of calcium carbonate (manufactured by Toyo Fine Chemical Co., Ltd .; Whiten P) -70)
Production and molding of BMC were performed in the same manner as in Example 1.

No inconvenience due to rapid thickening was observed in each step. BMC after aging has no stickiness,
Workability was good. The obtained molded article was glossy and had excellent surface smoothness. When the weather resistance and the water resistance were evaluated, the gloss was slightly inferior to that of Example 1, and slight discoloration was observed. In the water resistance test, slight discoloration was observed.

Example 7 [Production of Acrylic Syrup 4] 1000 g of toluene was placed in a reaction vessel equipped with a stirrer, thermometer, nitrogen inlet tube, and cooler.
Charged and sufficiently replaced with nitrogen. 190 parts of methyl methacrylate, 10 parts of methacrylic acid, 0.5 part of azobisisobutyronitrile and n-
A mixture of 0.3 parts of dodecyl mercaptan was added dropwise over about 4 hours, and polymerization was carried out in a nitrogen atmosphere while maintaining the temperature at 90 ° C. After completion of the dropwise addition, 0.5 parts of azobisisobutyronitrile was added, and the mixture was further reacted at 90 ° C. for 3 hours.
After completion of the polymerization reaction, toluene was removed to some extent by heating under reduced pressure, the polymer was reprecipitated with methanol, and washed several times with methanol. The resulting polymer is 12 ° C at 60 ° C.
It dried under reduced pressure for hours. As a result of measuring the molecular weight by GPC, the number average molecular weight was 50,000. The carboxyl group as determined by KOH titration was 0.58 mol per 1000 g of the polymer. 20 parts of this polymer is treated with methyl methacrylate 80
To obtain an acrylic syrup 4. The viscosity of this syrup 4 was 6 poise at 25 ° C.

[Manufacture and molding of SMC] 100 parts of acrylic syrup 4, 2 parts of pentadodecenyl succinic acid,
1 part of a polymerization initiator t-butylperoxy-2-ethylhexanoate, 4 parts of a release agent of zinc stearate, 0.01 part of a polymerization inhibitor p-benzoquinone, and silane-coupled aluminum hydroxide ( Heidilight H-3
20ST) were mixed. This resin material compound was applied on a polyethylene film to a constant thickness, and 1-inch glass fiber chopped roving was uniformly spread thereon. Another one coated with a compound on a polyethylene film was sprinkled with glass fibers and then layered to obtain an SMC in which the glass fibers were sandwiched by the compound. The glass fibers were sprayed to make up 25% of the total weight. Wrap the obtained SMC with cellophane film,
Aged at ℃ for 1 day. No stickiness was observed in the aged SMC.

Using the aged SMC, heating and press molding was performed in a mold to obtain a molded product having a thickness of 3 mm. Molding condition is B
Same as for MC. The obtained molded article was glossy and excellent in surface smoothness. When the strength was measured in the same manner as in Example 1, the bending strength was 203MP.
a, The tensile strength was 87 MPa. No substantial discoloration or chalking was observed in the accelerated weather resistance test, and good results were obtained in the water resistance test. Further, in each of the steps of coating, impregnation, aging and molding, no inconvenience due to excessive thickening was observed. The SMC after aging is 2
After being left at 5 ° C. for 2 weeks, molding was performed in the same manner, but an excellent molded product comparable to the molded product was obtained.

Comparative Example 8 Example 7 except that pentadodecenyl succinic acid was not added.
Molding was carried out in the same manner as described above. When the SMC immediately after aging was used, a molded article comparable in particular was obtained.
With the SMC left at 5 ° C., it was felt that the material became harder in one week, and even after molding, the material did not flow evenly, and only a molded article having poor surface smoothness was obtained.

Example 8 In the preparation of the acrylic syrup of Example 7, instead of dissolving 20 parts of the obtained polymer in 80 parts of methyl methacrylate, the polymer was dissolved in a mixture of 70 parts of methyl methacrylate and 10 parts of ethylene glycol dimethacrylate. Acrylic syrup 5 was prepared in the same manner as in Example 7 except for
I got The viscosity of this syrup 5 was 6 poise at 25 ° C.

Using this syrup 5, SMC was manufactured and molded in the same manner as in Example 7. Coating, impregnation, aging,
No inconvenience due to excessive thickening was observed in each step of molding. In addition, the gloss, surface smoothness,
The strength, weather resistance, water resistance, and storage stability of SMC were excellent as in Example 7.

Example 9 Example 8 was repeated except that 1 part of magnesium oxide was added in the production of SMC using the acrylic syrup 5 of Example 8.
Production and molding of SMC were performed in the same manner as described above. No inconvenience due to rapid thickening was observed in each step. The obtained molded article was glossy and had excellent surface smoothness. When the weather resistance and the water resistance were evaluated, the gloss was slightly inferior to that of Example 8, and slight discoloration was observed.
In the water resistance test, slight discoloration was observed.

Reference Example 1 In the production of the acrylic syrup of Example 7, the use of 190 parts of methyl methacrylate and 10 parts of methacrylic acid was carried out.
Methyl methacrylate was changed to 199.4 parts and methacrylic acid was changed to 0.6 parts. The other conditions were the same as in Example 7, to obtain an acrylic syrup 6. The molecular weight of the polymer was 520,000 in number average molecular weight, and according to titration with KOH, a carboxyl group was contained in 0.03 mol per 1000 g of the polymer.

Example 7 using this acrylic syrup 6
Production and molding of SMC were performed in the same manner as described above. Due to the small amount of carboxyl groups, stickiness remained after aging at 40 ° C. for 1 day. Further, the obtained molded product was slightly inferior in performance to the molded product of Example 7 in which pinholes and cracks were slightly observed.

Reference Example 2 In the production of the acrylic syrup of Example 7, the use of 190 parts of methyl methacrylate and 10 parts of methacrylic acid was carried out.
166 parts of methyl methacrylate and 3 parts of methacrylic acid
4 parts. The other conditions were the same as in Example 7, to obtain an acrylic syrup 7. The molecular weight of the polymer was 51,000 in number average molecular weight, and according to titration with KOH, the carboxyl group was contained in 2.00 mol per 1000 g of the polymer.

Example 7 using this acrylic syrup 7
SMC was manufactured in the same manner as described above. Since the viscosity increased during the production and the material became relatively high in viscosity, a perfect impregnation state could not be obtained even when the sheet-like materials were overlaid after spraying glass fibers. After aging at 40 ° C. for 1 day, the mixture was molded in the same manner as in Example 7. As a result, a portion where the glass fiber was in a poorly dispersed state and had poor surface smoothness was observed.

Example 10 [Production of artificial marble] A mixture of 100 parts of acrylic syrup 1 and 20 parts of trimethylolpropane trimethacrylate was mixed with 6 parts of pentadodecenylsuccinic acid, and a polymerization initiator bis (4-t (Butylcyclohexyl) peroxydicarbonate (1 part) and aluminum hydroxide (Heidilite H-320ST) (200 parts) were added, kneaded and defoamed. The obtained molding material is poured into a glass cell mold,
Cured at ℃ for 1 hour. After demolding, after-curing was further performed at 100 ° C. for 3 hours. The obtained molded article had a high-grade feel and texture sufficient as artificial marble. The viscosity of the molding material was low enough to enable casting, and no change in viscosity or sedimentation of aluminum hydroxide was observed even after several days of standing.

Comparative Example 9 An artificial marble was produced in the same manner as in Example 10 except that pentadodecenylsuccinic acid was not used. However, during the kneading, the viscosity of the material was excessively increased, so that defoaming could not be performed well. No sedimentation of the aluminum hydroxide was observed due to the presence of the foam, but the foam did not come off at the time of casting, and the resulting molded article had a poor appearance full of foam. Tables 3 to 5 summarize the above results.

[0083]

[Table 3]

[0084]

[Table 4]

[0085]

[Table 5]

[0086]

According to the (meth) acrylic molding material of the present invention, aluminum hydroxide is used not only as an inorganic filler and a bulking agent but also as a thickening agent. It is possible not only to increase the viscosity of the molding material but also to suppress the excessive thickening of the molding material by using the succinic acid derivative and aluminum hydroxide in combination. Therefore, the molding material of the present invention is used for BMC, S
It is applicable to both for MC and casting, and it is possible to produce high-performance molded products excellent in appearance, strength, etc. with good workability in each molding method.

In particular, the present invention is excellent in workability and storage stability during the production of the BMC / SMC molding material and since the viscosity of the obtained SMC or BMC has a very small change with time.
Defoaming and casting operations are also easy in casting.
In addition, since the optimum fluidity can be maintained for a long time, the appearance of the obtained molded product, such as surface smoothness and gloss, becomes beautiful using any of the molding means. Furthermore, since the workability of impregnating the reinforcing fiber is excellent and the dispersibility of the fiber at the time of hot press molding is also good, a high-performance (meth) acrylic FRP having excellent strength and uniform physical properties and appearance is used. Can be manufactured.

The (meth) acrylic molding material of the present invention has the above constitution and can produce molded articles excellent in weather resistance, beautiful appearance, strength, etc., and is therefore applied to molded articles for various uses. be able to. In particular, lighting domes, outdoor benches and tables, outdoor tanks, components such as automobiles and rail cars, ships, exterior members such as roofs and walls of building structures, members exposed outdoors such as advertising boards, and artificial marble It is useful as a bathtub, kitchen counter, waterproof pan, etc. for applications that make use of the water resistance and appearance, and as other electrical components.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI C08K 5/11 C08K 5/11 (56) References JP-A-63-68655 (JP, A) JP-A-4-81448 (JP) , A) JP-A-5-194651 (JP, A)

Claims (8)

(57) [Claims] 1. A (meth) acrylic polymer obtained by polymerizing (A) a monomer component essentially containing a carboxyl group-containing vinyl monomer and a (meth) acrylic acid alkyl ester monomer, and (B) having a vinyl group A (meth) acrylic molding material containing an acrylic syrup composed of at least one monomer is obtained by adding 30 to 600 parts by weight of aluminum hydroxide to 100 parts by weight of the total of the polymer (A) and the monomer (B) , Has an acid skeleton or succinic anhydride skeleton,
First, a succinic acid derivative having a total number of carbon atoms of 8 to 30 having an alkenyl group as a substituent in the ethylene group is used in an amount of 0.01 to 1%.
A (meth) acrylic molding material characterized by containing 0 parts by weight. 2. The molding material according to claim 1, wherein the (meth) acrylic polymer (A) is obtained by polymerizing a monomer component essentially containing (meth) acrylic acid and methyl methacrylate. . 3. (A) (meth) acrylic polymer 1
The molding material according to claim 1, wherein the number of carboxyl groups in 000 g is 0.05 to 1.5 mol. 4. The molding material according to claim 1, wherein the (meth) acrylic polymer (A) is 7 to 80 parts by weight, and the monomer (B) is 93 to 20 parts by weight. 5. A further molding material according to any one of claims 1-4 oxide of an alkaline earth metal and / or hydroxides are those containing more than 5 parts by weight. 6. A method of manufacturing a molding material according to any one of claims 1 to 5 mass weight of the carboxyl group-containing vinyl monomer and (meth) monomer component containing an acrylic acid alkyl ester monomer as essential Polymerized legally,
An acrylic syrup is produced by terminating the polymerization before the polymerization rate reaches 100%, and then 30 to 600 parts by weight of aluminum hydroxide, 100 parts by weight of the acrylic syrup, and a succinic acid skeleton or succinic acid.
It has an acid anhydride skeleton and has an alkenyl group as a substituent
Of a succinic acid derivative having 8 to 30 carbon atoms and having a total of 8 to 30 carbon atoms in an ethylene group portion, wherein 0.01 to 10 parts by weight of a (meth) acrylic molding material is added. 7. The method according to claim 6, wherein a monomer component essentially containing a carboxyl group-containing vinyl monomer and an alkyl (meth) acrylate monomer is polymerized by a bulk polymerization method, and the polymerization is performed before the polymerization rate reaches 100%. The method according to claim 6 , wherein after the polymerization is completely stopped, one or more monomers having a vinyl group (B) are added to form an acrylic syrup. 8. Polymerization of stopping method according to claim 6 or 7 is performed by cooling with the addition to one or more of the polymerization vessel a monomer having a vinyl group (B).