JP2000129066A - (meth)acrylic molding material and molded item using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a molding material which has excellent strength, heat stability, heat strength and anti-fouling property by making the material contain aluminum hydroxide having specific whiteness and acrylic syrup comprising a (meth)acrylic polymer and a vinyl monomer. SOLUTION: A molding material of the present invention contains 300-600 pts.wt. of aluminum hydroxide having whiteness of 80-97, an average diameter of 3-50 μm, specific surface area of 1.8-2.5 m2/g and DOP absorption of not less than 33 l/100 g and 100 pts.wt. of (meth)acrylic syrup comprising 7-80 wt.% of thermosetting (meth)acrylic polymer and 93-20 wt.% of a vinyl monomer such as styrene or the like. The compound for sheet molding preferably contains 30-300 pts.wt. of aluminum hydroxide and 100 pts.wt. of (meth)acrylic syrup and the compound for bulk molding preferably contains 150-600 pts.wt. of aluminum hydroxide and 100 pts.wt. of (meth)acrylic syrup.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a (meth) acrylic molding material and a molded article using the same, and more particularly, to excellent strength, heat resistance, heat strength and excellent phase separation during curing. The present invention relates to a (meth) acrylic molding material which becomes a molded article having stain resistance and thermochromic properties.

[0002]

2. Description of the Related Art A (meth) acrylic syrup containing a (meth) acrylic polymer and a vinyl monomer as main components provides a molded article having good weather resistance and appearance. It has been conventionally used as a molding material.
As such (meth) acrylic syrup, conventionally, for example, (meth) acrylic syrup obtained by dissolving polymethyl methacrylate in methyl methacrylate, and (meth) acrylic syrup obtained by partially polymerizing methyl methacrylate are widely used. Was used.

On the other hand, aluminum hydroxide as an inorganic filler has excellent properties such as transparency, chemical stability and flame retardancy, and has a lower hardness than silica or the like. Since it has little wear in a mold, it has been widely used as a molding material such as artificial marble. Among the aluminum hydroxides, those having high whiteness of 98 or more have been particularly preferably used because the obtained molded article has little coloring and gives a sense of quality.

[0004]

However, in the above-mentioned conventional (meth) acrylic syrup, since the (meth) acrylic polymer has no polymerizable double bond, that is, it is thermoplastic, it is cured by radical polymerization. When the vinyl monomer is polymerized alone, the molecule extends only linearly,
In some cases, the properties of the obtained cured product, such as heat resistance and hot strength, were insufficient. Therefore, in order to improve the above properties, a method of adding a polyfunctional polymerizable monomer has been proposed, but in such a method, phase separation occurs during curing, the cured product becomes brittle, and the strength decreases. There was a problem.

[0005] In addition, the molded article using the high-white aluminum hydroxide has a problem that not only the stain is conspicuous but also easily stained by colored contaminants and the like because the whiteness of the molded article itself becomes high. In addition, there is a problem that discoloration is noticeable when partially heated.

The present invention has been made in view of the above problems, and has as its object to achieve excellent strength without causing phase separation during curing.
An object of the present invention is to provide a molding material which has heat resistance and strength during heat, has a small degree of thermal discoloration, and is excellent in stain resistance.

[0007]

According to the present invention, aluminum hydroxide having a whiteness in the range of 80 to 97 and a (meth) acrylic polymer having a polymerizable double bond and a vinyl monomer are used. The present invention provides a (meth) acrylic molding material characterized by containing a (meth) acrylic syrup.
At this time, the average particle size of the aluminum hydroxide is preferably in the range of 3 to 50 microns.

Further, according to the present invention, there is provided a molded article characterized by being molded from the (meth) acrylic molding material.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have conducted intensive studies on the polymer used for acrylic syrup and the aluminum hydroxide used in order to solve the above-mentioned problems. As a result, a polymerizable double polymer was obtained as a (meth) acrylic polymer. By using an aluminum hydroxide having a specific degree of whiteness and having a bond, the molded product has excellent strength, heat resistance, heat strength, and thermal discoloration degree without phase separation during curing. The present inventors have found that a molding material which is small and has excellent stain resistance can be obtained, and the present invention has been accomplished.

Hereinafter, the present invention will be described in detail. The whiteness of the aluminum hydroxide used in the present invention is in the range of 80 to 97, preferably in the range of 80 to 95. 97 whiteness
By using aluminum hydroxide having a lower whiteness than the conventionally used aluminum hydroxide, the following are superior in apparent stain resistance, and are less noticeable even when dirt adheres. Become smaller. Here, the whiteness means the Hunter whiteness of the powder.

The average particle size of the aluminum hydroxide used in the present invention is preferably in the range of 3 to 50 microns. Preferably it is in the range of 5-30 microns. When the average particle size is smaller than 3 microns, when adding a large amount of the aluminum hydroxide, the viscosity at the time of filling the radically polymerizable resin becomes too high, and it becomes difficult to uniformly disperse the aluminum hydroxide in the resin. Sometimes. For this reason,
For uniform dispersion, the amount of addition must be reduced. In this case, heat shrinkage at the time of curing becomes large and the appearance of the molded product may be deteriorated, but heat resistance discoloration, stain resistance and the like are not impaired. On the other hand, if the average particle size is larger than 50 microns, the mechanical strength may be reduced or the material may be slightly tacky. In this case, the tackiness can be eliminated by increasing the amount of addition. In addition, the average particle size is determined by using a pore-passing type particle size distribution analyzer “CULT”.
ER MULTISIZER II ".

The aluminum hydroxide used in the present invention is
The other physical properties are not particularly limited, but the specific surface area is
1.8-2.5m^Two / G, preferably 2.0 to
2.4m ^Two / G is desirable. The ratio table
Area is 1.8m^Two / G, the radical polymerizable tree
The viscosity at the time of filling the fat decreases and the handling property deteriorates.
There is. On the other hand, the specific surface area is 2.5 m^Two / G
And the viscosity when filling the radical polymerizable resin becomes too high.
It becomes difficult to uniformly disperse aluminum hydroxide in the resin.
May be affected. Here, the specific surface area is a low-temperature nitrogen gas
Specific surface area measurement method by adsorption (BET specific surface area measurement method)
Value. In addition, the DOP absorption of the aluminum hydroxide
Oil amount is 33ml / 100g or more, preferably 35ml /
Desirably, the weight is 100 g or more. DOP oil absorption 3
If less than 3 ml / 100 g, the radical polymerizable resin
There is a risk that the viscosity at the time of filling will decrease and handling properties will deteriorate.
is there. Here, the DOP oil absorption means aluminum hydroxide 1
Add DOP (dioctyl phthalate) little by little to 00g
Observing the state while kneading, it was dispersed separately
Find a point that makes a lump from the state, then
Means the number of ml of DOP.

For the purpose of improving resin dispersibility and mechanical strength, the surface of aluminum hydroxide may be treated with a surface treating agent before use. Examples of the surface treatment agent include silane coupling agents such as methacrylic silane, acrylic silane, vinyl silane, epoxy silane, and amino silane.

The (meth) acryl syrup used in the present invention contains a (meth) acrylic polymer having a polymerizable double bond and a vinyl monomer. Since the acrylic polymer has a polymerizable double bond, phase separation of the cured product does not occur, and excellent strength, heat resistance and heat strength of the cured product can be obtained.

As the (meth) acrylic polymer having a polymerizable double bond, a polymer having a polymerizable double bond in a side chain is particularly preferable. In order to allow a polymerizable double bond to be present in the side chain, a polymerizable double bond may be introduced into a polymer after polymerization of a monomer component containing a (meth) acrylate. As a method of introducing a double bond into a side chain of the polymer, specifically, a method of reacting an unsaturated epoxy compound with a (meth) acrylic polymer having a carboxyl group in the side chain, a method of reacting a hydroxyl group in a side chain And the method of reacting an unsaturated isocyanate compound or an unsaturated acid anhydride with a (meth) acrylic polymer having Hereinafter, each of the above methods will be described in detail.

First, an unsaturated epoxy compound is reacted with a (meth) acrylic polymer having a carboxyl group (hereinafter sometimes referred to as a “polymer having a carboxyl group”) to obtain a side chain of the polymer. A method for causing a polymerizable double bond to be present in the polymer will be described. In order to introduce a carboxyl group into the (meth) acrylic polymer, the (meth)
A monomer component containing an acrylate ester and a monomer having a carboxyl group (hereinafter sometimes referred to as “monomer component”) may be polymerized.

The above (meth) acrylic acid esters include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, s -Butyl (meth) acrylate,
(meth) acrylic acid alkyl esters such as t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and lauryl (meth) acrylate; (meth) acrylic acid cycloalkyl esters such as cyclohexyl (meth) acrylate; dimethylaminoethyl Basic (meth) acrylates such as (meth) acrylate and diethylaminoethyl (meth) acrylate are exemplified. These (meth) acrylic acid esters may be used alone or as a mixture of two or more.

Among the above exemplified compounds, methyl methacrylate and a (meth) acrylate ester containing methyl methacrylate as a main component are particularly preferable. By using methyl methacrylate as the main component, the cured product obtained by curing the (meth) acrylic resin composition is further improved in various physical properties such as weather resistance, transparency, surface gloss, appearance, safety and the like. Can be done. When a basic (meth) acrylate is used as the (meth) acrylate, 100% by weight or more of a neutral (meth) acrylate is mixed with the basic (meth) acrylate. It is preferable to use them. As the neutral (meth) acrylate, the above-mentioned alkyl (meth) acrylate, cycloalkyl (meth) acrylate and the like can be used.

The monomer having a carboxyl group is not particularly limited as long as it has a polymerizable double bond and a carboxyl group in one molecule. Specifically, for example, unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid and vinylbenzoic acid; unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid and citraconic acid; Monoesters include long-chain monomers having a carboxyl group such as monoesters of acid anhydrides. Examples of the monoester of the unsaturated dicarboxylic acid include monomethyl maleate, monoethyl maleate, monobutyl maleate, monooctyl maleate, monomethyl fumarate, monoethyl fumarate, monobutyl fumarate, monooctyl fumarate, monoethyl citraconic acid and the like. Is mentioned. Examples of the acid anhydride monoester include succinic acid monoester, phthalic acid monoester, and hexaphthalic acid monoester. These monomers having a carboxyl group may be used alone, or two or more kinds may be appropriately mixed and used.

The above-mentioned long-chain monomer having a carboxyl group can be obtained by esterifying the hydroxyl group of a (meth) acrylic acid ester having a hydroxyl group with an acid anhydride. Examples of the acid anhydride include succinic anhydride, phthalic anhydride, and hexahydrophthalic anhydride. Examples of the (meth) acrylic acid ester having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, ε-caprolactone ring-opened adduct to 2-hydroxyethyl (meth) acrylate, or 2-hydroxyethyl (meth) acrylate And ring-opening adducts of γ-butyrolactone.

The amount of the monomer having a carboxyl group may be in the range of 0.5% to 20% by weight, with the total of the (meth) acrylate and the monomer having a carboxyl group being 100% by weight. And more preferably in the range of 1% by weight to 15% by weight.
More preferably, it is in the range of 10% by weight to 10% by weight. When the proportion of the monomer having a carboxyl group is less than 0.5% by weight, the polymer can be introduced by reacting an unsaturated epoxy compound with a polymer obtained by polymerizing the monomer component. The number of sexual double bonds is limited. On the other hand, the ratio of the monomer having a carboxyl group is 20
If the amount exceeds 10% by weight, the weather resistance and water resistance of the obtained cured product may be reduced.

The monomer component contains a vinyl compound (monomer) having no carboxyl group, if necessary. The vinyl compound may be any compound having a polymerizable double bond, such as styrene and α-.
Styrene monomers such as methylstyrene, vinyltoluene and chlorostyrene; vinyl esters such as vinyl acetate; allyl compounds; (meth) acrylamide; (meth) acrylonitrile; N-methoxymethylacrylamide;
N-alkoxy-substituted (meth) acrylamides such as ethoxymethylacrylamide; unsaturated basic monomers such as aminoethylacrylamide; N-phenylmaleimide;
Maleimide monomers such as -cyclohexylmaleimide and N-isopropylmaleimide; and the like, but are not particularly limited thereto. These vinyl compounds may be used alone or in combination of two or more.

In the case where the vinyl compound is mixed with the (meth) acrylate, the mixing ratio of the two, that is, the content of the vinyl compound in the monomer component, depends on the type of the vinyl compound and the (meth) acrylate. Although it depends on the combination and the like, 50% by weight or less is preferable.

When polymerizing the above monomer components, it is desirable to use a polymerization initiator. There is no particular limitation on the polymerization initiator, for example, benzoyl peroxide,
Organic peroxides such as lauroyl peroxide and methyl ethyl ketone peroxide; 2,2′-azobisisobutyronitrile, 2-phenylazo-2,4-dimethyl-
Examples include azo compounds such as 4-methoxyvaleronitrile, but are not particularly limited. These polymerization initiators may be used alone or in combination of two or more. The amount of the polymerization initiator to be added to the monomer component is not particularly limited.

When polymerizing the above monomer component, it is more preferable to add a chain transfer agent in order to adjust the average molecular weight of the polymer. Such a chain transfer agent is not particularly limited, but a thiol compound, α-methylstyrene dimer, carbon tetrachloride, or the like is preferably used because the polymerization reaction of the monomer component is extremely easily controlled.
Examples of the thiol compound include alkyl mercaptans such as t-butyl mercaptan, n-octyl mercaptan, and n-dodecyl mercaptan; aromatic mercaptans such as thiophenol and thionaphthol; thioglycolic acid; octyl thioglycolate; Thioglycolic acid alkyl esters such as ethylene glycol dithioglycolate, trimethylolpropane tris- (thioglycolate) and pentaerythritol tetrakis- (thioglycolate); β-mercaptopropionic acid; β
Octyl mercaptopropionate, 1,4-butanediol di (β-thiopropionate), trimethylolpropane tris- (β-thiopropionate), pentaerythritol tetrakis- (β-thiopropionate), etc. Examples include β-mercaptopropionic acid alkyl ester, but are not particularly limited. One of these chain transfer agents may be used alone, or two or more thereof may be appropriately mixed and used.

The amount of the chain transfer agent to be used may be selected according to the type of the chain transfer agent, the combination with the (meth) allylic acid ester and the like, and is not particularly limited. Is preferably in the range of 0.1% by weight to 15% by weight, but is not particularly limited.

When polymerizing the above monomer components, a crosslinking agent can be used. The crosslinking agent may be any compound having a plurality of functional groups that react with the functional groups contained in the monomer component. As the crosslinking agent, specifically, for example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, neopentyl glycol di ( Polyfunctional (meth) acrylates such as meth) acrylate, trimethylolpropane tri (meth) acrylate, and pentaerythritol tetra (meth) acrylate; epoxy (meth) acrylates; divinylbenzene, diallyl phthalate, diallyl isophthalate, triallyl cyanurate , Triallyl isocyanurate and the like, but are not particularly limited. The amount of the cross-linking agent to be used may be set according to the type thereof, the combination with the acrylate or the like, the use of the resin material, the desired physical properties, and the like, and is not particularly limited.

The method for polymerizing the monomer component is not particularly limited, but a method for terminating the polymerization of the monomer component, that is, a partial polymerization is preferable. When the monomer component is partially polymerized in this manner, a mixture of the polymer and the unreacted monomer component is obtained. Therefore, only by introducing a polymerizable double bond into the polymer in the mixture, ( A (meth) acrylic syrup can be obtained. The polymerization method of the monomer component is not particularly limited, and examples thereof include known polymerization methods such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization. preferable.
The reaction conditions such as the reaction temperature and the reaction time for performing the above polymerization are not particularly limited, and for example, known reaction conditions can be adopted. The polymerization is preferably performed in a nitrogen atmosphere.

As described above, a reaction mixture containing a polymer having a carboxyl group is obtained. The average molecular weight of the polymer has a weight average molecular weight (Mw) of 6,000 to
About 1,000,000, number average molecular weight (Mn) is 3,
It is particularly preferable that it is about 000 to 500,000.

When an unsaturated epoxy compound is added to the polymer having a carboxyl group formed by the above treatment, the carboxyl group of the polymer reacts with the epoxy group of the unsaturated epoxy compound to open a ring. By the reaction, a polymerizable double bond can be introduced into a side chain of the polymer.

The unsaturated epoxy compound may be any compound having an epoxy group capable of reacting with a carboxyl group and a polymerizable double bond. Specific examples of the unsaturated epoxy compound include allyl glycidyl ether; glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate; and mono (meth) acrylate of epoxy resin. These compounds may be used alone or in a combination of two or more.

The amount of the unsaturated epoxy compound to be used may be determined according to the combination with the polymer having a carboxyl group, and is not particularly limited. It is preferably in the range of 0.5 to 2 moles, more preferably in the range of 0.8 to 1.5 moles with respect to the monomer having a carboxyl group. When performing the esterification reaction, an esterification catalyst can be added. This allows the esterification reaction to proceed efficiently. The esterification catalyst is not particularly limited as long as it can promote a ring-opening reaction of an epoxy group by a carboxyl group. Specifically, tertiary amines such as dimethylbenzylamine, triethylamine, tetramethylethylenediamine, and tri-n-octylamine; quaternary ammonium salts such as tetramethylammonium chloride, tetramethylammonium bromide, and tetrabutylammonium bromide; Quaternary phosphonium salts such as phenylphosphonium chloride; and metal salts. One of these esterification catalysts may be used alone, or two or more of them may be used by appropriately mixing.

The amount of the esterification catalyst to be added may be set in accordance with the type of the esterification catalyst, the combination with the monomer component, and the like.
Although not particularly limited, a reaction mixture 1 obtained by polymerizing a monomer component containing a monomer having a carboxyl group
The amount is preferably in the range of 0.01 to 5 parts by weight, more preferably 0.1 to 3 parts by weight, based on 00 parts by weight.

In carrying out the esterification reaction, a polymerization inhibitor may be present. As the above-mentioned polymerization inhibitor, hydroquinone, methylhydroquinone, methoxyhydroquinone, t-butylhydroquinone and the like can be used. In addition, a solvent can be used when performing the above esterification reaction. Water and / or an organic solvent can be used as the solvent.

As described above, a thermosetting (meth) acrylic polymer in which the side chain having a polymerizable double bond is bonded to the main chain via an ester bond is obtained.

As a method of introducing a polymerizable double bond into an (meth) acrylic polymer via an ester bond, a method in which a carboxyl group is added to the epoxy group of a (meth) acrylic polymer having an epoxy group. May be reacted with a monomer having the formula:

Next, an unsaturated isocyanate compound or an unsaturated acid anhydride is reacted with a (meth) acrylic polymer having a hydroxyl group (hereinafter sometimes referred to as a “polymer having a hydroxyl group”). A method for introducing a polymerizable double bond into a side chain of a polymer will be described. In order to introduce a hydroxyl group into the (meth) acrylic polymer, a monomer component containing a (meth) acrylic acid ester and a monomer having a hydroxyl group may be polymerized.

The monomer having a hydroxyl group may be any compound having a polymerizable double bond and a hydroxyl group in one molecule and not having a carboxyl group, and is not particularly limited. is not. As the monomer having a hydroxyl group, a (meth) acrylic acid ester having a hydroxyl group such as glycol (meth) acrylate obtained by esterifying a part of the hydroxyl group of the glycol is particularly preferable. As the glycol (meth) acrylate, specifically, a (meth) acrylic ester having a hydroxyalkyl group such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate; glycerin mono (meth) acrylate Polyhydric alcohol (meth) acrylates such as acrylate, glycerin di (meth) acrylate, pentaerythritol mono (meth) acrylate, pentaerythritol di (meth) acrylate; and high molecular weight glycols such as polyethylene glycol mono (meth) acrylate (Meth) acrylate and the like. In addition, as the monomer having a hydroxyl group,
Other monomers other than (meth) acrylic acid esters, for example, allyl alcohols such as allyl alcohol, ethylene glycol monoallyl ether, and propylene glycol monoallyl ether can also be used. These monomers having a hydroxyl group may be used alone,
Further, two or more kinds may be appropriately mixed and used.

The proportion of the monomer having a hydroxyl group in the monomer component is determined as follows.
Assuming that the total of the acrylate ester and the monomer having a hydroxyl group is 100% by weight, it is preferably in the range of 0.5% by weight to 20% by weight, and more preferably in the range of 1% by weight to 15% by weight. More preferably, 3% by weight to 10%
More preferably, it is within the range of weight%. When the proportion of the monomer having a hydroxyl group is less than 0.5% by weight, the polymerization can be introduced by reacting an unsaturated isocyanate compound with a polymer obtained by polymerizing the monomer component. The number of sexual double bonds is limited. On the other hand, the ratio of the monomer having a hydroxyl group is 20% by weight.
If it exceeds 30, the weatherability and water resistance of the obtained cured product may be reduced.

The polymerization conditions and the polymerization method of the above-mentioned monomer components, and other raw materials which may be used, are the same as in the method of reacting an unsaturated epoxy compound with a polymer having a carboxyl group.

By reacting a polymer having a hydroxyl group formed by the above treatment with an unsaturated isocyanate or an unsaturated acid anhydride, a thermosetting (meth) acrylic polymer having a double bond in a side chain can be easily prepared. Can be obtained. In addition, by reacting a polyfunctional isocyanate or an isocyanate prepolymer with the (meth) acrylic resin composition, the viscosity of the (meth) acrylic resin composition can be easily increased to a range suitable for molding.

When an unsaturated isocyanate compound is reacted with a polymer having a hydroxyl group, the hydroxyl group and the isocyanate group undergo a urethanization reaction, and a side chain having a polymerizable double bond is attached to the main chain via the urethane bond. A bonded thermosetting (meth) acrylic polymer is obtained. still,
A polymer having a hydroxyl group obtained by partially polymerizing a monomer component containing a monomer having a hydroxyl group may be a mixture with an unreacted monomer component, and may be an isolated polymer. It may be.

The unsaturated isocyanate compound may be any compound having an isocyanate group capable of reacting with a hydroxyl group and a polymerizable double bond. As the unsaturated isocyanate compound, specifically, a reaction product of a polyvalent isocyanate such as isocyanate ethyl methacrylate, tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and the monomer having a hydroxyl group, m -Isopropenyl-α, α-dimethylbenzyl isocyanate. These compounds may be used alone or in a combination of two or more.

The amount of the unsaturated isocyanate compound to be used may be set according to the combination with the polymer having a hydroxyl group, and is not particularly limited. It is preferably in the range of 0.5 to 2 moles, more preferably in the range of 0.8 to 1.6 moles with respect to the monomer having a hydroxyl group. The above-mentioned solvent, polymerization inhibitor and the like can also be used when performing the above urethane-forming reaction.

When the above urethanization reaction is performed, a urethanization catalyst can be added in order to efficiently advance the urethanization reaction. The urethanization catalyst is not particularly limited as long as it can promote the urethanization reaction, but dibutyltin dilaurate is preferred. One of these urethane-forming catalysts may be used alone, or two or more of them may be appropriately mixed and used.

The amount of the urethanization catalyst to be added may be set according to the type thereof, the combination with the monomer component, and the like.
Although not particularly limited, a reaction mixture 1 obtained by polymerizing a monomer component containing a monomer having a hydroxyl group is used.
The amount is preferably in the range of 0.01 to 5 parts by weight, more preferably 0.1 to 3 parts by weight, based on 00 parts by weight.

When an unsaturated acid anhydride is allowed to react with a polymer having a hydroxyl, a thermosetting (where a side chain having a polymerizable double bond is bonded to a main chain via an ester bond by an esterification reaction) A (meth) acrylic polymer is obtained. The polymer having a hydroxyl group obtained by partially polymerizing a monomer component may be a mixture with an unreacted monomer component or may be an isolated polymer.

The unsaturated acid anhydride may be any acid anhydride which can react with a hydroxyl group and has a polymerizable double bond. Specific examples of the unsaturated acid anhydride include maleic anhydride, itaconic anhydride, citraconic anhydride and the like. These compounds may be used alone or in a combination of two or more.

The amount of the above-mentioned unsaturated acid anhydride to be used may be determined according to the combination with the polymer having a hydroxyl group, and is not particularly limited. The molar ratio is preferably in the range of 0.5 to 2 moles, more preferably in the range of 0.8 to 1.5 moles with respect to the used hydroxyl group-containing monomer. When performing the above-mentioned esterification reaction, the above-mentioned solvent, polymerization inhibitor and the like can be used.

The vinyl monomer used together with the thermosetting (meth) acrylic polymer as the (meth) acrylic syrup according to the present invention is a double monomer of the thermosetting (meth) acrylic polymer. The monomer is not particularly limited as long as it has a double bond capable of reacting with a bond.
Specific examples of the vinyl monomer include the above-mentioned (meth) acrylate, a monomer having a carboxyl group, and a vinyl compound. Among these, alkyl methacrylate and styrene monomers are particularly preferred. Further, as the alkyl methacrylate, methyl methacrylate, ethyl methacrylate, n
-Propyl methacrylate, n-butyl methacrylate, s-butyl methacrylate, and t-butyl methacrylate are particularly preferable, and styrene is particularly preferable as the styrene monomer. This makes it possible to further improve various physical properties such as weather resistance, transparency, surface gloss, etc., appearance, and safety of a cured product obtained by curing the (meth) acrylic resin composition. These vinyl monomers are
They may be used alone or as a mixture of two or more.

The vinyl monomer may be the same as or different from the above-mentioned monomer components. Therefore, the mixture of the thermosetting (meth) acrylic polymer obtained by the esterification or the urethanization and the unreacted monomer component is preferably used as the (meth) acryl syrup according to the present invention. Can be. The (meth) acrylic syrup in which the vinyl monomer is different from the monomer component is obtained, for example, by a method of mixing an isolated thermosetting (meth) acrylic polymer with a vinyl monomer.

The ratio (ratio) of the thermosetting (meth) acrylic polymer and the vinyl monomer in the (meth) acrylic syrup is determined by setting the total amount of both to 100% by weight. 7% to 80% by weight of polymer
It is preferable to adjust so that the vinyl monomer content is in the range of 93% by weight to 20% by weight.

The amount of the aluminum hydroxide used in the (meth) acrylic syrup depends on its type, combination with the (meth) acrylic syrup, etc., the use of the molding material, and the physical properties required for the molding material. The amount may be determined and is not particularly limited, but a range of 30 to 600 parts by weight with respect to 100 parts by weight of (meth) acrylic syrup is preferable. When the molding material is used as a sheet molding compound (SMC), 3 parts per 100 parts by weight of the (meth) acrylic syrup is used.
When it is used as a bulk molding compound (BMC) from 0 parts by weight to 300 parts by weight, the range is preferably from 150 parts by weight to 600 parts by weight. When used as a casting material, the amount is preferably in the range of 30 parts by weight to 350 parts by weight.

The (meth) acrylic molding material of the present invention may contain a thickener, a succinic acid derivative, a reinforcing material, a low-shrinking agent, a release agent, a coloring agent, if necessary, as long as the effects of the present invention are not impaired. An agent may be added.

The thickener is not particularly restricted but includes, for example, alkaline earth metal oxides such as magnesium oxide and calcium oxide; and alkaline earth metal hydroxides such as magnesium hydroxide and calcium hydroxide. One or more of these thickeners can be used. The amount of the thickener used depends on the type and use of the molding material, but is preferably 5 parts by weight or less based on 100 parts by weight of the (meth) acrylic syrup. By using the compound in an amount of 5 parts by weight or less, the viscosity of the compound after thickening can be set to a range suitable for a molding operation or the like. If the amount used exceeds 5 parts by weight, the viscosity of the compound after thickening becomes too high, and the working efficiency such as the molding operation is reduced, and the weather resistance and water resistance of the obtained molded product may be reduced. .

The succinic acid derivative has a function of suppressing the excessive thickening behavior by the thickener, particularly the initial thickening behavior. As the succinic derivative, a succinic acid skeleton or a succinic anhydride skeleton is provided in the molecule, and the ethylene group of the skeleton is substituted with an alkyl group, an alkenyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or the like. Any compound having a group may be used, and is not particularly limited, but a compound having 8 to 30 carbon atoms is preferable. A succin derivative having a total carbon number of 7 or less has poor solubility in a (meth) acrylic resin composition, especially in a (meth) acrylic syrup.
On the other hand, the succin derivatives having 31 or more carbon atoms have poor functions and effects expected by using the succin derivatives. That is, the effect of suppressing the excessive thickening behavior by the thickener is low.

Specific examples of the succinic derivatives include hexylsuccinic acid, heptylsuccinic acid, octylsuccinic acid, nonylsuccinic acid, decylsuccinic acid, dodecylsuccinic acid, tetradecylsuccinic acid, pentadecylsuccinic acid, hexadecylsuccinic acid, and heptasuccinic acid. Compounds having an alkyl group having 4 or more carbon atoms, such as decylsuccinic acid, octadecylsuccinic acid, pentadodecylsuccinic acid, and eicosylsuccinic acid; hexenylsuccinic acid, heptenylsuccinic acid, octenylsuccinic acid, nonenylsuccinic acid, decenylsuccinic acid, dodecenylsuccinic acid, Such as tetradecenyl succinic acid, pentadecenyl succinic acid, hexadecenyl succinic acid, heptadecenyl succinic acid, octadecenyl succinic acid, pentadodecenyl succinic acid, eicosenyl succinic acid, etc. A compound having an alkenyl group; B dodecyl succinic acid, a compound having an alicyclic hydrocarbon group such as cyclopropyl-dodecenyl succinic acid;
Compounds having an aromatic hydrocarbon group such as diphenylbutenylsuccinic acid; and anhydrides of these succinic acids, but are not particularly limited. These succinic acid derivatives may be used alone, or two or more of them may be appropriately mixed and used. The method for preparing the succinic derivative is not particularly limited.

The amount of the succinic acid derivative to be used depends on its type, combination with the (meth) acrylic syrup and the thickener and the use of the (meth) acrylic resin composition. The range of 0.01 to 10 parts by weight relative to part by weight is preferred. If the amount of the succinic acid derivative is less than 0.01 parts by weight, the expected action and effect of using the succinic acid derivative will be poor. That is, the effect of suppressing the excessive thickening behavior by the thickener may be poor. If the amount of the succinic acid derivative is more than 10 parts by weight, the viscosity of the compound after the thickening does not reach a predetermined value suitable for molding work,
Or it may take a long time to reach.

Examples of the reinforcing material include inorganic fibers such as glass fiber, carbon fiber, metal fiber, and ceramic fiber; and synthetic fibers such as aramid, polyester, and polyamide, and recycled fibers, and organic fibers including natural fibers. These can be used alone or in combination of two or more. As the fiber form, for example, roving, chopped strand, mat, cloth (woven fabric, knitted fabric) and the like can be used.

The amount of the reinforcing material to be used may be determined according to its type, combination with syrup, etc., the use of the molding material, desired physical properties, etc., and is not particularly limited. 2% to 40% by weight based on weight
Is preferably within the range. When the molding material is a sheet molding compound (SMC), the amount of the fiber reinforcing material used is more preferably in the range of 10% by weight to 40% by weight based on the total weight of the molding material. When the molding material is a bulk molding compound (BMC), the use amount of the fiber reinforcement is more preferably in the range of 2% by weight to 30% by weight based on the total weight of the molding material. By using the fiber reinforcing material within the above range, a molding material having excellent strength and elastic modulus when the molding material is formed into a molded product can be obtained.

As a low-shrinking agent, polymethyl methacrylate, polyethylene, polypropylene, polystyrene, polyethylene glycol, polypropylene glycol, cellulose butyrate, acetate, polyvinyl chloride, polyvinyl acetate, polycaprolactam, saturated polyester, or a copolymer thereof may be used. A high degree of dimensional accuracy can be achieved by blending these in an appropriate amount.

The amount of the low-shrinkage agent may be determined according to the type, combination with (meth) acrylic syrup, etc., the use of the molding material and the desired physical properties, and is not particularly limited. However, the amount is preferably in the range of 5 to 50 parts by weight based on 100 parts by weight of the (meth) acrylic syrup.

The release agent is not particularly limited, and examples thereof include stearic acid, zinc stearate, aluminum stearate, calcium stearate, barium stearate, stearic acid amide, alkyl phosphate, and silicone oil. By mixing the agent, the mold can be easily separated from the mold.

The colorant is not particularly limited, and a known colorant such as an inorganic pigment or an organic pigment can be used.

The (meth) acrylic molding material of the present invention comprises:
It is particularly suitable as a molding material such as SMC, BMC, and casting material, and can be used in both casting and press molding methods. Kitchen counters, vanities, bathtubs, tables, wall materials It is molded into various forms such as floor materials, furniture, interior accessories, and seals, and is used for various purposes.

The mold to be used may be made of any material, for example, iron, aluminum, resin and the like.

[0067]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples. In the examples, "part" and "%"
Unless otherwise specified, “parts by weight” and “% by weight” are used, respectively.
Shall be expressed.

Example 1 In a reactor equipped with a thermometer, a cooler, a nitrogen gas inlet tube, and a stirrer, methyl methacrylate (hereinafter sometimes referred to as “MMA”) 92 as a (meth) acrylate ester 92 Part and methacrylic acid as a monomer having a carboxyl group (hereinafter may be referred to as “MAA”) 8
After charging the reactor, the inside of the reactor was replaced with nitrogen gas. Next, the mixture was heated to 80 ° C. while stirring, and then 0.03 parts of 2,2′-azobisisobutyronitrile (hereinafter sometimes referred to as “AIBN”) as a polymerization initiator. N-dodecyl mercaptan 0.4 as a chain transfer agent
And a copolymerization reaction was performed for 4 hours to obtain a (meth) acryl syrup containing an MMA / MAA copolymer as a (meth) acrylic polymer.

Next, 13 parts of glycidyl methacrylate (hereinafter sometimes referred to as “GMA”) as an unsaturated epoxy compound, 0.1 part of zinc octylate as a catalyst were added to the above (meth) acrylic syrup. After adding 0.02 parts of p-methoxyphenol as a polymerization inhibitor, the temperature was raised to 100 ° C., and the esterification reaction was performed in an air atmosphere for 7 hours.

The (meth) acrylic syrup obtained was GP
The weight average molecular weight of the (meth) acrylic polymer measured using C (gel permeation chromatography) was 105,000, the solid content was 43%, and the acid value was 20 mgKOH / g. Further, the double bond equivalent of the (meth) acrylic polymer determined from the difference between the acid value before the esterification reaction and the acid value after the esterification reaction was 1,600.

Next, the above (meth) acrylic syrup 1
In 00 parts, as a filler, 250 parts of aluminum hydroxide having a whiteness of 96 and an average particle diameter of 8 microns, a silane coupling agent ("A-174" manufactured by Nippon Unicar Co., Ltd.)
2.5 parts, pentadodecenylsuccinic acid 0.5 part as a succinic acid derivative, 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane (Nippon Oil & Fat Co., Ltd.) as a curing agent Company-made "Perhexa TMH") 1
Parts, 0.5 parts of magnesium oxide as a thickener, 2 parts of zinc stearate as an internal mold release agent, and 1 mm long glass fiber (“RES” manufactured by Nippon Glass Fiber Co., Ltd.) as a fiber reinforcing material.
O10-BM53 ") were kneaded for 30 minutes using a double-arm kneader. Thereafter, the obtained material was placed in a closed container and aged at 40 ° C. for 24 hours to obtain a material with good stickiness and good handleability.

Using a mold having a cavity of 300 mm × 300 mm, the upper mold temperature was set to 120
℃, the mold temperature of the lower mold to 110 ℃, the thickener 1,
700 g was filled in the above mold, clamped at a pressure of 6 MPa, and heated and pressed for a predetermined time to form a 9 mm thick molded plate. The following evaluation was performed. Table 1 shows the results.

(Heat discoloration resistance) 1) Iron test: The degree of discoloration after the iron set at 200 ° C. was left on the molded product for 10 minutes was measured, and the difference in the degree of discoloration before and after standing was calculated. did. 2) Oven test: The degree of discoloration after placing the molded article in an oven at 170 ° C. for one hour was measured, and the difference in the degree of discoloration before and after the oven test was calculated and used as an index of heat discoloration resistance. The degree of discoloration was measured using a color difference meter (“Sigma 90 System” manufactured by Nippon Denshoku Co., Ltd.).

(Evaluation of Stain Resistance) The contaminants listed below were left on the molded product for 24 hours, washed with water and a neutral detergent, and visually evaluated for changes in appearance such as gloss and coloring of the molded product. . Contaminants: soy sauce, sauce, food red, red ginger, whiskey, coffee, tea, tabasco, mustard, lipstick, hair dye, red ink, blue ink, crayon

(Heat cycle resistance) 300 mm × 30
A 100 mm × 100 mm square hole was provided in the center of a 0 mm test piece. The corners (corners) of the holes were finished with a curved surface with a radius of 10 mm, and the edges (sides) were finished with a curved surface with a radius of 2 mm. Then, an iron heated to 180 ° C. was placed in the corner portion for 10 minutes, and a cooling and heating cycle in which ice was placed in the corner portion for 10 minutes as one cycle was repeated until cracks occurred in the molded product. The greater the number of repetitions, the more excellent the molded article is in heat cycle resistance. The number of repetitions of 5 or more was used as an evaluation standard for heat cycle resistance.

If no cracks were found even after 10 cooling / heating cycles, the test was terminated and the test result was indicated as 10 or more times.

Example 2 Instead of the aluminum hydroxide used in Example 1, 300 parts of aluminum hydroxide having a whiteness of 94 and an average particle diameter of 15 μm was used, and the amount of the silane coupling agent used was changed to 3. A molded plate was prepared and evaluated in the same manner as in Example 1 except that 0 part was set. Table 1 shows the results.

Example 3 Instead of the aluminum hydroxide used in Example 1, 350 parts of aluminum hydroxide having a whiteness of 90 and an average particle diameter of 25 microns were used, and the amount of the silane coupling agent used was changed to 3. A molded plate was prepared and evaluated in the same manner as in Example 1 except that 5 parts were used. Table 1 shows the results.

Example 4 Instead of the aluminum hydroxide used in Example 1, 180 parts of aluminum hydroxide having a whiteness of 97 and an average particle diameter of 1 micron was used, and the amount of the silane coupling agent used was 1. 9 mm in thickness in the same manner as in Example 1 except that the thickness was 8 parts.
Was prepared and evaluated. Table 1 shows the results.

Example 5 Instead of the aluminum hydroxide used in Example 1, 350 parts of aluminum hydroxide having a whiteness of 95 and an average particle diameter of 75 microns were used, and the amount of the silane coupling agent used was changed to 3. 9 m in thickness in the same manner as in Example 1 except that the thickness is 5 parts.
A molded plate of m was prepared and evaluated. Table 1 shows the results.

Example 6 The (meth) acrylic syrup used in Example 1 was 100
And polymethyl methacrylate (weight average molecular weight 6
(0000)), and a molded plate was prepared and evaluated in the same manner as in Example 1 except for further using 20 parts. Table 1 shows the results.

Example 7 In a reactor equipped with a thermometer, a cooler, a nitrogen gas inlet tube, and a stirrer, MM as (meth) acrylate was added.
After charging 97 parts of AA and 3 parts of MAA, the inside of the reactor was purged with nitrogen gas. Next, the mixture was stirred at 80 ° C.
Then, 0.1 parts of AIBN as a polymerization initiator, and 0.7 parts of n-dodecyl mercaptan as a chain transfer agent.
And a copolymerization reaction was performed for 4 hours to obtain a (meth) acryl syrup containing an MMA / MAA copolymer as a (meth) acrylic polymer.

Then, 5 parts of GMA and 0.1% of zinc octylate as a catalyst were added to the above (meth) acrylic syrup.
Parts and 0.1 part of p-methoxyphenol as a polymerization inhibitor.
After adding 02 parts, the temperature was raised to 100 ° C., and the esterification reaction was performed in an air atmosphere for 5 hours.

The obtained (meth) acrylic syrup was GP
The weight average molecular weight of the (meth) acrylic polymer measured using C (gel permeation chromatography) was 61,000, the solid content was 41%, and the acid value was 7.3 mgKOH / g. Was. Further, the double bond equivalent of the (meth) acrylic polymer determined from the difference between the acid value before the esterification reaction and the acid value after the esterification reaction was 4,700.

Next, 100 parts of the (meth) acrylic syrup obtained above were mixed with 180 parts of aluminum hydroxide having a whiteness of 89 and an average particle diameter of 25 microns, and a silane coupling agent (“A-174” manufactured by Nippon Unicar Co., Ltd.). ") 1.8
Parts, an antifoaming agent (“BYK A-555” manufactured by Big Tecky Japan Co., Ltd.), and bis-4-t-butylcyclohexylperoxydicarbonate (“Percadox 16” manufactured by Akzo Corporation) as a curing agent ) Mix 0.5 parts,
A raw material slurry for casting was prepared.

After the slurry was degassed under reduced pressure, it was cast into a cell in which the periphery of two glass plates opposed to each other so that the distance (gap) between them was 8 mm was sealed with a so-called elastic gasket. Then, at 60 ° C. for 1 hour,
So-called post-curing was performed at 0 ° C. for 2 hours to obtain a flat plate having a thickness of 8 mm. This plate was evaluated in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 1 Evaluation was performed in the same manner as in Example 1 except that aluminum hydroxide having a whiteness of 98 and an average particle diameter of 8 μm was used instead of the aluminum hydroxide used in Example 1. Was. Table 1 shows the results.

Comparative Example 2 In place of the aluminum hydroxide used in Example 1, 300 parts of aluminum hydroxide having a whiteness of 99 and an average particle diameter of 17 microns were used, and the amount of the silane coupling agent used was changed to 3. A molded plate was prepared and evaluated in the same manner as in Example 1 except that 0 part was set. Table 1 shows the results.

Comparative Example 3 98.5 parts of MMA and 1.5 parts of MAA were charged into a reactor equipped with a thermometer, a cooler, a nitrogen gas inlet tube and a stirrer, and the inside of the reactor was replaced with nitrogen gas. . Next, the temperature of the mixture was raised to 80 ° C. with stirring.
And 0.7 part of n-dodecyl mercaptan were added and a copolymerization reaction was carried out for 4 hours. Thereby, MMA /
A (meth) acrylic syrup containing the MAA copolymer was obtained. No double bond is introduced into (meth) acrylic syrup. The weight average molecular weight measured by GPC was 55,000, the solid content was 41%, and the acid value was 12 m.
gKOH / g.

80 parts of this (meth) acrylic syrup,
Except that a mixture with 20 parts of trimethylolpropane trimethacrylate was used as a crosslinking agent, the same operation as in Example 1 was performed to obtain a molding material and a thickness of 9%.
mm molded plate was prepared. Evaluation was performed in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 4 A molded plate was produced in the same manner as in Example 4 except that 180 parts of aluminum hydroxide having a whiteness of 98 and an average particle diameter of 25 microns was used instead of the aluminum hydroxide used in Example 4. Was prepared and evaluated. Table 1 shows the results.

[0092]

[Table 1]

In the molded articles of the present invention of Examples 1 to 7, excellent results were obtained in any evaluation items of heat discoloration resistance, stain resistance and heat cycle resistance. On the other hand, in the molded products of Comparative Examples 1, 2, and 4 using aluminum hydroxide having high whiteness, the heat cycle resistance was good, but the heat discoloration resistance and stain resistance were poor. . Also (meta)
Comparative Example 3 in which acrylic polymer has no polymerizable double bond
Although the molded article of Example 1 showed good results in heat discoloration resistance and stain resistance, cracks occurred in the molded article in one cooling / heating cycle.

[0094]

According to the (meth) acrylic molding material of the present invention, there is no phase separation at the time of curing, the heat resistance is excellent, the heat strength is excellent, the thermal discoloration is small, and the molded article has excellent stain resistance. Can be obtained.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F071 AA33 AA39 AB18 AD06 AE17 AF14 AF34 AF45 AH03 AH19 BB01 BB03 4J002 BG041 BG071 CD191 DE146 EA047 EB127 EH077 EP017 ET007 EU027 FB096 FD016 PA02 PA02 PA02 PA02 PA02A AB05 AB06 AB07 AB08 AE07 AJ01 BA05 BA07 BA30 CB01 CC02 CD01

Claims (3)

[Claims] 1. A (meth) acryl syrup containing aluminum hydroxide having a whiteness of 80 to 97 and a (meth) acrylic polymer having a polymerizable double bond and a vinyl monomer. Characterized (meth) acrylic molding material. 2. The aluminum hydroxide has an average particle size of 3 to 3.
2. The (meth) acrylic molding composition according to claim 1, wherein the range is 50 microns. 3. A molded article formed from the (meth) acrylic molding material according to claim 1.