JPH0573780B2 - - Google Patents

Description

[Detailed description of the invention]

Industrial Application Field: The present invention relates to a methyl methacrylate syrup composition used for producing molded articles such as kitchen counters. Problems to be solved by the prior art and the invention: The syrup whose main component is methyl methacrylate can be used for glass fiber reinforced boards, kitchen countertops,
It is used for molding things such as washstands, and has excellent weather resistance, such as preventing molded products from yellowing. However, with conventional syrup,
Pressure molding equipment is required due to shrinkage during molding.
In addition, under harsh conditions such as prolonged immersion in boiling water when filled with fillers such as glass fiber, silica sand, alumina, etc., the molded product may become glossy,
It had the disadvantage of causing whitening, etc. Means for solving the problem: The present inventors have developed a syrup containing a functional group that is reactive with a glycidyl group, and a syrup that has a glycidyl group and has a part of the glycidyl group replaced with an ethylenically unsaturated bond. The resulting syrup is mixed in a tank equipped with a stirrer, and radical polymerization is carried out using a catalyst such as benzoyl peroxide, and an addition reaction between glycidyl groups and reactive functional groups is simultaneously carried out. By applying this method, the composition has moldability under normal pressure, and the molded product has excellent water resistance under harsh conditions, and has also been successfully shown to have improved impact resistance. , completed the invention. That is, the present invention is a methyl methacrylate syrup composition prepared by mixing 1 to 99 parts by weight of the following syrup (A) and 99 to 1 part by weight of syrup (B) in a total of 100 parts by weight. Siltup (A): (a) Methyl methacrylate monomer 5~
95% by weight, (b) 95 to 1% by weight of a monomer reactive with glycidyl groups and copolymerizable with methyl methacrylate having at least one ethylenically unsaturated bond, and (c) glycidyl groups. A mixture consisting of 0 to 94% by weight of a monomer copolymerizable with methyl methacrylate and having at least one ethylenically unsaturated bond,
10 to 60% copolymerized (however, monomer
The total of (a), monomer (b) and monomer (c) is 100% by weight
It is. ). Siltup (B): (d) Monomer 3 having a glycidyl group
97% by weight of other copolymerizable monomers 97-3
Copolymerized with weight%, number average molecular weight is 1500~
5 to 95% by weight of a (meth)acrylic copolymer having 50,000 glycidyl groups, which has no reactivity with (e)methyl methacrylate monomers and/or glycidyl groups, and has at least one ethylenically unsaturated bond. a monomer that is copolymerizable with methyl methacrylate, and a monomer that is copolymerizable with methyl methacrylate that is reactive with (b)glycidyl groups and has at least one ethylenically unsaturated bond. After dissolving in 95 to 5% by weight of the mixture, 1 to 99% of the glycidyl groups in the (meth)acrylic copolymer are further reacted (with the exception of (meth)acrylic copolymer (d),
The total of monomer (e) and monomer (b) is 100% by weight. ). The present invention will be explained in detail below. The content of (a) methyl methacrylate monomer in the syrup (A) must be in the range of 5 to 95%, preferably 20 to 90%, more preferably 40 to 80%. If the above value is less than 5%, the storage stability of the syrup composition after mixing with syrup (B) will be poor, and the increase in viscosity over time during storage will be extremely large. Moreover, if it exceeds 95%, the water resistance of the molded product will deteriorate.
On the other hand, 95 to 1% of monomers are copolymerizable with methyl methacrylate, which is reactive with (b)glycidyl groups and has at least one ethylenically unsaturated bond.
Preferably 50-1%, more preferably 20-1%,
(c) The monomer copolymerizable with methyl methacrylate, which has no reactivity with glycidyl groups and has at least one ethylenically unsaturated bond, is 0 to 94%, preferably 50 to 94%, more preferably 80% ~94% is required. If the former (b) is less than 1% or the latter (c) exceeds 94%, the molded product will have poor water resistance. In the present invention, monomers that are reactive with (b)glycidyl groups and copolymerizable with methyl methacrylate having at least one ethylenically unsaturated bond in the syrup (A) include methacrylic acid, Monomers containing carboxyl groups such as maleic anhydride, maleic acid, fumaric acid, acrylic acid; 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, neopentyl glycol monomethacrylate, trimethylolpropane monomethacrylate, trimethylolpropane Monomers containing hydroxyl groups such as dimethacrylate, polyethylene glycol monomethacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, neopentyl glycol monoacrylate, trimethylolpropane monoacrylate, trimethylolpropane diacrylate, polyethylene glycol monoacrylate, etc. mer; orthophosphoric acid ester of 2-hydroxyethyl methacrylate, phosphite ester of 2-hydroxyethyl methacrylate, orthophosphoric acid ester of 2-hydroxyethyl acrylate, 2-
Monomers containing phosphoric acid groups such as phosphorous esters of hydroxyethyl acrylate; N-methylaminoethyl methacrylate, 4-N-methylaminocyclohexyl methacrylate, N,N-dimethylaminoethyl methacrylate, methacrylamide, crotonic acid Amino groups such as amide, vinylamine, N-ethylvinylamine, allylamine, diallylamine, N-methylallylamine, N-methylaminoethyl acrylate, 4-N-methylaminocyclohexyl acrylate, N,N-dimethylaminoethyl acrylate, acrylamide, etc. Specific examples include monomers and the like contained therein. One or more of these monomers may be used. Examples of monomers copolymerizable with methyl methacrylate in the syrup (A) of the present invention (c) which have no reactivity with glycidyl groups and have at least one ethylenically unsaturated bond include ethyl methacrylate, butyl Methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, vinyl acetate, styrene, 2-methylstyrene, chlorstyrene, t-butylstyrene, vinyl versatate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate,
Neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, divinylbenzene, triallyl isocyanurate, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate,
lauryl acrylate, ethylene glycol diacrylate, polyethylene glycol diacrylate, neopentyl glycol diacrylate,
Examples include monomers such as trimethylolpropane triacrylate and butyl fumarate. The syrup (A) is prepared by stirring and mixing a mixture of the above monomers in a reaction tank equipped with a stirrer and heating/cooling equipment, and then azobisisobutyronitrile, benzoyl peroxide, t-butyl peroxyneodecanoate. , t-butylperoxypivalate, t-
from 50°C using a catalyst such as butyl peroxy-2-ethylhexanoate and a chain transfer agent such as t-dodecyl mercaptan, n-dodecyl mercaptan, thioglycolic acid, or mercaptoethanol.
It is obtained by reacting at a temperature of 110°C for 3 to 24 hours to achieve a 10 to 60% copolymerization. If the polymerization rate is less than 10%, the water resistance of the molded product will deteriorate, and if it exceeds 60%, the syrup will become highly viscous and workability will deteriorate significantly. The (meth)acrylic copolymer having a (di)glycidyl group in the syrup (B) in the present invention includes 3 to 97% by weight of a monomer having a glycidyl group and a monomer that can be copolymerized with a monomer having a glycidyl group. Monomer 97-3
The number average molecular weight of copolymerized with weight% is 1500~
50,000 copolymers are used. As the monomer having a glycidyl group, for example, one or more of glycidyl methacrylate, glycidyl acrylate, β-methylglycidyl methacrylate, β-methylglycidyl acrylate, allyl glycidyl ether, etc. can be used. Examples of monomers that can be copolymerized with the polymer include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, and benzyl (meth)acrylate. Acrylate, cyclohexyl (meth)
(Meth)acrylic acid esters such as acrylate, 2-hydroxyethyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate;
Fumaric acid esters such as butyl fumarate; maleic esters; and others such as (meth)acrylic acid, styrene, α-methylstyrene, vinyl acetate, (meth)acrylamide, and (meth)acrylonitrile are used. The monomer having a glycidyl group in the (meth)acrylic copolymer having a glycidyl group must be in the range of 3 to 97% by weight, and if it is less than 3% by weight, the water resistance of the molded product will deteriorate. It gets worse and then again
If it exceeds 97% by weight, it is not preferable because gel is likely to be generated during polymerization. In addition, the number average molecular weight of the (meth)acrylic copolymer having glycidyl groups is
It is necessary that the number is in the range of 1,500 to 50,000; if it is less than 1,500, the water resistance of the molded product will be poor, and if it exceeds 50,000, the viscosity of the syrup will increase, making workability undesirable. The (meth)acrylic polymer (d) having a glycidyl group in the syrup (B) in the present invention is
48-38617, Japanese Patent Publication No. 52-15090, and the like can be used. For example, expression ()

[Formula] (In the formula, R ₁ is H or CH ₃ , R ₂ is an alkyl group having 1 to 14 carbon atoms) and a (meth)acrylic ester represented by the formula ()

[Chemical formula] (In the formula, R ₁ represents H or CH ₃ ) Copolymerized (meth)acrylic acid glycidyl ester has a secondary transition point of 5 to 60°C and a number average molecular weight of 1500 to 50000 preferably 1500~
30,000, or a vinyl monomer such as methacrylic acid ester or styrene, and the formula ()

(meth)acrylic acid (methyl)glycidyl ester represented by the formula (wherein R ₁ and R' ₁ represent H or CH ₃ ) and the formula ()

Softening point 85-150 obtained by copolymerizing with ( _methyl )glycidyl ( _meth ) _allyl ether represented by
Any polymer having a number average molecular weight of 3,000 to 12,000 at ℃ can be used. In addition, in the syrup (B) in the present invention, monomers (ho)
Among them, monomers that are not reactive with glycidyl groups and can be copolymerized with methyl methacrylate having at least one ethylenically unsaturated bond include:
All of the monomers (c) exemplified in the above syrup (A) can be used. Furthermore, in the syrup (B), monomers that are reactive with (b)glycidyl groups and copolymerizable with methyl methacrylate having at least one ethylenically unsaturated bond include the aforementioned syrup (A). All of the monomers exemplified in monomer (b) can be used. In the present invention, the syrup (B) comprises the above-mentioned specified (meth)acrylic copolymer (d) and the above-mentioned specified monomer.
After dissolving the mixture consisting of (e) and monomer (b) in a tank equipped with a stirrer, the mixture is further preferably heated to room temperature.
It can be produced by reacting 1 to 99%, preferably 30 to 99%, of the glycidyl groups in the (meth)acrylic copolymer by heating at a temperature of 108°C. Further, during the reaction, a reaction catalyst such as a tertiary amine and/or a polymerization inhibitor may be used in combination. If the reaction rate to glycidyl groups is less than 1%, the molded product will become brittle, and if it exceeds 99%, the shrinkage rate will increase during molding, and fading may occur. The methyl methacrylate syrup composition of the present invention is obtained by mixing 1 to 99 parts of the syrup (A) obtained as described above and 99 to 1 part of the syrup (B) to a total of 100 parts. However, if the syrup (A) is less than 1 part by weight or exceeds 99 parts by weight, the water resistance of the molded product will deteriorate. In order to manufacture a molded article using the syrup composition of the present invention, the following operations may be performed, for example.
That is, syrup (A) and syrup (B) in the above proportions are mixed in a tank equipped with a stirrer, and to 100 parts of the resulting syrup composition, azobisisobutyronitrile, benzoyl peroxide, and t-butyl peroxide are added. 0.1 to 10 parts of a catalyst such as oxyneodecanoate, t-butylperoxypivalate, t-butylperoxy-2-ethylhexanoate, etc., and 10 to 300 parts of a filler such as glass fiber, silica sand, alumina, etc. The molding mixture obtained by adding and mixing is injected into a mold whose inner surface has been coated with a release agent such as silicone or polyvinyl alcohol, or onto a release paper such as polyester film or cellophane paper, and then heated at a temperature of 40 to 120°C. It may be hardened and molded at ℃ for about 20 to 200 minutes. Hereinafter, embodiments of the present invention will be specifically explained with reference to Examples. Note that all parts are based on weight. Example 1 The following composition consisting of a monomer, a polymerization initiator, and a chain transfer agent was charged into a flask equipped with a stirrer.103
Reacted at ~107℃ for 7 hours, polymerization rate 31%, viscosity 520
A centipoise syrup (A-1) was obtained. In addition, the polymerization rate, including the following Examples and Comparative Examples, was determined from the refractive index using an Atsube refractometer. Methyl methacrylate 70.0 parts Styrene 25.0 parts Trimethylolpropane trimethacrylate
3.0 parts Methacrylic acid 1.6 parts T-dodecyl mercaptan 0.1 part Azobisisobutyronitrile 0.3 parts Total 100.0 parts Example 2 The following composition consisting of a monomer, a polymerization initiator, and a chain transfer agent was placed in the same flask as in Example 1. prepare
Reacted at 103-107℃ for 12 hours, polymerization rate 27%, viscosity
A syrup (A-2) of 480 centipoise was obtained. Methyl methacrylate 70.0 parts Styrene 25.0 parts Neopentyl glycol dimethacrylate 3.0 parts N-methylaminoethyl methacrylate 1.6 parts t-dodecyl mercaptan 0.1 part Azobisisobutyronitrile 0.3 parts Total 100.0 parts Example 3 Into the same flask as Example 1 , the following composition consisting of a monomer, a polymerization initiator and a solvent was charged, and 110
Polymerization was carried out by heating at °C for 8 hours. Then, toluene was distilled off under heating and reduced pressure to obtain a solid methacrylic copolymer (d) having glycidyl groups. The number average molecular weight of the methacrylic copolymer (d) was 12,000. Methyl methacrylate 25.0 parts Styrene 4.0 parts Glycidyl methacrylate 10.0 parts Benzoyl peroxide 1.0 parts Toluene 60.0 parts Total 100.0 parts 50 parts of the above methacrylic copolymer (d) and the following monomers
By dissolving (B) and 50 parts of monomer (E) and further heating at 90℃ for 8 hours, the viscosity becomes 1900 centipoise and the acid value
100 parts of 3.9 syrup (B-1) were obtained. Methyl methacrylate 32.0 parts Styrene 13.0 parts Methacrylic acid 2.0 parts Trimethylolpropane trimethacrylate
3.0 parts Monomer (B) and Monomer (E) Total 50.0 parts For this syrup (B-1), methacrylic copolymer was determined according to a known method for quantifying epoxy groups.
When the reaction rate of the glycidyl group contained in (d) was measured, it was 61.5%. Example 4 The following composition consisting of a monomer, a polymerization initiator, and a solvent was charged into the same flask as in Example 1, and the mixture was heated at 110°C.
Polymerization was carried out by heating for 8 hours. Next, toluene was distilled off under heating and reduced pressure to obtain a solid methacrylic copolymer (d) having glycidyl groups.
The number average molecular weight of the methacrylic copolymer (d) was 7,000. Methyl methacrylate 20.0 parts Styrene 5.0 parts N-butyl methacrylate 5.0 parts Glycidyl methacrylate 8.5 parts Benzoyl peroxide 1.5 parts Toluene 60.0 parts Total 100.0 parts A syrup (B-2) having a viscosity of 3100 centipoise and an acid value of 0.8 was obtained by dissolving the mixture in 50 parts of polymer (E) and further heating at 40°C for 6 hours. Methyl methacrylate 33.0 parts Styrene 10.0 parts 2-hydroxyethyl methacrylate 3.0 parts Trimethylolpropane trimethacrylate
3.0 parts Orthophosphoric acid ester of 2-hydroxyethyl methacrylate 1.0 parts Monomer (b) and monomer (e) Total 50.0 parts This syrup (B-2) was prepared according to the known method for quantifying epoxy groups. methacrylic copolymer
When the reaction rate of the glycidyl group contained in (d) was measured, it was 98.6%. Comparative Example 1 In the same flask as in Example 3, monomer (B) and monomer (B) in which methacrylic acid was replaced with methyl methacrylate among Monomer (B) and Monomer (E) of Example 3 were prepared. e)
50 parts of the same methacrylic copolymer (d) as in Example 3 was dissolved in 50 parts of the same as in Example 3 to obtain 100 parts of syrup (C) having a viscosity of 1750 centipoise. Examples 5-8, Comparative Examples 2-4 The syrups obtained in Examples 1-4 and Comparative Example 1 described above were cured under the conditions shown in Table 1 to obtain transparent molded products. Furthermore, 70 parts of silica sand powder was mixed with 30 parts of the syrup of the composition shown in Table 1, poured into a mold made of stainless steel, aluminum, etc. coated with a mold release agent such as silicone or polyvinyl alcohol, and cured under the curing conditions shown in Table 1. A molded product with a glossy surface was obtained. Table 2 shows the results of the transparent mold plate test for the molded product obtained, and Table 3 shows the test results for the molded product containing silica sand powder. As is clear from Tables 2 and 3, the syrup
When producing (B), a part of the glycidyl groups in the methacrylic copolymer (d) is co-coated with methyl methacrylate, which is reactive with glycidyl groups and has at least one ethylenically unsaturated bond. By reacting with a monomer (e) containing a polymerizable monomer (b), molded products produced using the syrup composition of the present invention have excellent water resistance under harsh conditions, Not only does it cause almost no shrinkage during curing, but its impact resistance is dramatically improved, and there is no cracking on the cut surface when cutting the molded product into products of the desired size and shape. .

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Claims (1)

[Claims] 1 to 99 parts by weight of the following syrup (A) and syrup (B)
A methyl methacrylate syrup composition prepared by mixing 99 to 1 part by weight to a total of 100 parts by weight. Siltup (A): (a) Methyl methacrylate monomer 5~
95% by weight, (b) 95 to 1% by weight of a monomer reactive with glycidyl groups and copolymerizable with methyl methacrylate having at least one ethylenically unsaturated bond, and (c) glycidyl groups. A mixture consisting of 0 to 94% by weight of a monomer copolymerizable with methyl methacrylate and having at least one ethylenically unsaturated bond,
10 to 60% copolymerized (however, monomer
The total of (a), monomer (b) and monomer (c) is 100% by weight
It is. ). Siltup (B): (d) Monomer 3 having a glycidyl group
97% by weight of other copolymerizable monomers 97-3
Copolymerized with weight%, number average molecular weight is 1500~
5 to 95% by weight of a (meth)acrylic copolymer having 50,000 glycidyl groups, which has no reactivity with (e)methyl methacrylate monomers and/or glycidyl groups, and has at least one ethylenically unsaturated bond. a monomer that is copolymerizable with methyl methacrylate, and a monomer that is copolymerizable with methyl methacrylate that is reactive with (b)glycidyl groups and has at least one ethylenically unsaturated bond. After dissolving in 95 to 5% by weight of the mixture, 1 to 99% of the glycidyl groups in the (meth)acrylic copolymer are further reacted (with the exception of (meth)acrylic copolymer (d),
The total of monomer (e) and monomer (b) is 100% by weight. ).