JPH0757778B2 - Bicycloheptane ring-containing silyl (meth) acrylate copolymer - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a silyl (meth) acrylate having a side chain of a silicon atom to which a monovalent hydrocarbon group containing a bicycloheptane ring is bonded, and a silicon atom in the molecule. The present invention relates to a bicycloheptane ring-containing silyl (meth) acrylate copolymer that is a copolymer with an ethylenically unsaturated compound that does not include In addition, in this specification, (meth) acrylate means a generic term for acrylate and methacrylate.

[Technical Background of the Invention and Problems Thereof] Trimethylsilyl (meth) acrylate and various vinyl compounds, that is, methyl methacrylate, butyl methacrylate, styrene, 9-vinylphenanthrone, vinylpyridine, p-dimethylaminostyrene, etc. Polymers are known. (DNAndreev et al .; Izvestya Aka
demiya Nauk SSSR, Ser, Khim, 1972 No. 6, pp. 1411-1413; M. Kurihara et al .; Journal of Polymer Science, Polym
er Chemistry, Vol. 11, No. 3, pp. 587-610 (1973)).

However, in these copolymers, the polymerization rate of trimethylsilyl (meth) acrylate is extremely high, and it is difficult to obtain a copolymer with good control, and the trimethylsilyl group of the polymer is removed from the main chain by hydrolysis. There is a problem in that the stability required for handling cannot be obtained due to easy release and poor water resistance.

An antifouling paint that gradually dissolves in seawater to give a fresh surface and releases a biologically active tin compound to prevent the growth of adhering organisms can be added to (meth) acrylic acid ester and tributyltin (meth) acrylate. There is a copolymer, and it is disclosed that tributylsilyl acrylate or triphenyl acrylate is used in combination as a part of the monomer (see JP-A-60-231771). However, in the case of the copolymer synthesized by the usual method, the tributylsilyl group and the triphenylsilyl group do not show hydrolyzability under the conditions of pH 8.2 to 8.3 like seawater, and therefore the tributyltin group is not present. It does not achieve the same purpose as the copolymers of the present invention, while the presence of tributyltin groups releases them into seawater by hydrolysis and thus pollutes the ocean due to their toxicity.

Further, there are provided a copolymer of a triorganosilyl (meth) acrylate and an ethylenically unsaturated compound having a hydrolyzability that is easily controlled, and a ship bottom paint containing these as a binder and a toxic substance (US Patent Number 4,593,055
Specification). However, among the triorganosilyl (meth) acrylates used here, the copolymer obtained from trimethylsilyl (meth) acrylate has a large hydrolyzability as described above and is not practical. Further, dimethylphenylsilyl (meth) acrylate, methyldiphenylsilyl (meth) acrylate, and triphenylsilyl (meth) acrylate are difficult to synthesize because they need to be synthesized using the Grignard method. In triisopropylsilyl (meth) acrylate and tributyl (meth) acrylate, it is necessary to introduce three isopropyl groups or butyl groups by a Grignard reaction or the like, and a complicated operation is required to remove by-produced salts. . Therefore, the triorganosilyl (meth) acrylates exemplified in the above-mentioned prior art all have practical problems, and it is easy to synthesize and control the hydration by solving these problems. There is a need for base polymers that have a decomposition rate.

[Object of the Invention] An object of the present invention is to provide a bicyclopentane ring-containing silyl (meth) acrylate-based copolymer that is easy to synthesize and has a controlled hydrolysis rate.

[Structure of the Invention] The present invention has the general formula: [In the formula, R ¹ represents a hydrogen atom or a methyl group; R ² represents a monovalent hydrocarbon group containing a bicycloheptane ring; R ³ represents a hydrogen atom or a methyl group; R ⁴ represents a phenyl group or- C
Represents an O ₂ R ⁵ group (wherein R ⁵ represents an alkyl group); n and m
Represents a number in which n + m is 100 to 10,000 and n / n + m is 10 to 95%].] Is a bicycloheptane ring-containing silyl (meth) acrylate copolymer.

The meanings of the groups R ^{1 to} R ⁴ in the above general formula are as described above, but as the monovalent hydrocarbon group containing a bicycloheptane ring of the group R ¹ , raw materials are easily available and synthesis is easy. Therefore, a norbornyl group and an ethylidene norbornyl group are preferred, and when the group R ⁴ is a —CO ₂ R ⁵ group, the alkyl group of R ⁵ includes a methyl group, an ethyl group, a propyl group, a butyl group and pentyl. Group, hexyl group, octyl group and the like.

m + n is the degree of polymerization of the copolymer and is 100 to 10,000. Those outside this range are difficult to synthesize. Also n /
n + m is the ratio of units containing a silyl group having a bicycloheptane ring bonded to a silicon atom as a side chain, and this value is 10 to 95%, preferably 20 to 70%. If this value is less than 10%, a controlled hydrolysis rate and controlled dissolution cannot be obtained, and if it exceeds 95%, the adhesion between the coating film before hydrolysis and the substrate is deteriorated.

The copolymer represented by the general formula is a silyl (meth) acrylate in which one monovalent hydrocarbon group containing a bicycloheptane ring and two methyl groups are bonded to a silicon atom, and an ethylenic group containing no silyl group. It can be obtained by copolymerizing with an unsaturated compound.

Examples of the silyl (meth) acrylate used here include dimethylnorbornylsilyl (meth) acrylate and dimethylethylidenenorbornylsilyl (meth) acrylate. Examples of the ethylenically unsaturated compound containing no silicon atom in the molecule include styrene, α-methylstyrene, methyl (meth) acrylate, ethyl (meth) acrylate,
Examples thereof include propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate and the like. These dimethylorganosilyl (meth) acrylates and ethylenically unsaturated compounds containing no silicon atom in the molecule may be used alone or in combination of two or more.

The copolymerization is carried out, for example, in the presence of a polymerization initiator in a suitable organic solvent, in the presence of the above-mentioned bicycloheptane ring-containing silyl (meth).
The acrylate and the ethylenically unsaturated compound containing no silicon atom in the molecule are heated and stirred.

As the organic solvent, for example, used for controlling the polymerization reaction and preventing gel formation during the reaction, benzene, toluene,
Examples thereof include hydrocarbon solvents such as xylene; ester solvents such as ethyl acetate and butyl acetate; alcohol solvents such as isopropanol and butanol; and aprotic polar solvents such as dimethylmeformamide and dimethyl sulfoxide. These are used in an amount of 20 to 1,000 parts by weight, preferably 50 to 500 parts by weight, based on 100 parts by weight of the monomer.

Examples of the polymerization initiator include benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, t-butyl peroctoate, methyl ethyl ketone peroxide, cumene hydroperoxide, and other organic peroxides and azobisisobutyronitrile. Can be mentioned. These polymerization initiators are used in an amount of 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the monomer.

[Effect of the Invention] The bicycloheptane ring-containing silyl (meth) acrylate copolymer of the present invention has a property of gradually hydrolyzing in the presence of water to release a silyl group to be water-solubilized. The rate of such hydrolysis is very slow due to the large steric hindrance of the bicycloheptane ring attached to the silicon atom. Therefore, the bicycloheptane ring-containing silyl (meth) acrylate of the present invention is useful as a base polymer for a slowly soluble coating material.

[Examples] Hereinafter, the present invention will be described with reference to Examples and monomer production examples. In these examples, parts represent parts by weight.

Production Example 1 400 parts of benzene, 86 parts of methacrylic acid and 0.02 part of hydroquinone were charged into a reaction vessel equipped with a stirrer, a condenser, a thermometer and a cooling jacket, and stirred so as to be uniform. Then, 101 parts of triethylamine was added, and 188 parts of dimethylnorbornylchlorosilane were added dropwise over 15 minutes while stirring while maintaining the temperature at 50 ° C.
The reaction was completed by continuing stirring for another 30 minutes. After the reaction was completed, the triethylamine hydrochloride was separated, and the benzene solution containing the reaction product was distilled to obtain a fraction 176 with a boiling point of 87 ° C / 2 Torr.
I got a part. The reaction product had a molecular weight of 238 and a refractive index (▲ n ²⁵ _D ▼) of 1.4734 as measured by gas mass spectrometry.
From the infrared absorption spectrum and the NMR spectrum, it was confirmed to be dimethylnorbornylsilylmetalylate. The yield was 74% based on the theoretical amount.

Production Examples 2 and 3 Silyl (meth) acrylate was produced in the same manner as in Production Example 1 except that the raw materials shown in Table 1 were used. The yield, molecular weight, boiling point and refractive index of the reaction product were as shown in Table 1. From the infrared absorption spectrum and the NMR spectrum, it was confirmed that the product of Production Example 2 was dimethyl ethylidene norbornyl acrylate and the product of Production Example 3 was dimethyl ethylidene norbornyl methacrylate.
The yield based on the theoretical amount is shown in Table 1.

Examples 1 to 3 Using the three types of bicycloheptane ring-containing silyl (meth) acrylates obtained in Production Examples 1 to 3, copolymers were produced at the compounding ratios shown in Table 2. That is, xylene was charged into a reaction vessel equipped with a dropping device, a stirring device, a thermometer, and a heating / cooling device, and the temperature was raised to 80 ° C. with stirring. In addition to this, the above silyl (meth) acrylate, second
A mixed solution of an ethylenically unsaturated compound containing no silicon atom in the molecule shown in the table and azobisisobutyronitrile was added dropwise from the dropping device over about 1 hour. After the dropping is completed,
After maintaining at 80 ° C. for 5 hours for polymerization, the temperature was raised to 100 ° C. and maintained for 30 minutes.

The obtained polymer solution is heated under reduced pressure to remove the solvent, and gel permeation chromatography (GPC)
The polymerization rate and the number average molecular weight of the polymer were determined by. These were as shown in Table 2.

Infrared spectroscopic analysis and NMR analysis were performed on the copolymers obtained in these examples. The results are shown in Table 3.

[Brief description of drawings]

1 and 2 are the copolymers obtained in Example 1, FIGS. 3 and 4 are the copolymers obtained in Example 2, 5
FIG. 6 and FIG. 6 show infrared spectroscopy and NMR charts of the copolymer obtained in Example 3, respectively.

Claims (2)

[Claims] 1. A general formula: [In the formula, R ¹ represents a hydrogen atom or a methyl group; R ² represents a monovalent hydrocarbon group containing a bicycloheptane ring; R ³ represents a hydrogen atom or a methyl group; R ⁴ represents a phenyl group or- C
Represents an O ₂ R ⁵ group (wherein R ⁵ represents an alkyl group); n and m
Represents a number in which n + m is 100 to 10,000 and n / n + m is 10 to 95%.] A bicycloheptane ring-containing silyl (meth) acrylate copolymer. 2. The copolymer according to claim 1, wherein R ² in the general formula is a norbornyl group or an ethylidene norbornyl group.