JPH038644B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a copolymer A portion having a peroxy group in the main chain of a polymer mainly composed of one or more types of (meth)acrylic acid ester monomers,
The present invention relates to a method for producing a block copolymer useful for modifying resins, which is comprised of a (co)polymer B portion which has a different monomer composition and does not contain a peroxy group. In recent years, with the development of new technology for polymer blends, attempts to add functional groups to polymers have been actively investigated. Among these, materials with peroxy groups added to the polymer main chain are very interesting materials because they have high reactivity. (Conventional technology) For example, "plaste und couch check"
(Plaste und Kautschuku, 26(3) 121 (1979))
In addition, it has been proposed that a peroxide having a (meth)acrylic type double bond is copolymerized with a (meth)acrylic acid ester monomer to introduce a peroxy group into the main chain of the polymer. Furthermore, as a similar product, Japanese Patent Publication No. 55-30790 proposes a radical copolymerizable peroxycarbonate having an allylic double bond represented by the following general formula (). The radical copolymerizable peroxycarbonate represented by the general formula () is: (In the formula, R ₆ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ₇ and R ₈ are an alkyl group having 1 to 4 carbon atoms, and R ₉ is an alkyl group having 1 to 12 carbon atoms or an alkyl group having 3 to 4 carbon atoms. 12 cycloalkyl groups). Regarding this radical copolymerizable peroxycarbonate having an allyl type double bond,
In Japanese Patent Publication No. 57-26617 and Japanese Patent Publication No. 57-26619, copolymers with vinyl chloride, JP-A No. 56-266-
139514, a copolymer with ethylene-vinyl acetate; Japanese Patent Publication No. 57-50802, a copolymer with diallyl phthalate; Japanese Patent Publication No. 57-42083
In the above publications, methods for producing copolymers with vinyl acetate have been proposed, and it has already been confirmed that these copolymers have self-crosslinking properties and grafting properties. (Problem to be Solved by the Invention) However, when attempting to blend these copolymers with other resins, there is generally no compatibility between the resins, so grafting reactions occur locally, resulting in the blended resin It had the disadvantage of causing a decrease in mechanical strength and a decrease in physical properties due to a phase separation phenomenon. Furthermore, since the radical copolymerizable peroxycarbonate represented by the general formula () has an allylic double bond, it has good copolymerizability with a monomer having a non-conjugated double bond. However, it has the drawback that it does not copolymerize with conjugated monomers such as aromatic vinyl monomers and (meth)acrylic acid ester monomers. Furthermore, in order to improve this drawback, attempts have been made to add or contain copolymerizable monomers, but this has resulted in the problem that it is difficult to exhibit the intended physical properties. On the other hand, in recent years, various methods for producing block copolymers have been developed, and it is now possible to produce blended resins with new properties by blending the obtained block copolymers with other resins under melting conditions. is being attempted. According to this method, large phase separation in the blend resin disappears due to the properties of the block copolymer, and a uniform blend resin is obtained. However, since there are no chemical bonds at the interface between the blended resins, there is a drawback in that the mechanical strength of the blended resin is significantly reduced. In order to improve these drawbacks, the present inventors previously proposed in Kokka Technical Report No. 83-6603 that the present invention consists of a copolymer (a) and a (co)polymer (b), and only copolymer (a) contains peroxycarbonate. A block copolymer into which groups have been introduced is disclosed. This block copolymer has excellent properties such as good dispersion stability during polymer blending and improved interfacial strength between blended resins. However, since the peroxide having a double bond used is a radically copolymerizable peroxycarbonate represented by the above general formula (), the monomer composition of copolymer A is a combination of vinyl acetate and vinyl chloride. It is limited to monomers with non-conjugated double bonds such as
The drawback was that it had a negative effect on electrical insulation. Furthermore, since the (co)polymer 2 is a styrene polymer, it is possible to impart rigidity, surface gloss, etc., but it has been difficult to impart impact resistance, weather resistance, etc. (Means for Solving the Problems) The present inventors further conducted intensive research to eliminate these conventional drawbacks, and as a result, the method for producing the block copolymer of the present invention described below has been improved compared to these conventional disadvantages. The present invention was completed based on the knowledge that all the drawbacks could be eliminated. That is, the present invention uses one or more (meth)acrylic acid ester monomers with a weight of 80 to 99.5 and a general formula (). (In the formula, R ₁ represents a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, R ₂ represents a carbon atom or a methyl group, and R ₃ and R ₄ each have 1 to 4 carbon atoms.)
R ₅ represents a group selected from the group consisting of an alkyl group having 1 to 12 carbon atoms, a phenyl group, an alkyl-substituted phenyl group, and a cycloalkyl group having 3 to 12 carbon atoms. n represents an integer of 1 or 2. ) is radically copolymerized with 0.5 to 20 parts by weight of a radically copolymerizable peroxycarbonate represented by the following at a temperature of 90°C or lower to obtain copolymer A, and then, unlike the (meth)acrylic acid ester monomer described above, copolymer A is obtained. , one or two radical (co)polymerizable monomers constituting the (co)polymer B part and the copolymer A are copolymerized at a temperature of 90°C or less to form a copolymer A part. 5-95% by weight and (co)polymer B
This is a method for producing a block copolymer consisting of 95 to 5% by weight. In the present invention, when producing copolymer A,
(Meth)acrylic acid ester monomer is an essential component. The reason is that (meth)acrylic acid ester polymers have excellent heat resistance, weather resistance, and processability. Furthermore, since the (meth)acrylic acid ester monomer derived from a long-chain alcohol has rubber elasticity, it is effective as an impact modifier. In the present invention, (meth)acrylic acid ester monomers that can be used include methyl (meth)acrylate, ethyl (meth)acrylate, i-propyl (meth)acrylate, and (meth)acrylic acid.
n-propyl, n-butyl (meth)acrylate,
Examples include 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, and stearyl (meth)acrylate. Preferred are methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. The amount used is 80-99.5 parts by weight, preferably
It is 85.5 to 99.5 parts by weight. If it is less than 80 parts by weight, the copolymer A portion will lose its properties as a (meth)acrylic acid ester copolymer, which is not preferable. moreover,
Naturally, the radical copolymerizable peroxycarbonate represented by the general formula () exceeds 20 parts by weight, which is not preferable. Moreover, if it exceeds 99.5% by weight, the radical copolymerizable peroxycarbonate represented by the general formula () will necessarily be less than 0.5% by weight, which is not preferable. Furthermore, with this amount, the amount of active oxygen in the block copolymer obtained by the present invention becomes less than 0.002% by weight, which is not preferable. That is, when blending with other resins, since the amount of active oxygen is small, the grafting efficiency of the other resins and the block copolymer obtained by the present invention is extremely reduced. Furthermore, in the present invention, when producing copolymer A, a radically copolymerizable peroxycarbonate represented by the general formula () is also an essential component. This is because, when this radical copolymerizable peroxycarbonate is introduced into the copolymer A, it thermally decomposes during melting to generate radicals, which causes a graft reaction. Specifically, the radical copolymerizable peroxycarbonate used is t-butyl peroxyacryloyloxyethyl carbonate, t-
Hexylperoxyacryloyloxyethyl carbonate, 1,1,3,3-tetramethylbutylperoxyacryloyloxyethyl carbonate, cumylperoxyacryloyloxyethyl carbonate, p-isopropylcumylperoxyacryloyloxyethyl carbonate, t-butyl Peroxymethacryloyloxyethyl carbonate, t-amylperoxymethacryloyloxyethyl carbonate, 1,1,3,3-tetramethylbutylperoxymethacryloyloxyethyl carbonate, cumylperoxymethacryloyloxyethyl carbonate, t-butylperoxyacryloyl Roxyethoxyethyl carbonate,
t-Hexylperoxyacryloyloxyethoxyethoxyethyl carbonate, cumylperoxyacryloyloxyethoxyethyl carbonate, t-butylperoxymethacryloyloxyethoxyethyl carbonate, t-amylperoxymethacryloyloxyethoxyethoxyethyl carbonate, cumylperoxymethacryloyloxyethoxyethoxy Ethyl carbonate, t-butylperoxyacryloyloxyisopropyl carbonate, t-hexylperoxyacryloyloxyisopropyl carbonate, 1,1,3,3-tetramethylbutylperoxyacryloyloxyisopropyl carbonate, cumylperoxyacryloyloxyisopropyl carbonate, Examples include t-butylperoxymethacryloyloxyisopropyl carbonate, t-amylperoxymethacryloyloxyisopropyl carbonate, 1,1,3,3-tetramethylbutylperoxymethacryloyloxyisopropyl carbonate, cumylperoxymethacryloyloxyisopropyl carbonate, etc. be able to. Preferably, t-butyl acryloyloxyethyl carbonate, t-hexylperoxyacryloyloxyethyl carbonate, t-butylperoxymethacryloyloxyethyl carbonate, t-hexylperoxymethacryloyloxyethyl carbonate, t-butylperoxyacryloyloxyethyl carbonate. An example is ethyl carbonate. The amount used is 0.5-20 parts by weight based on copolymer A. Preferably, it is 1 to 15 parts by weight.
If it is less than 0.5 parts by weight, the amount of peroxycarbonate groups introduced into copolymer A will be small, and the amount of active oxygen in the block copolymer will be less than 0.002% by weight.
Therefore, the grafting ability with other resins is not sufficiently exhibited, which is not preferable. Also, if it exceeds 20 parts by weight,
This is not preferable because it may cause gelation during polymerization or copolymer A may lose the physical properties of the (meth)acrylic acid ester copolymer. In the present invention, there is no particular restriction on the radical (co)polymer used for (co)polymer B, as long as the monomer composition of copolymer A is different. If anything,
This is because monomers are selected depending on the properties required for the block copolymer obtained in the present invention and the purpose of modifying other resins. Typically, the radically polymerizable monomers include aromatic vinyl monomers such as styrene, α-methylstyrene, p-methylstyrene, (meth)
Methyl acrylate, ethyl (meth)acrylate,
(Meth) such as n-butyl (meth)acrylate
Acrylic acid ester monomers, vinyl ester monomers such as vinyl acetate and vinyl propionate, unsaturated nitrile monomers such as acrylonitrile and methacrylonitrile, conjugated diene monomers such as butadiene and isoprene, acrylic acid, methacryl Examples include unsaturated fatty acid monomers such as acids, α-olefin monomers such as ethylene, propylene, and butene-1, and halogenated vinyl monomers such as vinyl chloride and vinylidene chloride. The block copolymer obtained in the present invention must have properties specific to block copolymers, such as good dispersion stability in other resins. Therefore, the copolymer A part in the block copolymer is 5 to 95% by weight, and the (co)polymer B part is 95% by weight.
It should be ~5%. When the copolymer A portion is less than 5% by weight and the (co)polymer B portion exceeds 95% by weight, or when the copolymer A portion exceeds 95% by weight and the (co)copolymer B portion If the amount is less than 5% by weight, the resulting block copolymer will take on the properties of a homo or random (co)polymer, and the dispersibility and dispersion stability in other resins will be significantly reduced. It loses its distinctive properties and is not desirable. The block copolymer of the present invention may be produced by any method as long as the radical copolymerizable peroxycarbonate represented by the general formula () is not decomposed by a catalyst or the like. Specifically, examples include an anion living method, a sequential addition method, a polymer reaction method, a polymer peroxide (polymer azo compound) method, and the most preferred is a polymer peroxide (polymer azo compound) method. When producing with this method, care must be taken to select the radical copolymerizable peroxycarbonate represented by the general formula ().
Since the 10-hour half-life temperature is 95 to 105°C, in order to copolymerize this peroxy group without decomposing it, the polymerization temperature should be 90°C or lower, more preferably 85°C.
Should be: Further, in that case, any method such as bulk polymerization, suspension polymerization, emulsion polymerization, or solution polymerization may be employed as the polymerization method. The chemical structure of the copolymer A portion in the block copolymer of the present invention can be determined from the presence and amount of peroxycarbonate groups based on the infrared absorption spectrum (characteristic infrared absorption band) and measurement of the amount of active oxygen by iodometry. Confirm the alkyl group by pyrolysis gas chromatography and nuclear magnetic resonance spectroscopy,
By clarifying the structure of the cycloalkyl group and phenyl group, the monomer composition can be clarified. Furthermore, the blocking efficiency of the block copolymer can be measured by extraction method and fractional precipitation method, and the molecular weight and molecular weight distribution can be measured by gel permeation chromatography (hereinafter abbreviated as GPC). Can be done. (Effects of the Invention) As detailed above, the method for producing a block copolymer of the present invention consists of a copolymer A part and a (co)polymer B part, and the copolymer A part is (meth) ) A method for producing a block copolymer which is an acrylic acid ester copolymer and is characterized in that peroxide bonds are pendantly bonded in the main chain of copolymer A. Therefore, other resins such as polyethylene, polypropylene,
Olefin (co)polymers such as ethylene-propylene copolymer, ethylene-propylene-diene copolymer, ethylene-vinyl ester copolymer, ethylene-(meth)acrylate copolymer,
It can be used to modify condensed engineering plastics such as polyphenylene ether, polycarbonate, and thermoplastic polyester, celluloses, and silicone resins. In this method, the block copolymer obtained by the present invention may be dissolved in a monomer during the polymerization or condensation reaction, but it is preferably carried out in a molding machine such as an extruder, an injection molding machine, or a kneading machine. When melt blending the block copolymer composition obtained according to the invention and other resins, it is preferable to carry out a grafting reaction at the same time. At this time, the melting temperature is preferably 150 to 300°C. When the above operation is performed, due to the properties of the block copolymer, the block copolymer is uniformly dispersed in the other resin (matrix resin), and the peroxycarbonate localized in the block copolymer is dispersed. As the group decomposes, the block copolymer is grafted onto the matrix resin.
The interfacial strength between the matrix resin and the block copolymer is improved, and the particle size of the block copolymer dispersed in the matrix resin is further reduced. Furthermore, since copolymer A is a (meth)acrylic acid ester copolymer, it is also expected to improve heat resistance, weather resistance, and moldability. As described above, the block copolymer obtained by the present invention is an excellent block copolymer that can exhibit the properties of the matrix resin without deteriorating its mechanical properties. Combinations can be easily manufactured. (Examples, Comparative Examples, and Reference Examples) The present invention will be specifically described below using Examples, Comparative Examples, and Reference Examples. Example 1 When copolymer A was polymerized, 95% by weight of methyl methacrylate and 5% by weight of t-butylperoxymethacryloyloxyethyl carbonate as a radical copolymerizable peroxycarbonate were mixed to make 100 parts by weight. Then the following formula (Average degree of condensation = 4.5, theoretical active oxygen amount = 3.96,
Add 5 parts by weight of a polymeric peroxide with a selected 10-hour half-life temperature of 63.5°C as a polymerization initiator, stir well, and place in a four-necked flask with a condenser containing 600 parts by weight of a 1% by weight aqueous polyvinyl alcohol solution. Suspension polymerization was carried out at a temperature of 60 DEG C. to 80 DEG C. for 5 hours while stirring, and when it was confirmed that the polymerization conversion was 95% or higher and the polymerization was completed, the polymerization was stopped to obtain copolymer A. Next, 100 parts by weight of styrene as a monomer to become (co)polymer B was added to the suspension of copolymer A, and polymerization was continued at a polymerization temperature of 70°C to 85°C to complete the polymerization. After that, the polymer was filtered, washed with water, and dried to obtain the desired block copolymer composition. The test results for this block copolymer composition were as follows. Active oxygen content 0.154% Number average molecular weight 125000 Blocking efficiency 61% Polymerization conversion rate 98.5% Unblocked styrene polymer ((co)
Amount of active oxygen in polymer B) 0.000% The test methods include measuring the amount of active oxygen using iodometry, measuring the number average molecular weight using GPC, and measuring unblocked polystyrene using cyclohexane as a solvent using a Soxhlet extractor. Blocking efficiency was determined by extraction. The polymerization conversion rate was calculated by the following formula according to the polymerization method. Weight of produced block copolymer composition x 100/weight of all monomers used Furthermore, as a result of measuring the heat distortion temperature of this block copolymer composition in accordance with JIS K-7207 method,
It was 110℃. Comparative Example 1 The procedure of Example 1 was followed except that methyl methacrylate was used as the monomer to form copolymer A and t-butylperoxymethacryloyloxyethyl carbonate was not added. A block copolymer composition was obtained. The test results were: active oxygen amount 0.000%, number average molecular weight 132000, blocking efficiency 63%, and polymerization conversion rate 98.5%. Example 2-5, Comparative Example 2-5 In Example 1, the types, compositions, and t of monomers to become copolymer A and (co)polymer B
- The amount of butylperoxymethacryloyloxyethyl carbonate and the blending ratio of copolymer A and (co)polymer B are shown in Table 1 for Example 2-5.
Comparative Example 2-5 was carried out according to Example 1 except for the changes shown in Table 2.
Each block copolymer composition was obtained. The blocking efficiency was measured by a fractional precipitation method in which the block copolymer composition was dissolved in benzene and then poured into petroleum ether. In addition, copolymer B
In Example 3 and Comparative Example 4, normal dodecyl mercaptan was used as a chain transfer agent. In addition, in Tables 1 and 2, t-butylperoxymethacryloyloxyethyl carbonate is MEC, methyl methacrylate is MMA, n-butyl acrylate is BA, methacrylate n-
Butyl was abbreviated as BMA, styrene as St, and acrylonitrile as AN.

【table】

[Table] The following can be seen from Tables 1 and 2. That is, in Comparative Example 2, in copolymer A
Since only 0.2% by weight of MEC is added, the amount of active oxygen in the block copolymer composition is only 0.001%. In Comparative Example 3, the content of copolymer A or (co)polymer B was 5% by weight or less, and when it was made into a solution, it clearly lost its properties as a block copolymer composition. Example 6 The decomposition temperature of the block copolymer composition produced in Example 1 was measured using a thermobalance, and the decomposition temperature was 230°C. Comparative Example 6 In Example 1, the monomers of copolymer A were 95% by weight of vinyl acetate and 5% by weight of t-butyl peroxyacrycarbonate, and a block copolymer composition was prepared in accordance with Example 1 except for the following. Obtained. This block copolymer composition has an active oxygen content of 0.218%, a number average molecular weight of 98000, a blocking efficiency of 67%, and a polymerization conversion rate of 98.0%.
The amount of active oxygen in Polymer B) was 0.000%, and the decomposition temperature by thermobalance was 160°C. Reference Example 1 As a matrix resin, 10 parts by weight of the block copolymer composition produced in Example 1 was added to 90 parts by weight of ethylene-vinyl acetate copolymer ("Flowback K-2010" manufactured by Seitetsu Kagaku Kogyo Co., Ltd.). were melt-blended at 230°C in a Banbury mixer, and the grafting efficiency, flexural modulus, and elongation were measured. Incidentally, the grafting efficiency was determined by a fractional precipitation method using a benzene-acetone system. Grafting efficiency 67% Flexural modulus 340Kg/cm ² Elongation 790% Flowback K-2010 has a flexural modulus of 205
Kg/cm ² and elongation rate was 795%. Reference Example 2 In the same manner as in Reference Example 1, 90 parts by weight of Flowback K-2010 was used as a matrix resin.The block copolymer composition produced in Comparative Example 1 was used as a matrix resin.10
Parts by weight were blended. As a result of measurement in the same manner as in Reference Example 1, the graft efficiency was 7% and the flexural modulus was 250 Kg/cm ² elongation 270%. Reference Example 3 The block copolymer composition produced in Comparative Example 2 was used, and a grafting reaction was carried out in accordance with Reference Example 1 except for the same. As a result, the grafting efficiency was 15
It was %.

Claims (1)

[Claims] 1. 80-99.5 parts by weight of one or more (meth)acrylic acid ester monomers, and general formula () (In the formula, R ₁ represents a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, R ₂ represents a hydrogen atom or a methyl group, R ₃ and R ₄ each represent an alkyl group having 1 to 4 carbon atoms, and R ₅ represents an alkyl group having 1 to 4 carbon atoms.) Represents a group selected from the group consisting of an alkylphenyl group having 1 to 12 carbon atoms, an alkyl-substituted phenyl group, and a cycloalkyl group having 3 to 12 carbon atoms. n represents an integer of 1 to 2.)
Copolymer A is obtained by radical copolymerization with 0.5 to 20 parts by weight of a radically copolymerizable peroxycarbonate represented by the following at a temperature of 90°C or lower, and then, unlike the (meth)acrylic acid ester monomer, One or two of the radical (co)polymerizable monomers constituting the (co)polymer B portion and the copolymer A are copolymerized at a temperature of 90°C or lower to form a copolymer A portion 5. A method for producing a block copolymer consisting of ~95% by weight and 95-5% by weight of the (co)polymer B portion.