JPS63207802A - Polymerizable composition and its production - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to interpenetrating polymer networks.

In particular, the present invention relates to semi-interpenetrating polymer networks that can be utilized in a variety of applications including printing inks or coatings for sterile food packaging.

BACKGROUND OF THE INVENTION Polymeric coatings used in various packaging materials consist of polymeric films. In many instances, the film is comprised of polyacrylate made by radiation curing of acrylate monomers and oligomers. However, when using this type of coating,
There are certain disadvantages, especially when the coating comes into contact with edible substances.

This is due to the fact that portions of the uncured acrylate material leach out of the coating or film and are absorbed into the edible material. There is therefore a need to provide new types of coatings, or films, particularly for materials used in sterile food packaging. Furthermore, another disadvantage that exists when using uncured acrylate materials in industry is the sensitivity of workers to the materials, which may include potential disruption of work due to worker health problems. There is.

Generally speaking, it is desirable in the coatings industry to use materials that are free-flowing liquids in their natural state and that are capable of undergoing rapid phase changes to the solid state. monomer,
Alternatively, the phase change carried out by the polymeric material should occur at a rate commensurate with the successive processing steps of the process.

The coatings industry utilizes a variety of methods to effect or produce the desired phase change. For example, the conversion of various compounds from a liquid state to a solid state, as exemplified by paints, inks, paints, etc., involves a phase change when the volatile solvent used to provide the liquid phase is driven off. conduct. On the other hand, other methods of effecting the desired phase change are used when using two-component systems where a chemical reaction between the compounds causes or effects a change in phase. Furthermore, the phase change is caused by a polymerization reaction,
Alternatively, some systems are carried out as a result of a crosslinking reaction, producing a material having a higher molecular weight than the monomeric or oligomeric compound.

Polymerization of the monomer or polymeric precursor can occur by thermal activation of the compound or can occur by application of radiant energy to the monomer or oligomeric compound. When utilizing the latter approach to polymerization, two types of radiation are most commonly used, including ultraviolet light or electron beam energy. Although both types of radiation are used to induce polymerization reactions, their properties are quite different.

Ultraviolet light is selectively absorbed by molecules with appropriate chromophores. The commonly applied wavelength is about 50 (1
~200 nm (57-143 Kcal/mol). This range provides enough energy to place some molecules in an electronically excited state, but not enough energy to directly ionize many molecules.

The electronically excited molecules react to produce species that can initiate polymerization reactions. Or,
Decay to ground state.

In contrast, an electron beam consists of a stream of charged particles generated by a cathode ray gun. An electron is usually about 1
00~500Kev (2300~1150Kcal
/mol).

This energy is more than enough to easily ionize any organic material. The species thus ionized then participate in the polymerization reaction.

Many commercial coatings that are cured by the application of ultraviolet light are
It contains a photoinitiator along with a monomer and/or a low polymer having an acrylate functional group at its end. Photoinitiators absorb light and then react to produce radical species. This radical species initiates rapid long chain polymerization with acrylic double bonds to produce a polymeric film consisting of a cured film.

Furthermore, almost all commercial systems that can be cured through the use of electron beams also contain acrylated monomers and oligomers. However, there is no need to utilize a photoinitiator in these acrylate systems as long as the electron beam provides sufficient energy to directly ionize the heptaacrylates. As mentioned before,
Acrylates comprise extremely useful materials for radiation-cured systems. They have cure speeds comparable to other process steps, and in addition, a wide range of acrylated monomers and oligomers allow manufacturers to produce many different types of radiation cured products. It is commercially available in sufficient quantities to be able to do so.

Although acrylates are cured by free radical polymerization, it is also possible to obtain the desired results by utilizing a curing system consisting of cationic polymerization. This type of polymerization is described in U.S. Patent No. 3.708.29.
No. 6, according to which aryl diazonium salts are decomposed by ultraviolet light to form Lewis acids (the Lewis acids thus formed are epoxy-functionalized). Catalytic cationic polymerization of monomers and oligomers. However, a major disadvantage that exists when utilizing this diazonium salt is that these compounds are relatively unstable, resulting in products with limited shelf life. This is a fact.

U.S. Patent Nos. 3,721.616 and 3.711.39
No. 0 and No. 3', 711.391 describes various additives that can be added to the formulation in an attempt to stabilize the system. However, despite the use of gelation inhibitors, these mixtures still
It has an instability that is generally unacceptable for commercial coatings.

U.S. Patent Nos. 4,058,296 and 4.058.4
No. 01 describes the use of aromatic onium salts of Group VIA elements that can be used to catalyze cationic polymerization reactions that utilize ultraviolet light radiation as the energy source. Coatings prepared using sulfonium salt initiators had significantly greater stability when compared to the same compositions prepared using diazonium salts as initiators. The latter patent mainly describes the polymerization of epoxy compounds, while the former
Other cationically polymerizable materials including polyfunctional vinyl ether monomers are described.

Other US patents also disclose radiation-induced cationic polymerization. For example, US Pat. No. 4,069,054 describes the photosensitized degradation of aromatic sulfonium salts. The use of such salts improves the spectral response of the system, thus allowing irradiation at longer ultraviolet light wavelengths.

U.S. Pat. No. 4,069,056 also describes the use of Group VA aromatic onium salts as radiation-sensitive catalysts for cationic polymerizations.

U.S. Pat. No. 4,090,936 describes a hybrid photocurable composition comprising a mixture of epoxides cured by cationic polymerization and acrylates cured by radical polymerization reaction.

Another US Pat. No. 4,173,476 describes initiators consisting of aromatic sulfonium salts having a structure different in nature from those used previously.

In this patent, the use of such a photoinitiator is claimed to form thick films as a result of polymerization of the epoxide compound, ie up to about 2 inches thick. U.S. Patent No. 4,250.20
No. 3 uses an organic sulfur compound scavenger in the cationic polymerization reaction to reduce or eliminate the sulfur odor generated by photodecomposition of the sulfonium salt photoinitiator.
(removal agent) is utilized. U.S. Patent No. 4,2
No. 64,703 also describes the use of aromatic iodonium salts as radiation-sensitive catalysts for cationic polymerizations.

As described in more detail below, the semi-interpenetrating polymer network composition is prepared by combining a mixture of vinyl ether and cellulose ester in the presence of a polymerization catalyst consisting of an onium salt.
It has been discovered that they can be produced by treatment with radiation emanating from an electron beam, and the resulting compositions have various types of uses.

Problems to be Solved by the Invention The present invention relates to interpenetrating polymer networks. For more information,
The present invention relates to semi-interpenetrating polymer networks that can be used in a variety of applications, including printing inks or coatings for sterile food packaging. The products of the invention are obtained by irradiating vinyl ethers and cellulose esters with an electron beam in the presence of onium salts which act as polymerization catalysts for the reaction. As mentioned above, polymer coatings have been produced by subjecting a polymer precursor to irradiation, such as that provided by ultraviolet light, in the presence of a photoinitiator.

In this type of reaction, radiation from a light source activates the initiator, which then decomposes to form a Lewis acid, thus causing the reaction, or polymerization, to occur. In contrast to this type of reaction, the reaction of the present invention primarily involves the ionization of vinyl ethers and cellulose esters. These ionized species activate the polymerization catalyst. Once activation of the onium salt occurs, the onium salt acts in a catalytic manner and provides a mechanism for the formation of a polymeric material consisting of a semi-interpenetrating network of cellulose esters and vinyl ethers. The resulting coating exhibits desirable properties including good gloss, flexibility, and good adhesion properties. Furthermore, by utilizing an electron beam as an energy source instead of ultraviolet light, when electron beam irradiation is used, ultraviolet light may be utilized unless the sulfonium salt decomposes into products that produce a characteristic sulfur odor. It is possible to eliminate undesirable properties present in the case. Furthermore, as will be shown in detail in the Examples below, another advantage that exists when using the process of the present invention is the speed of curing required to effect the liquid to solid phase transition.

It has been discovered that the phase change in the process of the present invention occurs at a rate that is commensurate with the next processing step, thus contributing to the overall efficiency of the process with simultaneous production of the desired product.

It is therefore an object of the present invention to provide a polymer composition consisting of a semi-interpenetrating polymer network.

Furthermore, it is an object of the present invention to provide polymeric materials that can be utilized in a variety of ways as coatings for food packaging.

In one embodiment, embodiments of the invention reside in a polymerizable composition comprising a mixture of a vinyl ether, a cellulose ester, and a polymerization catalyst comprising an onium salt.

Another embodiment of the invention is a polymer composition comprising a semi-interpenetrating polymer network of polyvinyl ether and cellulose ester.

In addition, in another embodiment of the present invention, in the presence of a polymerization catalyst consisting of an onium salt in a mixture of at least one vinyl ether and a cellulose ester under polymerization conditions,
A polymer consisting of a semi-interpenetrating polymer network of polyvinyl ether and cellulose ester, comprising irradiation from an electron beam at a low dose and recovering the composition of the resulting semi-interpenetrating polymer network. In the method for producing the composition.

A particular embodiment of the invention is a polymeric composition comprising a mixture of triethylene glycol divinyl ether, cellulose acetate buterate, and 4-di-t-butylphenyliodonium hexafluoroantimony.

Another particular embodiment of the invention is a polymer composition comprising a semi-interpenetrating polymer network of poly(triethylene glycol divinyl ether) and cellulose acetate buterate.

In addition, another specific embodiment of the present invention is to add 4 to di-t-butylphenyl iodonium hexafluoro to a mixture of triethylene glycol divinyl ether and cellulose acetate buterate at a temperature ranging from about ambient temperature to 50°C. In the presence of antimony, from about 0.1 to
10.0 Mrad, and irradiation from an electron beam at a dose in the range of about 150-300 Kev, and recovering the resulting semi-interpenetrating polymer network composition. A method of making a polymer composition comprising a semi-interpenetrating polymer network of esters.

SUMMARY OF THE INVENTION As mentioned above, the present invention relates to compositions of semi-interpenetrating polymer networks for use as printing inks or as coatings. Desired polymer compositions with many desired properties not available in other coatings can be obtained by irradiating a mixture of vinyl ether and cellulose ester with an electron beam in the presence of a polymerization catalyst consisting of an onium salt. Manufactured. The reaction is carried out by dissolving the cellulose ester and onium salt catalyst in vinyl ether to produce a homogeneous solution. The viscosity of this solution is adjusted by varying the proportion of cellulose ester present in the composition.

The vinyl ether used as a component of the reaction mixture to form the desired semi-interpenetrating polymer network has the general formula %. However, R consists of alkyl, aryl, cycloalkyl, alkoxy, aralkyl, alkaryl, arylalkoxy, or a heterocyclic group; n consists of an integer of 1 to 4. Specific examples of these vinyl ethers that may be used are ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, pentyl vinyl ether, hexyl vinyl ether, benzyl vinyl ether, totyl vinyl ether, cyclopentyl vinyl ether, cyclohexyl vinyl ether, 1,2-divinyloxyethane, 1,3 -divinyloxypropane, 1,
4-divinyloxybutane, 1,5-divinyloxyencune, 1,6-divinyloxyhexane, 1,3-divinyloxycyclopenkune, 1,4-divinyloxycyclohexane, bisphenol-8-diethoxyvinyl ether, ethylene Glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, tetraethylene glycol divinyl ether, propylene glycol divinyl ether, dipropylene glycol divinyl ether, tripropylene glycol divinyl ether, trimethylolpropane trivinyl ether, pentaerythritol trivinyl ether, pentaerythritol Includes tetravinyl ether, ethoxylated trimethylolprobant'rivinyl ether, and the like.

the second forming the semi-interpenetrating polymer network of the present invention;
Examples of cellulose esters used as components are cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, cellulose acetate buterate, cellulose proonate buterate, cellulose partially substituted with acrylamide groups. Includes esters, etc. These vinyl ethers and cellulose esters are merely representative of compounds that can be used to form the desired semi-interpenetrating polymer network composition, and the invention is not limited thereto. .

The treatment of the vinyl ethers and cellulose esters described above by exposure to radiation from an energy source consisting of an electron beam is carried out in the presence of a polymerization catalyst consisting of an onium salt. The onium salt acts as a catalyst after being activated by exposure to the irradiation described above. Examples of onium salts used as catalysts in the process of the invention are 4-zyl t-butylphenyliodonium hexafluoroantimony, triphenylsulfonium hexafluoroantimony, triphenylsulfonium hexafluoroantimony, diphenyliodonium hexafluorophosphate, Or Advancein Poly
er 5science+ 62+ 1984 pp 1
-48 (Advance in Polymer Science 6
It includes both iodonium and sulfonium salts, such as onium salts of the type described by J. V. Crvello (Vol. 2, pp. 1-48). In the case of vinyl ether and cellulose ester, the above-mentioned onium salts are only typical compounds used as polymerization catalysts, and the present invention is not limited thereto.

The process by which the semi-interpenetrating polymer network compositions of the present invention are manufactured can be carried out in a well-known manner.

For example, one method of preparing the desired composition is to dissolve a polymerization catalyst consisting of a cellulose ester and an onium salt in vinyl ether to form a homogeneous solution.

In a preferred embodiment of the invention, the vinyl ether is present in the mixture in an amount ranging from about 60 to 95% by weight of the mixture and the cellulose ester is present in an amount ranging from about 5 to 40% by weight of the mixture.
Present in an amount in the range of % by weight. Furthermore, onium salts are
It is present in relatively small amounts ranging from about 0.5 to 10 pph. Following obtaining a homogeneous solution, in a preferred embodiment of the invention it is exposed to radiation from an energy source consisting of an electron beam.

The energy dose applied to this mixture is relatively low, ranging from about 0.1 to 10.0 Mrad. Exposure of the solution to the energy source is conducted at polymerization conditions that include temperatures ranging from about ambient temperature to about 50°C.

The resulting polymer composition consists of a semi-interpenetrating polymer network, as opposed to a composition consisting of a two-component copolymer present in a mixture.

There is no obvious phase separation of polyvinyl ether and cellulose ester fElc. A new polymer system is formed that has the combined properties of the two polymers. In this system, the two polymers exhibit only physical interaction between the polymers and no chemical bonding of the two polymer chains. This physical interaction between the two polymers causes the polymer chains to become permanently entangled with each other, so that one polymer cannot be leached or eluted from the other. This gives the finished product desirable properties for use in food packaging, as it is impossible for one of the ingredients to precipitate out and be accidentally absorbed into the food.

(Example) Next, the present invention will be explained in more detail with reference to Examples.

However, the present invention is not limited to the examples.

A series of solutions were prepared by dissolving a cellulose ester partially substituted with a reactive acrylamide in diethylene glycol divinyl ether along with a polymerization catalyst consisting of a triarylsulfonium salt of hexafluorophosphate.

The catalyst was in an amount sufficient to ensure that 41)I)h was present. This mixture was coated onto a paper-based support with an outer layer of polyethylene.

Following this, the mixture was irradiated with an electron beam at an energy of 160 Rev. Furthermore, irradiation was performed with varying doses. The minimum dose required to give a tack-free cure was determined.

The results of these tests are shown in Table 1.

Derivative for tack-free cured cellulose DECVE Viscosity Minimum dose Gloss (
11t%) (Wtχ) (c s) (M
rad) 0 100---<0.25 Poor 5 95 16 0.5 Good 10
90 60 0.5 Altitude 15
85 201 1.0 Altitude 20 8
0 690 1.0 Voice DEGVE: Diethylene glycol divinyl ether 11Lu In this example, solutions containing various amounts of cellulose acetate buterate are dissolved in triethylene glycol divinyl ether along with the triarylsulfonium salt of hexafluorophosphate. did. Sufficient amounts were present to ensure that the sulfonium salt acting as a polymerization catalyst was present in an amount of 4 pph. Next, this solution was applied onto a support layered with polyethylene, and irradiated with an electron beam having an energy of 160 keys under a nitrogen atmosphere. A tack-free cure was carried out as in Example 1 by varying the energy dose. The results obtained with these semi-interpenetrating polymer network coatings are shown in Table 2.

T, F, MEK CAB TEGDVE for curing Viscosity Minimum dose Friction Gloss (Wtχ) (Schiχ) (c s)
(Mrads) a 2 Mradso 100
--- 0.5 >100 Low degree 5 95
--- 0.5 >100 Good 10
90 160 0.5 >100 Altitude 20 80 1.510 0.5 >10
0 Altitude 30 70 14.300 1.0
>100T, F, Curing: Non-stick cured CAB: Cellulose acetate buterate TEG
DVE: ) Liethylene glycol divinyl ether (IL-1) In this example, a cellulose ester consisting of cellulose acetate propionate was used as a component to form a semi-interpenetrating polymeric network coating.
A polymerization catalyst consisting of a triarylsulfonium salt of hexafluorophosphate was present in an amount of 3 pphO dissolved in varying amounts of this cellulose ester and triethylene glycol divinyl ether. After a homogeneous solution was obtained, this solution was applied onto a support layered with polyethylene and irradiated with an electron beam having an energy of 16QKev. The results obtained with these coatings are shown in Table 3.

T, F, for curing MEX CAP TEGDVE Viscosity Minimum dose Friction Gloss (Wtχ) (Schiχ) (c s)
(Mrads) a 2 Mradso 100
-1-0,5>100 Low degree 5 95 40
0.5 >100 Altitude 7 93
94 0.5 >100 Altitude - Above - 1st main - l knee ≧ Danhong - Member skin T, F, hardening:
Non-adhesive cured CAP: Cellulose acetate propionate T
EGDVE: ) Liethylene glycol divinyl ether From Tables 2 and 3, the resulting coatings, in addition to being highly glossy, had such excellent solvent resistance that there was no observable effect even after 100 rubbings with methyl ethyl ketone. It is recognized that they can demonstrate their abilities.

This example illustrates the difference in cure speed (energy dose) between the systems shown in Examples 1-3 and the epoxy/onium salt system. Commercially available cycloaliphatic epoxy resin (Union Carbide's Silacure U)
A solution containing 4% of triarylsulfonium salt of hexafluorophosphate was prepared in VR-6100). This mixture was coated onto polyethylene and irradiated with a 160 Kev electron beam at various doses. To produce a tack-free coating 12. A dose of OMrads was required. Furthermore,
A post-cure period of approximately 30 seconds at room temperature was required to reach a tack-free state. Even after a dose of 20 Mrads, the coating was completely removed with 4 rubs with methyl ethyl ketone.

This example illustrates the differences between the coating cured by ultraviolet light irradiation and the electron beam cured coating of Example 3.

A solution was prepared by mixing 9.1 g of triethylene glycol divinyl ether, 0.9 g of cellulose acetate propionate, and 0.3 g of lyarylsulfonium salt. This mixture was coated on a polyethylene laminate support and a Rayone Soto RPR100 equipped with a low pressure mercury arc lamp was used.
Irradiation was carried out in a photochemical reactor. Samples were exposed for periods ranging from 3 to 60 seconds. A tack-free film was formed with a minimum exposure of 7.0 seconds. All samples had a strong unpleasant odor that was not seen in Examples 1-3. Additionally, the UV light cured samples exhibited lower gloss and a non-uniform appearance suggesting that phase separation was occurring rather than a true semi-interpenetrating polymer network.

Claims (1)

[Scope of Claims] 1) A polymerizable composition comprising a vinyl ether, a cellulose ester, and a polymerization catalyst comprising an onium salt. 2) The vinyl ether is present in the mixture in about 60% of the mixture.
95% by weight of the mixture, and the cellulose ester is present in the mixture in the range of about 5-40% by weight of the mixture. 3) The polymerizable composition according to item 1, wherein the vinyl ether is an aliphatic vinyl ether, an aralkyl vinyl ether, or an arylalkoxy vinyl ether. 4) The polymerizable composition according to item 1, wherein the vinyl ether is diethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,4-divinyloxybutane, or bisphenol-A-diethoxyvinyl. 5) The polymerizable composition according to item 1, wherein the cellulose ester comprises cellulose acetate buterate or cellulose acetate propionate. 6) The polymerizable composition according to item 1, wherein the cellulose ester is partially substituted with an acrylamide group. 7) The polymerizable composition according to item 1, wherein the onium salt catalyst comprises 4-di-t-butylphenyl iodonium hexafluoroantimony or triphenyl sulfonium hexafluorophosphate. 8) Semi-polyvinyl ether and cellulose ester
A polymerizable composition comprising an interpenetrating polymer network. 9) subjecting the mixture of at least one vinyl ether and cellulose ester to irradiation from an electron beam at low doses in polymerization conditions in the presence of a polymerization catalyst consisting of an onium salt, resulting in a semi-interpenetrating polymer network; A method for preparing a polymerizable composition comprising a semi-interpenetrating polymer network of polyvinyl ether and cellulose ester comprising recovering the structural composition. 10) The method of clause 9, wherein the polymerization conditions include temperatures ranging from about ambient temperature to about 50°C. 11) The dose from the electron beam is about 0.1-10.
10. The method of clause 9, wherein the amount is 0 Mrads and in the range of about 150-300 Kev. 12) The method of item 9, wherein the vinyl ether comprises diethylene glycol divinyl ether, or triethylene glycol divinyl ether, or 1,4-divinyloxybutane, or bisphenol-A-diethoxyvinyl. 13) The method of item 9, wherein the cellulose ester comprises cellulose acetate buterate. 14) The method of item 9, wherein the onium salt catalyst comprises 4-di-t-butylphenyl iodonium hexafluoroantimony or triphenyl sulfonium hexafluorophosphate.