JP5933818B2 - Polymerizable compositions containing ethylenically unsaturated monomers having episulfide functional groups and related methods - Google Patents

Description

  This application claims the benefit of priority from US Provisional Application No. 61/638; 655, filed April 26, 2012, and is filed on September 8, 2011. A continuation-in-part of US Patent Application No. 13 / 605,100 filed on September 6, 2012, claiming priority benefit from US Provisional Patent Application No. 61 / 532,275, filed on is there. Note that the entire disclosure of these publications is incorporated herein by reference.

  The present invention relates to a polymerizable composition comprising an ethylenically unsaturated monomer having an episulfide functional group, such as a β-epithiopropyl functional group, in the monomer, and the yellow color of a sulfur-containing polymerization product produced by addition polymerization. Relates to a method of reducing the degree.

  Polymeric materials such as plastics have been developed as an alternative and substitute for silica-based inorganic glasses in applications such as optical lenses, optical fibers, windows, and automotive, marine and aircraft transparency. These polymeric materials can provide advantages such as shatter resistance, light weight for certain applications, ease of molding, and ease of dyeing to glass. Representative examples of such polymeric materials include poly (methyl methacrylate), polycarbonate, and poly (diethylene glycol bis (allyl carbonate)).

  The refractive index of many polymeric materials is generally lower than that of high refractive index glasses. For example, poly (diethylene glycol bis (allyl carbonate)) can have a refractive index of about 1.50, while high refractive glass can range from, for example, 1.60 to 1.80.

  Polymeric materials (polymerization products) made from the polymerization of monomers containing aromatic rings and / or sulfur typically have a high refractive index. Polymeric materials having a combination of high refractive index, eg at least 1.57, and low levels of chromatic dispersion (eg having an Abbe number of at least 30) are made from monomers having specific heteroatoms, eg sulfur atoms can do. Such polymerization products are very useful in the production of optical elements that require excellent optical properties. However, in many cases, yellowing becomes a problem in a polymerization product containing sulfur. Furthermore, the polymerization initiators customarily used in such compositions also have a safety risk. For example, peroxide is flammable and has an explosion risk. Certain initiators, including peroxides and azo initiators, can generate gasses during polymerization, which raises safety concerns and affects the final polymer product appearance. there is a possibility.

  It would be desirable to develop polymerizable compositions that provide the desired optical properties, such as high refractive index, at acceptable yellowness.

  According to the present invention, (a) a monomer composition comprising at least one ethylenically unsaturated monomer having a β-epithiopropyl functional group, and (b) optionally two or more β-epithiopropyl functional groups. A compound having a group but no polymerizable ethylenically unsaturated group, (c) an isourea functional polymerization initiator, and (d) a catalyst acting on the reaction between β-epithiopropyl functional groups. A polymerizable composition is provided.

  Further provided is a method for reducing the yellowness of a sulfur-containing polymerization product produced by addition polymerization. The method comprises (a) at least one ethylenic group having a β-epithiopropyl functional group in the presence of a catalyst acting on the reaction between the isourea functional polymerization initiator and the β-epithiopropyl functional group. Reacting a polymerizable composition comprising a monomer composition comprising a saturated monomer and optionally (b) a compound having two or more β-epithiopropyl functional groups but no polymerizable ethylenically unsaturated groups Including the step of

  As used herein, the molecular weight values of polymers, such as mass average molecular weight (Mw) and number average molecular weight (Mn), are determined by gel permeation chromatography using polystyrene standards.

  As used herein, the polydispersity index (PDI) value represents the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the polymer (ie, Mw / Mn).

  As used herein, the term “polymer” refers to homopolymers (eg, those made from a single monomer species) and copolymers (eg, those made from at least two monomer species). means.

  As used herein, the term “(meth) acrylate” and similar terms such as (meth) acryloyl and (meth) acrylic acid ester mean methacrylate and acrylate. Either or both can be present in the composition.

  As used herein, the term “thio (meth) acrylate” and similar terms, such as thio (meth) acryloyl and thio (meth) acrylate, mean thiomethacrylate and thioacrylate as above. To do.

As used herein, a “linear or branched” group, such as a linear or branched alkyl, is a methylene group or a methyl group; a linear group, such as a linear It is understood to include C ₂ -C ₂₅ alkyl groups; and appropriately branched groups such as branched C ₃ -C ₂₅ alkyl groups.

  As used herein, the term “halo” and like terms, such as halo, halogen, halogen, halide, and halide, are F, Cl, Br, and / or I, such as fluoro , Chloro, bromo, and / or iodo and the like.

  Unless otherwise stated, all ranges or ratios disclosed herein are to be understood to encompass any subranges or ratios subsumed therein. For example, a range or ratio declared as “1-10” is any sub-range between the minimum value 1 and the maximum value 10 (including the limit value), ie, starting with a minimum value of 1 or more and not exceeding a maximum value of 10 All ending subranges or ratios should be considered to include, for example, but not limited to, 1-6.1, 3.5-7.8, and 5.5-10 .

  As used herein, the articles “a”, “an”, and “the” encompass a plurality of indicating objects unless explicitly and explicitly limited to a single indicating object.

  Except for working examples or unless otherwise specified, all numbers expressing amounts of ingredients, reaction conditions, etc. used in the specification and claims are in all cases the term “about It should be understood that the

  The polymerizable composition of the present invention comprises (a) a monomer composition comprising at least one ethylenically unsaturated monomer having a β-epithiopropyl functional group. For example, the monomer composition (a) may comprise a compound having one or more (meth) acryloyl, allyl, and / or vinyl groups and one or more β-epithiopropyl functional groups in the molecule. Mixtures of such compounds can also be used. Examples of suitable monomers include, but are not limited to, thioglycidyl methacrylate (2,3-epithiopropyl methacrylate), allyl thioglycidyl ether, and the like.

  The ethylenically unsaturated monomer having a β-epithiopropyl functional group may be prepared in advance and then added to the polymerizable composition, or a “precursor” reaction present in the polymerizable composition. It may be produced from the agent in the polymerizable composition. For example, thioglycidyl methacrylate can be formed in a polymerizable composition as a reaction product of a reaction composition comprising glycidyl methacrylate and thiourea.

  The ethylenically unsaturated monomer having a β-epithiopropyl functional group may constitute up to 100 percent of the mass of the monomer composition (a) relative to the total mass of resin solids in the monomer composition. For example, the monomer may be present in an amount ranging from 5 to 100 weight percent, such as 25 to 100 weight percent, or 25 to 85 weight percent, or 25 to 80 weight percent.

  In the polymerizable composition of the present invention, the monomer composition (a) may further comprise at least one different polymerizable ethylenically unsaturated monomer. Ethylenically unsaturated groups include (meth) acryloyl, allyl, and / or vinyl groups. Useful alkyl esters of acrylic acid or methacrylic acid include aliphatic alkyl esters having 1 to 30, preferably 4 to 18 carbon atoms in the alkyl group, which are linear, branched May be circular, cyclic, and / or substituted. Representative alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, Decyl, and their structural isomers. Exemplary cycloalkyl groups include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cyclooctyl substituents. Exemplary polycondensed ring cycloalkyl groups include, but are not limited to, decahydronaphthalenyl, tetradecahydroanthracenyl, and tetradecahydrophenanthrenyl. Exemplary polycyclic alkyl groups include, but are not limited to, bicyclo [2.2.1] heptanyl (norbornyl) and bicyclo [2.2.2] octanyl. Exemplary heterocycloalkyl groups include, but are not limited to, tetrahydrofuranyl, tetrahydropyranyl, and piperidinyl such as, but not limited to, piperidin-4-yl. Representative polycyclic heterocycloalkyl groups include, but are not limited to, 7-thiabicyclo [2.2.1] heptanyl, 7-oxabicyclo [2.2.1] heptanyl, and 7 -Azabicyclo [2.2,1] heptanyl. Exemplary aralkyl groups include, but are not limited to, benzyl and phenethyl. Examples of monomers having a single ethylenically unsaturated radically polymerizable group that may be present in the monomer composition (a) of the polymerizable composition of the present invention include, but are not limited to: Acrylic acid; methacrylic acid; esters of acrylic acid such as methyl or ethyl acrylate and 2-hydroxyethyl acrylate; esters of methacrylic acid such as methyl or ethyl methacrylate, phenoxyethyl methacrylate, isobornyl methacrylate, cyclohexyl methacrylate, and 2- Examples include hydroxyethyl methacrylate; allyl esters such as allyl benzoate; allyl carbonates such as phenyl allyl carbonate; vinyl esters such as vinyl acetate; styrene; and vinyl chloride. In some embodiments, the monoethylenically unsaturated monomer includes methyl methacrylate, isobornyl methacrylate, phenoxyethyl methacrylate, cyclohexyl methacrylate, styrene, and mixtures thereof. Monomers having two or more ethylenically unsaturated groups, such as divinylbenzene, can also be used in the monomer composition (a). The ethylenically unsaturated monomer, when in use, is from 1 weight percent to 60 weight percent based on the total monomer weight of the polymerizable composition, such as 3 weight percent based on the total monomer weight of the polymerizable composition. It can be present in an amount of -55 weight percent, or 20-45 weight percent.

  The monomer composition (a) is 5 to 100 weight percent, such as 25 to 100 weight percent, or 25 to 75 weight percent, or 50 to 60 weight percent, based on the total weight of resin solids in the polymerizable composition. It can be present in the polymerizable composition of the present invention in an amount in the range of weight percent.

  The polymerizable composition of the present invention may further comprise a compound (b) having two or more β-epithiopropyl functional groups but no polymerizable ethylenically unsaturated groups. Examples of such compounds include bis (β-epithiopropyl) sulfide, bis (β-epithiopropyl) disulfide, and bis (β-epithiopropyloxyphenyl) propane. The compound (b) may be pre-manufactured and then added to the polymerizable composition, or it may be polymerized from a “precursor” reactant present in the polymerizable composition. You may manufacture in. For example, bis (β-epithiopropyloxyphenyl) propane is a reaction product of a reaction composition comprising 2,2-bis (4-glycidyloxyphenyl) propane and thiourea in the polymerizable composition. Can be formed. The 2,2-bis (4-glycidyloxyphenyl) propane can be formed as a reaction product of a reaction composition comprising 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) and epichlorohydrin. .

  Compound (b), when used, is 0.5 to 75 weight percent, such as 25 to 55 weight percent or 30 to 55 weight percent, based on the total weight of resin solids in the polymerizable composition. In an amount, it can be present in the polymerizable composition of the present invention.

  The mass ratio of monomer composition (a) to compound (b) in the polymerizable composition of the present invention can be in the range of 1: 3 to 3: 1. The ratio of (a) to (b) is generally 3: 2.

  The polymerizable composition of the present invention further comprises an isourea functional polymerization initiator (c) capable of initiating free radical polymerization of and between the ethylenically unsaturated groups of the monomers. Such initiators are thermally activated. “Thermal activation” means that the free radical initiator becomes active at an elevated temperature, eg, greater than ambient room temperature, eg, greater than 25 ° C., as described in further detail herein. Means.

［式中、Ｒ_１００およびＲ_１０１は、それぞれ、互いに独立して、Ｃ_１〜Ｃ_２０アルキルまたはＣ_６〜Ｃ_１０アリールであり；あるいはＲ_１００およびＲ_１０１は、一緒に単環式または多環式複素環を形成し、当該複素環は、場合により、さらにヘテロ原子Ｏ、Ｓ、Ｎ、およびＰを含有していてもよく；Ｒ_１０２およびＲ_１０３は、独立して、Ｃ_１〜Ｃ_１９アルキル、Ｃ_５〜Ｃ_１２シクロアルキル、Ｃ_６〜Ｃ_１０アリール、Ｃ_７〜Ｃ_１０アラルキル、（ＣＨ_３）_３Ｓｉ−であり、当該Ｃ_１〜Ｃ_１９アルキル、Ｃ_５〜Ｃ_１２シクロアルキル、Ｃ_６〜Ｃ_１０アリール、Ｃ_７〜Ｃ_１０アラルキル基は、場合により、ＯもしくはＮが導入されていてもよく、Ｃ_１〜Ｃ_１９アルキル基で置換されていてもよく、Ｃ_１〜Ｃ_１９アルキルアミノ、ビス（Ｃ_１〜Ｃ_１９アルキル）アミノ、またはトリス（Ｃ_１〜Ｃ_１９アルキル）アンモニウムから選択されるＮ含有基で置換されていてもよく；Ｒ_１０４は、Ｈ、Ｃ_１〜Ｃ_１９アルキル、Ｃ_１〜Ｃ_１２シクロアルキル、Ｃ_７〜Ｃ_１０アラルキル、または、以下のアシル：Ｃ（＝Ｏ）−Ｈ、−Ｃ（＝Ｏ）−Ｃ_１〜Ｃ_１９アルキル、−Ｃ（＝Ｏ）−Ｃ_２〜Ｃ_１９アルケニル、−Ｃ（＝Ｏ）−Ｃ_６〜Ｃ_１０アリール、−Ｃ（＝Ｏ）−Ｃ_２〜Ｃ_１９アルケニル−Ｃ_６〜Ｃ_１０アリール、−Ｃ（＝Ｏ）−Ｏ−Ｃ_１〜Ｃ_１９アルキル、−Ｃ（＝Ｏ）−Ｏ−Ｃ_６〜Ｃ_１０アリール、−Ｃ（＝Ｏ）−ＮＨ−Ｃ_１〜Ｃ_１９アルキル、−Ｃ（＝Ｏ）−ＮＨ−Ｃ_６〜Ｃ_１０アリール、および−Ｃ（＝Ｏ）−Ｎ（Ｃ_１〜Ｃ_１９アルキル）_２からなる群より選択されるアシルである］を有する。 The thermally activated free radical initiator can be selected from O-imino-isourea compounds, O-dialkylamino-isourea compounds, and combinations thereof. Suitable O-dialkylamino-isourea compounds are disclosed in WO 2010/079102 (A1), which is hereby incorporated by reference in its entirety. Such O-dialkylamino-isourea compounds have the general formula I:

[Wherein R ₁₀₀ and R ₁₀₁ are each independently C ₁ -C ₂₀ alkyl or C ₆ -C ₁₀ aryl; or R ₁₀₀ and R ₁₀₁ together are monocyclic or polycyclic Forms a heterocyclic ring, which may optionally further contain heteroatoms O, S, N, and P; R ₁₀₂ and R ₁₀₃ are independently C ₁ -C ₁₉ Alkyl, C ₅ -C ₁₂ cycloalkyl, C ₆ -C ₁₀ aryl, C ₇ -C ₁₀ aralkyl, (CH ₃ ) ₃ Si—, the C ₁ -C ₁₉ alkyl, C ₅ -C ₁₂ cycloalkyl, The C ₆ -C ₁₀ aryl, C ₇ -C ₁₀ aralkyl group may optionally be substituted with O or N, optionally substituted with a C ₁ -C ₁₉ alkyl group, or C ₁ -C Optionally substituted with an N-containing group selected from ₁₉ alkylamino, bis (C ₁ -C ₁₉ alkyl) amino, or tris (C ₁ -C ₁₉ alkyl) ammonium; R ₁₀₄ is H, C _1- C ₁₉ alkyl, C ₁ -C ₁₂ cycloalkyl, C ₇ -C ₁₀ aralkyl, or the following acyl: C (═O) —H, —C (═O) —C ₁ -C ₁₉ alkyl, —C ( = _{O) -C} 2 ~C _{19 alkenyl, -C (= O) -C 6} ~C 10 _{aryl, -C (= O) -C 2} ~C 19 alkenyl _-C 6 _{-C 10} aryl, -C (= O) _-O-C 1 ~C _{19 alkyl, -C (= O) -O-} C 6 ~C 10 _{aryl, -C (= O) -NH-} C 1 ~C 19 alkyl, -C (= O) _-NH-C 6 ~C ₁₀ aryl, and -C (= O) -N (C ₁ -C ₁₉ alkyl) is an acyl selected from the group consisting of ₂ ].

  The structure of (I) is such that the molecule (I) contains 2 or more, for example 2 to 10, isourea fragments (eg, dimer, trimer, oligomer, or polymer). There may be.

［式中、ｎは、１、２、３、または４であり、
Ｒ_２００およびＲ_２０１は、独立して、Ｈ、Ｃ_１〜１８アルキル、Ｃ_３〜Ｃ_１２シクロアルキル、Ｃ_６〜Ｃ_１４アリール、Ｃ_１〜Ｃ_１４ヘテロアリール、Ｃ_７〜Ｃ_１５アラルキル、Ｃ_２〜Ｃ_１４ヘテロアラルキル、シアノであり、あるいはＲ_２００およびＲ_２０１は、それらが結合している炭素と一緒に、単環式もしくは多環式Ｃ_３〜Ｃ_１８炭素環または単環式もしくは多環式Ｃ_１〜Ｃ_１８複素環を形成し；
Ｒ_２０２およびＲ_２０３は、独立して、Ｃ_１〜Ｃ_１８アルキル、Ｃ_３〜Ｃ_１２シクロアルキル、Ｃ_６〜Ｃ_１４アリール、Ｃ_１〜Ｃ_１８アルキルで１回もしくは２回以上置換されているＣ_６〜Ｃ_１４アリール；Ｃ_７〜Ｃ_１５アラルキル、（ＣＨ_３）_３Ｓｉ−であり；あるいはＲ_２０２およびＲ_２０３は、Ｃ_１〜Ｃ_１８アルキル、Ｃ_３〜Ｃ_１２シクロアルキル、Ｃ_６〜Ｃ_１４アリール、Ｃ_７〜Ｃ_１５アラルキルであり、あるいは、
Ｒ_２０２およびＲ_２０３は、Ｃ_１〜Ｃ_１８アルキル、（Ｃ_１〜Ｃ_１８アルキルアミノ、ビス（Ｃ_１〜Ｃ_１８アルキル）アミノ、トリス（Ｃ_１〜Ｃ_１１アルキル）アンモニウムから選択されるＯもしくはＮ含有基が導入または該ＯもしくはＮ含有基で置換されている）Ｃ_３〜Ｃ_１２シクロアルキルであり、
ｎが１の場合、Ｒ_２０４は、Ｈ、Ｃ_１〜Ｃ_１８アルキル、Ｃ_３〜Ｃ_１２シクロアルキル、Ｃ_７〜Ｃ_１４アラルキル、Ｃ_６〜Ｃ_１４アリール、または以下のアシル：
−Ｃ（＝Ｏ）−Ｈ、−Ｃ（＝Ｏ）−Ｃ_１〜Ｃ_１８アルキル、−Ｃ（＝Ｏ）−Ｃ_２〜Ｃ_１８アルケニル、−Ｃ（＝Ｏ）−Ｃ_８〜Ｃ_１４アリール、−Ｃ（＝Ｏ）−Ｃ_２〜Ｃ_１８アルケニル−Ｃ_６〜Ｃ_１４アリール、−Ｃ（＝Ｏ）−Ｏ−Ｃ_１〜Ｃ_１８アルキル、−Ｃ（＝Ｏ）−Ｏ−Ｃ_６〜Ｃ_１４アリール、−Ｃ（＝Ｏ）−ＮＨ−Ｃ_１〜Ｃ_１８アルキル、−Ｃ（＝Ｏ）−ＮＨ−Ｃ_６〜Ｃ_１４アリール、および−Ｃ（＝Ｏ）−Ｎ（Ｃ_１〜Ｃ_１８アルキル）_２；
からなる群より選択されるアシルであり；あるいは、
ｎが１の場合、Ｒ_２０２およびＲ_２０４は、それらが結合している窒素原子と一緒に、さらなるヘテロ原子を含有していてもよい５〜１２員環を形成し、
ｎが１を超える場合、Ｒ_２０４は、ジ−、トリ−、テトラ−Ｃ−ｉ−Ｃ−ｉｓアルキリデン、ジアシル、トリアシル、またはテトラアシル、およびそれらの塩である］を有する。 Suitable O-imino-isourea compounds are disclosed in WO 2010/128062 (A1), which is hereby incorporated by reference in its entirety. Such O-imino-isourea compounds have the general formula II:

[Wherein n is 1, 2, 3, or 4;
R ₂₀₀ and R ₂₀₁ are independently H, C _1-18 alkyl, C ₃ -C ₁₂ cycloalkyl, C ₆ -C ₁₄ aryl, C ₁ -C ₁₄ heteroaryl, C ₇ -C ₁₅ aralkyl, C _{2 to} C ₁₄ heteroaralkyl, cyano, or R ₂₀₀ and R ₂₀₁ together with the carbon to which they are attached are monocyclic or polycyclic C _{3 to} C ₁₈ carbocyclic or monocyclic or polycyclic cyclic _C 1 _{-C 18} heterocyclic to form;
R ₂₀₂ and R ₂₀₃ are independently substituted one or more times with C ₁ -C ₁₈ alkyl, C ₃ -C ₁₂ cycloalkyl, C ₆ -C ₁₄ aryl, C ₁ -C ₁₈ alkyl. C ₆ -C ₁₄ aryl; C ₇ -C ₁₅ aralkyl, (CH ₃ ) ₃ Si—; or R ₂₀₂ and R ₂₀₃ are C ₁ -C ₁₈ alkyl, C ₃ -C ₁₂ cycloalkyl, C _6- C ₁₄ aryl, C ₇ -C ₁₅ aralkyl, or
R ₂₀₂ and _{R 203,} C 1 _{-C 18 alkyl,} O or is selected (C 1 _{-C 18} alkylamino, bis _(C 1 _{-C 18} alkyl) amino, tris _(C 1 _{-C 11} alkyl) ammonium N-containing group is substituted with the introduction or the O or N-containing group) C ₃ -C ₁₂ cycloalkyl,
When n is 1, R ₂₀₄ is H, C ₁ -C ₁₈ alkyl, C ₃ -C ₁₂ cycloalkyl, C ₇ -C ₁₄ aralkyl, C ₆ -C ₁₄ aryl, or the following acyl:
-C (= O) -H, -C (= O) -C 1 ~C 18 _{alkyl, -C (= O) -C 2} ~C 18 _{alkenyl, -C (= O) -C 8} ~C 14 aryl _{, -C (= O) -C 2} ~C 18 alkenyl _-C 6 _{-C 14 aryl, -C (= O) -O-} C 1 ~C 18 _{alkyl, -C (= O) -O-} C 6 ~ C _{14 aryl, -C (= O) -NH-} C 1 ~C 18 _{alkyl, -C (= O) -NH-} C 6 ~C 14 aryl, and _{-C (= O) -N (C} 1 ~C ₁₈ alkyl) ₂ ;
An acyl selected from the group consisting of: or
when n is 1, R ₂₀₂ and R ₂₀₄ together with the nitrogen atom to which they are attached form a 5 to 12 membered ring that may contain additional heteroatoms;
When n is greater than 1, R ₂₀₄ is di-, tri-, tetra-Ci-C-is alkylidene, diacyl, triacyl, or tetraacyl, and salts thereof.

Examples of such rings R _{202 to} R ₂₀₄ are pyrrolidine, piperidine, morpholine, piperazine, N-methyl-piperazine, hexamethyleneimine.

  The structure of (II) is such that the molecule (II) contains 2 or more, for example, 2 to 10 isourea fragments (eg, dimer, trimer, oligomer, or polymer). ). A monomer structure (n is 1), a dimer structure (n = 2), or a trimer structure n = 3 is preferable.

  The isourea functional polymerization initiator is present at least in an amount sufficient to initiate polymerization of the components in the monomer composition (a). Typically, only the amount necessary to initiate and maintain the polymerization reaction is required, which may be referred to as the “starting amount”. According to some embodiments, the initiator is present in an amount of 0.01-7 parts, or 0.1-3.5 parts, or 0.5-2.5 parts, in each case initiation. The said part of an agent is a part (phm) per 100 parts of monomers which exist in a polymerizable composition.

  The polymerizable composition of the present invention further comprises a catalyst (d) that acts on or accelerates the reaction between β-epithiopropyl functional groups. The catalyst is present at least in an amount sufficient to affect the reaction between the β-epithiopropyl functional groups in the polymerizable composition, and the β-epithiopropyl functional group is a chemical reaction such as polymerization. React in reaction.

  Suitable catalysts for use as catalyst (d) include, but are not limited to, phosphines; quaternary phosphonium salts; 1,4-diazabicyclo [2.2.2] octane (1,4-diazabicyclo [2.2.2] Also known as octane or triethylenediamine); other amine catalysts such as amines with heterocycles; quaternary ammonium salts; tertiary sulfonium salts; secondary iodonium salts; One or more of boron and their complexes; organic acids and their esters; and metal halides.

  Non-limiting examples of suitable amines having a heterocycle include imidazoles such as imidazole, N-methylimidazole, N-methyl-2-mercaptoimidazole, 2-methylimidazole, 4-methylimidazole, N-ethylimidazole, 2-ethylimidazole, 4-ethylimidazole, N-butylimidazole, 2-butylimidazole, N-undecylimidazole, 2-undecylimidazole, N-phenylimidazole, 2-phenylimidazole, N-benzylimidazole, 2-benzyl Imidazole, 1-benzyl-2-methylimidazole, N- (2′-cyanoethyl) -2-methylimidazole, N- (2′-cyanoethyl) -2-undecylimidazole, N- (2′-cyanoethyl) -2 -Phenylimidazo , 3,3-bis (2-ethyl-4-methylimidazolyl) methane, adducts of alkylimidazole and isocyanuric acid, condensates of alkylimidazole and formaldehyde; and amidines such as 1,8-diazabicyclo [5.4 .0] undecene, 1,5-diazabicyclo [4.3.0] nonene, 5,6-dibutylamino-1,8-diazabicyclo [5.4.0] undecene.

  Specific non-limiting examples of suitable phosphines are trimethylphosphine, triethylphosphine, triisopropylphosphine, tributylphosphine, tricyclohexylphosphine, trioctylphosphine, triphenylphosphine, tribenzylphosphine, tris (2-methylphenyl) phosphine , Tris (3-methylphenyl) phosphine, tris (4-methylphenyl) phosphine, tris (diethylamino) phosphine, dimethylphenylphosphine, diethylphenylphosphine, dicyclohexylphenylphosphine, diethylphenylphosphine, dicyclohexylphenylphosphine, ethyldiphenylphosphine, diphenyl Cyclohexylphosphine, chlorodiphenylphosphine.

  Suitable non-limiting examples of quaternary ammonium salts that can be used as catalysts include tetramethylammonium chloride, tetramethylammonium bromide, tetramethylammonium acetate, tetraethylammonium chloride, tetraethylammonium bromide, tetraethylammonium acetate, tetra-n. -Butylammonium fluoride, tetra-n-butylammonium chloride, tetra-n-butylammonium bromide, tetra-n-butylammonium iodide, tetra-n-butylammonium acetate, tetra-n-butylammonium borohydride, tetra- n-butylammonium hexafluorophosphite, tetra-n-butylammonium hydrogen sulfite, tetra-n-butylammonium tetrasulfate Lafluoroborate, tetra-n-butylammonium tetraphenylborate, tetra-n-butylammonium paratoluenesulfonate, tetra-n-hexylammonium chloride, tetra-n-hexylammonium bromide, tetra-n-hexylammonium acetate, tetra- n-octylammonium chloride, tetra-n-octylammonium bromide, tetra-n-octylammonium acetate, trimethyl-n-octylammonium chloride, trimethylbenzylammonium chloride, trimethylbenzylammonium bromide, triethyl-n-octylammonium chloride, triethylbenzyl Ammonium chloride, triethylbenzylammonium bromide, tri-n-butyl-n-oct Ruammonium chloride, tri-n-butylbenzylammonium fluoride, tri-n-butylbenzylammonium chloride, tri-n-butylbenzylammonium bromide, tri-n-butylbenzylammonium iodide, methyltriphenylammonium chloride, methyltri Phenylammonium bromide, ethyltriphenylammonium chloride, ethyltriphenylammonium bromide, n-butyltriphenylammonium chloride, n-butyltriphenylammonium bromide, 1-methylpyridinium bromide, 1-ethylpyridinium bromide, 1-n-butylpyridinium Bromide, 1-n-hexylpyridinium bromide, 1-n-octylpyridinium bromide, 1-n-dodecylpyridinium bromide 1-phenylpyridinium bromide, 1-methylpicolinium bromide, 1-ethylpicolinium bromide, 1-n-butylpicolinium bromide, 1-n-hexylpicolinium bromide, 1-n-octylpicolinium bromide, 1 -N-dodecylpicolinium bromide, 1-phenylpicolinium bromide.

  Specific non-limiting examples of suitable quaternary phosphonium salts include tetramethylphosphonium chloride, tetramethylphosphonium bromide, tetraethylphosphonium chloride, tetraethylphosphonium bromide, tetra-n-butylphosphonium chloride, tetra-n-butylphosphonium. Bromide, tetra-n-butylphosphonium iodide, tetra-n-hexylphosphonium bromide, tetra-n-octylphosphonium bromide, methyltriphenylphosphonium bromide, methyltriphenylphosphonium iodide, ethyltriphenylphosphonium bromide, ethyltriphenylphosphonium Iodide, n-butyltriphenylphosphonium bromide, n-butyltriphenylphosphonium iodide, n-hexyltriphenyl Bromide, n- octyl bromide, tetraphenylphosphonium bromide, tetrakis hydroxymethyl phosphonium chloride, tetrakis hydroxymethyl phosphonium bromide, tetrakis hydroxyethyl phosphonium chloride include tetrakis hydroxybutyl phosphonium chloride.

  Specific non-limiting examples of tertiary sulfonium salts include trimethylsulfonium bromide, triethylsulfonium bromide, tri-n-butylsulfonium chloride, tri-n-butylsulfonium bromide, tri-n-butylsulfonium iodide, tri Examples include -n-butylsulfonium tetrafluoroborate, tri-n-hexylsulfonium bromide, tri-n-octylsulfonium bromide, triphenylsulfonium chloride, triphenylsulfonium bromide, and triphenylsulfonium iodide.

  Suitable secondary iodonium salts may include diphenyliodonium chloride, diphenyliodonium bromide, diphenyliodonium iodide, and the like.

  Specific examples of boron trihalides and their complexes include boron trifluoride, boron trifluoride-ethyl ether complex, boron trifluoride-n-butyl ether complex, boron trifluoride-phenol complex, boron trifluoride -Ethylamine complex, boron trifluoride-piperidine complex, boron trifluoride-acetic acid complex, boron trifluoride-triethanolamine complex, boron trifluoride-ammonia complex.

  Examples of catalytic organic acids and their esters can include sulfonic acids, carboxylic acids, and esters thereof. Specific examples thereof include methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, 10-camphorsulfonic acid, and their methyl and ethyl esters.

  Specific examples of metal halides can include zinc chloride, iron chloride, aluminum chloride, tin chloride, titanium chloride, methyl aluminum dichloride, ethyl aluminum dichloride, dimethyl aluminum chloride, and diethyl aluminum chloride.

  The amount of catalyst (d) present in the polymerizable composition is sufficient to affect the reaction between β-epithiopropyl functional groups in the polymerizable composition. The amount of the catalyst can be, for example, in the range of 0.001 to 3% by mass, for example 0.005 to 2% by mass, based on the total mass of the resin solids in the polymerizable composition.

  The polymerizable composition can be substantially free of inorganic compounds having sulfur and / or selenium atoms. “Substantially free” means that the composition does not contain these compounds in any required amount that can involve the measurable (measurable) extent of these compounds in any chemical reaction. Means. If any are present, only in trace amounts.

  The thermal cure cycle used to cure the polymerizable composition of the present invention is generally from 2 hours to 48 hours at room temperature (eg, 25 ° C.) to a temperature of 50 ° C. to 150 ° C. in the presence of an initiator. Or heating the polymerizable composition to a temperature of 55-90 ° C. or 100 ° C. for 12-24 hours, or to a temperature of 65-115 ° C. or 125 ° C. for 12-24 hours.

  A polymerization product is formed by polymerization of the polymerizable composition of the present invention, and the polymerization product may be in the form of a molded article. The polymerization product resulting from the polymerization of the polymerizable composition of the present invention is a solid and in some embodiments is transparent. The transparent polymerization product produced from the polymerizable composition of the present invention can be used for optical or ophthalmic applications, for example, for the production of lenses.

  In the polymerization of the composition of the present invention and the formation of the polymerization product, the polymerization product does not contain an isourea functional polymerization initiator and a catalyst for the reaction of the β-epithiopropyl functional group described above. Compared to the polymerizable composition of, it exhibits reduced yellowing. Polymerization products made using the compositions of the present invention are considerably more in comparison to similar polymerizable compositions polymerized using conventional initiators such as peroxides or azo compounds. Shows low yellowness. Therefore, the present invention is further a method for reducing the yellowness of a sulfur-containing polymerization product produced by addition polymerization, which acts on the reaction between an isourea functional polymerization initiator and a β-epithiopropyl functional group. In the presence of a catalyst, (a) a monomer composition comprising at least one ethylenically unsaturated monomer having a β-epithiopropyl functional group; and optionally (b) two or more β-epithiopropyl functional groups Also provided is a method comprising the step of reacting a compound having a group but not having a polymerizable ethylenically unsaturated group. An ethylenically unsaturated monomer (a) having a β-epithiopropyl functional group and a compound (b) having two or more β-epithiopropyl functional groups but no polymerizable ethylenically unsaturated group are: Each is one of those previously described.

  For purposes of the present invention, yellowness is measured according to ASTM E313-10 as described in the Examples below.

  Furthermore, the use of isourea functional polymerization initiators and catalysts in the compositions of the present invention may reduce gas evolution during polymerization compared to conventional initiators such as peroxides. it can. The ignition and combustion hazards often associated with the use of peroxide initiators can be avoided by using the above-described isourea functional polymerization initiators and catalysts.

Polymerization products made from the polymerizable compositions of the present invention typically have a refractive index of at least 1.57, or at least 1.58, or at least 1.59; at least 30, or at least 33, or At least 35 Abbe number of; having at least 50 N / mm ^2, or at least 70N / mm ^2, or at least 90 N / mm ² Fisher microhardness value,. According to some embodiments, the polymerization product made from the polymerizable composition of the present invention has an initial (zero second) Barcol hardness of at least 1, or at least 10, or at least 20. The refractive index, Abbe number, and Fischer hardness value can be specified according to methods recognized in the art. The refractive index value (n _D ²⁰ ) and the Abbe number can be determined according to the manufacturer's Operation and Maintenance Guide by using the Metricon Model 2010 Prism Coupler, Thin Film Thickness / Refractive Index Measure value. Identified according to ISO 14577 using the Fischer Technologies H100C Microhardness Measurement System.

  The polymerization product produced from the polymerizable composition of the present invention can be used to form solid articles, such as optical elements or optical devices. As used herein, the term “optical” means associated or associated with light and / or vision. For example, an optical element or optical device may include ophthalmic elements and devices, display elements and devices, windows, mirrors, and / or active and passive liquid crystal cell elements and devices. As used herein, the term “ophthalmic” means associated or associated with the eye and vision. Non-limiting examples of ophthalmic elements include corrective and non-corrective lenses, such as single vision or multivision lenses (which are not limited to segmented or non-segmented multivision lenses, such as Can be either bifocal lenses, trifocal lenses, and progressive lenses), and other elements used to correct, protect, and enhance vision (for cosmetic or other reasons) For example, but not limited to, contact lenses, intraocular lenses, magnifying lenses, and protective lenses or visors As used herein, the term “display” , Words, numbers, symbols, designs, or diagrams, visible or machine-readable Non-limiting examples of display elements include screens, monitors, and security elements such as security marks, etc. As used herein, the term “window” refers to radiation. Non-limiting examples of windows include automotive and aircraft transparency materials, filters, shutters, and optical switches. As used herein, the term “mirror” means a surface that specularly reflects most of the incident light.

  The present invention is described in more detail in the following examples, which are intended to be exemplary only, since many modifications and variations therein will be apparent to those skilled in the art. Unless otherwise indicated, all parts and percentages are on a mass basis.

  The preparation of Examples 1-6 and Comparative Examples (CE) 1-13 is described in Part 1. Part II describes the preparation of polymerization product sheets of Examples 1-6 and CE1-7 and viscous liquid polymerization products of CE8-13. The results in Table 1 showed that Examples 1-6 showed a lower yellowness than CE1-7. The results in Table 2 show that in the case of CE9, 11, 13 monomer compositions without thiirane, the isourea functional polymerization initiator was compared to the peroxy functional initiators of CE8, 10, and 12 monomer compositions. And showed no unexpected results of reduced yellowness.

Part I-Preparation of Polymerization Products of Examples 1-6 and Comparative Examples (CE) 1-13 Example 1
Process A
To a 50 mL round bottom flask under N ₂ was added cyclohexanone oxime (2.87 g, 25.3 mmol) and tetrahydrofuran (THF) (15 mL). To control the exotherm, the round bottom of the flask was immersed in a room temperature water bath (but no exotherm was observed), diisopropylcarbodiimide (3.8 g, 30.1 mmol) was added and immediately crushed NaOH (0. 1 g, 2.5 mmol) was added. The resulting solution was stirred for 6 hours with a magnetic stirrer in a room temperature water bath, and turbidity occurred in some parts. The mixture was filtered using a Buchner funnel and Whatman # 4 filter paper. The resulting mixture was cooled to 4 ° C., then filtered and concentrated under reduced pressure to give a pale yellow solid (3.27 g). NMR showed that the product had a structure consistent with 1,3-diisopropyl-O- (N-cyclohexylideneamino) -isourea.

Process B
To a 20 mL glass scintillation vial was added 100 parts by weight of thioglycidyl methacrylate filtered through a 0.45 μm syringe filter, 1 part of N-methylimidazole, and 1 part of the product of Step A. The components were mixed at room temperature and / or placed in an ultrasonic bath until a uniform solution was obtained. The mixture was poured into a glass sheet mold having the appropriate diameter for a 3 mm thick casting volume. The mixture in the mold was cured by heating from 30 ° C. to 110 ° C. at a constant rate in an oven for 22 hours, followed by cooling to 85 ° C. at a constant rate for 2 hours and demolding.

Comparative Example 1 (CE-1)
1,1-diisopropyl-O- (N-cyclohexylideneamino) -isourea is reported to be 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate instead of 1 part The procedure of Step B of Example 1 was followed except that 1 part of TRIGONOX® 421 polymerization initiator was used.

Example 2
Use 1 part of tetrabutylphosphonium bromide instead of 1 part of N-methylimidazole and 1.5 parts of 1,3-diisopropyl-O- (N-cyclohexylideneamino) -isourea instead of 1.0 part The procedure of Step B of Example 1 was followed except that.

Comparative Example 2 (CE-2)
The procedure of Example 2 was followed except that 0.8 parts of TRIGONOX® 421 was used instead of 1.5 parts of 1,3-diisopropyl-O- (N-cyclohexylideneamino) -isourea. I followed.

Example 3
90 parts of filtered thioglycidyl methacrylate, 10 parts of bis- (β-epithiopropyl) sulfide, 1 part of boron trifluoride diethyl ether, and 1,3-diisopropyl-O- (N-cyclohexylideneamino) -iso The procedure of Step B of Example 1 was followed except that 1 part of urea was used.

Comparative Example 3 (CE-3)
The procedure of Example 3 was followed except that 1 part of TRIGONOX® 421 was used instead of 1 part of 1,3-diisopropyl-O- (N-cyclohexylideneamino) -isourea.

Example 4
41.7 parts filtered thioglycidyl methacrylate, 41.7 parts 4,4-isopropylidenediphenol-di (2,3-epithiopropyl) ether, 12.5 parts methyl methacrylate, 4.17 parts butyl acrylate, and The procedure of Step B of Example 1 was followed except that 1 part of 1,3-diisopropyl-O- (N-cyclohexylideneamino) -isourea was used.

Comparative Example 4 (CE-4)
The procedure of Example 4 was followed except that 1 part of TRIGONOX® 421 was used instead of 1 part of 1,3-diisopropyl-O- (N-cyclohexylideneamino) -isourea.

Example 5
Filtered thioglycidyl methacrylate 46.5 parts, 4,4-isopropylidenediphenol-di (2,3-epithiopropyl) ether 46.5 parts, methyl methacrylate 4.7 parts, butyl acrylate 2.3 parts, tetra The procedure of Example 1, Step B was followed except that 1 part of butylphosphonium bromide and 1 part of 1,3-diisopropyl-O- (N-cyclohexylideneamino) -isourea were used.

Comparative Example 5 (CE-5)
The procedure of Example 5 was followed except that 0.6 parts of TRIGONOX® 421 was used instead of 1 part of 1,3-diisopropyl-O- (N-cyclohexylideneamino) -isourea. .

Example 6
The procedure of Example 5 was followed except that 1.25 parts instead of 1 part of 1,3-diisopropyl-O- (N-cyclohexylideneamino) -isourea was used.

Comparative Example 6 (CE-6)
The procedure of Example 5 was followed except that 0.8 parts of TRIGONOX® 421 was used instead of 1 part of 1,3-diisopropyl-O- (N-cyclohexylideneamino) -isourea. .

Comparative Example 7 (CE-7)
Instead of 1 part of 1,3-diisopropyl-O- (N-cyclohexylideneamino) -isourea, it should be 2,5-dimethyl-2,5-di- (2-ethylhexanoylperoxy) hexane. The procedure of Example 5 was followed except that 0.8 part of the reported LUPEROX® 256 polymerization initiator was used.

Comparative Example 8 (CE-8)
To a 50 mL three-necked round bottom flask equipped with a magnetic stirrer under a nitrogen atmosphere, 12.85 g (100 mmol) of n-butyl methacrylate and 444 mg (1 mmol) of LUPEROX® 256 were added. The flask was immersed in a water bath maintained at 80 ° C. in equilibrium. After 5 hours, the viscous mixture was dissolved in n-butyl acetate. The solid concentration was adjusted to 26.5% by weight. The percent solids described herein were identified by weighing the sample before and after 1 hour heating at 110 ° C. and reporting the residual mass as a percentage of the initial mass measured before heating.

Comparative Example 9 (CE-9)
Process A
To a 50 mL round bottom flask under N ₂ was added cyclohexanone oxime (6.56 g, 49.9 mmol) and THF (30 mL). Dicyclohexylcarbodiimide (11.34 g, 55.0 mmol) was added and immediately ground NaOH (0.2 g, 5 mmol) was added. The resulting solution was stirred at room temperature for 4 hours, becoming reddish brown and turbid in some parts. Dichloromethane (25 mL) was added and the resulting mixture was filtered and concentrated. Acetonitrile (25 mL) was added to the resulting liquid residue and the suspension was stirred vigorously for 30 minutes. The resulting upper layer was decanted and discarded, and the residue was diluted with dichloromethane, filtered and concentrated to give an orange oil (8.73 g). NMR showed that the product had a structure consistent with 1,3-dicyclohexyl-O- (N-cyclohexylideneamino) -isourea.

Process B
The CE-8 procedure was followed except that the product of Step A (319 mg (1 mmol)) was used in place of LUPEROX®256.

Comparative Example 10 (CE-10)
Following the polymerization, the procedure of CE-8 was followed except that the resulting material was dissolved in a 1: 1 (mass basis) mixture of n-butyl acetate and tetrahydrofuran (THF) and adjusted to 22.2% solids. I followed.

Comparative Example 11 (CE-11)
Substituting 240 mg (1 mmol) of 1,3-diisopropyl-O- (N-cyclohexylideneamino) -isourea in place of LUPEROX® 256 and the resulting material was converted to the CE-10 procedure after polymerization. The procedure of CE-8 was followed except that the procedure was followed.

Comparative Example 12 (CE-12)
Except that 222 mg (0.5 mmol) of TRIGONOX® 421 was used instead of LUPEROX® 256 and after polymerization the resulting material was dissolved in THF and adjusted to 20% solids The procedure of CE-8 was followed.

Comparative Example 13 (CE-13)
120 mg (0.5 mmol) of 1,3-diisopropyl-O- (N-cyclohexylideneamino) -isourea was used in place of LUPEROX® 256 and the resulting material was polymerized after CE The CE-8 procedure was followed except that the procedure was followed according to the procedure of -12.

Part II-Polymerization Product Properties Polymerization product sheet samples of Examples 1-6 and CE1-7 were tested for Fisher microhardness (FMH), refractive index, and yellowness, and the results are reported in Table 1 To do. CE-8-13 viscous liquid polymerization product samples were tested for molecular weight and yellowness and the results are reported in Table 2.

The test was performed according to the following procedure. Fischer microhardness was tested according to ISO 14577-07, and Fischer Technology, Inc. Measured using FISCHERSCOPE® H-100SMC available from The Fischer microhardness (FMH) (± 3 Newton / mm ² ) of the polymerization product was measured at a load of 300 millinewtons (mN), followed by a load application of 0-300 mN for 15 seconds. The result is an arithmetic average of five measurements.

  The refractive indices of the solid samples of Examples 1-6 and CE1-7 were measured at 546 nm (mercury electron beam) and 23 ° C. using a METRICON® Model 2010M prism coupler according to ASTM C1648-06.

  Yellowness was measured using HunterLab ULTRASCAN® PRO according to ASTM E313-10. The passage lengths of the sheet samples of Examples 1 to 6 and CE1 to 7 were equal to the sample thickness (3 mm), and the passage length of the liquid samples of CE-8 to 13 was 2 cm.

The viscous polymerization product of CE-8-13 was dissolved in tetrahydrofuran and the weight average molecular weight (Mw) was measured by gel permeation chromatography (also called size exclusion chromatography) using an appropriate polystyrene standard.

  The result of Table 1 showed the unexpected result that the yellowness of Examples 1-6 was lower than the yellowness of Comparative Examples 1-7. In most cases, the comparative examples showed comparable Fisher microhardness and refractive index test results.

  The yellowness reported in Table 2 indicates that for the monomer compositions of Comparative Examples (CE) 8-13 without the presence of thiirane, the results for the isourea functional polymerization initiators in CE-9 and CE-11 are CE- It showed higher yellow levels than the peroxyesters of 8 and CE-10, indicating similar results when comparing CE-12 and CE-13. Based on the reported mass average molecular weight, the degrees of polymerization of CE-8 to C-11 and CE-13 were shown to be comparable.

  The invention has been described with reference to details of those specific embodiments. Such details are not intended to be regarded as limitations on the scope of the invention, except to the extent they fall within the scope of the appended claims.

Claims (21)

(A) a monomer composition comprising at least one ethylenically unsaturated monomer having a β-epithiopropyl functional group;
(B) optionally a compound having two or more β-epithiopropyl functional groups but no polymerizable ethylenically unsaturated groups;
(C) an isourea functional polymerization initiator;
(D) a polymerizable composition comprising a catalyst present in an amount sufficient to effect a reaction between said β-epithiopropyl functional groups.   2. In polymerization and formation of a polymerization product, the polymerization product exhibits reduced yellowing compared to a similar polymerizable composition that does not contain the isourea functional polymerization initiator and the catalyst. 2. The polymerizable composition according to 1.   The polymerizable composition of claim 1, wherein the ethylenically unsaturated monomer having a β-epithiopropyl functional group comprises thioglycidyl methacrylate.   The polymerizable composition of claim 3, wherein the thioglycidyl methacrylate is formed in the polymerizable composition as a reaction product of a reaction composition comprising glycidyl methacrylate and thiourea.   The polymerizable composition of claim 1, wherein the monomer composition (a) further comprises at least one different polymerizable ethylenically unsaturated monomer.   6. The polymerizable composition of claim 5, wherein the different polymerizable ethylenically unsaturated monomer comprises at least one of styrene, alkyl acrylate, and alkyl methacrylate. The polymerizable composition comprises two or more β- epithiopropyl polymerizable ethylenically unsaturated group has a functional group having no said compound (b),
The compound (b) having two or more β-epithiopropyl functional groups but not having a polymerizable ethylenically unsaturated group is 2,2-bis (4-β-epithiopropyloxyphenyl) propane. The polymerizable composition of claim 1 comprising .   The polymerizable composition of claim 1, wherein the isourea functional polymerization initiator (c) comprises at least one of O-dialkylamino-isourea and O-imino-isourea.   A polymerization product of the polymerizable composition of claim 2. An optical element comprising the polymerization product according to claim 9 .   The catalyst (d) is 1,4-diazabicyclo [2.2.2] octane, amine having a heterocyclic ring, phosphine, quaternary ammonium salt, quaternary phosphonium salt, tertiary sulfonium salt, secondary The polymerizable composition of claim 1 comprising at least one of iodonium salts, boron trihalides and their complexes, organic acids and their esters, and metal halides. A method for reducing the yellowness of a sulfur-containing polymerization product produced by addition polymerization, in the presence of a catalyst acting on a reaction between an isourea functional polymerization initiator and a β-epithiopropyl functional group,
(A) a monomer composition comprising at least one ethylenically unsaturated monomer having a β-epithiopropyl functional group, and optionally
(B) reacting a polymerizable composition comprising a compound having two or more β-epithiopropyl functional groups but no polymerizable ethylenically unsaturated groups. 2. In polymerization and formation of a polymerization product, the polymerization product exhibits reduced yellowing compared to a similar polymerizable composition that does not contain the isourea functional polymerization initiator and the catalyst. 12. The method according to 12 . The method of claim 12 , wherein the ethylenically unsaturated monomer having a β-epithiopropyl functional group comprises thioglycidyl methacrylate. 15. The method of claim 14 , wherein the thioglycidyl methacrylate is formed within the polymerizable composition as a reaction product of a reaction composition comprising glycidyl methacrylate and thiourea. The method of claim 12 , wherein the monomer composition (a) further comprises at least one different polymerizable ethylenically unsaturated monomer. The method of claim 16 , wherein the different polymerizable ethylenically unsaturated monomer comprises at least one of styrene, alkyl methacrylate, and alkyl acrylate. The compound (b) having two or more β-epithiopropyl functional groups but no polymerizable ethylenically unsaturated groups is present in the polymerizable composition, and 2,2-bis 13. The method of claim 12 , formed within the polymerizable composition as a reaction product of a reaction composition comprising (4-glycidyloxyphenyl) propane and thiourea. The 2,2-bis (4-glycidyloxy-phenyl) propane, the reaction product of 2,2-bis (4-hydroxyphenyl) reaction composition comprising propane and epichlorohydrin, according to claim 18 the method of. 13. The method of claim 12 , wherein the isourea functional polymerization initiator (c) comprises at least one of O-dialkylamino-isourea and O-imino-isourea. The catalyst is 1,4-diazabicyclo [2.2.2] octane, an amine having a heterocyclic ring, a phosphine, a quaternary ammonium salt, a quaternary phosphonium salt, a tertiary sulfonium salt, a secondary iodonium salt, 13. The method of claim 12 , comprising at least one of boron trihalides and their complexes, organic acids and their esters, and metal halides.